Autoantibodies and primary Sjögren's syndrome in a hypocitraturic stone population

Primary Sjögren's syndrome may be complicated by distal renal tubular acidosis (dRTA) and hypocitraturia, which are risk factors for calcium stone formation. Approached from a different perspective, in patients with urolithiasis and dRTA, autoantibodies and various autoimmune diseases are not uncommon. In search for signs of autoimmune disease, we analysed antinuclear antibodies and total levels of serum IgG in 197 hypocitraturic stone formers (67 women and 130 men). Antinuclear antibodies were present in 1.5% of the men and in 18% of the women. An isolated increase in serum IgG was found in 9% of the men and in 3% of the women. Anti-SS-A antibodies were analysed in a subgroup of 46 women and were estimated to occur in 16% of all hypocitraturic stone forming women. Four of 4 examined women, but no men, fulfilled the criteria of definite or possible primary Sjögren's syndrome. We recommend the analysis of anti-SS-A antibodies in female hypocitraturic stone formers.