Idiopathic membranous glomerulopathy in Canadian children: a clinicopathologic study.

The 1,205 renal biopsies performed at The Hospital for Sick Children, Toronto, were reviewed to identify membranous glomerulopathy. Fourteen patients had a clinicopathologic diagnosis of idiopathic membranous glomerulopathy. Typical thickening of glomerular capillary basement membranes, a spike-and-dome pattern, and subepithelial electron-dense deposits were noted. Strong deposits of IgG and weaker deposits of C3, IgM, and IgA were present in glomeruli. Stages of membranous glomerulopathy on electron microscopy were I in one biopsy, II in nine biopsies, and III in four biopsies. Two additional biopsies from one child initially showed minimal lesion-type disease; later, a third showed membranous glomerulopathy. At presentation 11 patients had nephrotic syndrome, seven had hypertension, and eight had hematuria. Now four are in remission, seven have active disease with normal renal function, and three have renal failure. Patients with hypertension tended to do worse than those without. Age at onset, presence of nephrotic syndrome or hematuria, and administration of steroids or immunosuppressive drugs did not adversely affect outcome. Furthermore, clinical outcome did not correlate with stage of disease. Hence pathologic and most clinical features do not predict long-term prognosis in children with membranous glomerulopathy.