Abstract
Background Various cytokines are involved in the pathogenesis of sarcoidosis, but their expression in the myocardium has not been documented for cardiac sarcoidosis. Methods and Results Myocardial tissue was obtained from 12 patients with cardiac sarcoidosis at the time of left ventriculoplasty, biopsy or autopsy. mRNA expression of various inflammatory cytokines was analyzed using quantitative real-time polymerase chain reaction, as well as by immunohistochemistry. Ten patients with dilated cardiomyopathy (DCM) served as controls. Enhanced expression of interleukin (IL)-1α, IL-2, IL-12 p40 and interferon (IFN)-γ mRNA was limited to the myocardium of cardiac sarcoidosis patients. Expression of IL-1β, IL-8, IL-10, IL-15 and TNF-αoccurred in both cardiac sarcoidosis and DCM patients, but IL-4 and IL-5 were not detected in either disease. Immunohistochemistry of the myocardial tissue of sarcoidosis revealed positive staining for IL-12 and IFN-γ. IL-12 was localized in multinucleated giant cells and macrophages of the sarcoid granulomas, whereas IFN-γwas detected in lymphocytes and vascular endothelial cells. Conclusions Type 1 helper T-cell cytokines may be involved in the pathogenesis of cardiac sarcoidosis. (Circ J 2008; 72: 1303 -1307)
