Impact of chemiluminescent enzyme immunoassay screening for human parvovirus B19 antigen in Japanese blood donors

Parvovirus B19 DNA and antibodies in Chinese plasma donors, plasma pools and plasma derivatives

BACKGROUND

Human parvovirus B19 (B19V) is a common contaminant found in plasma pools and plasma derivatives. Previous studies were mainly focused on limited aspects, further assessment of prevalence of B19V DNA and antibodies in plasma donors, the contamination of B19V in pooled plasma and plasma derivatives should be performed in China.

STUDY DESIGN AND METHODS

Individual plasma donors' samples from four provinces and pooled plasma from four Chinese blood product manufacturers were collected and screened using B19V DNA diagnostic kits between October 2018 and May 2020. The positive samples were investigated for the seroprevalence of B19V antibodies and subjected to sequence analysis and alignment for phylogenetic studies. Moreover, 11 plasma donors who were B19V DNA-positive at their first testing were also followed during the later donation period. Additionally, 400 plasma pools and 20 batches of plasma derivatives produced by pooled plasma with a viral load of B19V DNA exceeding 104IU/mL were also collected and tested for B19V DNA and antibodies.

OBJECTIVES

To comprehensively and systematically determine the frequency and viral load of B19V DNA in plasma donors, pooled plasma, and plasma derivatives from four Chinese blood product manufacturers.

RESULTS

A total of 17,187 plasma donors were analyzed and 44 (0.26%) specimens were found positive for B19V DNA. The quantitative DNA levels ranged from 1.01 × 101 to 5.09 × 1012 IU/mL. Forty-four DNA-positive specimens were also investigated for the seroprevalence of B19V antibodies, 75.0% and 2.3% of which were seropositive for B19V IgG and IgM antibodies, respectively. The phylogenic analyses showed that the prevalent genotypes in the four provinces' plasma donors belonged to B19V Genotype 1. Eleven individual plasma donors who were B19V DNA-positive at the first donation were then followed for a period, and in general, the DNA levels of B19V gradually decreased. Moreover, 64.8% (259/400) of the pooled plasma was contaminated by B19V, with concentrations of 1.05 × 100-3.36 × 109IU/mL. Approximately 72.6% of the DNA-positive plasma pools were only moderately contaminated (<104 IU/mL), while 27.4% contained >104 IU/mL. Twenty batches of plasma derivatives produced by pooled plasma with a viral load of B19V DNA exceeding 104IU/mL were also tested. B19V was detected in 5/5 PCC samples and 5/5 factor VIII samples but was not found in the intravenous immune globulin and albumin samples.

CONCLUSION

The contamination of B19V in pooled plasma and plasma-derived clotting factor concentrates is serious. Whether B19V nucleic acid testing (NAT) screening of plasma and plasma derivatives is launched in China, blood product manufacturers should spontaneously perform B19V NAT screening in plasma donors and mini-pool plasma. These measures can ensure that samples with high titer B19V DNA are discarded in order to prevent and control this transfusion transmitted virus.

Screening for parvovirus B19 antigen through chemiluminescent enzyme immunoassay is equivalent to B19 nucleic acid amplification test-based screening of pooled plasma

BACKGROUND

Human parvovirus B19 (B19) is a pathogen that threatens the quality of plasma products. Therefore, health authorities have mandated measures against B19 contamination of plasma pools. The US FDA has recommended a B19 genome level of 10⁴  IU/ml or lower in pooled plasma lots. Therefore, the B19 nucleic acid amplification test (B19-NAT) has been introduced in many plasma fractionators. However, in the Japanese Red Cross, which is the only approved blood collector in Japan, the B19 antigen test has been introduced for screening donated blood in Japan. Therefore, to clarify whether the antigen test is robust enough to screen blood samples according to the FDA recommendation, we evaluated B19 genome levels in each pooled plasma lot from 2003 to 2020.

STUDY DESIGN AND METHODS

Data of 5576 pooled plasma lots from factories A and B, which were derived from plasma bags and passed the B19 antigen-based tests, receptor-mediated hemagglutination assay (B19-RHA), or chemiluminescent enzyme immunoassay (B19-CLEIA), during 2003 to 2020, were evaluated. The amount of B19 genome in each lot was determined using quantitative or semiquantitative B19-NAT.

RESULTS

The B19 genome levels in pooled plasma lots screened using B19-RHA did not meet the FDA recommendation, whereas the lots derived from B19-CLEIA fulfilled the FDA recommendation, even during the B19 epidemic in Japan.

DISCUSSION

The results suggest that the B19-CLEIA donor screening for plasma pools is also useful in light of the US FDA recommendation.

Prevalence and Phylogenetic Analysis of Parvovirus (B19V) among Blood Donors with Different Nationalities Residing in Qatar

Human parvovirus (B19V) is the causative agent of erythema infectiosum in children and is linked to a wide range of clinical manifestations. Studies related to B19V prevalence in the Middle East and North Africa (MENA) region and other parts of Asia are very scarce. The objectives of this study were to estimate the seroprevalence (anti-B19V IgM and IgG), the viremia rate (B19V DNA), and the circulating genotypes of B19V among blood donors in Qatar. Methods: Donors’ blood samples (n = 5026) from different nationalities, mainly from the MENA region and South East Asia, were collected from 2014–2016. Samples were tested for the B19V DNA using RT-PCR. Furthermore, 1000 selected samples were tested to determine the seroprevalence of B19V antibodies using enzyme-linked immunosorbent assay (ELISA). Genotyping was performed on 65 DNA positive samples by sequencing of nested PCR fragments (NS1-VP1u region, 927 nt). Results: Only 1.4% (70/5026) of the samples had detectible B19V DNA in their blood. B19V DNA prevalence statistically decreased with age (p = 0.03). Anti-B19V IgG was detected in 60.3% (561/930) of the tested samples, while only 2.1% (20/930) were IgM-positive and 1.2% (11/930) were both IgM- and IgG-positive. B19V genotyping showed a predominance of Genotype 1 (100%). Sequence analysis of the NS1-VP1u region revealed 139 mutation sites, some of which were amino acid substitutions. Conclusion: Our results indicated a relatively high seroprevalence of B19V in Qatar. Most importantly, B19 DNA was detected among Qatari and non-Qatari blood donors. Therefore, blood banks in Qatar might need to consider screening for B19V, especially when transfusion is intended for high-risk populations, including immunocompromised patients.

Parvovirus B19 seroprevalence, viral load, and genotype characterization in volunteer blood donors from southern Brazil

Usually transmitted via respiratory droplets, parvovirus B19 (B19V) can also be acquired by blood transfusion especially because of viral persistence, resistance to blood treatment procedures, and high viral load during the early infection phase. This is particularly problematic in immunocompromised or anemic patients where the infection can have a severe outcome. As B19V DNA was detected in blood donations from South Brazil during a viral metagenomic survey performed by Next-Generation Sequencing, the objective of this retrospective study was to evaluate the seroprevalence, B19V DNA presence and circulating genotypes in a Hospital Blood Transfusion Service in Santa Maria city in South Brazil (Rio Grande do Sul state). Among 480 volunteer blood donors, 53.9% (n = 258 of 479) were anti-B19V IgG-positive, and 9 (1.9%) plasma samples presented B19V DNA. In almost all cases (n = 7 of 9, 77.8%), B19V DNA load was accompanied by the presence of anti-B19V IgG suggesting a persistent infection. The sequencing of the strains demonstrated that all belong to genotype 1 which is the most prevalent worldwide. The analysis of the recipient information of the positive for B19V DNA units revealed no related posttransfusion adverse effects. Our results demonstrate for the first time, B19V seroprevalence, viral load, and genotypes among blood donors from South Brazil and give a light for the circulation and impact of this B19V in this part of the country.

Persistent symptomatic parvovirus B19 infection with severe thrombocytopenia transmitted by red blood cell transfusion containing low parvovirus B19 DNA levels

BACKGROUND

Transfusion-mediated human parvovirus B19 (PVB19) infection is rare but often causes severe hematologic disorders. In Japan, routine blood donor screening for PVB19 antigen (detection sensitivity, 10^6.4 IU/mL) using a chemiluminescent enzyme immunoassay (CLEIA) was introduced in 2008. However, there is no consensus on the minimal infectious dose of PVB19 permissible for red blood cells (RBCs).

CASE REPORT

A 64-year-old man, who had received hemodialysis for diabetic nephropathy for 5 years, underwent an RBC transfusion for anemia caused by hemorrhagic enterocolitis. He developed persistent high fever and progressive thrombocytopenia. He was diagnosed with PVB19 infection when a marrow examination showed giant erythroblasts, and his serum was positive for PVB19 DNA. His serum was negative for PVB19 immunoglobulin (Ig)M and IgG before transfusion, but positive for both after transfusion. This PVB19 infection was deemed to be transmitted by the RBC transfusion because low levels of PVB19 DNA (1.10 × 10⁴ IU/mL) were detected in one of the blood donors. A DNA homology test of PVB19 showed complete genomic identity between the virus in the donor and our patient.

CONCLUSION

We report a patient who developed persistent PVB19 infection from an RBC transfusion containing low levels of PVB19. This is the second case of transfusion-mediated PVB19 infection since the introduction of CLEIA in 2008. Transmission may occur in immunocompromised patients lacking PVB19-neutralizing antibodies. The report of further such cases will allow the establishment of minimal threshold values and more effective screening tests for PBV19 transmission through RBC products.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.