Corticosteroids could improve the renal outcome of IgA nephropathy with moderate proteinuria

The specific treatment regimens of IgA nephropathy (IgAN) patients with moderate proteinuria (1.0-3.5 g/day) remain controversial. The purpose of this study was to explore the optimized therapeutic regimen for IgAN patients through analyzing the clinical data.

A retrospective study was conducted, 449 patients with biopsy-proven IgAN were enrolled. Patients were divided into three groups according to proteinuria levels: urine protein 1.0-1.5 g/day (UP1, n = 111), urine protein 1.5-2.5 g/day (UP2, n = 213), urine protein 2.5-3.5 g/day (UP3, n = 125). Clinical pathological features, treatment regimens and renal outcome were compared. Responses to therapy included complete remission (CR), partial remission (PR), no response (NR) and end-stage renal disease (ESRD). The composite endpoints of renal outcome were defined as 50% decline in eGFR and/or progressing into end-stage renal disease.

During the average follow-up of 44.27 months, 71 (63.9%), 150 (70.4%) and 68 (54.4%) patients achieved CR + PR among three groups, respectively. Whereas 15 (13.5%), 28 (13.1%) and 39 (31.2%) patients progressed to the primary endpoint (P < 0.001). Patients who received corticosteroids (CS) treatment had better remission rate than those with supportive care (SC) or combined corticosteroid plus immunosuppressant (CS + IT) therapy (P < 0.05). Kaplan-Meier survival analysis revealed that patients received CS and CS + IT treatments had better renal prognosis compared with SC therapy in UP2 and UP3 groups (P < 0.05). However, no statistical difference was found among three treatment regimens in UP1 group (P = 0.358).

Corticosteroids therapy might better improve renal prognosis compared with supportive care alone or corticosteroids plus immunosuppressant in IgAN patients with moderate proteinuria (1.5-3.5 g/day).