RESUMO
IgA nephropathy (IgAN) is the most common glomerulonephritis in humans worldwide; its prevalence and prognosis vary according with geographical areas. The incidence is higher in adults under 30 years of age and in children, it occurs more frequently in patients between 3 and 10 years. Hematuria is the predominant manifestation at presentation of the disease and 20-40% of the cases progress to terminal chronic renal disease. Renal biopsies were performed in 426 children during the period 1980-2002, of them, 12 cases corresponded to IgAN. The clinico-pathological characteristics and evolution of patients were evaluated during an average of 3.85 years. Mean age of patients was 6.2 years, and it was more frequent in males. Hematuria and proteinuria were found in 100% of cases and proteinuria of nephrotic range in 75%. Hypertriglyceridemia and hypercholesterolemia in 91%, arterial hypertension in 50% and acute renal failure at presentation in 25%. The predominant histopathological patterns (WHO) were II and III, deposits of mesangial IgA, IgG and C3 were observed in all cases and C4 deposits in 25%. 41.7% of cases had complete remission, 41.7% maintained normal renal function with persistent proteinuria and 16% progressed to terminal chronic renal failure. The actuarial survival of patients was 100% at 3 years, 87% at 4 years and 76% at 8 years. Two patients died during the period of study, at 3.5 and 8.5 years. The variability of presentation of IgA nephropathy was confirmed in this study, which could be attributable to geographical differences, racial influences and clinicopathological features related to sanitary conditions. Despite of the frequency of bad prognosis characteristics at presentation of IgAN in our series, the evolution was similar to reports of other groups.