IgA nephropathy. A comparative study of the clinicopathologic features in children and adults.

A comparative study of the clinicopathologic features of IgA nephropathy in 24 children and 46 adults was undertaken. In children, microscopic hematuria was present in all cases and was associated with gross hematuria in 83% and proteinuria in 58%. In adults, microscopic hematuria was present in 91%, gross hematuria in 25%, and proteinuria in 80%. During followup, renal failure was recorded among 5.5% of children and 10% of adults. Biopsy specimens were obtained from all patients and were examined by light, electron, and immunofluorescence microscopic technics. Morphologic changes in the glomeruli were classified according to the degree of mesangial hypercellularity, sclerosis, and crescent formation into four groups. The most common glomerular pattern in children was diffuse, mesangial hypercellularity, while mesangial proliferation associated with focal segmental glomerulosclerosis predominated among adults. These observations suggest that glomerular morphology correlates with age at diagnosis and influences the clinical outcome of the disease.