Prognosis of IgA Nephropathy with Stages 3b-5 CKD

Introduction: There are conflicting opinions regarding the use of immunosuppressant treatment in IgA nephropathy (IgAN) patients with an estimated glomerular filtration rate (eGFR) of less than 45 mL/min/1.73 m2 and persistent proteinuria with a daily excretion of ≥1.0 g. Methods: This retrospective study involved 110 IgAN patients for whom clinical data were 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 endpoints 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). Conclusion: IgAN patients with stages 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.