Age-related histologic alterations after prednisolone therapy in children with IgA nephropathy.

To examine whether the age of onset of clinical symptoms in childhood IgA nephropathy may affect changes of histologic alterations after receiving prednisolone therapy, an evaluation of glomerular lesions seen in biopsy specimen was done. Eighteen children with IgA nephropathy met study criteria. They received alternate-day prednisolone therapy within a month after the first renal biopsy. Renal biopsies were done at presentation and repeated at a mean interval of 23 months. The patients were grouped as follows: Group A, 8 cases which showed clinical symptoms at the age of 9 or under; Group B, 10 cases which showed the symptoms at the age of 10 or over. At the initial presentation, histologic indices including a percentage of mesangial area occupying glomeruli (the M/G ratio) in the 2 groups did not show a significant difference. The activity score and the M/G ratio in the group A decreased significantly at the second biopsies (4.6+/-0.9 vs. 1.8+/-1.0 and 25.7+/-6.1% vs. 21.4+/-2.7%, respectively), while in the group B did not. These observations may indicate the age of onset of clinical symptoms in childhood IgA nephropathy affects changes of histologic alterations after receiving prednisolone therapy.