Impaired activation of IFN-γ+CD4+ T cells in peripheral blood of patients with dilated cardiomyopathy

Viral persistence and autoantibodies are pathogenic components in patients with idiopathic dilated cardiomyopathy (DCM). The aim was to evaluate T-cell function in DCM using different flow cytometry based detection techniques. Following stimulation, the frequency of IFN-γ-producing CD4+ T cells was significantly lower in patients compared with controls. In contrast, the frequency of IL-4 producing CD4+ T cells was no different. In supernatants of cultured PBMC, IFN-γ and IL-10 were significantly lower in patients. In addition, lymphocyte proliferation was significantly lower in patients compared with controls, whereas major lymphocyte subsets were not different. IFN-γ and IL-10 are key cytokines in the ability to mount protective immune responses and to maintain self-tolerance. A reduced activation of T-helper 1 (IFN-γ producing) cells and a decreased capacity to produce IL-10, found in the present study, could explain parts of the autoimmune features seen in patients with DCM.