Distal renal tubular acidosis (dRTA) can be associated with autoimmune diseases such as primary Sjögren's syndrome (SS). Our objective was to study SS-associated symptoms, autoantibodies and renal histopathology in patients with urolithiasis and dRTA.
The patients were from the Departments of Nephrology and Rheumatology. University Hospital of Linköping, which is a tertiary referral hospital, as well as a secondary referral centre for the immediate area around the city of Linköping.
Ten female patients with dRTA, who presented with urolithiasis and not with subjective sicca symptoms, were from the Department of Nephrology, University Hospital, Linköping. Autoantibodies were detected in eight of these patients, and they were studied with respect to clinical and laboratory evidence of SS (urolithiasis group). Fifteen women with SS, who presented with sicca symptoms and not with urolithiasis or dRTA, served as the reference group.
In the urolithiasis group, all of the eight patients had anti-SS-A antibodies, and SS (or possible SS) developed in seven of the eight patients 1-48 (mean 15) years after the onset of urolithiasis. Histological features of tubulointerstitial nephritis were found in four of five biopsied patients in the urolithiasis group, and in two of four patients (with dRTA) in the reference group.
Urolithiasis and dRTA can precede subjective sicca symptoms, and patients with dRTA may have SS in the absence of subjective sicca symptoms. Anti-SS-A antibodies are common in patients with urolithiasis and dRTA. Therefore, we hypothesize the possibility of a Sjögren-related renal disease in these patients.