Efficacy of corticosteroids in immunoglobulin A nephropathy with less than 25% crescents

Background Crescent formation in immunoglobulin A nephropathy (IgAN) has been demonstrated to be a risk factor for worse outcomes. For IgAN patients with 0–25% crescentic glomeruli (C1), whether corticosteroids (CS) can improve the prognosis remains unclear. We tried to investigate the need for using CS in IgAN patients with C1 in different proteinuria levels. Methods A total of 120 eligible IgAN patients with C1 from two academic medical centers were retrospectively studied, and 57 (47.5%) received CS. Patients were grouped according to with or without CS. The outcomes were the rate of estimated glomerular filtration rate (eGFR) decline (ml/min per 1.73 m 2 /year) and a composite outcome (50% decrease in eGFR, end stage renal disease (ESRD) or death due to kidney disease). The progression of adverse outcome among them were analyzed in Kaplan–Meier curve. The independent significance of CS on renal outcome or eGFR decline rate were analyzed by multivariable Cox regression or linear regression. Results Unadjusted Kaplan–Meier showed that the outcome of treated patients was better than that of the untreated patients. Multiple Cox regression and linear regression analysis found that CS independently protected the renal outcome and decreased the eGFR decline rate. In the subgroup analysis, multivariate linear regression showed that CS decreased the eGFR decline rate both in proteinuria ≥ 1 g/day and < 1 g/day. Conclusions CS protected the renal outcome and slowed the eGFR decline rate of IgAN patients with C1, it also decreased the eGFR decline rate even in those with initial proteinuria < 1 g/day.