Immunosuppressants or corticosteroids compared with supportive therapy: a systematic review and meta-analysis on the efficacy and safety for IgA nephropathy treatment.

Background: Corticosteroids or immunosuppressants and supportive treatment in reducing the risk of proteinuria and end-stage kidney disease (ESKD) in immunoglobulin A (IgA) nephropathy (IgAN) patients were still controversial. The purpose of this meta-analysis was to evaluate the efficacy and safety of immunosuppressants or corticosteroids compared with supportive therapy for treatment of IgAN in order to provide guidance for clinical practice. Methods: We conducted an online search in PubMed, Embase, Cochrane Library, and Web of Science databases to collect randomized control trials (RCTs) about the efficacy and safety of immunosuppressants or corticosteroids compared with supportive therapy for treatment of IgA for relevant literature published from the databases' inception to August 21, 2021. The Cochrane risk assessment tool was used to assess the risk of bias in the included studies and analyzed by Revman 5.4 software, and Stata 15.0 statistical software was adopted for meta-analysis. Results: A total of 10,622 related studies were retrieved, and 11 RCTs were finally included in the meta-analysis, with a total sample size of 809 cases. The primary outcome measures for immunosuppressants or corticosteroids were better than those for supportive therapy: proteinuria [weighted mean difference (WMD) =-0.54, 95% confidence interval (CI): -0.63, -0.44, Z =10.79, P<0.001] and ESKD [relative risk (RR) =0.189, 95% CI: 0.059, 0.605, Z =2.81, P=0.005]. The secondary outcome measures were also better than that for supportive treatment: glomerular filtration rate [standardized mean difference (SMD) =0.32, 95% CI: 0.09, 0.54, Z =2.48, P=0.013]. The incidence of adverse reactions was consistent with that of supportive treatment, and the difference was not statistically significant (RR =1.06, 95% CI: 0.71, 1.59, Z =0.28, P=0.777). Discussion: Current evidence shows that immunosuppressants and corticosteroids can significantly reduce the risk of proteinuria and ESKD in IgAN patients. Due to limited quality and quantity of the included studies, more high-quality studies are need to verify above conclusion. In addition, we hope that more rationally designed multicenter RCTs that are not limited to short-term treatment outcomes will be conducted in the future.