[Distal renal tubular acidosis and nephrolithiasis in 3 cases of primary Sjögren syndrome].

Tubulo interstitial nephritis, the main manifestation of renal involvement in Sjögren syndrome, may lead to a tubular dysfunction that is usually subclinical. We report three women, aged 32, 35 and 35 years old, with a primary Sjögren syndrome and symptomatic type I or distal tubular acidosis. Two patients had nephrolithiasis and one a nephrocalcinosis. Two had a basal hyperchloremic metabolic acidosis. The ammonium chloride acidification test was abnormal in all, demonstrating a distal tubular defect. None had proximal tubular dysfunction. All had an urinary pH over 6.5 and hypocitraturia and none had hypercalciuria. Renal calculi were composed of calcium oxalate and calcium phosphate in two patients and calcium phosphate and ammonium phosphate in the other. All women had positive antinuclear antibodies with mottled pattern, two had anti Ro antibodies and positive rheumatoid factor and one had hypergammaglobulinemia. None had anti La antibodies, crioglobulinemia or monoclonal proteins.