[Primary nephrotic syndrome. Follow-up of 202 pediatric patients]

Two hundred and two children with primary nephrotic syndrome were studied. Clinical features at onset and evolution were studied and correlated with microscopic findings and response to treatment. Histologic type and steroid-response were correlated with urinary protein selectivity in a group of them. Mean follow-up (by the same group of nephrologists) was 6.6 years; 22% were followed for over 8 years. The presence of hematuria, hypertension and renal failure at onset and during the course of the disease were evaluated. 122 patients were steroid-responders, 64 of them had frequent relapses. After a mean follow-up of 6.3 years, 81% were on remission; 14% had transient proteinuria, and 5% developed persistent proteinuria with late resistance to steroid therapy. 80 children were steroid-resistant. Their mean follow-up period was 5.5 years (1.0-10.5 years). 65 of them were biopsied: 12 had minimal glomerular change; 27 focal and segmental sclerosis. 9 membrano-proliferative glomerulonephritis, 4 focal and global sclerosis, 4 membranous nephropathy, 4 diffuse mesangial proliferation, 2 diffuse mesangial sclerosis and 2 were not classifiable. Hematuria had a prognostic value only when it was permanent or macroscopic. Urinary protein selectivity was measured in 43 patients, and C3 in 81; hypocomplementemia was found only in the 9 children with membranoproliferative glomerulonephritis. 8 children had tubular dysfunction: 7 had focal and segmental sclerosis, and 1 diffuse mesangial sclerosis; glycosuria and aminoaciduria were present in all 8, but only 4 of them had deficient urinary acidification. Secondary infections appeared in 42 patients; 19 were steroid-resistant and 23 steroid-responders, 17 of them showed frequent-relapses, 3 had localized thromboembolism. 23 children went into chronic renal failure and 17 of them died, 13 in end-stage renal failure and 4 because of complications. Their first biopsies showed minimal change in 1, focal and segmental sclerosis in 8, membranoproliferative glomerulonephritis in 3, diffuse mesangial proliferation in 1, diffuse sclerosis in 2, and 2 were not classifiable.