Expression of monocyte chemoattractant protein-1 in idiopathic dilated cardiomyopathy

Immunological factors have been involved in the pathogenesis of dilated cardiomyopathy (DCM). The cytotoxic action of macrophages is one of the main factors causing cardiac myocyte damage. Monocyte chemoattractant protein-1 (MCP-1) is a major signal for the accumulation of monocytes/macrophages. We examined whether MCP-1 was expressed in the myocardium of DCM patients and whether the expression level was correlated with the degree of impairment of cardiac function. The expression of MCP-1 in the myocardium was determined by immunohistochemistry in endomyocardial biopsy samples from 13 patients. The expression of MCP-1 was found in all myocardial samples from DCM patients but not in those from control subjects. Positive staining for MCP-1 was distinct in cardiac myocytes, interstitium and infiltrating cells. Semi-quantitative analysis revealed that the expression of MCP-1 was inversely correlated with left ventricular ejection fraction. In conclusion, the expression level of MCP-1 in the myocardium was correlated with the degree of impairment of cardiac function in patients with DCM.