Distal renal tubular acidosis associated with Sjogren syndrome

Renal Tubular Acidosis Type I with Prominent Hypokalemia and Nephrolithiasis as a Presentation of Sjögren's/Systemic Lupus Erythematosus Disease

Female patient, suffering from nephrolithiasis, at the age of 32 was admitted for renal colic caused by a stone obstructing UP junction with left hydronephrosis. Nephrostomy was placed, resulting in brisk diuresis. Severe metabolic acidosis with normal anion gap and urine pH of 6.5 was noted. Potassium level dropped to extremely low level (1.6 mEq/L), causing muscle paralysis and respiratory failure, necessitating mechanical ventilation. The patient was treated by potassium chloride infusion, followed by correction of severe metabolic acidosis by sodium bicarbonate. Diagnosis of distal type renal tubular acidosis type I (dRTA) was made based on normal anion gap metabolic acidosis, alkaline urine, hypokalemia, and nephrolithiasis. Five years later, the patient presented with severe hypoxia, lung opacities, and bronchiolitis obliterans organizing pneumonia which was confirmed by bronchoscopy with lung tissue biopsy. Concurrently, the patient presented with dry mouth, pruritus, skin rash with hypocomplementemia, elevated anti-DNA, anti-Ro, and anti-SmAb. Diagnosis of overlap Sjögren's/systemic lupus erythematosus disease was done and treatment by hydroxychloroquine, prednisone, and azathioprine was started. Possible presence of Sjögren's syndrome should be considered in adult patients with unexplained dRTA.

Epidemiology of Distal Renal Tubular Acidosis: A Study Using Linked UK Primary Care and Hospital Data

INTRODUCTION

Distal renal tubular acidosis (dRTA), or RTA type 1, a rare inherited or acquired disease, is a disorder of the distal tubule caused by impaired urinary acid secretion. Due to associated conditions and nonspecific symptoms, dRTA may go undetected. This analysis aims to estimate the prevalence of dRTA in the UK Clinical Practice Research Datalink (CPRD) databases and extrapolate it to European Union Five (EU5) populations.

METHODS

A retrospective analysis was conducted using the CPRD GOLD database and linked Hospital Episode Statistics (HES) data to identify diagnosed and potentially undiagnosed or miscoded patients (suspected patients). Patients' records with at least one diagnosis code for dRTA, RTA, specific autoimmune diseases, or renal disorders recorded between January 1987 and November 2017 were obtained and analyzed. An algorithm was developed to detect potentially undiagnosed/miscoded dRTA, based on associated conditions and prescriptions.

RESULTS

A total of 216 patients with diagnosis of RTA or dRTA were identified (with 98 linked to hospital data), and 447 patients were identified as having suspected dRTA. dRTA prevalence for 2017 was estimated between 0.46 (recorded cases, of which 22.1% were considered primary) and 1.60 when including suspected cases (7.6% primary) per 10,000 people. Prescription and clinical records of diagnosed patients revealed a wide range of comorbidities and a need for pharmacological treatment to manage associated symptoms.

CONCLUSION

The study provides new estimates of dRTA prevalence in Europe and suggests that patients may often be unreported or miscoded, potentially confounding appropriate disease management.

Hypokalemic Paralysis Secondary to Renal Tubular Acidosis Revealing Underlying Sjogren's Syndrome

There is a well-established association of Sjogren's syndrome with renal tubular acidosis (RTA). Rarely there is a retrospective diagnosis where the patient presents with RTA and the workup reveals Sjogren's syndrome. Our case report is about a patient who presented with generalized weakness and hypokalemia, which upon further workup turned out to be RTA. Various tests were performed to find out the cause of RTA. A favorable profile for the anti-nuclear antibody, anti-Ro/SSA, and anti-La/SSB was consistent with Sjogren's syndrome. Treatment with corticosteroid improved hypokalemia. The patient did not have typical glandular symptoms of Sjogren's syndrome, and follow-up is needed to see whether the patient develops symptoms in the future and to prevent any possible complication.

A Case of Kidney Involvement in Primary Sjögren's Syndrome

BACKGROUND Sjögren's syndrome is an autoimmune disorder caused by the infiltration of monocytes in epithelial glandular and extra-glandular tissues. Hallmark presentations include mouth and eye dryness. Although renal involvement is uncommon in primary Sjögren's syndrome (pSS), patients may experience renal tubular acidosis type I (RTA I), tubulointerstitial nephritis, diabetes insipidus (DI), nephrolithiasis, and Fanconi syndrome. However, it is atypical to see more than 1 of these manifestations in a single patient. CASE REPORT We present the case of a 24-year-old woman with polyuria and polydipsia, who was initially diagnosed with nephrogenic diabetes insipidus. She also had chronic hypokalemia and nephrolithiasis. Based on clinical presentation and work up, she was diagnosed with pSS and treated accordingly. CONCLUSIONS This was a pSS patient with tubulointerstitial nephritis, diabetes insipidus, renal tubular acidosis, hypokalemia, and nephrolithiasis, who was receiving symptomatic treatment for diabetes insipidus. Diagnosis and treatment of pSS led to significant improvement in systemic and renal presentations of the patient. pSS should be considered as one of the differential diagnoses in patients with diabetes insipidus and renal tubular acidosis.

Metabolic acidosis in renal transplantation: neglected but of potential clinical relevance

Chronic metabolic acidosis (CMA) is a common complication of the more advanced stages of chronic kidney diseases (CKD), and is associated with morbidity and mortality of CKD patients and possibly with the progression of renal disease. Nevertheless, there is limited evidence or information on the prevalence, the potential causal factors, the clinical impact and the effects of correction of CMA in kidney transplant recipients. In this review, we briefly look at the more relevant, though scanty, studies which have, over time, addressed the above-mentioned points, with the hope that in the future the interest of transplant nephrologists and surgeons will grow towards this unreasonably neglected issue.