Renal tubular acidosis as the initial presentation of Sjögren’s syndrome

Abstract

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.

Comprehensive analysis of clinical and laboratory features of 440 published cases of Sjögren's syndrome and renal tubular acidosis

“…Jha et al 35 and Pisanty and Markitzio 36 reported a history of similar disease in an identical twin sister and paternal aunt of their index patients, respectively. Ho et al 37 reported a history of hypokalemia requiring supplementation in the aunt and cousin of the index patient. Family history of systemic autoimmune diseases reported in the first‐degree relatives of index patients included lupus in two, and one each of SS, lupus/scleroderma overlap and discoid lupus, respectively.…”

Distal Renal Tubular Acidosis in Sjögren's Syndrome: A Case Report

“…Recurrent parotid swelling has been documented as the most common presenting feature in the pediatric population, occurring more frequently than sicca symptoms [8]. The most common renal manifestation of Sjögren's syndrome is tubulointerstitial nephritis, which may present as RTA in adult populations; however, RTA is a rare occurrence in the pediatric population as it accounts for 7.1-19.2% of cases who present with renal potassium wasting or hypokalemic paralysis [9]. Our patient first presented with an episode of muscle weakness and syncope in the setting of severe hypokalemia at the age of 14 years, often exacerbated by menses.…”

Distal Renal Tubular Acidosis in Patients with Autoimmune Diseases—An Update on Pathogenesis, Clinical Presentation and Therapeutic Strategies

“…Two additional case reports with this association were published in 2020, and another study published recently showed a prevalence of 14.81% of DRTA (16 patients) in a cohort of 108 patients with SLE [ 6 , 7 , 8 ]. Generally, the majority of cases with complete DRTA published in literature are diagnosed due to severe symptoms associated with hypokalemia, such as quadriparesis or even respiratory arrest, and therefore, the real prevalence of DRTA associated with autoimmune diseases is difficult to estimate [ 6 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Therefore, urinary acidification tests are essential in diagnosing those patients who did not develop any symptoms and would otherwise escape undiagnosed.…”

“…Aiming for a better understanding of the disease, we performed a search of the PubMed database using MeSH descriptors (Acidosis, Renal Tubular; Lupus Erythematosus, Systemic; Sjogren’s Syndrome, Systemic Vasculitis, Rheumatoid Vasculitis, Arthritis, Rheumatoid, Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis, Churg-Strauss Syndrome, IgA Vasculitis, Spondylitis, Ankylosing, Cryoglobulins, Hepatitis, Autoimmune, Liver Cirrhosis, Biliary), and we identified 37 individual case reports published since December 2016 with the association of distal renal tubular acidosis and the following autoimmune disorders: SLE, Sjögren’s syndrome, autoimmune hepatitis, primary biliary cirrhosis and rheumatoid arthritis (see Table 1 ) [ 6 , 10 , 11 , 13 , 15 , 16 , 17 , 18 , 20 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. We also identified a case of hereditary autoimmune polyendocrine syndrome (DRTA, hypoparathyroidism, Addison disease), published in a series of cases, which was not included in our analysis, due to the lack of individual data availability [ 39 ].…”

“…After 4 years of treatment, eGFR improved from 46 mL/min/1.73 m 2 to 71 mL/min/1.73 m 2 and the patient no longer needed oral potassium and alkali supplements suggesting that DRTA might respond to Rituximab. Another immunosuppressive drug used for two patients was mycophenolate-mofetil, without signs of DRTA improvement [ 17 , 33 ]. In only one case out of these 33 reports, cyclophosphamide was used, with eGFR improvement and potassium value amelioration [ 33 ].…”