The prevalence, clinical features, and long-term outcome of patients with primary Sjögren’s syndrome with renal involvement

This multicenter, retrospective longitudinal study identified primary Sjögren's syndrome (pSS) patients with clinically significant renal involvement, and analyzed factors associated with predisposition. To investigate clinical features and long-term prognosis of renal involvement, we compared the clinical outcomes for the entire cohort based on the presence or absence of renal involvement. Among 1306 pSS patients (mean age, 51 ± 12 years; 98% female), 36 (2.8%) had renal involvement; 17 patients had tubular involvement, 15 had glomerular involvement, one had both, and 3 were unclassified. The presence of anti-La antibodies was associated with renal involvement. Over the median 5-year follow-up period, the renal function did not change significantly; however, 44% of patients with renal involvement showed impaired renal function at the last visit. Impaired renal function at the last visit was inversely associated with baseline renal function and hemoglobin levels. Among the entire cohort, the prevalence of lymphoproliferative disease (LPD) was significantly higher in pSS patients with renal involvement than those without. Renal involvement is a rare manifestation of pSS; however, it is associated with impaired renal function and LPD. Therefore, screening for renal involvement is important for preserving renal function and early detection of LPD.