Renal involvement and followup of 130 patients with primary Sjögren's syndrome.

OBJECTIVE: To identify the clinical characteristics, pathological changes, and outcome of patients with primary Sjögren's syndrome (pSS).

METHODS: All patients with pSS and renal involvement who were admitted to Ruijin Hospital from April 1993 to December 2006 were included. All the data of clinical features and pathological changes were retrospectively analyzed. Forty-one patients underwent renal biopsies. RESULTS Our study included 130 patients with pSS: 122 women and 8 men. Ages ranged from 16 to 68 years (mean 44.1 +/- 11.52). Ninety-five patients (73.1%) developed renal tubular acidosis (RTA); 91 were found to have distal RTA. Nine patients presented with hypokalemic paralysis. Four patients developed Fanconi syndrome and 3 were proved to have nephrogenic diabetes insipidus. Twenty-seven of 130 patients (20.8%) developed tubular proteinuria and 18/130 (13.8%) presented glomerular involvement. Thirty-five patients (27.7%) developed renal failure (serum creatinine > 115 micromol/l). Most patients (70.8%) had increased serum IgG levels. The incidence of chronic interstitial nephritis was 80.5% among all the biopsy materials. Immunofluorescent staining was negative in most renal tissue. Ninety-six patients were treated with corticosteroids and/or immunosuppressant. Eighteen recovered renal function.

CONCLUSION: Patients with pSS commonly present with renal impairment, mainly from renal tubular dysfunction. The combination of corticosteroids and immunosuppressors significantly improves the renal function of patients with pSS. There is a correlation between hypergammaglobulinemia and distal RTA. The renal acidification capacity for patients with hypergammaglobulinemia. should be monitored.