IMMUNOHISTOCHEMICAL DEMONSTRATION OF MEMBRANE COFACTOR PROTEIN (MCP) OF COMPLEMENT IN NORMAL AND DISEASED KIDNEY TISSUES

The immunohistochemically stained membrane cofactor protein of complem ent (MCP/Cd46, one of the complement regulatory proteins, was up-regul ated in some diseased kidney tissues. MCP in diseased kidneys was stro ngly concentrated along the glomerular capillary walls as well as in t he mesangial regions, while MCP in normal kidneys was weakly detected in all glomerular structural cells and in the epithelial cells of tubu les. Since the enhanced staining was noted in those areas where deposi tions of C3b/C3c occurred, ongoing complement reaction might be respon sible for the up-regulation of MCP expression. MCP expression may be u p-regulated by complement fragments generated during complement activa tion in glomerulonephritis. Furthermore, anti-MCP staining was stronge r in intensity in patients with moderate to massive proteinuria, indic ating that up-regulation of MCP expression could be directly correlate d to the kidney damage.