Renal involvement in primary Sjögren's syndrome: A retrospective study of 103 biopsy‐proven cases from a single center in China

Abstract

Aim To retrospectively investigate the features of renal involvements in patients with primary Sjögren's syndrome (pSS) with biopsy results. Methods A total of 2096 pSS inpatients at Peking Union Medical College Hospital in China from 2005 to 2015 were identified. Patients with biopsy‐proven renal involvement (SS‐renal) and matched controls (SS‐only) were recruited. The clinical and pathologic features as well as treatments and outcomes were systematically analyzed. Results One hundred and three pSS nephritis (inpatients had biopsy‐proven renal involvement. Tubulointerstitial 53, 51.5%) was the prominent pathologic pattern with glomerulonephritis (GN) present in 50 (48.5%) of the renal lesions. The patterns of GN lesions included membranous nephropathy (37, 35.9%), mesangial proliferative glomerulonephritis (six, 5.8%) or immunoglobulin A nephropathy (three, 2.9%), minimal change disease (four, 3.9%) and focal segmental glomerulosclerosis (three, 2.9%). Compared to SS‐only patients, SS‐renal patients had fewer dry eyes and positive objective xerostomia (P < 0.05). They presented with a significantly lower incidence of interstitial lung disease (ILD), leukocytopenia and elevated immunoglobulin G levels (P < 0.05). They received a larger initial dosage of corticosteroid and had a higher mortality rate (P < 0.05). Conclusion This Chinese SS‐renal population with biopsy results has diverse pathologic patterns and distinct clinical features. They are characterized with prominent renal‐associated and mild SS‐associated features. They received more vigorous treatment but had poorer prognosis.