A clinicopathological study of idiopathic nephrotic syndrome in children.

This paper retrospectively examines the association of outcome with histological and clinical manifestations in 107 pediatric patients with idiopathic nephrotic syndrome (INS). At the time of renal biopsy, the patients were between 2 and 15 years of age. The interval from the onset of the disease to renal biopsy ranged from 1 to 156 months with a mean of 21 months. Continuous clinical follow-up was successfully conducted in 96 patients. The average duration of INS in these patients was 86.6 months (31 to 208 months). IgM deposition in the mesangium may play an important role in the pathogenesis of INS and our data showed that even in a minor glomerular abnormality (MCNS) subgroup, nearly half of the cases (42.9%) showed mesangial IgM deposition. However, the severity of hematuria, response to drug therapy with either steroids or cyclophosphamide, and the outcome, were not related to the presence or absence of IgM deposition, but were more closely associated with the type of histological category. The subgroup of patients with focal segmental glomerulosclerosis (FSGS) and diffuse mesangial proliferation (FSGS + DP) showed the most significant ultrastructural changes with positive mesangial IgM deposition (73.6%). The presence of IgM deposition in most of the patients in the subgroups with diffuse mesangial proliferative glomerulonephritis (DPGN) and FSGS + DP closely corresponded to the presence of electron-dense mesangial deposition. The FSGS + DP subgroup had a high incidence of denudation, vacuolization and detachment of podocytes, partial collapse of the glomerular basement membrane, and a very high incidence of resistance to steroid therapy.(ABSTRACT TRUNCATED AT 250 WORDS)