Thin glomerular basement membranes in patients with hematuria and minimal change disease

A detailed morphometric analysis of glomerular basement membrane (GBM) thic kness was carried out on biopsies from 16 patients exhibiting normal histol ogy and unremarkable immunofluorescence. Eleven of these patients presented with proteinuria, 8 in the nephrotic syndrome range, while 5 had hematuria as well. The remaining 5 patients presented with hematuria only. Eight pat ients had an initial diagnosis of minimal change disease, 4 were diagnosed as thin-membrane nephropathy, 2 had Alport syndrome, and the remaining 2 ha d hypertensive nephropathy. Quantitative morphometric analysis of GEM ident ified 3 subsets of patients. The first subset consisted of 6 patients: 5 ad ults, with an average GBM width of 361 +/- 34 nm, and 1 child. The second s ubset included 8 patients with thin GBMs and a mean thickness of 253 +/- 15 nm. The last subset comprised 2 patients with Alport syndrome showing mark ed variability in GEM thickness. This study has confirmed the presence of t hin GBMs in hematurics, but has also revealed GEM thinning in 50% of patien ts with a diagnosis of minimal change disease.