IgA localisation in glomerular diseases.
The structural changes found on light and electron microscopy study of 25 renal biopsy specimens that showed significant glomerular IgA deposition on immunofluorescence were correlated with relevant clinical data. The morphology of a wide range of glomerulopathies seeen included mesangial proliferative (60%), membranous (12%), rapidly progressive proliferative (8%), mesangio-capillary (8%), and no light microscope change (8%). Four of the 15 cases (60%) of mesangial proliferative glomerulonephritis were associated with focal segmental sclerosis and 10 with focal segmental and focal global sclerosis. In addition, 7 of the 15 cases showed capsular crescents. The clinicopathological correlations indicated that the prognosis in this group is unfavourable when focal global sclerosis and capsular crescents are present, particularly when both occur in the same biopsy specimen.