Abstract:
PVB19 and HHV6, among others, have been identified as cardiotropic viruses capable of triggering a myocarditis. The purpose of this study was to use morphological and molecular pathological methods to observe the course of a myocarditis triggered by one of these two viruses, taking clinical parameters – insofar as these exist – into account.
The source material used in this study consisted of 86 formalin-fixed, paraffin-embedded endomyocardial biopsies (initial biopsies and consecutive biopsies) taken from a total of 49 patients. The cardiac biopsies were examined using routine histological, immune histological and molecular pathological methods.
Based on examinations of the endomyocardial biopsies, which were carried out with a great deal of consistency, the following findings emerged:
PVB19-associated inflammatory cardiomyopathies are characterized by a chronic persisting viral infection which, as the illness progresses, results in a remodeling of the myocardial tissue of the sort seen in a DCM-like interstitial fibrosis. The pathogenetic considerations relating to the onset of acute and chronic PVB19-associated myocarditis are discussed in detail. As for HHV6-associated inflammatory cardiomyopathies, it should be noted that, in the case of myocardial tissue infection with HHV6 alone, the pathogenic virus is eliminated as the illness progresses. Another striking finding is the high degree of coincidence observed of PVB19 and HHV6 infections, the etiology and pathogenesis of which has to date remained obscure.