Detection of Coxsackie-B-virus-specific RNA sequences in myocardial biopsy samples from patients with myocarditis and dilated cardiomyopathy.

Full-length virus genomic RNA (7.4 kilobases; kb) was isolated from Coxsackie B2 virus purified from infected monkey kidney cells in culture. DNA complementary to 6.3 kb of virus RNA was prepared by reverse transcription and cloned in a plasmid vector. A 1.6 kb Coxsackie-B-virus-specific DNA clone derived from the conserved 3' region of the virus genome was used as a hybridisation probe to test for the presence of virus nucleic acid sequences in myocardial biopsy samples. Positive hybridisation signals, quantified by densitometry, were obtained with 9 of 17 samples from patients with histological evidence of active or healing myocarditis or dilated cardiomyopathy with inflammatory changes. No Coxsackie-B-virus-specific sequences were detected in 4 samples from patients in whom a viral aetiology was unlikely and the histological diagnosis was negative for myocarditis.