Detection of viral and bacterial protein in endomyocardial biopsies of patients with inflammatory heart muscle disease?

The development of highly sensitive molecular biological methods such as in -situ hybridization and polymerase chain reaction (PCR) made it possible to detect viral/bacterial nucleic acid in human endomyocardial biopsies. Howe ver, only a few investigations addressed the problem of latent persistence of viral and bacterial genome and the detection of the corresponding protei ns, which could have important consequences for the clinical course of the disease. The purpose of this study was to determine whether protein of various virus es (adenovirus, enterovirus, cytomegalovirus, influenza A and B virus, herp es simplex virus 1 and 2) and bacteria (chlamydia pneumonia) can be detecte d in endomyocardial biopsies of patients with myocarditis and dilated cardi omyopathy with and without inflammation by use of an immunofluorescence ass ay and to compare the frequency of its detection with the results of PCR, i mmunohistology and serology. Thirty-nine patients with myocarditis and dilated cardiomyopathy with and w ithout inflammation were examined by a direct immunofluorescence assay usin g the endomyocardial biopsy as antigen. Each of the samples was additionall y studied by immunohistological methods and PCR for the detection of infilt rating cells and the genome of cardiotropic viruses or bacteria. Fourteen o f patients were considered to have myocarditis (group 1), 9 dilated cardiom yopathy with inflammation (group 2), 10 dilated cardiomyopathy (group 3), 6 to have no myocarditis or dilated cardiomyopathy (group 4). Using a direct immunofluorescence assay we could show only that 1 patient w ithout histological myocarditis or dilated cardiomyopathy (group 4) was pos itive for influenza B and chlamydia pneumonia antigens in the endomyocardia l biopsy. In addition we have determined influenza B-specific antibodies, s uch as IgG (marginal titer) and IgA (high titer) and chlamydia pneumonia-sp ecific antibodies, such as IgG (marginal titer) in serum of this patient. A second patient with dilated cardiomyopathy was found to be positive for pr otein of chlamydia pneumonia, who was shown to have chlamydia pneumonia-spe cific antibodies, such as IgG thigh titer) in serum. There was no correlati on with PCR results, but good correlation with influenza B and chlamydia pn eumonia-specific antibodies in sera of these patients. In this investigatio n we have determined viral/bacterial-specific antibodies using serological methods and proteins of these agents using immunoflourescence. Despite the detection of virus or bacteria-specific antibodies in the sera and detectio n of viral and/or bacterial protein in the biopsies of some of the patients viral and/or bacterial genome was not found in the biopsy. This may be exp lained by the focal character of myocarditis and sampling error, because fo r technical reasons we use different biopsies for immunohistochemical and m olecular biological investigations.