Presentation, prognosis and outcome of IgA nephropathy in Indian adults

BACKGROUND: IgA nephropathy (IgAN) is not well characterized in India. This retrospective study of 478 patients with IgAN was performed to clarify the presenting features, prognostic factors and the renal survival rates of the disease. METHODS: Three hundred and forty-seven patients who had been followed on average for 27 months after diagnosis were divided into two groups based on renal function at diagnosis. In group 1 (229 patients), the creatinine clearance estimated by the Modification of Diet in Renal Disease formula was <85 mL/min and in group 2 (118 patients) it was >/=85 mL/min. RESULTS: The predominant modes of presentation were nephrotic syndrome, hypertension and renal failure. Twenty-nine percent of patients had more than a 20% decline in renal function at the last follow up. Multivariate analyses with stepwise logistic regression identified hypertension (odds ratio (OR) 3.5), nephrotic range proteinuria (OR 3.4) and sclerosed glomeruli on biopsy (OR 4.1) to be independently associated with progression in group 1 and hypertension (OR 2.3) in group 2. Seventeen percent of patients progressed to end-stage renal disease (ESRD). Using multivariate analysis by the Cox model, four risk factors for developing ESRD were identified: hypertension (hazard ratio (HR) 3.1); nephrotic proteinuria (HR 1.9); interstitial fibrosis (HR 2.5); and sclerosed glomeruli (HR 1.8). The renal survival rates at 1, 5 and 10 years were 84, 55 and 33%, respectively, with a median renal survival of 61 months from the time of biopsy. CONCLUSION: The relatively rapid rate of progression of IgAN in India is suggestive towards a 'malignant' nature of the disease in this country.