Idiopathic membranous nephropathy in children.

To determine the prognosis in children with membranous nephropathy, we reviewed the clinicopathologic features and outcome of 22 patients, 11 male and 11 female, age 11 months to 19.9 years (mean 12.0 years). Patients had biopsies within six months of onset of symptoms and were divided into two groups according to the biopsy findings: group 1 (Stages I and II) and group 2 (Stages III and IV). Follow-up time was identical in both groups (mean 4.8 years). The nephrotic syndrome was present in 13 of 16 patients in group 1 and in all six patients in group 2. In group 1, eight of the 16 patients had repeat biopsies one to 11 years (mean three years) after onset. Of these, two progressed to Stages III and IV, whereas progression to renal insufficiency occurred in only one. In group 2, two of the six patients had repeat biopsies two years after onset and remained in the same group; progression to renal insufficiency occurred in five of the six patients. The difference in progression to renal insufficiency between the two groups is significant (P = 0.001). The stage of glomerular lesion at the time of onset seems to be a factor in predicting the prognosis of membranous nephropathy in pediatric patients.