A molecular and serologic evaluation of enteroviral involvement in human myocarditis

Murine coxsackie B virus infection models of myocarditis and numerous human serologic studies associating elevated enterovirus-specific IgM titers with the clinical diagnosis of myocarditis have been used to support an etiologic role for enteroviruses in human myocarditis. Of the human enteroviruses, coxsackie B viruses (CVB) are the enterovirus group most commonly associated with the human disease. While hybridization probes exist to detect most, if not all, human enteroviruses, no probe capable of specifically detecting an enteroviral group (such as the CVB) to the exclusion of all others has been described to date. Thus, to test the hypothesis that enteroviral involvement in human myocarditis is commonplace, we examined a case series of human myocarditic heart tissues for enteroviruses by in situ hybridization using a generic enterovirus probe. These results were then compared with CVB-specific IgM levels in the cognate patient sera. Comparison of the hybridization data with the CVB-specific IgM levels in the cognate sera yielded no valid correlation between the detection of enteroviral RNA and specificity of CVB identification in any patient. The data are consistent with common enterovirus infections in humans and a possible etiologic role in myocarditis but do not support a specific etiologic role for CVB in this study group.