| Abstract: | Immunofluorescence and immunoperoxidase staining were carried out to determine the correlations between the progression of glomerular sclerosis and changes in the amount and distribution of glomerular extracellular components, such as Type I, III, IV, V, VI collagen, laminin (LN) and fibronectin (FN) in patients with various types of glomerulonephritis and diabetic nephropathy. Six patients with IgA nephropathy, four patients with membrano-proliferative glomerulonephritis, four patients with rapidly progressive glomerulonephritis and six patients with diabetic nephropathy were examined. The intensity and distribution of Type IV collagen, LN and FN were similar between the glomeruli from normal individuals and patients with mild stages of glomerulonephritis and diabetic nephropathy. However, staining of Type I, III or V collagen was not observed in the glomeruli from normal individuals and such patients. In more advanced stages of glomerulonephritis and diabetic nephropathy, the amounts of Types IV and VI collagen, LN and FN were increased markedly in the mesangium, and their distribution extended along the glomerular capillary walls. The intensity of Type IV collagen, LN or FN in the nodular sclerotic lesions of glomeruli was decreased significantly in patients with glomerulonephritis and diabetic nephropathy. On the other hand, staining of Types I, III and V collagen was observed focally in the sclerotic or hyalinotic glomeruli and around such glomeruli in these patients. In light microscopic examinations, the patients who had marked staining of Type I, III or V collagen by immunofluorescence showed severe damage of the basement membrane in Bowman's capsules. It is concluded that hyperproduction and/or infiltration of interstitial collagens, i.e. Types I, III and V collagen, is closely linked to the progression of glomerular sclerosis and hyalinosis in patients with various types of glomerulonephritis and diabetic nephropathy. |
