Long-term outcomes of IgA nephropathy patients with less than 25% crescents and mild proteinuria

Background Whether immunosuppressive therapy in IgA nephropathy (IgAN) patients with less than 25% crescents (C1) and mild proteinuria can improve the renal outcome is still unclear. Methods We recruited 140 IgAN patients with C1 and proteinuria < 1 g/24 h who received supportive care ( n = 52) or steroid-based immunosuppressive therapy ( n = 88) in Xijing Hospital from July 2008 to December 2016. The primary outcome was the rate of renal function decline. Results The median of proteinuria was 575.5 mg/24 h, the fraction of crescents was 7% (5%, 12%) and follow-up time was 69.1 months. The rate of renal function decline [0.5 (− 1.5, 3.2) vs − 0.7 (− 3.5, 0.5) ml/min per 1.73 m 2 per year; P = 0.01] was slower in steroid-based immunosuppressive therapy group than supportive care group. Multivariate linear regression analyses showed steroid-based immunosuppressive therapy significantly slowed down the rate of renal function decline ( β = − 0.220, 95% CI − 3.804 to − 0.449, P = 0.013) after adjusting age, sex, MAP, proteinuria, eGFR, M1, E1, S1, T1–2, the fraction of crescents and RASB. In the matched cohort, the rate of renal function decline was also slower in steroid-based immunosuppressive therapy group. The incidence of adverse events was similar between the two groups. Conclusion Steroid-based immunosuppressive therapy may slow down the rate of renal function decline of IgAN patients with C1 and proteinuria ≤ 1 g/24 h.