Detection of parvovirus mRNAs as markers for viral activity in endomyocardial biopsy-based diagnosis of patients with unexplained heart failure.

Heiko Pietsch,Claus-Thomas Bock,Ganna Aleshcheva,Dirk Lassner,Felicitas Escher,Heinz-Peter Schultheiss

doi:10.1038/s41598-020-78597-4

Abstract

Erythroparvovirus (B19V) genomes have been detected in various organs of infected individuals including endothelial cells of the heart muscle. However, the role of B19V as a causative pathogen of myocardial damage is still unknown. The majority of reports focus on the presence of viral DNA ignoring proof of viral RNAs as important markers for viral activity. During this study, we established (RT-) qPCR to characterize expression of B19V RNAs (NS1 and VP1/2) in endomyocardial biopsies (EMBs) of 576 patients with unexplained heart failure. 403/576 (70%) EMBs were positive for B19V DNA. B19V mRNAs NS1 and/or VP1/2, indicating viral activity, could be detected in 38.5% of B19V DNA positive samples using the newly established B19V RT-PCRs. 22.1% of samples were characterized by only NS1 mRNA detection while 6.0% revealed only VP1/2 mRNA expression. Detection of both intermediates was successful in 10.4% of samples. Applying the molecular testing, our study revealed that a high proportion (38.5%) of B19V DNA positive EMBs was characterized by viral transcriptional activity. Further prospective studies will evaluate relevance of viral transcription intermediates as a diagnostic marker to differentiate between latent B19V infection and clinically relevant transcriptionally active B19V-infection of the heart muscle.

Highlights

Primate parvovirus (B19V), a non-enveloped single stranded linear DNA virus, belongs to the genus Erythro‐ parvovirus
The 5.6 kb linear single stranded DNA genome contains two major open reading frames (ORFs) coding for the NS1 and VP1 and VP2 proteins being flanked by inverted terminal repeat regions (ITRs) that are necessary for self-priming during viral genome replication
Routine analysis of B19V genome detection revealed that 403/576 (70%) of endomyocardial biopsies (EMBs) were positive for B19V DNA with a median viral load of 944.3 genome equivalents/μg genomic DNA (GE/μg) ranging from 15 to 51,118 GE/μg (Table 1)

Summary

Introduction

Primate parvovirus (B19V), a non-enveloped single stranded linear DNA virus, belongs to the genus Erythro‐ parvovirus. The classical viral pathogen associated with myocarditis or inflammatory dilated cardiomyopathy (DCMi) is Coxsackievirus B. B19V genomes are the most frequently detected viral genomes in endomyocardial biopsies (EMBs) of patients with suspected heart failure[8,9]. The 5.6 kb linear single stranded DNA genome contains two major open reading frames (ORFs) coding for the NS1 (non-structural protein) and VP1 and VP2 (capsid) proteins being flanked by inverted terminal repeat regions (ITRs) that are necessary for self-priming during viral genome replication. In semi-permissive cells, such as endothelial cells, transcripts are polyadenylated at polyadenylation site proximal (pA)p leading to an increased expression of NS1 intermediates. The blockade at (pA)p is overcome by replication of the viral genome in the late phase of infection and readthrough (pA)p leads to expression of VP1/216

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Conclusion