[IgA nephropathy in Japanese children and adults: a comparative study of clinico-pathological features].

A comparative clinico-pathological study was performed on 61 children and 51 adults with IgA nephropathy. Hematuria and/or proteinuria found by chance was the most common initial clinical sign, being observed in 82.0% of the children and 52.9% of the adults (p less than 0.001). At renal biopsy, hypertension and severe proteinuria were found in 9.8% and 33.3% of the adults and 0 and 14.8% of the children (p less than 0.05, p less than 0.05). Elevations of blood urea nitrogen and serum creatinine were found at the time of biopsy in 21.6% and 9.8% of the adults but in none of the children (p less than 0.001, p less than 0.05). On histological studies, proliferative changes of the glomerulus were similar in the two groups, and diffuse mesangial proliferation was found in 62.3% of the children and 51.0% of the adults (although the difference was not significant). Focal glomerulosclerosis and tubular atrophy were found in 52.9% of the adults and 32.8% of the children (p less than 0.05). These results suggest that focal glomerulosclerosis with tubular atrophy is correlated with deterioration of renal function, hypertension and age at renal biopsy, and has an important influence on the prognosis of patients with IgA nephropathy.