Combined Immunosuppressive Treatment May Improve Short-Term Renal Outcomes in Chinese Patients with Advanced IgA Nephropathy

Abstract

Background/Aims: Treatment of advanced Immunoglobulin A nephropathy (IgAN) patients with estimated glomerular filtration rate (eGFR) below 45 mL/min per 1.73 m² remains inconsistent. The aim of this study is to compare the effects of corticosteroid and immunosuppressant therapies among these patients. Methods: A total of 201 adult patients with advanced IgAN (eGFR < 45 mL/min/1.73 m² and proteinuria > 1 g/24h at biopsy) grouped into supportive care (SC), steroids alone (CS), and steroids plus immunosuppressant (IT) groups, were investigated between 30^th December 2002 and 30^th June 2016. The primary endpoint was the combined endpoint of a 50% decline in eGFR and/or end stage renal disease (ESRD: eGFR < 15 mL/min/1.73 m² or maintenance renal replacement treatment). Responses to therapy included complete remission (CR: urinary protein excretion < 0.5 g/24h, with eGFR decrease less than 10% baseline), partial remission (PR: proteinuria decrease by > 50% baseline, with eGFR decrease less than 10% baseline), no response (NR: proteinuria decrease < 50% baseline, or eGFR decrease > 10% baseline) and ESRD. Kaplan–Meier and Cox proportional hazards analyses were performed. Results: During the follow-up period (37.2 ± 22.7 months), 6.8% patients in SC group, 25.0% in CS group, and 38.0% in IT group achieved CR or PR, while 78.4%, 62.5% and 49.3% patients in these 3 groups reached primary endpoint respectively (p < 0.001). Three-year renal survival rates in SC and combined immunosuppressive treatment groups (CS and IT groups) were 33.8% vs 51.2% (p = 0.02), and 5-year renal survival rates were 12.2% vs 21.3% (p = 0.1) respectively. Multivariate Cox regression analysis showed that hypertension (HR = 2.44, 95% CI 1.51–3.95; p < 0.001), Scr (HR = 1.01, 95% CI 1.00-1.01; p < 0.001), T1-T2 lesion (HR = 1.99, 95% CI 1.35–2.93; p = 0.001) were independent indicators of poor renal outcome. Conclusion: Immunosuppressive treatment (CS and IT therapy) may improve short-term renal outcome compared with supportive treatment in advanced IgAN patients.