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Renal Tubular Acidosis

What is renal tubular acidosis.

Renal tubular acidosis is an illness that happens when the kidneys are damaged and can’t remove a waste, called acid, from the blood. 

Untreated renal (REE-nul) tubular acidosis can affect a child's growth, cause kidney stones , and other problems like bone or kidney disease . Fortunately, treatment is very helpful at preventing these things from happening. So it’s important to start treatment as soon as the condition is diagnosed.

What Happens in Renal Tubular Acidosis?

Each time a person’s body exercises, digests food, or heals damaged tissue, chemical reactions take place in its cells. These reactions put acid in the blood.

The kidneys’ main job is to remove waste — including acid — and extra water from the blood through tiny tubes called tubules. The waste is turned into urine (pee). This cleans the blood.

But with renal tubular acidosis, the kidney’s tubules are damaged, so they can’t remove the acid.

What Causes Renal Tubular Acidosis?

There are a few different types of renal tubular acidosis, and each has its own cause. They’re named based on the part of the tubule that’s damaged:

What Are the Signs & Symptoms of Renal Tubular Acidosis?

Often, kids with renal tubular acidosis don't have any symptoms. They might not know they have the condition until it shows up on a blood test or urine (pee) test.

When symptoms do happen, they can include:

If your child shows any of these signs, see a doctor right away. The sooner treatment starts, the more helpful it will be.

How Is Renal Tubular Acidosis Diagnosed?

To diagnose renal tubular acidosis, doctors do an exam and order blood tests and urine tests.

How Is Renal Tubular Acidosis Treated?

Treatment depends on the cause:

Treatment for renal tubular acidosis helps most kids. Some might need to take alkaline medicines for the rest of their lives. But sticking to their treatments keeps them healthy.

What Else Should I Know?

Often the medical team will suggest a diet rich in fruits and vegetables and lower in animal sources of protein to help kids with the condition. Talk to the health care team to make sure your child’s diet has the best sources of nutrition.


clinical case report renal tubular acidosis

distal Renal Tubular Acidosis

A resource center for patients and their families

clinical case report renal tubular acidosis

What is dRTA? dRTA is a rare type of kidney disease that can have a have major impact on a person’s health throughout their life. National Kidney Foundation has created this website to raise awareness and understanding about dRTA for patients and their families.

dRTA Resources

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dRTA is a rare but serious disease that can be inherited (primary dRTA) or be caused by another disorder or medication (secondary dRTA). When someone has dRTA, the kidneys have trouble removing circulating acids from the blood into the urine. dRTA affects people differently, but it can lead to many health problems, such as muscle aches and pains, fatigue, bone disease, kidney stones, and possibly hearing impairment and kidney failure.

You can learn more about dRTA with these resources:

Additional Resources

clinical case report renal tubular acidosis

Living with dRTA or other chronic kidney diseases is a challenge, and there is a lot to learn. You can learn more with these resources on kidney disease:

Need personal support? Contact our helpline. Toll–free 1.855.653.2273 [email protected]

Support for this educational initiative is provided by


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Case Report

Renal tubular acidosis as the initial presentation of sjögren’s syndrome.

1 University of Saskatchewan College of Medicine, Saskatoon, Canada

Pouneh Dokouhaki

Mark mcisaac, bhanu prasad.

2 Regina General Hospital, Regina, Canada

We present a 44-year-old female with an initial presentation with distal renal tubular acidosis (RTA) after she presented with hypokalaemia and normal anion gap acidosis. Three years following the diagnosis, she presented with progressive renal impairment. In the absence of any clinical, biochemical and radiological clues, she underwent a renal biopsy which showed severe tubulitis secondary to lymphocytic infiltration. Serological investigations subsequently revealed positive anti-nuclear, anti-Sjögren’s syndrome related antigen A (SS-A), and anti-Sjögren’s syndrome related antigen B (SS-B) antibodies, supporting the diagnosis of Sjögren’s syndrome. This case is unique in that distal RTA was the presenting clinical manifestation of Sjögren’s syndrome. We hope that a consideration for Sjögren’s syndrome is made in patients with seemingly idiopathic RTA.

Sjögren’s syndrome is a rare autoimmune condition typically involving chronic inflammation of exocrine organs such as lacrimal and salivary glands, typically manifesting as dry eyes and mouth. 1 However, extra-glandular renal involvement is not uncommon. Pathologically, the disease is characterised by lymphocytic infiltration with tissue damage in affected organs. Based on biopsy reports in the available literature, tubulointerstitial nephritis (TIN) is the most common histological abnormality, followed by glomerulonephritis as a distant second. 2 While TIN is the most common histological finding, the biochemical presentation of hypokalaemia suggestive of distal renal tubular acidosis has been infrequently reported. 3 In this case report, we present a middle-aged Caucasian female who initially presented with hypokalaemia and acidosis and subsequently was diagnosed as having Sjögren’s syndrome.

Case presentation

A 44-year-old female was initially seen in the nephrology outpatient clinic for evaluation of hypokalaemia. She reported feeling tired and listless for 4 months prior to her review. She denied any fever, night sweats, lymphadenopathy or weight loss. There was no history of diabetes mellitus, hypertension or rheumatological illnesses, and in particular, she denied a history of dry eyes and mouth. She had no history of nephrolithiasis or pre-existing renal disease. Systems review did not reveal abdominal pain, emesis, diarrhoea, painful swollen stiff joints or the use of non-steroidal anti-inflammatories (NSAIDs). Her past medical history was significant for pernicious anaemia and hypothyroidism for which she was prescribed vitamin B12 1200 mcg daily and L-thyroxine 75 mcg daily.

There was no personal or family history of autoimmune disease, but she appeared to recollect that her aunt and cousin were also hypokalaemic on supplements. She quit smoking 15 years ago, reported minimal alcohol intake, worked as a receptionist and was single. Her vital signs were unremarkable and no abnormal finding was identified on physical examination. Initial lab investigations revealed sodium 136 mmol/L, potassium 2.8 mmol/L, chloride 116 mmol/L and bicarbonate 16 mmol/L (normal anion gap acidosis). The pH on venous gas was 7.29. Her serum potassium, chloride and bicarbonate were within the normal limits 6 months prior to her review. Urine sodium was 61 mmol/L, urine potassium 38 mmol/L and urine chloride 55 mmol/L (+ve urine anion gap: 44 mmol/L).

Without a history of gastrointestinal losses or administration of intravenous fluids, a diagnosis of renal tubular acidosis (RTA) was contemplated. The presence of metabolic acidosis and a urine pH of 6.5 support a diagnosis of distal (type I) RTA. A 24 hours urine for calcium was 3.7 mmol/day (normal for her dietary intake). Incidentally, her total protein level was elevated at 88 g/L (60 to 80 g/L). Serum IgG 30.10 g/L (5.5 to 17.2 g/L), IgA <0.25 g/L (0.87 to 3.94 g/L) and IgM g/L 1.08 (0.44 to 2.47 g/L). As myeloma is associated with renal tubular anomalies including RTA, she was investigated further with serum protein electrophoresis, which revealed polyclonal elevation of IgG. There was no monoclonal band identified on serum immunofixation. Urine for immunofixation did not reveal any Bence Jones protein. Urinalysis did not reveal any blood or protein. Her serum albumin was 39 g/L and serum creatinine was 116 μmol/L. Renal ultrasound revealed normal sized kidneys with preserved cortical thickness and corticomedullary distinction. Specifically, there was no evidence of nephrocalcinosis or calculus. Potassium citrate (K-Lyte) was initiated at a dose of 45 mEq twice daily and she felt better on the medication. She was followed for a year and discharged back to primary care.

However, 3 years later, she was referred by her family physician for a progressive increase in her serum creatinine (elevated at 172 μmol (initially 116 μmol)). She denied any recent illnesses. There had been no change in her medications and she claimed adherence with K-Lyte. Her potassium (4.1 mmol/L) and bicarbonate (24 mmol/L) had been maintained within a normal range for the last 2 years. Specifically, she denied any recent exposure to NSAIDs, over-the-counter medications or chemotherapeutic agents. She denied swollen joints, early morning joint stiffness, rash, haemoptysis or bloody sinus discharge. Her urea was 6.4 mmol/L, creatinine 172 μmol, potassium 4.1 mmol/L and bicarbonate 24 mmol/L. Urinalysis was negative for blood and protein and the albumin-to-creatinine ratio was 0.3 mg/mmol (normal range: <2.8 mg/mmol). A 24 hours urine did not reveal any protein. Ultrasound scan of the kidneys revealed no evidence of obstruction, with preserved cortex bilaterally.

In the absence of any clinical or biochemical cause to account for the acute rise in creatinine, a renal biopsy was performed. The primary pathological alteration was evident in the tubulointerstitial compartment with a diffuse multifocal dense plasma cell rich interstitial inflammation and many foci of lymphocytic tubulitis ( figures 1–3 ). There was multifocal acute tubular injury accompanying the interstitial inflammation. In-situ hybridisation for kappa/lambda light chains highlighted the polyclonality of the infiltrating plasma cells ( figure 4 ). There were only rare IgG4-expressing plasma cells among the infiltrate. The less pronounced lymphocytic population was composed of both T cells and B cells with the predominance of T lymphocytes. B cells did not express aberrant surface markers and had low proliferation rate. Immunofluorescent microscopy was unremarkable and electron microscopy showed unremarkable glomerular architecture and no electron-dense deposits. Many tubuloreticular inclusions were seen inside the endothelial cytoplasm. The case was reviewed by a haematologist to rule out the possibility of a haematological neoplasm, who concurred with the reactive nature of the plasma cell and lymphoid population.

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Sections of paraffin-embedded tissue stained with haematoxylin and eosin shows core needle biopsy of kidney cortex with multifocal dense interstitial inflammation (arrows) - 100x magnification.

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Higher magnification of the inflamed tissue reveals plasma-cell rich infiltrate (inside black arrows) surrounding one tubule affected by lymphocytic tubulitis (white arrow) - 400x magnification; haematoxylin and eosin stain.

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Sections of paraffin-embedded tissue stained with periodic acid-Schiff shows one tubule (arrow) attacked by many lymphocytes invading its epithelial lining (400x magnification).

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Object name is bcr-2019-230402f04.jpg

In-situ hybridisation for kappa (A) and lambda (B) light chain reveals the expression of both light chains in the infiltrating plasma cells.

On the quantitative immunoglobulin panel, IgA levels were low at 0.27 g/L (0.87 to 3.94 g/L). IgG was elevated at 34.80 g/L (5.5 to 17.2 g/L) and IgM levels were normal. On serum immunofixation, there was a very faint IgG kappa restriction band of undetermined significance. A 24 hours urine for protein failed to detect Bence-Jones protein. Serum free light chains revealed that both kappa and lambda were elevated but the ratio was 2.22. Due to diffuse plasma cell infiltration, she underwent a CT scan of the chest, abdomen and pelvis and there was no evidence of enlarged lymph node or lymphoma. Based on the findings of TIN on histology, and the absence of enlarged lymph nodes and lymphoma on imaging, an autoimmune workup was performed. Serological biochemical markers are listed in table 1 .

Results of serological investigations

ANA, anti-nuclear antibody; anti-GBM, anti-glomerular basement membrane antibody; anti-MPO, anti-myeloperoxidase antibody; anti-PR3, anti-proteinase 3 antibody; anti-RNP, anti-ribonucleoprotein; anti-SCL, anti-topoisomerase; anti-SS-A, anti-Sjögren’s syndrome related antigen A; anti-SS-B, anti-Sjögren’s syndrome related antigen B; C3, Complement 3; C4, Complement 4.

Despite the presence of positive rheumatoid factor, in the absence of small joint stiffness, arthritis and other clinical manifestations, rheumatoid arthritis was not considered as a potential diagnosis. However, on further questioning, she revealed having dry eyes and mouth for 2 years and attributed the symptoms to side effects of her existing medications. Based on positive anti-Sjögren’s syndrome related antigen A (anti-SS-A) and anti-Sjögren’s syndrome related antigen B (anti-SS-B) antibodies in the presence of sicca symptoms, a presumed diagnosis of Sjögren’s syndrome was made.

Differential diagnosis

Common causes of distal RTA include: autoimmune disorders (Sjögren’s syndrome, systemic lupus erythematosus (SLE) and rheumatoid arthritis), medications (ifosfamide, amphotericin B, lithium carbonate and ibuprofen), hypercalciuric conditions (hyperparathyroidism, vitamin D intoxication and sarcoidosis) and others, including familial causes (medullary sponge kidney and Wilson’s disease).

Common causes of TIN include: medications (NSAIDs, penicillins and cephalosporins, sulfonamides, diuretics, allopurinol, proton pump inhibitors), infections (Legionella, Corynebacterium diphtheriae, Cytomegalovirus, Epstein-Barr virus, Leptospira, mycobacterium, streptococcus), tubulointerstitial nephritis and uveitis syndrome and autoimmune disorders (sarcoidosis, Sjögren’s syndrome, SLE).

The patient was initiated on prednisolone at a dose of 1 mg/kg body weight, but within a month developed cushingoid features. Steroids were rapidly tapered and she was eventually initiated on mycophenolate mofetil at a dose of 750 mg three times per day.

Outcome and follow-up

Creatinine levels measured 3 months post initiation of therapy had improved to 123 μmol. Her dryness of eyes responded to artificial tears. No specific therapy was needed for her dry mouth, which improved significantly in the 3 months since treatment was initiated. She continues to work full-time and does not report any noticeable changes in her health, with the understanding that the progression of renal disease can often be asymptomatic.

Sjögren’s syndrome is an autoimmune condition which typically involves lymphocytic infiltration of the salivary, parotid and lacrimal glands, resulting in the characteristic symptoms of xerosis (dry eyes) and xerostomia (dry mouth). This immune process can also affect non-exocrine organs, such as the skin, lungs, gastrointestinal tract and the kidneys.

Although Sjögren’s syndrome is often characterised by sicca symptoms, they are not always present. A case series by Shioji et al 4 described four cases of Sjögren’s syndrome complicated by RTA, in which three of the four patients presented with arthralgia or muscle weakness. Only two reported dry mouth and none reported any ocular abnormality. 4 A number of case reports have also reported muscle weakness, 5 pathological fractures 6 and hypokalaemic paralysis 7 as the presenting symptoms of Sjögren’s syndrome secondary to distal RTA. Therefore, symptoms related to RTA, even in the absence of sicca symptoms, may be a clue that triggers the discovery of Sjögren’s syndrome.

The diagnosis of Sjögren’s presents a challenge to clinicians, particularly when the initial presentation differs from the exocrine manifestation of dry eyes and mouth. This is highlighted by the emphasis diagnostic criteria have placed on ocular and oral findings. To make a diagnosis of primary Sjögren’s, the American-European Consensus Classification Criteria requires four of six criteria, including: ocular or oral symptoms, objective ocular or oral signs, histopathology from a lip biopsy and the presence of autoantibodies. 1 Our patient only met three of the criteria (dry eyes and mouth for more than 3 months and positive anti-SS-A and anti-SS-B antibodies), which led to a presumed diagnosis of primary Sjögren’s.

Although findings on renal biopsy are not a part of the diagnostic criteria of Sjögren’s, they can help support the diagnosis. The incidence of renal involvement in Sjögren’s syndrome varies in the literature from 0.3% to 27%, based on either biopsy findings or biochemical impairment. 8 9 Tubulointerstitial inflammation in the form of TIN is the most common renal manifestation of Sjögren’s syndrome. 8 10 Depending on the segment of the nephron impacted by lymphocytic infiltration, TIN has been shown to manifest as hypokalaemia, acidosis, RTA (predominantly distal and rarely proximal), Gitelman syndrome, Fanconi syndrome and diabetes insipidus. 11 Similarly, it can also lead to nephrocalcinosis and renal calculi. 12 Histological findings in RTA secondary to Sjögren’s are typically described as diffuse lymphocytic infiltration in the renal interstitial tissues, interspersed with plasma cells. 4 In cases of Sjögren’s syndrome with RTA, similarities in histological findings in the lacrimal glands, salivary glands and kidneys suggest that tubular dysfunction is likely a result of the same immunologic process underlying Sjögren’s syndrome. 4

IgG-4 related disease is often confused with Sjögren’s syndrome, as the former can similarly affect the lacrimal and salivary glands, and present with TIN. Although there are some epidemiological differences between the two entities (with Sjögren’s more commonly affecting women between the ages of 30 to 50 and IgG-4 related diseases mainly affecting men older than 60), differentiation is made largely based on serological and histopathological findings. 13 Patients with IgG-4 related diseases generally test seronegative for anti-SS-A and SS-B antibodies, and have a significantly elevated serum level of IgG4. 13 Demonstration of IgG4-positive plasma cells (with a ratio of IgG4-positive/IgG-positive plasma cells over 40%) is characteristic of IgG-4 related disease, while lymphocytes with a T-cell dominance are found in Sjögren’s-related TIN. 14 In contrast to in Sjögren’s syndrome, severe tubulitis is extremely rare in IgG-4 related disease, 15 where storiform fibrosis are the characteristic histopathological features. 16

Our patient presented with renal tubular acidosis 2 years prior to the onset of sicca symptoms. Her creatinine at the time was elevated (but unfortunately not pursued), raising the possibility that an infiltrative process may have already been taking place. By the time a renal biopsy was performed, the extent of inflammation was already quite severe. This case emphasises the need to consider a wide set of differential diagnoses, including Sjögren’s syndrome, in cases of unexplained renal tubular acidosis. Diagnosis at an early stage may allow for better control and prevent the progression of disease.

Learning points


The authors would like to acknowledge Dr Elan Paluck and her entire team at the Research and Performance Support at the Regina General Hospital.

Contributors: KH wrote the initial draft. PD contributed to the pathology images, MM assisted with the drafts and BP wrote the final version. All the authors have read the final version.

Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

Competing interests: None declared.

Provenance and peer review: Not commissioned; externally peer reviewed.

Patient consent for publication: Obtained.

Distal renal tubular acidosis and severe hypokalemia: a case report and review of the literature

Journal of Medical Case Reports volume  13 , Article number:  103 ( 2019 ) Cite this article

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Distal renal tubular acidosis is a relatively infrequent condition with complex pathophysiology that can present with life-threatening electrolyte abnormalities.

Case presentation

We describe a case of a 57-year-old Caucasian woman with previous episodes of hypokalemia, severe muscle weakness, and fatigue. Upon further questioning, symptoms of dry eye and dry mouth became evident. Initial evaluation revealed hyperchloremic metabolic acidosis, severe hypokalemia, persistent alkaline urine, and a positive urinary anion gap, suggestive of distal renal tubular acidosis. Additional laboratory workup and renal biopsy led to the diagnosis of primary Sjögren’s syndrome with associated acute tubulointerstitial nephritis. After potassium and bicarbonate supplementation, immunomodulatory therapy with hydroxychloroquine, azathioprine, and prednisone was started. Nonetheless, her renal function failed to improve and remained steady with an estimated glomerular filtration rate of 42 ml/min/1.73 m 2 . The literature on this topic was reviewed.


Cases of renal tubular acidosis should be carefully evaluated to prevent adverse complications, uncover a potentially treatable condition, and prevent the progression to chronic kidney disease. Repeated episodes of unexplained hypokalemia could be an important clue for diagnosis.

Peer Review reports

Distal renal tubular acidosis (dRTA) is characterized by a failure to acidify the urine in the distal parts of the nephron [ 1 , 2 ]. Frequently, patients present with minimal or no symptoms, which can lead to a delay in diagnosis. Progressively, it can lead to marked acid-base abnormalities, including hyperchloremic metabolic acidosis and severe hypokalemia, which can be fatal. In children, dRTA is usually associated with a genetic defect or anatomic abnormality of the urinary system [ 3 ]. In contrast, dRTA in adults is frequently related to acquired conditions such as infections, drugs, and autoimmune diseases. We describe a case of a woman with multiple episodes of severe hypokalemia and weakness as the main reason for admission.

A 57-year-old Caucasian woman presented to our institution with severe muscle weakness, fatigue, and weight loss for the past 2 years. Her medical history included well-controlled migraines and depression, which were treated with sumatriptan and citalopram, respectively. In addition, she had chronic hypokalemia leading to multiple visits to the emergency department for muscle weakness. These episodes were treated with potassium supplementation, with only transient improvement. She denied smoking, drinking alcohol, or using recreational drugs. On further questioning, she complained about dry eyes and dry mouth for the past 5 months. Also, she mentioned unintentional weight loss of 8 pounds during the same time. Upon examination, her vital signs were within acceptable limits. She was cachectic, with marked temporal wasting, dry mouth, and poor dentition. No thrush was noticed. Her cardiopulmonary evaluation was unremarkable, and no organomegaly was palpated. Her neurological examination revealed decreased muscle strength in upper and lower extremities, both proximally and distally. Furthermore, her tendon reflexes were decreased throughout. However, her sensory and vibratory function was intact.

Diagnostic methods

Biochemical studies showed hyperchloremia (122 mEq/L), nonanion gap (non-AG) metabolic acidosis (HCO 3 − , 16 mEq/L; AG corrected for albumin, 7.8 mEq/L), and severe hypokalemia (2.5 mEq/L). In addition, her serum creatinine (Cr) was 1.3 mg/dl (estimated glomerular filtration rate [eGFR], 42 ml/min/1.73 m 2 per the Modification of Diet in Renal Disease formula [MDRD]), and her blood urea nitrogen was 16 mg/dl. The remaining electrolytes, including calcium, magnesium, and phosphorus, were within normal limits. Her arterial blood gas showed pH 7.29, partial pressure of carbon dioxide 26 mmHg, and partial pressure of oxygen 134 mmHg. Her urine biochemistry revealed specific gravity 1.004, urine osmolality 175 mOsm/L, and pH 7.0. On further evaluation, the patient had a high urine anion gap (UAG) of + 23 and an inappropriately high potassium-to-creatinine ratio (K/Cr) of 3.9 mEq/mg. Repeated urine studies showed persistent alkaline urine (pH range, 6.5–7) with no evidence of glycosuria or phosphaturia. These findings were concerning for dRTA complicated with severe symptomatic hypokalemia. Additionally, her urine sediment was notable for sterile pyuria, as well as the presence of eosinophils, which suggested an ongoing tubulointerstitial process.

She had mild polyclonal gammopathy with predominance of immunoglobulin G (IgG) antibodies and undetectable IgG4 levels. Furthermore, antinuclear antibody titers (1:1280, speckled pattern), antibodies against Sjögren’s syndrome antigen A (116.4; reference, 0–19.9), and antibodies against Sjögren’s syndrome antigen B (58.3; reference, 19.9) were very high, suggesting Sjögren’s syndrome (SS). The patient had no antibodies against salivary protein 1 or parotid-specific proteins. Antibodies against carbonic anhydrase (CA) type VI were negative as well. A renal biopsy was conducted, which revealed acute tubulointerstitial nephritis (TIN) with abundant eosinophils and significant lymphocytic and plasmatic cell infiltration (Fig.  1 a and b). We concluded that our patient had primary SS with acute TIN.

figure 1

a Periodic acid-Schiff stain showing tubular atrophy, interstitial fibrosis, and inflammatory infiltrate in the glomeruli. b H&E stain showing eosinophil infiltrate in the interstitium, tubular atrophy, and intact glomeruli

Treatment and outcome

The patient received aggressive therapy with potassium chloride (180 mEq/day), sodium bicarbonate (1960 mg/day), and amiloride (10 mg/day). In addition, she was treated with immunomodulatory therapy, including hydroxychloroquine (HCQ; 300 mg/day), azathioprine (50–100 mg/day), and a taper of prednisone. The patient tolerated the therapy and was reevaluated as an outpatient. After 2 weeks of inpatient treatment, her potassium level remained stable (3–3.5 mEq/dl), and she was minimally symptomatic. She was discharged with close follow-up.

Her strength and weight increased over the following 5 months. However, her renal function remained decreased with a serum Cr of 1.3–1.5 mg/dl, mild hypokalemia (K + , 3.1–3.4 mEq/dl), and mild metabolic acidosis (HCO 3 − , 20 mEq/L), punctuated by recurrent episodes of severe hypokalemia and acidosis when she was unable to maintain the high-dose potassium and bicarbonate supplementation. Figure  3 shows the trajectories of serum potassium levels and renal function as well as the influence of medical therapy during the clinical course of the patient. Her clinical course was affected by her intermittent compliance with prednisone owing to its side effects, most importantly edema and lipodystrophy. She developed chronic kidney disease (CKD) in the setting of TIN.

This case report describes a patient with recurrent hypokalemia. Her clinical manifestations included severe muscle weakness in upper and lower extremities, weight loss, and marked acid-base disorders such as hyperchloremic metabolic acidosis and severe hypokalemia. Her urine studies showed persistent alkaline urine, a positive UAG, and urinary eosinophils, suggestive of dRTA and an underlying nephritis. On further evaluation, the patient was diagnosed with SS and acute TIN. She was treated with prednisone, azathioprine, and HCQ in addition to potassium and bicarbonate supplementation, which helped to maintain acceptable serum potassium levels. However, the patient’s renal function failed to improve and transitioned to CKD. This is a unique case of repeated episodes of hypokalemia related to an immunological insult that ultimately induced progressive renal failure. Despite combined immunomodulatory therapy, the patient’s outcomes were marginal. This case provides a physiological perspective on a poorly understood condition: TIN and SS.

Distal RTA, also known as type 1 RTA or classic RTA, is a complex entity characterized by an inability to acidify the urine; a process that occurs in the distal parts of the nephron, including the connecting tubule and the collecting duct [ 4 ]. Little is known about the prevalence of this condition in the general population. In Thailand, one study revealed that the prevalence of dRTA was 2.8%, concerning for an endemic form of this disease [ 5 ]. However, the prevalence of dRTA can be as high as 22–25% in specific populations, such as in patients with osteopenia and SS [ 6 , 7 , 8 , 9 ]. In children, dRTA may result from genetic mutations that affect the normal acidification system, including the genes ATPV0A4 and ATP6V1B1 , which encode the subunits A4 and B1 of the proton ATPase (H + -ATPase), respectively, or defects in the gene SCL4A1 that encodes anion exchange proteins [ 10 , 11 , 12 ]. In addition, dRTA can result from an abnormality of the ureteropelvic system, such as medullary sponge kidney, obstructive uropathies, or pyelonephritis. Conversely, dRTA is frequently associated with autoimmune diseases, medications, and parathyroid disorders in the adult population [ 1 , 2 ].

Acid secretion by the kidney can be conceptualized as having two components: (1) reclamation, which involves the reabsorption of the filtered bicarbonate load, a mechanism that is preserved in patients with dRTA; and (2) regeneration, which occurs in the distal parts of the nephron to further excrete the excess of nonvolatile acids generated from the diet. Urinary acidification and regulation of acid-base balance result from the integrated function of the collecting duct, where the transport pathways for sodium, potassium, and protons (H + ) are tightly intertwined. The cortical collecting duct is comprised of three distinct cell types that conduct very different transepithelial transport activities: principal cells, α-intercalated cells (A-intercalated cells), and β-intercalated cells (B-intercalated cells). The principal cells are the site of electrogenic sodium reabsorption via the apical epithelial sodium channel and the basolateral sodium-potassium ATPase (Na + /K + -ATPase). Transport through this pathway is upregulated by aldosterone and can be limited by apical sodium delivery and urine flow. The net effect of this transport is the generation of a lumen-negative transepithelial electrical potential. Principal cells also express voltage-gated apical potassium channels that, also in concert with the basolateral Na + /K + -ATPase, support K + secretion. Hence, the lumen-negative electrical potential generated by sodium reabsorption is a key driving force for K + secretion to the urine.

A-intercalated cells are the site of electrogenic H + secretion that is responsible for urinary acidification. These cells express high levels of intracellular CA type II, which generates carbonic acid (H 2 CO 3 ) from carbon dioxide (CO 2 ) and water. In the intracellular compartment, H 2 CO 3 dissociates to H + and a bicarbonate ion (HCO 3 − ). The proton is secreted into the lumen across the apical membrane via the H + -ATPase, whereas HCO 3 − exits across the basolateral membrane in exchange for chloride via the chloride-bicarbonate exchanger (AE1). Furthermore, chloride recycles in the basolateral aspect of the cell through a chloride channel. Thus, A-cells dissipate the lumen-negative potential generated by sodium reabsorption through the secretion of both H + and K + , a unique feature of the distal regulation of acid load. B-intercalated cells are involved in HCO 3 − secretion and K + reabsorption and are not discussed further here. Figure  2 shows some of the main functions of the principal, A-intercalated, and B-intercalated cells.

figure 2

Main physiological functions of the principal cell, α-intercalated cell, and β-intercalated cell. AE1 Anion exchanger 1, eNAC Epithelial sodium channel

The most common form of dRTA is due to selective failure of activity or expression of the H + -ATPase. The decreased transit through the proton pump inhibits urine acidification and reduces the electrical dissipation of the membrane potential. The latter has been suspected to be a driving force for K + secretion and eventual potassium wasting in previous studies [ 13 , 14 , 15 , 16 , 17 ]. Norgett et al. [ 18 ] reproduced this hypothesis in knockout mice with deficient expression of the gene ATP6V0A4 and found that these mice developed severe hyperchloremic metabolic acidosis, hypokalemia, and early nephrocalcinosis when challenged with acid load, features encountered in patients with severe dRTA. As hypokalemia progresses, storage tissues such as the skeletal muscle compensate by releasing K + to the extracellular compartment, for which laboratory data may fail to uncover a K + imbalance. However, a serum K +  < 3 mEq/L is related to a total body deficit of > 200 mEq, which varies with weight [ 19 ]. Patients with SS and dRTA can present life-threatening complications owing to massive intracellular potassium depletion, including rhabdomyolysis, respiratory paralysis, or malignant arrhythmias [ 13 , 14 , 20 , 21 ].

The exact mechanism by which SS can induce dRTA remains unclear. However, previous studies evidenced a downregulated expression of the vacuolar H + -ATPase in the A-intercalated cells in patients with SS with concomitant underexpression of AE1 (pendrin) in the B-intercalated cells. It is hypothesized that the reduced secretion of H + is the primary dysfunction in SS, whereas the underregulation of pendrin is a compensation to suppress HCO 3 − secretion and prevent further acidosis [ 13 , 14 , 17 ]. Despite the presence of H + -ATPase and AE1 in other parts of the nephron, patients with SS present selective underexpression of these proteins in the collecting duct. Furthermore, patients with SS can also develop antibodies against components of the cellular membrane or intracellular proteins. Devuyst et al. [ 15 ] found IgG autoantibodies in a patient with SS that reacted against A-intercalated cells of a human control kidney. However, the target protein was not identified. Additional studies have identified antibodies against enzymes involved in the acid excretion system and bicarbonate generation, including CA type II, CA type IV, and CA type VI [ 22 , 23 , 24 , 25 , 26 ]. It is not clear whether these antibodies are part of the pathogenesis of SS or if they result from the exposure of intracellular epitopes to the immune system during tubular damage [ 13 , 14 , 22 , 27 ]. Our patient tested negative for CA-VI specific antibodies. However, a prospective evaluation is needed because these antibodies may appear over the course of disease.

Our patient was treated with K + and sodium bicarbonate supplementation to correct her acid-base imbalance. She also received amiloride as recent literature suggests that patients with severe disease may respond to this therapy [ 28 ]. Amiloride inhibits electrogenic sodium transport through the epithelial sodium channel in the principal cells and thus decreases the driving forces for electrogenic potassium secretion [ 28 ]. On follow-up, she maintained mild hypokalemia (K + , 3.1–3.4 mEq/L) as well as mild metabolic acidosis (HCO 3 − , 19–23 mmol/L). No further improvement was seen in these clinical parameters after the introduction of immunomodulatory therapy. Discontinuation of prednisone was related to worsening renal function as described in Fig.  3 .

figure 3

Serum potassium levels, medical therapy implemented, and clinical course of the patient

Up to 71% of the patients with SS and renal involvement may develop acute or chronic TIN, whereas cryoglobulinemic glomerulonephritis and focal segmental glomerulosclerosis are infrequent, accounting for < 5% of the cases [ 29 ]. Our patient presented an acute form of TIN with significant eosinophil/plasmatic cell infiltration and minimal tubular atrophy, which has been described elsewhere [ 30 ]. Figures  1 and 2 present the patient’s renal biopsy with characteristic findings described in SS. Some studies have reported specific histological findings in patients with SS and TIN, including lymphocytic infiltrate with predominance of T-helper cell populations, most prominently the Th-17 subpopulation [ 31 ]. These findings have also been noted in biopsy samples of the salivary gland of patients with SS, suggesting that blunting the primary immune response affecting salivary glands could also attenuate the inflammation in the kidneys. Thus, several reports extrapolate the therapy for patients with SS without renal disease to those with SS and renal involvement. To the best of our knowledge, very few studies have evaluated the response to immunomodulatory therapy in biopsy-proven TIN secondary to SS [ 29 , 30 ]. Evans et al. [ 30 ] included 12 patients treated with a course of prednisone associated with mycophenolate mofetil (11 of 12) or azathioprine (1 of 12) to effectively affect both B-cell and T-cell populations. Interestingly, patients presented a significant response evidenced in their serum Cr levels and eGFR. Maripuri et al . [ 29 ] demonstrated that a mixed population including patients with SS and membranous proliferative glomerulonephritis would effectively respond to HCQ, cyclophosphamide, and rituximab. However, such therapy is difficult to reproduce in clinical practice, based on the low power of the study and the clinical characteristics of the participants.

While the immunomodulatory effect of HCQ relays in suppressing Toll-like receptors in a wide range of cells, azathioprine is an antimetabolite that inhibits synthesis of DNA, RNA, and proteins predominantly in T cells and B cells. Although both medications have been used for the management of this condition, outcomes have been variable in the literature. After 5 months of follow-up, our patient’s renal function was steady with an eGFR of 38–42 ml/min/1.73m 2 (MDRD formula). She was dependent on high-dose potassium and bicarbonate supplementation to maintain her electrolyte homeostasis, which suggests that tubulointerstitial injuries in SS can have minimal response to standard immunomodulatory therapy. This group of patients benefits from follow-up and further management to prevent progression of CKD to end-stage renal disease [ 32 ].

This case highlights the importance of an early detection and physiology-based approach to dRTA. Accurate characterization of this condition is pivotal to uncover an underlying disease, tailor a specific therapy, and prevent further renal function decline. Episodes of symptomatic hypokalemia could be a clue for diagnosis and should be carefully addressed to prevent life-threatening complications. Evaluating the renal response to immunomodulatory therapy in SS is of paramount interest as it can lead to a progressive decline in renal function.


Carbonic anhydrase

Distal renal tubular acidosis

Estimated glomerular filtration rate


Immunoglobulin G

Modification of Diet in Renal Disease

Sjögren’s syndrome

Tubulointerstitial nephritis

Urine anion gap

Both T, Zietse R, Hoorn EJ, van Hagen PM, Dalm VA, van Laar JA, et al. Everything you need to know about distal renal tubular acidosis in autoimmune disease. Rheumatol Int. 2014;34(8):1037–45.

Article   CAS   Google Scholar  

Yaxley J, Pirrone C. Review of the diagnostic evaluation of renal tubular acidosis. Ochsner J. 2016;16(4):525–30.

PubMed   PubMed Central   Google Scholar  

Agarwal A, Kumar P, Gupta N. Pediatric Sjogren syndrome with distal renal tubular acidosis and autoimmune hypothyroidism: an uncommon association. CEN Case Rep. 2015;4(2):200–5.

Article   Google Scholar  

Bagga A, Sinha A. Evaluation of renal tubular acidosis. Indian J Pediatr. 2007;74(7):679–86.

Nimmannit S, Malasit P, Susaengrat W, Ong-Aj-Yooth S, Vasuvattakul S, Pidetcha P, et al. Prevalence of endemic distal renal tubular acidosis and renal stone in the northeast of Thailand. Nephron. 1996;72(4):604–10.

Pongchaiyakul C, Domrongkitchaiporn S, Stitchantrakul W, Chailurkit LO, Rajatanavin R. Incomplete renal tubular acidosis and bone mineral density: a population survey in an area of endemic renal tubular acidosis. Nephrol Dial Transplant. 2004;19(12):3029–33.

Weger W, Kotanko P, Weger M, Deutschmann H, Skrabal F. Prevalence and characterization of renal tubular acidosis in patients with osteopenia and osteoporosis and in non-porotic controls. Nephrol Dial Transplant. 2000;15(7):975–80.

Both T, Hoorn EJ, Zietse R, van Laar JA, Dalm VA, Brkic Z, et al. Prevalence of distal renal tubular acidosis in primary Sjogren’s syndrome. Rheumatology (Oxford). 2015;54(5):933–9.

Duffles Amarante GB, Zotin MC, Rocha E, Delgado AG, Leite M Jr, Gomes CP. Renal tubular dysfunction in patients with primary Sjogren syndrome. Clin Nephrol. 2014;81(3):185–91.

Besouw MTP, Bienias M, Walsh P, Kleta R, Van’t Hoff WG, Ashton E, et al. Clinical and molecular aspects of distal renal tubular acidosis in children. Pediatr Nephrol. 2017;32(6):987–96.

Palazzo V, Provenzano A, Becherucci F, Sansavini G, Mazzinghi B, Orlandini V, et al. The genetic and clinical spectrum of a large cohort of patients with distal renal tubular acidosis. Kidney Int. 2017;91(5):1243–55.

Ashton EJ, Legrand A, Benoit V, Roncelin I, Venisse A, Zennaro MC, et al. Simultaneous sequencing of 37 genes identified causative mutations in the majority of children with renal tubulopathies. Kidney Int. 2018;93(4):961–7.

Cohen EP, Bastani B, Cohen MR, Kolner S, Hemken P, Gluck SL. Absence of H + -ATPase in cortical collecting tubules of a patient with Sjogren’s syndrome and distal renal tubular acidosis. J Am Soc Nephrol. 1992;3(2):264–71.

CAS   PubMed   Google Scholar  

DeFranco PE, Haragsim L, Schmitz PG, Bastani B. Absence of vacuolar H + -ATPase pump in the collecting duct of a patient with hypokalemic distal renal tubular acidosis and Sjogren’s syndrome. J Am Soc Nephrol. 1995;6(2):295–301.

Devuyst O, Lemaire M, Mohebbi N, Wagner CA. Autoantibodies against intercalated cells in Sjogren’s syndrome. Kidney Int. 2009;76(2):229.

Tzioufas AG, Tatouli IP, Moutsopoulos HM. Autoantibodies in Sjogren’s syndrome: clinical presentation and regulatory mechanisms. Presse Med. 2012;41(9 Pt 2):e451–60.

Kim HY, Kim SS, Bae EH, Ma SK, Kim SW. Decreased renal expression of H + -ATPase and pendrin in a patient with distal renal tubular acidosis associated with Sjogren’s syndrome. Intern Med. 2015;54(22):2899–904.

Norgett EE, Golder ZJ, Lorente-Canovas B, Ingham N, Steel KP, Karet Frankl FE. Atp6v0a4 knockout mouse is a model of distal renal tubular acidosis with hearing loss, with additional extrarenal phenotype. Proc Natl Acad Sci U S A. 2012;109(34):13775–80.

Asmar A, Mohandas R, Wingo CS. A physiologic-based approach to the treatment of a patient with hypokalemia. Am J Kidney Dis. 2012;60(3):492–7.

Garza-Alpirez A, Arana-Guajardo AC, Esquivel-Valerio JA, Villarreal-Alarcon MA, Galarza-Delgado DA. Hypokalemic paralysis due to primary Sjogren syndrome: case report and review of the literature. Case Rep Rheumatol. 2017;2017:7509238.

CAS   PubMed   PubMed Central   Google Scholar  

Cherif E, Ben Hassine L, Kechaou I, Khalfallah N. Hypokalemic rhabdomyolysis: an unusual presentation of Sjogren’s syndrome. BMJ Case Rep. 2013;2013:bcr2013201345.

Takemoto F, Hoshino J, Sawa N, Tamura Y, Tagami T, Yokota M, et al. Autoantibodies against carbonic anhydrase II are increased in renal tubular acidosis associated with Sjogren syndrome. Am J Med. 2005;118(2):181–4.

Krishnan D, Pan W, Beggs MR, Trepiccione F, Chambrey R, Eladari D, et al. Deficiency of carbonic anhydrase II results in a urinary concentrating defect. Front Physiol. 2017;8:1108.

Nishimori I, Miyaji E, Morimoto K, Kohsaki T, Okamoto N, Onishi S. Diminished cellular immune response to carbonic anhydrase II in patients with Sjogren’s syndrome and idiopathic chronic pancreatitis. JOP. 2004;5(4):186–92.

PubMed   Google Scholar  

De Langhe E, Bossuyt X, Shen L, Malyavantham K, Ambrus JL, Suresh L. Evaluation of autoantibodies in patients with primary and secondary Sjogren’s syndrome. Open Rheumatol J. 2017;11:10–5.

Pertovaara M, Bootorabi F, Kuuslahti M, Pasternack A, Parkkila S. Novel carbonic anhydrase autoantibodies and renal manifestations in patients with primary Sjogren’s syndrome. Rheumatology (Oxford). 2011;50(8):1453–7.

Konishi K, Hayashi M, Saruta T. Renal tubular acidosis with autoantibody directed to renal collecting-duct cells. N Engl J Med. 1994;331(23):1593–4.

Oguejiofor P, Chow R, Yim K, Jaar BG. Successful management of refractory type 1 renal tubular acidosis with amiloride. Case Rep Nephrol. 2017;2017:8596169.

Maripuri S, Grande JP, Osborn TG, Fervenza FC, Matteson EL, Donadio JV, et al. Renal involvement in primary Sjogren’s syndrome: a clinicopathologic study. Clin J Am Soc Nephrol. 2009;4(9):1423–31.

Evans RD, Laing CM, Ciurtin C, Walsh SB. Tubulointerstitial nephritis in primary Sjogren syndrome: clinical manifestations and response to treatment. BMC Musculoskelet Disord. 2016;17:2.

Rosenberg ME, Schendel PB, McCurdy FA, Platt JL. Characterization of immune cells in kidneys from patients with Sjogren’s syndrome. Am J Kidney Dis. 1988;11(1):20–2.

Liu BC, Tang TT, Lv LL, Lan HY. Renal tubule injury: a driving force toward chronic kidney disease. Kidney Int. 2018;93(3):568–79.

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The authors express their gratitude to Dr. David Brink and the Pathology Department at St. Louis University School of Medicine for assistance with clinical pathological images.

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GVR drafted the manuscript. GVR conducted the literature review. GVR, DJW, JCE, and SS were part of the medical team responsible for the care of the patient. DJW, IP, JCE, and SS evaluated the patient’s results and outcomes and provided valuable technical and intellectual support to this report. JCE and SS provided expert consultation during the management of the patient and elaboration of the manuscript. All the authors made substantial contributions to the manuscript, critically reviewed the content, and accepted the final version of it.

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Vasquez-Rios, G., Westrich, D.J., Philip, I. et al. Distal renal tubular acidosis and severe hypokalemia: a case report and review of the literature. J Med Case Reports 13 , 103 (2019).

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clinical case report renal tubular acidosis

clinical case report renal tubular acidosis

clinical case report renal tubular acidosis

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clinical case report renal tubular acidosis

Renal tubular acidosis (RTA) is a pathophysiological alteration of acid–base metabolism, characterised by the presence of hyperchloraemic metabolic acidosis, which is caused by renal loss of bicarbonate or a reduction in hydrogen ion excretion by the renal tubules. 1 A suspicion of RTA is based on the clinical presentation of various signs and symptoms such as anorexia, vomiting, polyuria, polydipsia, delayed growth, muscle weakness, rickets, nephrocalcinosis and sensorineural deafness. 2 The diagnosis is validated with laboratory examinations that should include the demonstration of hyperchloraemic metabolic acidosis, with a normal blood anion gap and a blood pH lower than 7.35, in patients with decompensated metabolic acidosis. In the case of secondary RTA, it is important to diagnose the systemic disease that is causing it. 1 It should be noted that intestinal losses of bicarbonate, whether they are due to diarrhoea or a fistula, are a common cause of the same acid–base alterations, and so they should not be present when a diagnosis of RTA is made.

RTA has been reported to be overdiagnosed in Mexico, 3,4 and it has been associated with allergy. 4–6 For this reason, we conducted a study with the aim of documenting the diagnosis of RTA in children from different hospitals. A total of 170 children with a prior diagnosis of RTA were enrolled; the majority were receiving alkaline treatment. Treatment was suspended 5 to 7 days prior to the initial assessment, which consisted of a medical history, laboratory examinations and an assessment by the allergy department. A diagnosis of RTA was only confirmed in 3 patients (1.8%), one with distal RTA and 2 with RTA secondary to cystinosis, which were accompanied by Fanconi syndrome. None of them had an allergy. The rest of the patients’ prior diagnosis of RTA was erroneous; failure to thrive was caused by other conditions such as nutritional deficiency, Turner syndrome, giardiasis, coeliac disease, familial short stature, hypophosphataemic rickets, coenzyme Q10 deficiency or cardiomyopathy. The cases with RTA are described below.

Case 1: A 12-year-old eutrophic female patient with normal anthropometric measurements for her age and gender. She was diagnosed with RTA at one month of age, and since then she has been receiving a potassium citrate solution. On the third day of suspending alkaline treatment she had vomiting, metabolic acidosis, blood pH 7.22; [HCO 3 − ] 10 mmol/l; blood anion gap 11; K + 2.2 mEq/l; Cl − 114 mEq/l; urine calcium/creatinine 1.38; urinary pH: 7.5. Alkaline treatment — bicarbonate and potassium — was restarted. Kidney ultrasound: grade III medullary nephrocalcinosis. Molecular study: mutation of the ATPV60A4 gene, not previously reported in the literature, which shall be the subject of a subsequent publication.

Case 2: A 22-month-old male patient with delayed growth since sixth months of age. At 11 months, he was diagnosed with distal ATR, with vomiting, polydipsia and polyuria, and he received treatment with a potassium citrate solution. Entry into the study: weight 7.88 kg ( p 3); height 71 cm ( p 3); weight/age 71%; weight/height 86.3%; height/age 91.8%; BMI Z -score: −1.47. Blood gases pH 7.39; [HCO 3 − ] 16.2 mmol/l; K + 3.0 mEq/l; HPO 4 − 2.4 mg/dl; urine pH: 7.5; trace albumin, +glucosuria; microscopic haematuria, 45% tubular reabsorption of phosphate. Administration of furosemide: did not have urinary acidification. Ophthalmology: birefringent crystals in the cornea with a slit lamp. A diagnosis of infantile nephropathic cystinosis was considered. Molecular study of the CTNS gene (17p13, NG_012489.1 RefSeqGene): compound heterozygous genotype, predictor of severe form of infantile nephropathic cystinosis with deletion of 57 kb, deletion of the first 10 exons, mutation more common in Caucasian, Mexican and Latin American patients 7,8 with cystinosis and a minor deletion previously reported in European populations. 9 Treatment with cysteamine bitartrate, phosphates, bicarbonate and potassium, with satisfactory evolution.

Case 3: A 20-month-old female patient with polyuria, polydipsia, anorexia and delayed growth. RTA was suspected, and she was referred to our institution without being treated. Weight 6.9 kg ( p 3); height 75.5 cm ( p 3); weight/age 60.9%; weight/height 73%; height/age 91.3%. Blood gases: pH 7.47; [HCO 3 − ] 13.8 mmol/l; K + 3.6 mEq/l; HPO 4 − 2.2 mg/dl; Cl − 114 mEq/l; urine pH 7.0; glucosuria 100 mg/dl; +albumin. Ophthalmology: birefringent corneal cystine crystals. Molecular study of the CTNS gene: homozygous genotype, microdeletion of exon 12, which deleted amino acids 346–349 of the 7th transmembrane domain of cystinosin, which confirmed the diagnosis of infantile nephropathic cystinosis, reported in Europeans 10 . Treatment with cysteamine bitartrate, phosphates, bicarbonate and potassium.

We concluded that RTA is an uncommon tubulopathy, not associated with allergy, and confirmed that it is overdiagnosed in Mexico. We recommend a comprehensive paediatric approach in children with delayed growth, considering other diseases in addition to RTA, with special caution in the studies that are requested and their quality. When RTA is diagnosed, the presence of primary diseases with secondary RTA should be ruled out, and suitable guidance and nutritional support should be provided.

The study was funded by Federal Funds for Hospital Infantil de México Federico Gómez protocol HIM/2012/036. Molecular study of the CTNS gene for patients with cystinosis was funded by Federal Research Funds of the Mexican National Institute of Paediatrics (INP) (Modality A, summons 2014–2015).

The authors have no conflict of interest to declare.

The authors would like to thank Lourdes Ortiz, Ruben Aldana, Cristina Alcantara, Humberto Gonzalez, Gregoria Morales, Fabiola García, Alejandra Sanchez and Joanna Salazar; the Mexican Foundation for Renal AcidosisTubular Mexicana (FUNATIM), and Dr. RosaVargas Possou.

Please cite this article as: Medeiros M, Enciso S, Hernández AM, Hernández HRG, Toussaint G, Pinto C, et al. Informe de casos de acidosis tubular renal y errores de diagnóstico. Nefrología. 2016;36:323–325.

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clinical case report renal tubular acidosis

Article Contents

A case of distal renal tubular acidosis (type 1) presenting with musculoskeletal pain

A. Negi, C. Rhys-Dillon, J. P. Camilleri, A case of distal renal tubular acidosis (type 1) presenting with musculoskeletal pain, Rheumatology , Volume 43, Issue 6, June 2004, Pages 809–810,

S ir , Musculoskeletal symptoms are often the presenting complaint in patients with renal tubular acidosis (RTA) [ 1 ]. The biochemical picture can, however, be incomplete during the early stage of RTA, thus making it difficult to diagnose.

We present a 46-yr-old lady, referred with a 9-month history of widespread myalgia and arthralgia. Past history included hyperthyroidism requiring subsequent thyroidectomy followed by thyroxine replacement. At presentation she was receiving regular lithotripsy, having had recurrent renal stones for 4 yr. Her family history included her grandmother, father and one sister suffering from renal problems, and her brother had recently been diagnosed with nephrolithiasis.

Examination of the cardiovascular, respiratory and abdominal systems was unremarkable. She had generalized muscle weakness but her tendon reflexes, plantar responses and sensory examination were normal. There were no joint abnormalities. She had a wide-based gait and was using one elbow crutch. Investigations showed a normal full blood count, erythrocyte sedimentation rate (ESR), sodium, potassium, urea and creatinine; she was negative for antinuclear antibody (ANA) and rheumatoid factor (RF); alkaline phosphatase was 337 IU/l (normal range 40–140 IU/l), aspartate aminotransferase 13 IU/l (normal range 10–60 IU/l), bilirubin 7 μmol/l (normal range 5–17 μmol/l), parathyroid hormone 3.3 pmol/l (normal range 0.9–5.4 pmol/l) and 25-hydroxyvitamin D3 25.5 IU (normal range 8–50); urinary calcium and creatine kinase were normal. The raised alkaline phosphatase was shown to be bone-derived. The bone scan, requested because of the high alkaline phosphatase, showed symmetrical abnormal uptake in both sacroiliac regions and in both femoral heads, suggestive of avascular necrosis. It also showed an abnormal focus on the left ninth rib that was suggestive of a fracture. The report commented that the overall picture was confusing and an MRI was suggested.

MRI showed abnormal bone texture and marrow and a chronic insufficiency fracture of the sacrum and femoral neck with subchondral bone collapse of the right femoral head. A differential diagnosis between metabolic bone disease and a widespread marrow infiltrative process was suggested.

During this period she also had sudden loss of vision in the left eye due to retinal artery occlusion. The thrombophilia screen, including lupus anticoagulant and anticardiolipin antibodies, was negative.

Repeat investigations showed sodium 140 mmol/l, potassium 2.9 mmol/l, chloride 118 mmol/l, normal urea and creatinine, corrected calcium 2.05 mmol/l, phosphate 0.91 mmol/l, alkaline phosphatase 328 IU/l, parathyroid hormone 3.2 pmol/l, negative urine microscopy and culture, and creatinine clearance 33 ml/min. Urine pH was 7. Arterial blood gases showed pH 7.24, P a o 2 106 mmHg, P a co 2 36 mmHg, bicarbonate 16 mmol/l and Sa o 2 95.8%, confirming a hyperchloraemic metabolic acidosis. The history of recurrent renal stones, a hyperchloraemic metabolic acidosis and alkaline urine was in keeping with a diagnosis of type 1 (distal) RTA.

Her musculoskeletal pain and mobility improved with oral potassium replacement. Oral bicarbonate was added once serum potassium was stable and >4.0 mmol/l. Biochemistry after treatment showed alkaline phosphatase 56 IU/l, corrected calcium 2.31 mmol/l, phosphate 1.19 mmol/l, sodium 139 mmol/l, potassium 5.1 mmol/l, and normal urea and creatinine.

RTA is a disorder of renal acidification out of proportion to the reduction in glomerular filtration rate. It is characterized by hyperchloraemic metabolic acidosis [ 2 ]. Type 1 RTA is a disorder of the distal nephron resulting in failure to lower urinary pH, due either to excessive back-diffusion of hydrogen ions from the lumen to the blood or to inadequate transport of hydrogen ions [ 2 ], and can be familial or acquired. Type 1 RTA may be associated with hypercalciuria, hypocitraturia, nephrocalcinosis, nephrolithiasis, hypokalaemia, progressive renal failure, growth retardation and metabolic bone disease [ 3 ]. Secondary causes include Sjögren's syndrome, hypergammaglobulinaemia, chronic active hepatitis and systemic lupus erythematosus. Familial cases are mostly autosomal dominant and likely to be a consequence of an inherited defect in the AE1 gene [ 4 , 7 ]. Our patient's family history suggests a familial cause. The renal conversion of 25-hydroxyvitamin D3 to 1,25-dihydroxyvitamin D3 is impaired causing osteomalacia and rickets [ 2 ]. The muscle and joint manifestations in RTA can partly be explained by hypokalaemia and metabolic bone disease [ 1 ]. The nephrolithiasis/nephrocalcinosis result from a combination of alkaline urine, hypercalciuria and decreased urinary citrate.

Treatment includes correction of hypokalaemia and alkali replacement [ 2 , 6 ]. The hypokalaemia should be corrected first, as alkali replacement can worsen the hypokalaemia with dangerous consequences. Correcting hypokalaemia improves the musculoskeletal symptoms. Early treatment also improves the nephrocalcinosis and prevents recurrence of renal stones and progression to chronic renal failure.

In retrospect, our case highlights some important learning points. (i) Musculoskeletal symptoms are a common clinical manifestation of RTA. Harrington et al . report 48 patients with RTA of whom 25 presented with rheumatic complaints [ 1 ]. (ii) Patients with renal stones must be screened for RTA. Osther et al . recommend using morning fasting urine pH followed by a short ammonium chloride loading test if urinary pH is above 6.0 [ 5 ]. (iii) Although uncommon, RTA must be included in the differential diagnoses in patients presenting with musculoskeletal symptoms and nephrolithiasis.

The investigations for RTA are simple and will obviate more expensive radiological investigations, thus avoiding a delay in diagnosis. It is important to make an early diagnosis, as many musculoskeletal manifestations resolve with treatment. Also, nephrocalcinosis/nephrolithiasis causes substantial morbidity and can be prevented by timely treatment.

We could not find any reports of retinal artery occlusion in association with RTA.

The patient has given consent for this material to appear in Rheumatology .

The authors have declared no conflicts of interest.

Harrington TM, Bunch TW, Van den Berg CJ. Renal tubular acidosis. A new look at treatment of musculoskeletal and renal disease. Mayo Clin Proc 1983 ; 58 : 354 –60.

Paillard M. Renal tubular acidosis. In: Davison AM, Cameron JS, Grunfeld J, Kerr DNS, Ritz E, Winearls CG, eds. Oxford Textbook of Clinical Nephrology, Vol. 2 , 2nd edn, Oxford: Oxford University Press, 1998 : 1063 –84.

Caruana RJ, Buckalew VM. The syndrome of Distal (type1) renal tubular acidosis. Clinical and laboratory findings in 58 cases. Medicine 1998 ; 67 : 84 –99.

Chaabani H, Hadj-Khlil A, Ben-Dhia N, Braham H. The primary hereditary form of distal renal tubular acidosis: clinical and genetic studies in 60-member kindred. Clin Genet 1994 ; 45 : 194 –99.

Osther PJ, Hansen AB, Rohl HF. Screening renal stone formers for distal renal tubular acidosis. Br J Urol 1989 ; 63 : 581 –3.

Richards P, Chamberlain MJ, Wrong OM. Treatment of osteomalacia of renal tubular acidosis by sodium bicarbonate alone. Lancet 1972 ; Nov. 11 : 994 –7.

DuBose TD. Autosomal dominant distal renal tubular acidosis and the AE1 gene. Am J Kid Dis 1999 ; 33 : 1190 –7.

Author notes

Wrexham Maelor Hospital, Wrexham, 1Prince Charles Hospital, Merthyr Tydfil and 2University Hospital of Wales, Cardiff, UK

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Type 2 renal tubular acidosis presenting with joint pain: A case report and literature review

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Copyright: © Nuransoy Cengi̇z et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

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Lignac-de Toni-Debré-Fanconi syndrome [termed Fanconi syndrome (FS)] is a proximal tubular defect that causes an impaired reabsorption of the glomerular filtrate. Patients with this condition can present with hypophosphatemia, renal glycosuria, hypouricemia and aminoaciduria ( 1 ). While it is mostly observed as a hereditary disease in childhood, the acquired form is more common in adults ( 2 ). It is difficult to define the epidemiology of FS, as it includes a wide variety of acquired, inherited and exogenous factors unrelated to each other ( 2 ).

Phosphate depletion is the most critical clinical aspect of FS as it leads to osteomalacia. Some patients present with symptoms and signs related to hypophosphatemic osteomalacia (HO) ( 3 ). These symptoms, including proximal myopathy, muscle weakness, chronic arthritis sign, and bone and back pain are non-specific ( 4 ). Thus, these patients present with these symptoms and are misdiagnosed ( 5 ).

To the best of our knowledge, there are currently only a limited number of publications available on the topic, and the majority of these are related to drug-induced FS. In the study conducted by Eguchi et al ( 6 ), the 25 cases of FS reported an improvement in phosphate levels following the cessation or dose reduction of adefovir-induced FS. The case reported in the study by Park et al ( 7 ) involved a patient diagnosed with idiopathic FS presenting with HO. The study by Yamaguchi et al ( 8 ) also reported a patient who presented with HO on the grounds of primary biliary cirrhosis. Finally, in the study by Li et al ( 9 ), there were nine cases that were initially misdiagnosed; the majority of these presented with HO due to drug-related FS.

The present study describes the case of a patient who presented with joint pain and was diagnosed with idiopathic FS with multiple osteoporotic fractures.

Case report

A 46-year-old male visited the outer center (Malatya Public Hospital, Malatya, Turkey) complaining of pain in his hip. The pain was also felt in the shoulders, arms and ankles. He complained of a 1-year history of sustained walking difficulty. He did not complain of any morning stiffness. The patient was diagnosed with rheumatoid arthritis in the outer center (Malatya Public Hospital) and was referred to our tertiary care hospital (Inonu University Faculty of Medicine Turgut Ozal Medical Center.

The patient was previously healthy, and no additional disease was known. His family history was unremarkable, and his vital signs were normal. According to the physical examination, the hip joint and ankle were sensitive and became painful with flexion or extension movement. There was no warmth, redness, or swelling around these joints. Moreover, he was stumbling.

The laboratory data revealed a creatinine level of 1.4 mg/dl, potassium level of 2.8 mmol/l (reference range, 3.5-5.5 mmol/l), calcium level of 7.8 mg/dl (reference range, 8.4-10.2 mg/dl), phosphorus level of 1.5 mg/dl (reference range, 2.7-4.3 mg/dl), uric acid level of 1.4 mg/dl (reference range, 3.5-4.2 mg/dl), serum glucose level of 90 mg/dl and urine glucose level of 716 mg (reference range, 1-35 mg; normoglycemic glycosuria), urine protein level of 887 mg (reference range, 50-80 mg), metabolic acidemia with a normal anion gap (pH 7.18; HCO3, 15.9 mmol/l), and low serum levels of phosphorus and 1,25-dihydroxyvitamin D3 (15.0 pg/dl). In addition, the serum levels of parathyroid hormone (PTH) were elevated (84.6 pg/ml; reference range, 14-72 pg/ml). Some of these laboratory values are summarized in Table I .

Some of the laboratory values of the case described in the present study.

Bilateral proximal femur fractures and fractures of the iliac and sacral bones and ankles were found via magnetic resonance imaging (MRI) and on the basis of osteoporosis ( Fig. 1 ). HO was diagnosed clinically on the basis of laboratory analyses, and bone densitometry and MRI findings. Thus, a bone biopsy was not performed. Blood and urine biochemical data, and the radiology findings revealed severe osteoporosis, thus indicating FS with proximal renal tubular acidosis (RTA).

Following the diagnosis, the patient was evaluated to determine the etiology of FS. Anti-SSA and anti-SSB tests were negative. The bone marrow biopsy performed following diagnosis was compatible with the normocellular bone marrow; there was no monoclonal component.

The patient was not on any medication in relation to FS. A light microscopic examination of a kidney biopsy demonstrated the cellular infiltration of the interstitium and proximal tubular epithelium composed mainly of C3 without glomerular involvement. Other common observations were moderate tubular degeneration and regeneration, and tubular atrophy consistent with features of TIN.

Idiopathic FS was considered for this patient. Supportive treatments were thus commenced. Serum bicarbonate, phosphorus, potassium and vitamin D were administered. He was referred to the Inonu University Faculty of Medicine Orthopedic Clinic and was not operated on for fractures. He was then followed-up by the Inonu University Faculty of Medicine Endocrinology Clinic for osteoporosis. It was recommended that he continue the supplement therapy and the patient is still taking the same supplements. His osteoporosis is stable and follow-up is being continued. In addition, he was referred to the Inonu University Faculty of Medicine Nephrology Clinic. The patient, who has stage 3 kidney disease, is still being followed-up at the nephrology clinic.

In summary, the diagnosis of osteomalacia and proximal tubular RTA remains a challenge for physicians due to its non-specific joint manifestations. Severe osteomalacia and osteoporosis are considered to be caused by tubulointerstitial nephritis with FS, a rare, asymptomatic renal involvement.

A total of 180 liters glomerular filtrate forms out of the proximal tubule (PT) every day. Of this amount, 98% is reabsorbed in the PT ( 10 ). However, defects in the PT can lead to reabsorption deficiency, primarily of bicarbonate and also of other solutes (such as phosphorus, amino acid, glucose and uric acid). This condition characterizes FS ( 11 ). Following the diagnosis of FS, the etiology causing the defect in the PT needs to be researched. Autosomal dominant hereditary diseases may be the cause.

A major cause of FS in adults is the increased excretion of monoclonal immunoglobulin light chains due to monoclonal gammopathies that are otherwise latent. Sjögren's syndrome, primary biliary cirrhosis, tyrosinemia, fructose intolerance, galactosemia, Wilson's disease, Dent's disease, Lowe syndrome and drug-induced cytopathic effects are also considered in the etiology ( 10 ). The most toxic agents for the PT are tenofovir, adefovir, ifosfamide, gentamicin, acetazolamide, sodium bicarbonate, sodium valproate, fumaric acid and deferasirox. Overall, any of these factors may be responsible for FS, and even rare cases may be idiopathic ( 12 ). The diagnosis of FS is generally made clinically with glycosuria, hypophosphatemia, aminoaciduria, normal anion gap metabolic acidosis and proteinuria ( 12 ).

Complaints at referral regarding HO can be generally non-specific, such as proximal myopathy, back pain, bone pain and joint pain ( 4 ). As such complaints are similar to those of rheumatologic patients, patients may be misdiagnosed ( 5 ). The general characteristics and clinical manifestation of patients with hypophosphatemic osteomalacia are presented in Table II . In addition, some laboratory values of cases are summarized in Table III . Li et al ( 9 ) considered HO and rheumatologic diseases, such as rheumatoid arthritis and ankylosing spondylitis, in nine patients who presented between 2011 and 2015. Following an etiology search, HO and FS were then diagnosed ( 9 ). In another case involving FS diagnosis on the grounds of primary cirrhosis, the patient first applied to an orthopedic clinic with complaints of year-long bilateral knee pain and walking difficulties. Later, her condition was diagnosed by internal medicine as HO ( 8 ). Thus, the awareness of HO is crucial. The present study aimed to increase the awareness of physicians by discussing the mentioned case and similar cases in the literature. Physicians have to be suspicious of HO, whose prevalence is difficult to specify and not stated in the literature. Likewise, medical history, physical examination and drug use need to be thoroughly investigated. Particularly in younger patients, the condition may be associated with HO, given the presentation of unexplained bone and joint pains.

General characteristics clinical manifestation of patients with hypophosphatemic osteomalacia.

[i] AS, ankylosing spondylitis; RA, rheumatoid arthritis.

Some laboratory values of cases of FS in the literature.

[i] NA, not available; PTH, parathyroid hormone.

Case presentations are generally on the grounds of osteoporosis, such as joint or bone pain and walking difficulties. In the case presented herein, the patient was initially considered to have arthritis, but an advanced search was subsequently conducted. The MRI and laboratory test results were examined. The existence of osteoporotic fractures in the MRI and proteinuria in the laboratory findings, normal anion gap metabolic acidosis and glycosuria were discussed in association with nephrology, and PT deficiency was considered. Following the diagnosis of FS, a bone marrow biopsy was performed for the purpose of etiological research, and a normocellular bone marrow was revealed. The patient had no additional drug use. Mouth and eye dryness were examined. Schirmer's test yielded negative results, and Sjögren's syndrome was not considered as the SSA and SSB antibody test results were negative. The patient had no heavy metal exposition. He was considered to suffer from idiopathic FS. Supportive treatment was thus commenced. Serum bicarbonate, phosphorus, potassium, vitamin D replacement was administered. He is still being followed-up by the nephrology clinic due to his stage 3 kidney disease.


Not applicable.

Funding: No funding was received.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Authors' contributions

ANC and SY were major contributors to the writing of the manuscript, and also made substantial contributions to the design of the study and to the interpretation of data for the study. SY, IS and BE revised and edited the manuscript and also advised on patient treatment. SY, IS, BE and ANC analyzed patient data. ZÖ and ANC contributed to the conception of the study and acquisition of the data, as well as in the analysis of data for the study and provided the radiological images. All authors gave the final approval of the version to be published and reviewed the literature. ANC and SY confirm the authenticity of all the raw data.

Ethics approval and consent to participate

The patient provided written informed consent for his clinical information to be used for the purposes of the present study.

Patient consent for publication

The patient provided written informed consent for the publication of his clinical data in the present case report study.

Competing interests

The authors declare that they have no competing interests.


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clinical case report renal tubular acidosis

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References (15), cited by (8), recommended articles (6).


The American Journal of the Medical Sciences

Case reports case report renal tubular acidosis in pregnancy.

Two pre-eclamptic females were seen in consultation by the Renal Service. Both had Renal Tubular Acidosis (RTA). One case resulted from the possible exacerbation of Lupus Erythematosus. The other patient’s RTA seemed to be related to ingestion of Dyazide for pre-eclampsia. Delivery of the child in the first case and discontinuance of Dyazide in the second resulted in the abrupt disappearance of RTA.

Urinary concentration, white blood cell excretion, acid excretion, and acid-base status in normal pregnancy: Alterations in pregnancy-associated hypertension

Am j obstet gynecol, primary empty sella, glactorrhea, hyperprolactinemia and renal tubular disease, distal renal tubular acidosis in children with chronic hydronephrosis, renal proximal tubular dysfunction and paroxysmal nocturnal hemoglobinuria, hereditary renal tubular acidosis, renal tubular acidosis after kidney transplantion: natural history and significance, ann intern med, bartter's syndrome in pregnancy: review of potassium homeostasis in gestation.

A 26-year-old G3P2 Hispanic female presented with acute urinary retention and profound hypokalemia (serum potassium 1.6   mEq/L) during her 13th week of pregnancy. Placement of an indwelling bladder catheter resulted in immediate urine output of 1700   mL. Potassium was administered aggressively and urinary retention resolved. She reported the use of herbal products containing licorice and corn silk tea (zea maize extract). She was taking no medication other than prenatal vitamins and had no known prior medical problems. Despite discontinuance of the herbal supplement and tea and aggressive oral potassium replacement, severe asymptomatic hypokalemia persisted. Twenty-four–hour urine studies and blood chemistry determinations, subsequently, were consistent with Bartter’s syndrome. At the time of hospital discharge, she was receiving 480   mEq of oral potassium daily. Potassium-sparing diuretics were not prescribed, because successful pregnancy outcomes have been reported in patients with Bartter’s syndrome and Gitelman syndrome without normalization of potassium levels. Hypokalemia (2.5–3.0   mEq/L) persisted throughout an otherwise uncomplicated pregnancy with delivery of a healthy child at 35   weeks of gestation.

Renal Tubular Acidosis: An Uncommon Cause of Bad Obstetric History

Proximal renal tubular acidosis in pregnancy: a case report and literature review, dietary reference intakes for water, potassium, sodium, chloride, and sulfate, hypocalemic paralysis secondary to renal tubular acidosis, transient renal tubular acidosis in pregnancy, decompressive craniectomy for stroke: early cranioplasty is a predictor for postoperative complications.

Previous clinical studies assumed that early cranioplasty (CP) was mandatory for a favorable neurologic recovery after decompressive craniectomy (DC) for malignant stroke. However, the appropriate timing of the CP procedure after DC remains controversial. This study assessed patients who underwent DC because of cerebral ischemia to determine the appropriate time point of CP and surgical-associated complications.

Data from the period 2007–2014 were retrospectively evaluated. CP was performed in 75 patients who previously underwent DC because of supratentorial cerebral infarction. Patients were divided into 2 groups (early CP vs. late CP) according to the time from DC to CP (<3 months vs. ≥3 months). Patient characteristics, timing of CP, and postoperative complications associated with CP were analyzed.

CP was performed early in 12 patients (16%) and late in 63 patients (84%). The complication rate after CP was 18%; complications included wound healing disturbance in 8 patients (11%), epidural hematoma or subdural hematoma in 4 patients (4%), and others in 2 patients (3%). Patients with early CP experienced significantly more complications compared with patients with late CP after initial DC (5 of 12 patients [42%] vs. 8 of 63 patients [13%]; P  = 0.02). In multivariate analysis, early CP was a significant predictor of postoperative complications after CP (odds ratio = 6.04; 95% confidence interval, 1.4–24.9; P  = 0.01).

The present data suggest that patients who underwent DC for stroke might benefit from CP performed >3 months after DC owing to a lower rate of wound infection.

Nigella sativa oil alleviates ultrastructural alterations induced by tramadol in rat motor cerebral cortex

Tramadol is an opioid analgesic used to alleviate acute and chronic pain. Nigella sativa oil is one of the traditional remedies with antioxidant activity. This study was designed in order to investigate the ultrastructural alterations induced by tramadol in the rat cerebral cortex and to find out any possible protective effect of N. sativa oil against these alterations. Twenty-four male albino rats were assigned to three groups. Group I received intraperitoneal and oral normal saline for 30 days. Group II received intraperitoneal injections of tramadol 20   mg/kg/day, 40   mg/kg/day and 80   mg/kg/day on the first, second and third 10 days of the study, respectively. Group III received intraperitoneal tramadol similar to Group II and oral N. sativa oil at a dose of 4   ml/kg/day for 30 days. Specimens from the motor area were obtained and processed for transmission electron microscopy. In the tramadol-treated group, pyramidal and granular cells appeared shrunken and showed ultrastructural features of apoptosis such as nuclear membrane invaginations, chromatin margination, dilated rough endoplasmic reticulum, dilated Golgi saccules, and mitochondria with disintegrated cristae. The myelinated axons showed disorganization and splitting of the myelin sheath and contained vacuoles and abnormal mitochondria. Administration of N. sativa oil partially protected the cortical neurons and myelinated axons against tramadol-induced changes. In conclusion, N. sativa oil alleviates ultrastructural apoptotic changes induced by tramadol in the rat motor cerebral cortex.

Successful treatment of giant invasive cutaneous squamous cell carcinoma by plum-blossom needle assisted photodynamic therapy sequential with imiquimod: Case experience

Giant cutaneous squamous cell carcinoma (cSCC) in elderly people is difficult to treat. Herein, we report a case of 96-year-old male who was diagnosed to have giant facial invasive SCC (4cm*4.5cm*2 cm). He was successfully treated with plum-blossom needle assisted photodynamic therapy (PDT) sequential with imiquimod. The patient achieved complete remission after 9 sessions of PDT and 3 months of imiquimod but developed residual vitiligo-like hypopigmentation. There was no recurrence at 18 months of follow-up. This case suggests that plum-blossom needle pretreated PDT sequential by topical imiquimod is a viable treatment option for refractory and giant thick SCC.

Effects of two different glycoprotein platelet IIb/IIIa inhibitors and the clinical endpoints in patients with intracranial Pipeline flow diverter implant

To compare the antiplatelet effect and major adverse cerebrovascular events of Pipeline for intracranial aneurysms using glycoprotein IIb/IIIa antagonists (GPI) eptifibatide and tirofiban.

Retrospective analysis of relevant data of patients using GPIs combined with oral antiplatelet therapy in Nanfang Hospital of Southern Medical University from December 2017 to December 2019. The study was approved by the ethics Committee of Nanfang Hospital of Southern Medical University. According to the random use of GPIs drugs, they were assigned to the eptifibatide group and tirofiban group. Basic data, platelet inhibition rates at baseline, 24h and 72h after administration, short-term major adverse cerebrovascular events, and bleeding complications were compared between the two groups.

A total of 47 patients were included in this study, including 24 patients in eptifibatide group and 23 patients in tirofiban group. There was no significant difference in average age (53.75 vs . 53.91 years) and body mass index (BMI) (24.39 vs . 22.73 ​kg/m2) between eptifibatide group and tirofiban group. There was no significant difference in coagulation factor function (R), fibrinogen function (K), fibrinolysis function (EPL), comprehensive coagulation index (Cl), arachidonic acid pathway inhibition rate (AA%) and adenosine diphosphate inhibition rate (ADP%). However, the baseline level of residual platelet function MA (ADP) in eptifibatide group was significantly higher than that in tirofiban group (50.79 vs . 35.29 ​mm, P ​= ​0.0026). There was a statistical difference in the platelet aggregation function MA (65.38 vs . 62.54 ​mm, p ​= ​0.0442), the rate of spontaneous hemorrhagic stroke (4.3% vs . 0%) and the rate of asymptomatic minor bleeding (26.08% vs . 4.1%) in the two groups (P ​< ​0.05).

Both eptifibatide and tirofiban can effectively inhibit platelets, but the effect of etifeptide is better than that of tirofiban in preventing intracranial microhemorrhage and asymptomatic cerebral infarction.

Deep intronic mis-splicing mutation in JAK3 gene underlies T   −   B   +   NK   − severe combined immunodeficiency phenotype

Severe combined immune deficiency (SCID) is a group of genetically heterogeneous diseases caused by an early block in T cell differentiation and present with life threatening infections, often within the first year of life. Janus kinase ( JAK )3 gene mutations have been found to cause autosomal recessive T   −   B   + SCID phenotype. In this study we describe three patients with a novel deep intronic mis-splicing mutation in JAK3 as a cause of T   −   B   +   NK   − SCID highlighting the need for careful evaluation of intronic regulatory elements of known genes associated with clearly defined clinical phenotypes. We present the cases and discuss the current literature.

Ablative fractional laser–assisted photodynamic therapy provides superior long-term efficacy compared with standard methyl aminolevulinate photodynamic therapy for lower extremity Bowen disease

Ablative fractional laser (AFL)-assisted methyl aminolevulinate (MAL) photodynamic therapy (PDT) (AFL-MAL-PDT) has shown significantly higher efficacy and lower recurrence rates at 12 months than conventional methyl aminolevulinate photodynamic therapy (MAL-PDT) for the treatment of Bowen disease (BD). However, long-term follow-up data are not available.

To compare the 5-year efficacy and recurrence rates of AFL-MAL-PDT with those of conventional MAL-PDT for the treatment of lower extremity BD.

A total of 60 patients with 84 BD lesions were randomly assigned to a single session of AFL-MAL-PDT or 2 sessions of MAL-PDT with a 1-week interval between sessions. Patients were followed up at 3, 12, 24, 36, 48, and 60 months after treatment. Efficacy, recurrence rates, and risk factors for unsuccessful treatments were assessed.

After 5 years, the overall clearance rate of AFL-MAL-PDT (84.78%) was significantly better than that of MAL-PDT (44.74%) for BD lesions. The recurrence rate was significantly lower for AFL-MAL-PDT (9.3%) than for MAL-PDT (41.38%). Diameters larger than 20 mm and lesions with a history of previous treatment were independent factors for treatment failure.

The small sample size and single-center study design were limitations.

For patients with lower extremity BD lesions, AFL-MAL-PDT showed significantly higher long-term efficacy and lower recurrence rates than standard MAL-PDT.

Logomarca do periódico: Brazilian Journal of Nephrology

Atypical clinical presentation of distal renal tubular acidosis: a case report registered in Amazonas, Brazil

We report an unusual case of a 24-year-old girl with a history of recurrent hypokalemic paralysis episodes and skin lesions on the lower limbs and buttocks, both of which had an acute evolution. In subsequent investigations, the patient also had nephrocalcinosis, nephrolithiasis, hyperchloremic metabolic acidosis and persistent alkaline urinary pH. The findings were consistent with distal renal tubular acidosis as the cause of hypokalemic paralysis. Clinical findings, immunological tests and the result of skin biopsy suggested primary Sjögren's syndrome as an underlying cause. The patient developed azotemia due to obstructive nephrolithiasis. All the features presented in this case are an unusual manifestation of distal renal tubular acidosis; so far, we are not aware of a similar report in the literature.

Keywords: Nephrocalcinosis; Nephrolithiasis; Acidosis, Renal Tubular; Hypokalemia; Hypokalemic Periodic Paralysis

Relatamos um caso incomum de uma jovem de 24 anos com história de episódios recorrentes de paralisia hipocalêmica e lesões cutâneas em membros inferiores e nádegas, ambas de evolução aguda. Em investigações subsequentes, verificou-se que a paciente apresentava nefrocalcinose, nefrolitíase, acidose metabólica hiperclorêmica e pH urinário persistentemente alcalino. Os achados foram consistentes com acidose tubular renal distal como causa da paralisia hipocalêmica. Achados clínicos, exames imunológicos e o resultado da biópsia de pele foram compatíveis com a síndrome de Sjögren primária como causa subjacente. A paciente evoluiu com azotemia em decorrência da nefrolitíase obstrutiva. Todas as características apresentadas nesse caso são uma manifestação incomum de acidose tubular renal distal; até o momento, não temos conhecimento de um relato semelhante na literatura.

Palavras-chave: Nefrocalcinose; Nefrolitíase; Acidose Tubular Renal; Hipopotassemia; Paralisia Periódica Hipopotassêmica


Type 1 renal tubular acidosis (RTA), or distal RTA (dRTA), is a renal tubular acidification disorder characterized by hyperchloremic metabolic acidosis and persistently high urinary pH. Hypokalemia has been reported in 28-53% of patients, and can rarely present as hypokalemic paralysis. The prevalence of dRTA in primary Sjögren’s syndrome (pSS) is estimated at 5% to 25%, and approximately 5% of patients develop nephrolithiasis (mainly calcium phosphate stones); while 56% of patients have significant nephrocalcinosis. 1 1 Aygen B, Dursun FE, Dogukan A, Ozercan IH, Celiker H. Hypokalemic quadriparesis associated with renal tubular acidosis in a patient with Sjögren's syndrome. Clin Nephrol. 2008 Apr;69(4):306-9. , 2 2 Moutsopoulos HM, Cledes J, Skopouli FN, Elisaf M, Youinou P. Nephrocalcinosis in Sjögren's syndrome: a late sequela of renal tubular acidosis. J Intern Med. 1991 Aug;230(2):187-91. , 3 3 Gera C, Mohapatra D, Calton N. Hypokalaemic paralysis secondary to distal renal tubular acidosis as the presenting symptom of systemic lupus erythematosus. Singapore Med J. 2011 Jan;52(1):e1-3. , 4 4 Bossini N, Savoldi S, Franceschini F, Mombelloni S, Baronio M, Cavazzana I, et al. Clinical and morphological features of kidney involvement in primary Sjogren's syndrome. Nephrol Dial Transplant. 2001 Dec;16(12):2328-36. , 5 5 Caruana RJ, Buckalew Junior VM. The syndrome of distal (type 1) renal tubular acidosis. Clinical and laboratory findings in 58 cases. Medicine (Baltimore). 1988 Mar;67(2):84-99. , 6 6 Brenner RJ, Spring DB, Sebastian A, McSherry EM, Genant HK, Palubinskas AJ, et al. Incidence of radiographically evident bone disease, nephrocalcinosis, and nephrolithiasis in various types of renal tubular acidosis. N Engl J Med. 1982 Jul;307(4):217-21. DOI: , 7 7 Arampatzis S, Röpke-Rieben B, Lippuner K, Hess B. Prevalence and densitometric characteristics of incomplete distal renal tubular acidosis in men with recurrent calcium nephrolithiasis. Urol Res. 2012 Jun;40(1):53-9. DOI: In this study, we describe an unusual case of dRTA, secondary to pSS, which clinically manifested with palpable purpura in the lower limbs, recurrent hypokalemic paralysis and azotemia. So far, we are not aware of a similar report in the literature.


Female patient, 24 years old, healthy until August 2013, when during the night she had the first episode of weakness and difficulty in moving her limbs, also having a palpable purpura in the lower limbs and buttocks, both of acute evolution. Her condition started after an extremely exhausting and stressful day. There were no changes in the level of consciousness, sphincter release, nausea, vomiting, diarrhea, fever, arthritis, dyspnea and she did not use medications. She had no family history of a similar disease. At the time, the only documented laboratory change was hypokalemia of 1.7 mEq/L. She reported repeated hospital admissions in the past three years for the same condition mentioned above, and recurrent urinary infections. The last episode was in 2016, with a recorded potassium of 1.4 mEq/L. She received potassium replacement intravenously, followed by oral dosing for maintenance purposes, which remained asymptomatic for two years and without kidney monitoring. However, she realized that, during periods of stress, the lesions appeared on the lower limbs and buttocks, with worsening asthenia, but without impairment to daily activities. The lesions were proportional to the intensity of the stress and self-limited, with an evolution of three to four weeks. In November 2018, she was admitted to the nephrology service at the Getúlio Vargas University Hospital to clarify the clinical situation. Three weeks before this admission, she was treated for urinary infection with ciprofloxacin, when she felt severe pain in the hypogastric region, with macroscopic hematuria and elimination of a kidney stone. She denied use of non-steroidal anti-inflammatory drugs. On admission, she complained of persistent asthenia, polyuria, polydipsia, dysuria, xeroderma, xerophthalmia, xerostomia, chronic constipation, abdominal cramps and difficulty in weight gain. Recurring complaints about three years ago. In the physical exam, we noticed current weight of 45 kilos, clear-minded and oriented in time and space, without lymphadenopathy. There were no changes in her cardiovascular, respiratory and neurological exams. Her blood pressure was 120 x 80 mmHg; the heart rate was 50/min; respiratory rate 22/min; abdomen: flat, no murmur on auscultation and with mild to medium intensity pain on deep palpation on the right flank and hypogastric regions. Extremities: palpable purple lesions in the lower limbs, with greater prevalence in the malleolar region ( Figure 1 ).

clinical case report renal tubular acidosis


It was evidenced through the reactive tape, persistent urinary pH 7.5, arterial blood gases with pH values = 7.164, pCO2 = 27 mmHg, HCO 3 = 9.8 mEq / L showing hyperchloremic respiratory and metabolic acidosis. Hypokalemia (serum potassium = 3.0 mEq/L), even with oral replacement and negative urine culture. Figure 2 shows the abdominal CT scan with nephrocalcinosis and ureteral lithiasis. The diagnosis was compatible with dRTA, according to the literature. 1 1 Aygen B, Dursun FE, Dogukan A, Ozercan IH, Celiker H. Hypokalemic quadriparesis associated with renal tubular acidosis in a patient with Sjögren's syndrome. Clin Nephrol. 2008 Apr;69(4):306-9. , 6 6 Brenner RJ, Spring DB, Sebastian A, McSherry EM, Genant HK, Palubinskas AJ, et al. Incidence of radiographically evident bone disease, nephrocalcinosis, and nephrolithiasis in various types of renal tubular acidosis. N Engl J Med. 1982 Jul;307(4):217-21. DOI: , 7 7 Arampatzis S, Röpke-Rieben B, Lippuner K, Hess B. Prevalence and densitometric characteristics of incomplete distal renal tubular acidosis in men with recurrent calcium nephrolithiasis. Urol Res. 2012 Jun;40(1):53-9. DOI:

clinical case report renal tubular acidosis

In the subsequent evaluation, regarding the dRTA etiology, the Schirmer test was positive in both eyes, with high titers of anti-SSA/Ro> 240.0 U/mL (normal <7.0 U/mL), anti- SSB/La > 320 U/mL (normal <7.0 U/mL) and antinuclear antibody (ANF), dotted nuclear pattern> 1: 640. On ultrasound, the glands and parotid glands were reduced and hypoechoic, with hyperechoic beams in between. The findings were conclusive for the diagnosis of pSS, according to the most recent criteria. 8 8 Shiboski CH, Shiboski SC, Seror R, et al. 2016 Colégio Americano de Reumatologia / Liga Européia Contra os critérios de classificação do Reumatismo para síndrome de Sjögren primária: uma metodologia baseada em consenso e dados envolvendo três coortes internacionais de pacientes. BMJ. 2017;69(1):35-45. DOI:

All results of viral serology were negative, ESR and thyroid function tests were normal. The search for autoantibodies: anti-SM, anti-DNA-double helix, rheumatoid factor, anti-neutrophil cytoplasmic antibodies, complement and serum cryoglobulin tests were non-reactive. She had azotemia; urea: 61 mg/dL, creatinine: 1.34 mg/dL and normal levels of platelets, hemoglobin, blood glucose and liver function. On abdominal CT, there was bilateral hydronephrosis with an obstructive factor on the right side.

She underwent rigid ureterolithotripsy with removal of the ureteral stone and implantation of a double J catheter, confirming the cause of azotemia, and renal biopsy was not performed. Her clinical condition improved significantly after the introduction of potassium citrate 120 mEq/day, with a weight gain of 3 kg, bicarbonate of 16.7 mmol/L, and serum potassium of 4.1 mEq/L being registered on the thirtieth day of hospitalization, and normal renal function, with no evidence of proteinuria.

Two months after discharge, there were recurrences of palpable purpura in her lower limbs, with complete regression with prednisone 40 mg/day. So far, the rheumatology, urology and nephrology teams are regularly monitoring her.


The patient was diagnosed with dRTA secondary to PSS, clinically manifested with skin vasculitis on the lower limbs, recurrent Hypokalemic Periodic Paralysis (PPH) and obstructive azotemia due to nephrolithiasis. In dRTA, the defect is found in the interspersed alpha cells of the cortical collecting duct, whose H+ - ATPase pumps fail to secrete acid in the urine, resulting in hypokalemia, hyperchloremic metabolic acidosis and alkaline urinary pH.

Although this is a classic clinical case of dRTA with systemic metabolic acidosis (called the complete form of dRTA), it is more common in SSD to occur without systemic metabolic acidosis (called the incomplete form of dRTA). In these cases the diagnosis can only be made through urinary acidification tests. 19 19 Duffles Amarante GB, Zotin MC, Rocha E, Delgado AG, Leite M Jr, Gomes CP.Clin Nephrol. 2014 Mar;81(3):185-91. doi: 10.5414/CN108142

HPP is a heterogeneous disease, characterized by symmetrical muscle paralysis crises, secondary to periodic variations in potassium, which was below 2.5-3.0 mEq/L. HPP can be familial or sporadic. The clinical picture of sporadic cases is similar to that of familial cases. HPP episodes begin in the first or second decades of life, most often between 15 and 30 years of age. A diet rich in carbohydrates, salt, emotional stress, and post-exercise rest precipitate the episodes. dRTA is generally asymptomatic and can rarely present as HPP. 1 1 Aygen B, Dursun FE, Dogukan A, Ozercan IH, Celiker H. Hypokalemic quadriparesis associated with renal tubular acidosis in a patient with Sjögren's syndrome. Clin Nephrol. 2008 Apr;69(4):306-9. , 9 9 Koul PA, Saleem SM, Bhat D. Sporadic distal tubular acidosis and periodic hypokalaemic paralysis in Kashmir. J Intern Med. 1993;233:463-6. , 10 10 Koul PA, Wahid A. Recurrent paralysis in a young man. Lancet. 2000 May;355(9215):1612. , 11 11 Stedwell RE, Allen KM, Binder LS. Hypokalemic paralysis: a review of the etiologies, pathophysiology, presentation, and therapy. Am J Emerg Med. 1992;10:143-8. , 12 12 Lin SH, Lin YF, Halperin ML. Hypokalaemia and paralysis. QJM. 2001 Mar;94(3):133-9. Secondary causes of HPP include thyrotoxicosis (47.1%), diuretics (11.8%), dRTA, Gitelman syndrome and primary hyperaldosteronism (2.9%). 13 13 Schwartz GJ. Potassium. In: Avner ED, Harmon WE, Niaudet P, Yoshikawa N, eds. Pediatric nephrology. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2005. p. 147-81. , 14 14 Sinharay R. Hypokalaemic thyrotoxic perodic paraysis in an Asian man in the United Kingdom. Emerg Med J. 2004 Jan;21(1):120-1. , 15 15 Bes C, Paksoy F, Namal E, et al. Thyrotoxic hypokalemic periodic paralysis (TPP). Turkish Med Sci J Nephrol. 2008;3(1):22-4.

Regarding the etiology of dRTA, the diagnosis of pSS was evident after clinical and laboratory tests, according to the most recent criteria. 8 8 Shiboski CH, Shiboski SC, Seror R, et al. 2016 Colégio Americano de Reumatologia / Liga Européia Contra os critérios de classificação do Reumatismo para síndrome de Sjögren primária: uma metodologia baseada em consenso e dados envolvendo três coortes internacionais de pacientes. BMJ. 2017;69(1):35-45. DOI: Sometimes systemic complications provide the first suspicion of the diagnosis, as seen in our case: muscle weakness, secondary to severe hypokalemia, palpable purpura and dRTA, leading to the suspicion of underlying autoimmune disease. Anti-SSA/Ro antibodies associated with Sjögren’s syndrome manifest in two thirds of patients, and should be evaluated in all cases. Biopsy of minor salivary glands is typically recommended to establish a diagnosis of pSS in the absence of anti-SSA/Ro antibodies. The recognition and early diagnosis of this disease are important for adequate therapeutic intervention and prevention of complications, since the treated disease has a slow course and a benign evolution. Skin biopsy was performed, which histopathological report strengthened the diagnosis of pSS, discarding other entities such as Henoch-Schönlein purple, among others. Palpable purpura is the most common dermatological manifestation associated with pSS, occurring in the lower extremities. 16 16 Ramos-Casals M, Anaya JM, García-Carrasco M, Rosas J, Bové A, Claver G, et al. Cutaneous vasculitis in primary Sjögren syndrome: classification and clinical significance of 52 patients. Medicine (Baltimore). 2004 Mar;83(2):96-106. , 17 17 Alexander EL, Provost TT. Cutaneous manifestations of primary Sjogren's syndrome: a reflection of vasculitis and association with anti-Ro (SSA) antibodies. J Invest Dermatol. 1983 May;80(5):386-91. Elaine L. et al. 17 17 Alexander EL, Provost TT. Cutaneous manifestations of primary Sjogren's syndrome: a reflection of vasculitis and association with anti-Ro (SSA) antibodies. J Invest Dermatol. 1983 May;80(5):386-91. evaluated 22 patients diagnosed with pSS, with skin lesions, submitted to skin biopsies and the analysis of the main laboratory tests. The most common clinical presentation was purpura, in 10 patients (45%). The most frequent symptoms of pSS are xeroderma and skin vasculitis, and of the 30.6% who have cutaneous vasculitis, 84% manifested palpable purpura. 18 18 Anaya JM, Restrepo C, Díaz LA, Cadena J, Gutiérrez J, Mantilla RD, et al. Compromiso dermatológico inflamatório en pacientes con Síndrome de Sjögren. Acta Med Colomb. 2003 Dec;28(4):185-9.

Nephrolithiasis and nephrocalcinosis are entities frequently associated with untreated dRTA, and both are late sequelae. Acidemia promotes bone demineralization because of the mobilization of calcium phosphate from the bone. The alkaline urinary pH facilitates the precipitation of calcium and, consequently, the formation of nephrocalcinosis. In ATRd, tubular calcium reabsorption is reduced and proximal citrate reabsorption is increased, findings consistent with the patient in the case in question, according to the values found in 239mg / 24h and citraturia = 84mg / 24h, favoring the formation of kidney stones. The crystallographic evaluation of the renal calculus was performed by physical-chemical analysis (qualitative), whose presence of the composites of carbonate, oxalate and calcium phosphate.

The diagnosis of distal renal tubular acidosis is made by clinical suspicion and laboratory findings. Early diagnosis is not easy, so subsequent investigations should be considered in any patient with hypokalemic paralysis and cutaneous manifestations of palpable purpura. As far as we know, this is the first reported case of skin vasculitis, due to primary Sjögren’s syndrome, accompanied by recurrent hypokalemic paralysis as the initial manifestation of dRTA.

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Figure 1   Palpable purpuric lesions of the lower limbs.

clinical case report renal tubular acidosis

Figure 2   3D abdominal CT scan: bilateral nephrocalcinosis, ureteral lithiasis in the crossing of the external iliac vessels on the right, 1 cm, density 1620 uh (Hounsfield units) and ureterovesical junction.

clinical case report renal tubular acidosis

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