Absence of persistent infection with enteroviruses in muscles of patients with inflammatory myopathies.

We searched for enteroviral nucleic acid sequences using the polymerase chain reaction and slot-blot hybridization in coded muscle biopsy specimens from 39 patients with active inflammatory myopathies (polymyositis, dermatomyositis, and inclusion-body myositis) and from 16 patients with other neuromuscular diseases, including patients with postpolio syndrome. For primers, we used sequences of the noncoding region at the 5' end of the viral RNA. We failed to detect specific enteroviral nucleic acid sequences in the muscle biopsy specimens. Because this sensitive technique can amplify even low copy numbers of the viral genome, it appears unlikely that a persistent enteroviral infection is the cause of inflammatory myopathies.