Transcriptional Active Parvovirus B19 Infection Predicts Adverse Long-Term Outcome in Patients with Non-Ischemic Cardiomyopathy.

Parvovirus B19 (B19V) is the predominant cardiotropic virus currently found in endomyocardial biopsies (EMBs). However, direct evidence showing a causal relationship between B19V and progression of inflammatory cardiomyopathy are still missing. The aim of this study was to analyze the impact of transcriptionally active cardiotropic B19V infection determined by viral RNA expression upon long-term outcomes in a large cohort of adult patients with non-ischemic cardiomyopathy in a retrospective analysis from a prospective observational cohort. In total, the analyzed study group comprised 871 consecutive B19V-positive patients (mean age 50.0 ± 15.0 years) with non-ischemic cardiomyopathy who underwent EMB. B19V-positivity was ascertained by routine diagnosis of viral genomes in EMBs. Molecular analysis of EMB revealed positive B19V transcriptional activity in n = 165 patients (18.9%). Primary endpoint was all-cause mortality in the overall cohort. The patients were followed up to 60 months. On the Cox regression analysis, B19V transcriptional activity was predictive of a worse prognosis compared to those without actively replicating B19V (p = 0.01). Moreover, multivariable analysis revealed transcriptional active B19V combined with inflammation [hazard ratio 4.013, 95% confidence interval 1.515-10.629 (p = 0.005)] as the strongest predictor of impaired survival even after adjustment for age and baseline LVEF (p = 0.005) and independently of viral load. The study demonstrates for the first time the pathogenic clinical importance of B19V with transcriptional activity in a large cohort of patients. Transcriptionally active B19V infection is an unfavourable prognostic trigger of adverse outcome. Our findings are of high clinical relevance, indicating that advanced diagnostic differentiation of B19V positive patients is of high prognostic importance.

Evaluation of Myocardial Gene Expression Profiling for Superior Diagnosis of Idiopathic Giant-Cell Myocarditis and Clinical Feasibility in a Large Cohort of Patients with Acute Cardiac Decompensation.

AIMS: The diagnostic approach to idiopathic giant-cell myocarditis (IGCM) is based on identifying various patterns of inflammatory cell infiltration and multinucleated giant cells (GCs) in histologic sections taken from endomyocardial biopsies (EMBs). The sampling error for detecting focally located GCs by histopathology is high, however. The aim of this study was to demonstrate the feasibility of gene profiling as a new diagnostic method in clinical practice, namely in a large cohort of patients suffering from acute cardiac decompensation. Methods and Results: In this retrospective multicenter study, EMBs taken from n = 427 patients with clinically acute cardiac decompensation and suspected acute myocarditis were screened (mean age: 47.03 ± 15.69 years). In each patient, the EMBs were analyzed on the basis of histology, immunohistology, molecular virology, and gene-expression profiling. Out of the total of n = 427 patient samples examined, GCs could be detected in 26 cases (6.1%) by histology. An established myocardial gene profile consisting of 27 genes was revealed; this was narrowed down to a specified profile of five genes (CPT1, CCL20, CCR5, CCR6, TLR8) which serve to identify histologically proven IGCM with high specificity in 25 of the 26 patients (96.2%). Once this newly established profiling approach was applied to the remaining patient samples, an additional n = 31 patients (7.3%) could be identified as having IGCM without any histologic proof of myocardial GCs. In a subgroup analysis, patients diagnosed with IGCM using this gene profiling respond in a similar fashion to immunosuppressive therapy as patients diagnosed with IGCM by conventional histology alone. Conclusions: Myocardial gene-expression profiling is a promising new method in clinical practice, one which can predict IGCM even in the absence of any direct histologic proof of GCs in EMB sections. Gene profiling is of great clinical relevance in terms of a) overcoming the sampling error associated with purely histologic examinations and b) monitoring the effectiveness of therapy.

Immunosuppressive treatment in fulminant myocarditis and gene expression pattern associated with, but no histological confirmation of giant cell myocarditis.

A healthy woman with acute onset of pulmonary oedema and severely depressed left ventricular function underwent endomyocardial biopsy under the clinical suspicion of fulminant myocarditis. While awaiting the results of biopsy, the situation deteriorated to Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) and extracorporeal membrane oxygenation was implanted. Finally, immunohistochemistry in biopsy specimen corresponded to fulminant lymphocytic myocarditis, although active myocarditis was excluded. Furthermore, gene expression profiling identified giant cell myocarditis although multinuclear cells were absent. This prompted the start of immunosuppression with cortisone and cyclosporine. The patient fully recovered.

Chromosomally integrated human herpesvirus 6 in heart failure: prevalence and treatment.

AIMS: Human herpesvirus 6 (HHV-6) A and B are two betaherpesviruses that are associated with many conditions including roseola, drug-induced hypersensitivity syndrome, limbic encephalitis, and myocarditis. HHV-6 is integrated in the germline [chromosomically integrated HHV-6 (ciHHV-6)] in ∼0.8% of the human population. To date, the prevalence, species distribution, and treatment responses of ciHHV-6 are unknown for cardiac patients. METHODS AND RESULTS: We determined the prevalence of HHV-6 and ciHHV-6 genotypes in 1656 endomyocardial biopsies of patients with persisting unexplained symptoms of heart failure. Infection of cardiac tissue was identified by nested PCR, electron microscopy, and immunohistochemistry. Virus load and mRNA levels were followed in ciHHV-6 patients treated with ganciclovir. HHV-6 was detected in 273 of 1656 cardiac tissues (16.5%; HHV-6B, 98.2%, HHV-6A, 1.8%) by PCR. Nineteen of the 1656 patients (1.1%) presented with persistently high HHV-6 copy numbers indicative of ciHHV-6. Sequencing confirmed ciHHV-6A in seven patients (36.8%) which was considerably higher than detected in non-ciHHV-6 patients. Inheritance was demonstrated in three selected families, confirming ciHHV-6 chromosomal integration by PCR and fluorescence in situ hybridization. HHV-6 reactivation and chromosomal integration were confirmed in peripheral blood mononuclear cells and heart tissue. Virus particles were identified in degenerating myocytes and interstitial cells. Antiviral treatment abolished viral mRNA and ameliorated cardiac symptoms. CONCLUSION: Virus replication in cardiac tissue of ciHHV-6 heart failure patients suggests that ciHHV-6 reactivation causes persistence of unexplained heart failure symptoms. We demonstrated that antiviral treatment, effective in decreasing viral transcripts and clinical complaints of cardiomyopathies, is a new therapeutic option for ciHHV-6-associated diseases.

Development of multinuclear giant cells during the degradation of Bioglass particles in rabbits.

Bioglass particles of the compositions 45s5, 52s, and 55s were implanted in the distal femoral epiphysis of rabbits. Animals were sacrificed at 7, 28, and 84 days postoperatively and specimens investigated using electron microscopy and electron dispersive X-ray analysis. The intention was to correlate the finding of different types of multinuclear giant cells (MNGC) in the center of the implantation bed with earlier hypothesized accumulated particle eluates and changed particle compositions. The distribution of Si, Na, Ca, P, O, S, and Cl throughout the implantation bed was analyzed. Bioglass particles degraded either in Si-rich remnants or in CaP-shells. MNGC of foreign body giant cell type in high numbers as well as of osteoclast-like type at later time intervals in small numbers were found on the surface of Si-rich as well as on Ca- and P-rich particle remnants. Osteoclast-like cells were detected on the particles after transformation in CaP-shells. It is concluded that the formation of different types of MNGC is determined by the composition of the substrate, that is, osteoclast-like cells develop exclusively on resorbable substrates. The absolute number of MNGC depended on the time after implantation and the solubility of the implant. Bone bonding, however, only occurred on Ca- and P-rich surfaces.