Molecular evaluation of enteroviruses in the pathogenesis of idiopathic dilated cardiomyopathy

There is great disparity in the literature as to the presence and relevance of enterovirus in heart tissue from patients with dilated cardiomyopathy (DCM). Published estimates of enteroviral positive tissue in DCM range from 0 to 50%. Very little sequence information is so far available on those samples which are positive.

Re-examination of fresh biopsy material from patients previously tested, plus 13 new cases of DCM, and sequencing the products would yield information on the validity of the technique and on the type of virus being detected.

RNA from biopsy or explant tissue was tested for the presence of enterovirus using reverse transcriptase polymerase chain reaction (PCR). The nucleotide sequences of all positive PCR products were determined by direct sequencing.

Positive PCR signals were found in 10% of samples from patients with DCM and in 16% of control tissues. Two DCM and 12 control samples gave the same nucleotide sequence, which was different from the CB3 used as a positive control. The other 4 DCM samples all produced multiple bands on sequencing.

The results do not support a major role for enterovirus in DCM. There is need for some caution, however, as a review of the literature shows that studies using single biopsies, such as this one, produce consistently lower estimates for enterovirus than do those wherein multiple biopsies are examined.