Thin Glomerular Basement Membrane Nephropathy: Incidence in 3471 Consecutive Renal Biopsies Examined by Electron Microscopy

Abstract

Abstract Context.—Thin glomerular basement membrane (GBM) nephropathy is often equated with benign familial hematuria, although it may occur sporadically and may not always be benign. Thin GBM nephropathy is reported to occur in at least 1% of the population, although its reported incidence varies considerably in different studies because there are presently no uniform criteria for its diagnosis by electron microscopy (EM). Objective.—To determine the incidence of thin GBM nephropathy in a large sample of renal biopsies using a basic methodology that can easily be applied in any diagnostic EM laboratory. Design.—Direct measurements of GBM thickness were made from electron micrographs at 3 specified points along each of 10 randomly selected glomerular capillaries to determine an average GBM thickness for each of 50 males and 50 females, ages 9 to 80 years, with minimal-change nephropathy or acute interstitial nephritis, without hematuria. The means of the average GBM thickness values were 330 ± 50 (SD) nm ...