Membranoproliferative glomerulonephritis type I in children: correlation of clinical features with pathologic subtypes.

Renal biopsies from 33 patients with membranoproliferative glomerulonephritis (MPGN) type I were reviewed to identify pathologic subtypes of this disease and assess their correlation to clinical features. The patients were divided into two groups: group A included 16 patients in chronic or end-stage renal failure and group B 17 patients with no evidence of renal insufficiency. At presentation, a nephrotic or nephritic syndrome and azotemia were equally common in both groups. The incidence of hypertension was significantly increased in group A (P less than 0.05), while recurrent gross hematuria was more common in group B. Nephrotic syndrome was more common during the course of illness in group A. Three subtypes of MPGN type I were recognized, based on whether duplication of glomerular capillary basement membranes was focal segmental (FS; 9 cases), diffuse global (DG; 18 cases), or mixed segmental and global (6 cases). Eight of nine patients showing FS MPGN type I were in group B (p less than 0.05). In contrast, 11 of 18 patients with DG MPGN type I and 4 of 6 with a segmental and global pattern were in group A (P = not significant). Therefore, FS MPGN is a good predictor of a favorable clinical outcome, whereas the other two subtypes are not. This was confirmed by a 100% actuarial kidney survival for the nine patients with FS MPGN and a 50% kidney survival of 7.5 years for patients with the other two subtypes.