Objective: To study the long-term outcome of idiopathic IgA nephropathy and analyze its clinical and histological prognostic factors.
Methods: We conducted a retrospective analysis of 495 cases of IgA nephropathy patients in our hospital from 1986 to 2002. Renal survival was analyzed by Kaplan-Meier method, univariate analysis and multivariate Cox regression analysis.
Results: The cumulative renal survival rate was 85% at 10 years and 70.9% at 15 years. Univariate analysis found the following parameters at the time of biopsy to be significantly correlated with poor renal survival: serum creatinine > or = 133 micromol/L (P < 0.001), hypertension (P < 0.05), 24-hour urine protein excretion > or = 3 g (P < 0.001), histological subclass V (P < 0.001), and without the history of gross hematuria (P < 0.05). The Cox regression analysis showed that only the presence of hypertension (HR=7.75, 95%CI 1.02 to approximately 2.19) and serum creatinine level (HR=1.49, 95%CI 1.54 to approximately 38.90) were independent prognostic indicators.
Conclusions: The findings in Chinese IgA nephropathy patients are in agreement with the results of many other studies worldwide.