Distal Renal Tubular Acidosis Associated with Autoimmune Diseases: Reports of 3 Cases and Review of Mechanisms

Abstract

Case series Patients: Female, 29-year-old • Female, 67-year-old • Female, 30-year-old Final Diagnosis: Distal renal tubular acidosis (dRTA) Symptoms: Hypokalemia • metabolic acidosis Medication: — Clinical Procedure: Diagnosis Specialty: Nephrology • Rheumatology Objective: Unusual clinical course Background: Distal renal tubular acidosis (dRTA) is a defect in the urinary acidification process that limits the elimination of protons [H+] by alpha intercalated cells in the collecting tubules, with consequent metabolic acidosis with a normal plasma anion gap. The relationship between this tubulopathy and immune-mediated diseases like Sjögren syndrome, rheumatoid arthritis, autoimmune hepatitis, primary biliary cirrhosis, systemic lupus erythematosus, and thyroiditis is well known. Further, the pathophysiological mechanisms are diverse, but, unfortunately, many are not yet fully understood. We report 3 cases of dRTA in patients with different autoimmune diseases and review the pathophysiological mechanisms already described. Case Reports: The first case involved a 29-year-old woman with autoimmune hepatitis. She had metabolic acidosis with persistent hypokalemia, and a kidney stone was also identified. The second case involved a 67-year-old woman diagnosed with rheumatoid arthritis. She had metabolic acidosis with hypokalemia. The third case involved a 30-year-old woman with Sjögren syndrome and persistent metabolic acidosis. In addition to the presence of metabolic acidosis with a normal plasma anion gap, all 3 patients exhibited urine with a supraphysiologic pH (above 5.3). Conclusions: Autoimmune diseases may be associated with deficits in urinary acidification with consequent metabolic acidosis and, therefore, systemic repercussions. This association must be remembered and researched because correct diagnosis and treatment will serve to reduce complications.

Rare renal proximal tubular dysfunctions in primary biliary cholangitis

“…The mechanism of renal tubular involvement in PBC is not yet fully understood. The potential hypotheses are a common genetic predisposition or cross-reacting local antigens between liver and kidney which may stimulate and attract autoantibodies or activated lymphocytes and plasma cells to kidney leading to TIN and tubular dysfunctions [ 29 , 39 ]. The cross-reactivity between hepatocyte membrane surface lipoproteins and Tamm-Horsfall glycoprotein produced by renal tubular cells were reported [ 40 , 41 ].…”

Acidose tubular renal associada ao novo coronavírus: relato de caso

“…Varshney et al, 2015. Muitas afecções podem causar a Acidose Tubular Renal Distal, que, costumeiramente mantém a taxa de filtração glomerular normal (Silveira, et al, 2021).…”

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

“…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 ].…”

“…In only one case out of these 33 reports, cyclophosphamide was used, with eGFR improvement and potassium value amelioration [ 33 ]. Immunosuppressive therapy was not used in those three cases of autoimmune hepatitis, primary biliary cirrhosis and rheumatoid arthritis included in our analysis [ 36 , 37 ]. A meta-analysis published in 2021 which included patients with renal tubular acidosis and liver pathology (autoimmune hepatitis and alcoholic hepatitis) showed that corticosteroids improved short term mortality in this group, but it is not mentioned any effect on the evolution of DRTA [ 55 ].…”