Absence of coxsackie viruses in idiopathic inflammatory muscle disease by in situ hybridization

The role of coxsackie virus infection in the pathogenesis of idiopathic inflammatory muscle disease (IIMD) has been investigated by many workers with conflicting results. This study uses in situ hybridization, with digoxigenin-labelled oligonucleotide probes complementary to the coxsackie B virus genome, to investigate the presence of virus RNA in muscle biopsies from 26 patients with IIMD. In the five cases of inclusion body myositis studied, there was focal probe-binding to nuclei and cytoplasm, and in nine cases probe-binding to mast cells was seen. In both of these instances probe-binding was non-specific and not due to hybridization. None of the cases showed the presence of coxsackie virus RNA within muscle and it is concluded that lytic infection of myocytes by coxsackie virus does not occur in IIMD.