Long-term outcome of biopsy-proven minimal change nephropathy in Chinese adults

Abstract

Background: Minimal change nephropathy is a common cause of primary nephrotic syndrome in adults. However, there are few studies of its clinical course, response to treatment, and long-term outcome.

Study design: Retrospective cohort study.

Setting & participants: 340 consecutive adult patients with nephrotic syndrome and biopsy-proven minimal change nephropathy treated in a university hospital from 1984 until 2004.

Factors: Treatment response groups: primary steroid resistance, frequent relapse (≥4 relapses within 1 year), infrequent relapse (≥1 relapse but not frequent relapse), and no relapse (reference group); disease pattern.

Outcome: Medical problems after diagnosis; patient survival; renal survival.

Results: Median time to remission was 10 (IQR, 8-12) weeks; 179 (52.6%) had no relapse, 42 (12.4%) had infrequent relapses, 86 (25.3%) were frequent relapsers or steroid dependent, and 33 (9.7%) had primary steroid resistance. After a median follow-up of 174.7 (IQR, 119.7-235.0) months, 32 patients developed end-stage renal disease and 62 died (25 after progression to end-stage renal disease). Cox regression analysis showed that age and treatment response groups were the independent predictors of patient survival. Compared to the no-relapse group, the infrequent-relapse group had significantly better patient survival (adjusted HR, 0.19; 95% CI, 0.08-0.44; P<0.001), whereas the primary-steroid-resistance group had significantly worse patient survival (adjusted HR, 5.87; 95% CI, 1.83-18.85; P<0.001). Renal survival was excellent except in the primary-steroid-resistance group.

Limitations: Retrospective study.

Conclusions: A substantial proportion of adult patients with minimal change nephropathy continue to have disease flares more than 10 years after the initial presentation, and medical problems after diagnosis are common.

Keywords: Minimal change nephropathy (MCN); adult onset; end-stage renal disease (ESRD); glucocorticoid; kidney biopsy; nephrotic syndrome; relapse, disease flare, remission, glomerulonephritis; renal survival; steroid resistant.