Glomerular abnormalities in nonsystemic diseases

The relationship between the immunofluorescent findings and the light microscopic findings in 433 adult patients suffering from primary glomerulonephritis is discussed. Diffuse deposition of immunoglobulin G (IgG) in a granular pattern along the glomerular basement membrane appears characteristic of membranous glomerulonephritis. Scattered deposits of β 1 C-globulin and IgG are found in acute proliferative glomerulonephritis. In focal glomerulonephritis the presence of diffuse mesangial immunoglobulin A (IgA) is one of the most frequent lesions encountered demonstrating a new clinicopathologic entity. In rapidly progressive glomerulonephritis with epithelial crescents, deposition of fibrinogeh is the most conspicuous immunofluorescent abnormality; the deposition of IgG in a linear smooth pattern is rare. In many instances, when the light microscopic findings are difficult to interpret, Immunofluorescence may reveal a pattern which is commonly associated with a characteristic abnormality on light microscopy.