Glomerular basement membrane thickness in primary diffuse IgA nephropathy: ultrastructural morphometric analysis.

Sixteen renal biopsy specimens from adult patients with IgA nephropathy (IgAN) for whom both light and electron microscopy as well as immunofluorescence microscopy and full clinical data were available were examined quantitatively and compared with six cases of normal controls. The electron micrographs of the glomeruli were scanned in a Primax flatbed A4 scanner and then morphometric investigations were performed by means of a computer image analysis system to evaluate glomerular basement membrane (GBM) thickness and to study whether this parameter could correlate with the degree of the haematuria, which is thought to be a main renal symptom in this glomerulopathy. The study revealed that the mean value of the GBM thickness was in IgAN patients significantly lower in comparison with normal controls (268.6 nm versus 338.8 nm). The authors also noted the tendency to negative correlation between GBM thinning and haematuria, although this relationship was not significant. It is suggested that deposits located in the vicinity of the capillary loops may play a role in this process.