Prognosis of IgA Nephropathy with Stage 3b-5 CKD.

Objective To investigate whether immunosuppressive therapy is beneficial in IgA nephropathy (IgAN) patients with eGFR < 45ml/min/1.73m2. Methods This retrospective study involved 110 IgAN patients for whom clinical data was available; of these, 90 had complete follow-up data. Patients were grouped based on whether they received immunotherapy during follow-up, their renal function, proteinuria levels, and the percentage of crescentic glomeruli observed at the time of renal biopsy. Results The mean eGFR for the participants was 32.0 ± 10.2 ml/min/1.73 m². The average follow-up duration was 46.1 ± 37.9 months. The mean rate of decline in eGFR was 3.6 ml/min/1.73 m² per year. There were 43 (47.8%) composite kidney endpoint occurred in these patients. In the group that received immunotherapy, the incidence of kidney endpoint events was lower than in the untreated group (45.1% vs. 57.9%), but the difference was not statistically significant (P = 0.320). Among patients with stage CKD 3b, the incidence of endpoint events was lower than in those with stages CKD 4 and 5 (36.8% vs. 66.7%, P = 0.006). Conversely, the high proteinuria group saw a higher incidence of endpoint events compared to the low proteinuria group (51.9% vs. 23.1%), although this difference was not statistically significant (P = 0.054). Meanwhile, there was no significant difference in the incidence of endpoint events between the two crescent glomerular ratio groups (48.7% vs. 41.7%, P = 0.649). Kaplan-Meier survival analysis indicated that renal function level (P＜0.001) and proteinuria (P = 0.023) were associated with renal survival in IgAN patients. In contrast, the administration of immunosuppressive therapy (P = 0.288) and the prevalence of C lesions (P = 0.982) did not show a significant association with renal survival. Further, Cox regression analysis identified systolic blood pressure, fibrinogen, and CKD stage as risk factors for eGFR decline in IgAN patients (all P < 0.05). Conclusions IgAN patients with stage 3b-5 CKD exhibited a poor prognosis. It appears that in this specific cohort of IgAN patients, immunosuppressive therapy may not provide significant advantages over supportive care therapeutic regimens in terms of disease management.