Background: It is debated whether patients with IgAN with heavy proteinuria and decreased eGFR benefit from aggressive treatment consisting of corticosteroids alone or combined with immunosuppressive agents.
Methods: A retrospective study was performed between January 2008 and December 2016 on patients with IgAN who had urinary protein excretion > 1.0 g/d and an eGFR between 15 and 59 mL/min/1.73 m2. These patients were assigned to receive supportive care alone or supportive care plus immunosuppressive therapy. The primary outcome was defined as the first occurrence of a 50% decrease in eGFR or the development of ESKD.
Results: All 208 included patients were followed for a median of 43 months, and 92 (44%) patients experienced the primary outcome. Cumulative kidney survival was better in the immunosuppression group than in the supportive care group (p < .001). The median annual rate of eGFR decline in the immunosuppression group was -2.0 (-7.3 to 4.2), compared with -8.4 (-18.9 to -4.1) mL/min/1.73 m2 in the supportive care group (p < .001). In multivariate Cox regression analyses, immunosuppressive therapy was associated with a lower risk of progression to ESKD, independent of age, sex, eGFR, proteinuria, MAP, kidney histologic findings and the use of RASi agents (HR = 0.335; 95% CI 0.209-0.601). Among the adverse events, infection requiring hospitalization occurred at similar rates in both groups (p = .471).
Conclusion: Immunosuppressive therapy attenuated the rate of eGFR decline and was associated with a favorable kidney outcome in IgAN patients with heavy proteinuria and decreased eGFR, and the side effects were tolerable.
Keywords: IgA nephropathy; immunosuppressive; prognostic; stage 3 or 4 chronic kidney disease; survival analysis.