Complete distal renal tubular acidosis in systemic lupus: clinical and laboratory findings

Abstract

We report two patients with systemic lupus erythematosus (SLE) who were found to have complete (acidotic) distal renal tubular acidosis (DRTA). One patient had nephrocalcinosis and renal magnesium wasting with tetany; the other patient had nephrolithiasis and nephrotic syndrome secondary to membranous glomerulopathy. Both patients had decreased urinary citrate excretion but neither had hypercalciuria. We discuss the association of DRTA with immunologic disorders and the possible role of hypocitraturia in promoting renal calcification in these patients. We suggest that patients with renal calcification be evaluated for DRTA, and that patients found to have DRTA be further evaluated for signs, symptoms, and laboratory evidence of immunologic disorders.