Frequency of viral nucleic acids detection using real-time PCR in endomyocardial biopsy samples, blood samples from the ventricle and peripheral blood in patients with dilated cardiomyopathy

Abstract

Aim: Viral infections are considered the most frequent causes of myocarditis and later dilated cardiomyopathy (DCM). We planned our study in order to assess the frequency of viral nucleic acids detected using real-time PCR in endomyocardial biopsy samples, blood samples from the ventricle and peripheral blood in patients with idiopathic DCM. Methodology: 100 patients diagnosed for idiopathic DCM in our department in years 2010-2012 were included in the investigation. All patients had endomyocardial biopsy and samples of blood from the ventricle and peripheral blood obtained. Then histopathological and immunohistochemical study of the biopsy samples was performed. In 40 (of 100) patients' clinical evaluation and/or results from the basic histopathological and immunohistochemical investigation indicated myocarditis. From those patients specimens were investigated using real-time PCR in order to detect viral nucleic acids. Real-time PCR was performed with use of TaqMan and HybProbe probes. Results: In biopsy specimens, viral nucleic acids were detected in 15 (of 40) patients. We detected in 7 patients parvovirus B19 (PB19V), in 4 enterovirus, in 3 adenovirus and in 2 human herpes virus 6 (HHV-6). In 1 patient coinfection of adeno- and enterovirus was detected. In blood samples from the ventricle in 6 (of 40) patients viral nucleic acids were detected. We detected in 3 adenovirus, in 2 enterovirus and in 1 HHV-6. In peripheral blood samples in 7 (of 40) patients viral nucleic acids were detected. We detected in 4 adenovirus, in 3 enterovirus and in 1 HHV-6. We observed PB19V only in biopsy specimen, none PB19V was detected in blood samples from the ventricle or from the peripheral blood. In 1 patient we detected HHV-6 in many copies as well as in blood samples from the ventricle or from the peripheral blood. In other cases we observed no correlation. Conclusions: Our findings suggest frequency of PB19V, entero-, adenovirus and HHV-6 DNA in patients with myocarditis and DCM more commonly than previously expected. Those viruses should be therefore recognized as a potential cardiotropic pathogen in patients of all ages and as a potential therapeutic target. Proper diagnosis of DCM and myocarditis should be therefore based on performing endomyocardial biopsy.