Human parvovirus 4 in Brazilian patients with haemophilia, beta-thalassaemia major and volunteer blood donors

Study on genotyping and coinfection rate of human parvovirus 4 among the HTLV-I/II infected blood donors in Khorasan Razavi, Iran

Human Parvovirus 4 (PARV4) is an emerging virus infecting individuals with other blood-borne diseases. This study aimed to determine the prevalence of PARV4 in confirmed HTLVI/II positive samples from blood donors, assessing PARV4 viral load (DNA) and genotyping.

METHODS

A novel qReal-Time PCR, based on a plasmid construct, was developed to simultaneously detect all three PARV4 genotypes using in-house primers and probes. Positive qPCR samples were subjected to nested PCR amplification and subsequent sequencing. Phylogenetic trees were constructed using the Neighbor-joining (N.J.) method.

RESULTS

The coinfection rate of PARV4-DNA in HTLVI/II confirmed infected donors, who were previously deferred, was 14.4 % (13 out of 90), with no observed association with donation status (p = 1.0). Phylogenetic analysis indicated that PARV4-positive samples closely resembled genotype 2 in Iran.qPCR quantification demonstrated significant PARV4 viral loads in positive samples, ranging between 104 and 106 DNA copies/mL of serum.

CONCLUSION

This study presents the first evaluation of HTLVI/II and PARV4coinfection rates among blood donors. Notably, elevated PARV4-DNA titers were detected in HTLVI/II-positive donors. Given PARV's resistance to standard plasma refinery inactivation methods and the absence of its targeted inactivation, its potential impact remains a concern.

Parvovirus 4 in Individuals with Severe Hemophilia A and Matched Control Group

Background: Hemophilia is a well-known bleeding disorder with worldwide distribution. Replacement therapy, using plasma-derived or recombinant coagulation factors, comprises a gold standard regimen for the treatment. Regardless of the advancements made in viral inactivation methods in the production of plasma-derived coagulation factors, the possibility of transmission of new viral infections remained as a noticeable concern yet. The aim of the current study was to investigate the status of parvovirus 4 (PARV4) in severe hemophilia A, von Willebrand disease (vWD), and healthy control. Materials and Methods: In the current case-control study, 76 patients with hemophilia and vWD and 60 individuals from their family members entered the study. Nested PCR used to determine the presence of PARV4 in study subjects (76 cases). To characterize the PARV4 genotype, positive samples subjected to sequencing and phylogenetic analysis. Results: PARV4 genome detected in 11 (14.47%) patients with bleeding disorders. Among whom, nine patients (14.75%) were with severe hemophilia A and two (13.33%) patients with vWD. Only five healthy controls (8.33%) were positive for PARV4. All PARV4 sequences were found to be genotype 1. Conclusion: PARV4 infection in patients with hemophilia and vWD was higher than the control group. While detection of PARV4 DNA in patients with bleeding disorders may not necessarily reflect a clinical urgency, future investigations are needed to define the clinical significance of PARV4. It seems the detection of the virus immune signature of PARV4 infection, particularly in the context of acute and persistent infections, needs to focus on cellular and tissue targets.

Human parvovirus 4 'PARV4' remains elusive despite a decade of study

Human parvovirus 4 ('PARV4') is a small DNA tetraparvovirus, first reported in 2005. In some populations, PARV4 infection is uncommon, and evidence of exposure is found only in individuals with risk factors for parenteral infection who are infected with other blood-borne viruses. In other settings, seroprevalence studies suggest an endemic, age-associated transmission pattern, independent of any specific risk factors. The clinical impact of PARV4 infection remains uncertain, but reported disease associations include an influenza-like syndrome, encephalitis, acceleration of HIV disease, and foetal hydrops. In this review, we set out to report progress updates from the recent literature, focusing on the investigation of cohorts in different geographical settings, now including insights from Asia, the Middle East, and South America, and discussing whether attributes of viral or host populations underpin the striking differences in epidemiology. We review progress in understanding viral phylogeny and biology, approaches to diagnostics, and insights that might be gained from studies of closely related animal pathogens. Crucial questions about pathogenicity remain unanswered, but we highlight new evidence supporting a possible link between PARV4 and an encephalitis syndrome. The unequivocal evidence that PARV4 is endemic in certain populations should drive ongoing research efforts to understand risk factors and routes of transmission and to gain new insights into the impact of this virus on human health.

Human parvovirus 4 prevalence among HTLV-1/2 infected individuals in Brazil

Human parvovirus 4 (PARV4), a Tetraparvovirus, has been largely found in HIV, HBV, or HCV infected individuals. However, there is no data for the PARV4 occurrence in Human T-lymphotropic virus (HTLV-1/2) infected individuals, despite similar transmission routes. Here, PARV4 viremia was evaluated in 130 HTLV infected patients under care of a Brazilian HTLV outpatient clinic. PARV4 viremia was detected in 6.2% of the HTLV-1 infected patients. Most PARV4 positives showed no evidence for parenterally transmitted infections. It is suggested that in Brazil, transmission routes of PARV4 are more complex than in Europe and North America and resemble those in Africa. J. Med. Virol. 89:748-752, 2017. © 2016 Wiley Periodicals, Inc.