Quantitative Analysis of Cytokine mRNA Expression in Hearts from Patients with Nonischemic Dilated Cardiomyopathy (DCM)

PURPOSE AND METHODS: There is increasing evidence that inflammatory cytokines play an important role in the development of heart failure. To evaluate the role of cytokines in nonischemic DCM, we analyzed the relative quantity of cytokine mRNA expression in the hearts from DCM patients with refractory heart failure, using the ABI PRISM7700 real-time PCR system. We used heart tissues resected from 32 DCM patients at the time of elective partial ventriculectomy (PLV), and five biopsy specimens with normal histological findings as control. RESULTS AND DISCUSSION: Interleukin (IL)-1beta, IL-10, and Tumor Necrosis Factor (TNF)-alpha mRNA were expressed at low levels in all normal hearts. The number of IL-10-positive DCM cases was significantly smaller than normal controls (P = 0.0036). One (10%) of 10 DCM patients with IL-10 mRNA expression died after PLV, and 10 (45%) of 22 DCM patients without IL-10 mRNA expression died. IL-1beta mRNA was overexpressed (over twice the mean of control subjects) in 15 of 32, and TNF-alpha mRNA in 10 of 32 patients. We propose the classification of DCM patients into subgroups on the basis of cytokine mRNA expression. Anticytokine therapy or cytokine therapy may have potential in improving the condition of heart failure in certain subgroups of DCM patients. CONCLUSIONS: We suggest that DCM patients with heart failure deteriorate without IL-10 mRNA expression in the myocardium. The classification of DCM patients into subgroups on the basis of cytokine mRNA expression may have great value in considering the treatment of this heterogeneous disease state.