A comparative study of human glomerular basement membrane thickness using direct measurement and orthogonal intercept methods

Abstract

Introduction Here we report estimates of glomerular basement membrane (GBM) thickness in the Brazilian population performed using direct (DM) and orthogonal interception methods (OIM), and comment on potential sources of variation among estimates made by different laboratories. Methodology A total of 38 patients, ranging from 3 to 78 years of age, 26 (68%) males and 12 (32%) females, were submitted to kidney biopsy procedures for renal disease diagnosis. Glomeruli were diagnosed with minor histological changes by conventional, immunofluorescence and electron microscopy. GBM thickness was estimated using both DM and OIM methods. Results Estimates of GBM thickness obtained using DM were higher than those obtained by OIM. However, the application of a correction for non-perpendicular membrane sectioning to DM estimates yielded similar results to those obtained under OIM. The estimated GMB thickness using DM after correction was 289 + 44 nm, versus 287 + 48 nm by OIM. No statistically significant differences were detected in GMB thickness, nor with respect to patient age or sex. Conclusions GBM thickness in the studied Brazilian population measured approximately 290 nm. The application of criteria for estimating the shortest distance between the endothelial and podocyte cell membranes with correction for non-perpendicular membrane sectioning can increase the accuracy of GBM thickness estimates using DM and OIM.

Collagen IV and Podocyte-Related Gene Variants in Patients with Concurrent IgA Nephropathy and Thin Basement Membrane Nephropathy

“…After excluding the cases with other systemic diseases, 296 cases remained. According to the adult normal GBM thickness standard (340 ± 70 nm) established in our laboratory, basement membrane thickness was confirmed using the direct measurement arithmetic mean ± SD by conventional transmission electron microscopy [4]. We identified 43 IgA nephropathy cases concurrent with Alport syndrome/thin basement membrane nephropathy or thinning basement membrane changes (<50% glomerular capillary loops or >250 nm).…”

Ultra-thin and ultra-porous nanofiber networks as a basement-membrane mimic

“…19 Although barrier properties are maintained by endothelial and epithelial monolayers, a key component is the basement membrane (BM). 20 The BM is a thin layer (about 50-300 nm) of extracellular matrix (ECM), composed of collagen, fibronectin, and laminin, 20,21 that provides support for endothelial and epithelial cells, while also separating these cells from supporting cells. Endothelial and epithelial cells are regulated by cell-cell crosstalk from the supporting cells across the BM.…”