Expression of glomerular antioxidant enzymes in human glomerulonephritis

Increased oxidative stress can be correlated with glomerular injury. By immunohistochemical studies, we found expression of glomerular antioxidant enzymes (AOEs), including CuZn-superoxide dismutase (SOD), Mn-SOD, and catalase, in a wide variety of glomerular diseases. The distribution of the AOEs was either localized the in mesangial region or along the luminal surface or epithelial surface of the glomerular capillary wall. There was no significant difference of glomerular AOE expression among minimal change disease (MCD), IgM nephropathy (IgM N), focal segmental glomerulosclerosis, and membranous glomerulonephritis (MGN). However, when compared with MCD, IgM N and MGN, the glomerulus of lupus nephritis and IgA nephropathy expressed a significantly higher positive rate of AOEs (p = 0.04-0.002). The expression of AOEs had a trend to be associated with increased proliferative cell nuclear antigen-positive cells in the glomerulus of diffuse proliferative lupus nephritis (p = 0.056). No association was found between infiltrating leukocytes and AOE expression in all the disease groups. The glomerulus in kidneys with renal cell carcinoma expressed a significantly higher positive rate of AOEs and therefore could not be regarded as a normal control group. In summary, the immunohistochemical evidence of glomerular AOE expression in this study provides supporting evidence of oxidative stress in a wide variety of glomerular diseases.