Session topic


Title: Detection of parvovirus mRNAs as a marker for viral activity in endomyocardial biopsy-based diagnosis of patients with unexplained heart failure
ID: PS 54
Type: Poster session
Talk time: 3 + 2 min
Session: Poster session 2
Clinical virology I

Speaker: Heiko Pietsch (Berlin/DE)

Abstract - Text

Abstract text (incl. references and figure legends)

Introduction: Human erythroparvovirus (B19V) is the most frequently found virus in endomyocardial biopsies (EMBs). Recent studies have detected B19V genomes in various organs of symptomatic and asymptomatic individuals, including endothelial cells of the heart muscle, questioning the relevance of B19V as a causative pathogen of myocardial damage. However, the majority of studies did not assess expression of viral RNA as markers for viral activity. In contrast to a latent infection with B19V, the expression of viral mRNAs seems to be of clinical importance.

Objectives: A sensitive and specific method to identify patients that will profit from B19V antiviral treatment is a prerequisite for successful therapy. We established a qPCR diagnostic method to characterize the expression of B19V RNAs coding for the non-structural (NS1) and capsid protein (VP1/2) in EMBs and demonstrated its feasibility in a clinical setting of molecular diagnostics.

Patients & methods: 576 consecutive patients with unexplained heart failure who underwent EMB (mean age: 53.6 ± 15.7 years, mean LVEF: 34.1% ± 15.7%) were tested for B19V genomes and transcription intermediates using qPCR and nested PCR. To quantify B19V RNA expression, we developed (RT-)qPCRs targeting the NS1 and VP1/2 regions of the B19V genome.

Results: 403 of 576 (69.9%) EMBs were positive for B19V genomes. Of the 403 B19V DNA-positive samples, B19V mRNAs NS1 and/or VP1/2, indicating viral activity, could be detected in 155/403 (38.4%). 89/403 samples were characterized by only NS1 mRNA detection while 24/403 revealed only VP1/2 mRNA expression. Detection of both intermediates was successful in 42/403 samples. Patients suffering from B19V infection with active replication presented with significantly reduced left ventricular ejection fraction in contrast to latently infected or virus free patients.

Conclusion: It is essential to screen for both viral transcription intermediates (NS1 and VP1/2) in order to precisely differentiate between latent infection or a clinically relevant B19V-infection with transcriptional activity of the myocardium. Our study revealed that a remarkable high proportion of 26.9% (155/576) of patients with unexplained heart failure is affected by transcriptional active B19V infection of the myocardium and presented with impaired clinical outcome. Prospective studies must be conducted to evaluate our findings and furthermore, effective antiviral treatment strategies need to be adapted.