[Electron microscopy study on alterations of glomerular basement membrane in IgA nephropathy]

To elucidate the morphological basis of glomerular hematuria in IgA nephropathy, morphometric analysis of GBM alterations was performed by electron microscopy in 73 cases of IgA nephropathy. These cases were divided into 2 groups by the degree of hematuria. The IgA (1) groups (52 cases) showed 1-30 Red Blood Cells (RBC)/hpf in urinary sediment and the IgA (2) group (21 cases) showed 30 or more RBC/hpf. The GBM alterations were observed in 67% of IgA nephropathy patients. Splitting and focal thinning of GBM were more frequent in the IgA (2) group than in the IgA (1) group. The gap was not associated with the degree of hematuria, but when accompanying splitting, it was with the degree of hematuria. It was concluded that most IgA nephropathy patients had GBM alterations, and splitting of the lamina densa, focal thinning of GBM, and a gap with splitting, which was associated with the degree of hematuria.