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Updated: Jul 13, 2026
Isolation and Analysis of Traceable and Functionalized Extracellular Vesicles from the Plasma and Solid Tissues
Published on: October 17, 2022
Analysis of two human parvovirus PARV4 genotypes identified in human plasma for fractionation
Jacqueline F Fryer1, Eric Delwart2,3, Flavien Bernardin2,3
1Division of Virology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK.
Abstract:
The presence of the novel parvovirus PARV4 and a related variant, PARV5, was recently demonstrated in pooled plasma used in the manufacture of blood and plasma-derived medicinal products. DNA sequence analysis of nearly full-length genomes of four PARV4 and two PARV5 strains from manufacturing plasma pools is now presented. Like PARV4, PARV5 encodes two non-overlapping open reading frames (ORF1 and ORF2), homologous to the non-structural and capsid proteins of other parvoviruses, respectively. A highly conserved region in ORF2 contains phospholipase A2 motifs involved in parvovirus infectivity. Hybridization of strand-specific probes to DNA extracted from high-titre, PARV4-positive plasma revealed that the positive and negative strands are packaged into PARV4 virions in similar quantities. This extended analysis of nearly full-length PARV4 and PARV5 sequences suggests that they are closely related genotypes and the use of a single virus name, PARV4, comprising genotypes 1 and 2 (previously termed PARV5) is proposed.
Insights
Researchers analyzed parvovirus PARV4 and its variant PARV5 in plasma products. They propose renaming PARV5 as PARV4 genotype 2, simplifying parvovirus classification in blood products.
Area of Science:
- Virology
- Molecular Biology
- Blood Product Safety
Background:
- The novel parvoviruses PARV4 and PARV5 have been detected in pooled plasma.
- These viruses are relevant to the safety of blood and plasma-derived medicinal products.
Purpose of the Study:
- To present DNA sequence analysis of nearly full-length genomes of PARV4 and PARV5 strains.
- To clarify the genetic relationship between PARV4 and PARV5.
- To propose a unified nomenclature for these parvoviruses.
Main Methods:
- DNA sequencing of nearly full-length parvovirus genomes from manufacturing plasma pools.
- Bioinformatic analysis of open reading frames (ORFs) and conserved regions.
- Strand-specific probe hybridization to analyze viral genome packaging.
Main Results:
- PARV4 and PARV5 encode homologous proteins (ORF1 and ORF2) similar to other parvoviruses.
- A conserved phospholipase A2 motif in ORF2 is implicated in parvovirus infectivity.
- Both positive and negative DNA strands of PARV4 are packaged into virions in comparable amounts.
Conclusions:
- PARV4 and PARV5 represent closely related parvovirus genotypes.
- A single virus designation, PARV4, encompassing genotypes 1 (PARV4) and 2 (formerly PARV5), is proposed.
- This unification simplifies the classification of these parvoviruses in the context of blood product safety.
