Analysis of clinical and laboratory characteristics and pathology of lupus nephritis-based on 710 renal biopsies in China

Abstract

Objectives: This study aimed to analyse the clinical and laboratory characteristics of different pathologic classifications of lupus nephritis (LN) patients in terms of age at systemic lupus erythematosus (SLE) diagnosis and nephritis onset.

Method: Clinical, laboratory, and pathological data of 710 LN patients diagnosed by renal biopsy at our institution between 2000 and 2018 were retrospectively analysed. Patients were divided into the different pathological classification groups; childhood-, adult- and elderly-onset SLE groups and early- and late-onset LN groups.

Results: Class IV occurred most frequently and had the lowest complement C3 level. There was an obvious increase in active index in class IV and class V + IV. Patients with class VI showed some clinical characteristics similar to end-stage renal disease. Patients with proliferative nephritis were younger at SLE diagnosis and had higher blood pressure, higher frequency of proteinuria and urinary erythrocyte and lower haemoglobin and complement C3. Pathologic classification between childhood-, adult- and elderly-onset SLE patients or between early- and late-onset LN patients was not significantly different. Elderly-onset SLE patients had the highest chronic index (CI), IgA, IgG and Sjögren's syndrome A antibodies and Sjögren's syndrome B antibodies rates, whereas late-onset LN patients showed significantly higher CI, haemoglobin, complement C3 and C4 but lower uric acid, IgM and IgG.

Conclusions: LN patients present with different clinical and laboratory characteristics according to pathological classification, age at SLE diagnosis and nephritis onset. These results might be valuable for estimating the pathology and guiding treatment and prognosis. Key Points • Patients with proliferative nephritis have more severe immune disorders, worse renal function and stronger inflammatory state. • The elderly-onset SLE patients showed a poorer condition. • The late-onset LN patients might have a more stable status.

Keywords: Lupus nephritis; Onset; Pathology; Systemic lupus erythematosus.