End-stage dilated cardiomyopathy. Persistence of enterovirus RNA in myocardium at cardiac transplantation and lack of immune response.

Tissue from the explanted hearts of 21 patients with idiopathic dilated cardiomyopathy or 19 patients with other specific heart muscle diseases were investigated for presence of enterovirus-specific RNA with an enterovirus group-specific cDNA probe. This was complementary to coxsackievirus B2 RNA sequences between nucleotide numbers 6,550 and 7,400, which are highly conserved between enteroviruses. Hearts from six patients with dilated cardiomyopathy and one patient with ischemic heart disease were found to contain virus RNA. Serology revealed that only one patient (dilated cardiomyopathy group) was positive for coxsackievirus B-specific IgM but negative for virus RNA in the myocardium. Quantitation of leukocytes and T-lymphocytes in the myocardium and expression of major histocompatibility locus antigens revealed no significant differences associated with persistence of virus RNA. These data demonstrate that enterovirus RNA persists in myocardium of a significant proportion of patients with end-stage dilated cardiomyopathy in the absence of a continuing cell-mediated or humoral immune response.