A new quantitative PCR for human parvovirus B19 genotypes

Parvovirus B19 and Human Herpes Virus 6B and 7 Are Frequently Found DNA Viruses in the Human Thymus But Show No Definitive Link With Myasthenia Gravis

Myasthenia gravis (MG) is a rare autoimmune disorder characterized by muscle weakness resulting from autoantibody-mediated disruption of the neuromuscular junction. Notably, it is also frequently associated with thymic pathology. This study explores the relationship between MG and DNA viruses in the thymus, employing targeted next-generation sequencing and quantitative polymerase chain reaction to analyze thymic tissue samples from both patients with MG and healthy controls. We detected human herpes virus 6B and 7, Epstein-Barr virus, and parvovirus B19 (B19V) across various tissue groups. However, no significant enrichment of these viruses was observed in the thymic tissue of patients with MG.

Reactivation of a Transplant Recipient's Inherited Human Herpesvirus 6 and Implications to the Graft

BACKGROUND

The implications of inherited chromosomally integrated human herpesvirus 6 (iciHHV-6) in solid organ transplantation remain uncertain. Although this trait has been linked to unfavorable clinical outcomes, an association between viral reactivation and complications has only been conclusively established in a few cases.

METHODS

We used hybrid capture sequencing for in-depth analysis of the viral sequences reconstructed from sequential liver biopsies. Moreover, we investigated viral replication through in situ hybridization (U38-U94 genes), reverse transcriptase polymerase chain reaction (U89/U90 genes), immunohistochemistry, and immunofluorescence. We also performed whole transcriptome sequencing to profile the host immune response.

RESULTS

We report a case of reactivation of a recipient's iciHHV-6B and subsequent infection of the graft. Using a novel approach integrating the analysis of viral and mitochondrial DNAs, we located the iciHHV-6B intragraft. We demonstrated active replication via the emergence of viral minor variants, in addition to positive viral messenger RNAs and antigen stainings in tissue sections. Furthermore, we detected significant upregulation of antiviral immune responses, arguing against immunotolerance.

CONCLUSIONS

Our analysis underscores the potential pathological impact of iciHHV-6B, emphasizing the need for monitoring reactivation in transplant recipients. Most crucially, it highlights the critical role that the host's virome can play in shaping the outcome of transplantation.

Multiple DNA Viruses and HPV Integration in Inverted Papilloma and Associated Sinonasal Carcinoma

OBJECTIVES

Sinonasal inverted papilloma (IP) has a locally destructive growth pattern, can relapse, and can undergo malignant transformation (IP-associated sinonasal squamous cell carcinoma (IP-SNSCC)). Human papillomaviruses (HPV)-6 and -16 are frequently detected in IPs. To clarify the possible roles of other DNA viruses in IPs, we explored viruses not studied in this context before. With the setting of pre- and post-malignant transformation samples, we investigated HPV genomes in depth to assess the integration of HPV into the human genome and the presence of minor intratypic variants.

MATERIALS AND METHODS

We analyzed 35 IP samples representing 28 individuals, of which six had IP-SNSCC. For virus screening, we applied qPCR to detect 16 different DNA viruses in three virus families, comprising herpesviruses, parvoviruses, and polyomaviruses. In addition, targeted next generation sequencing (NGS) was used for detailed HPV analysis.

RESULTS

We detected herpes-, parvo-, and polyomaviruses in 13/28 (46%) patients, with codetections of multiple viruses in six (21%) patients. NGS revealed HPV16 DNA in 2/6 IP-SNSCC and in their respective earlier benign IP samples, as well as in a plasma sample from one of these patients. HPV6 was detected in two IP samples without subsequent malignant transformation. We identified sequence reads containing junctions of HPV6 and HPV16 and host genome suggestive of viral integration. HPV6 and HPV16 minor intratypic variants were present across pre- and post-malignant transformation, with mostly nonsynonymous mutations.

CONCLUSIONS

Multiple DNA viruses were present in IPs. HPV16 was detected only in IP-SNSCCs or in tumors that later underwent malignant transformation.

LEVEL OF EVIDENCE

3 Laryngoscope, 135:677-686, 2025.

Presence of herpesviruses, parvoviruses, and polyomaviruses in sinonasal lymphoma

PURPOSE

Sinonasal lymphoma (SL) is a rare lymphatic neoplasm of the nasal cavities, paranasal sinuses and nasopharynx. Whereas some risk factors for SL subtypes have been identified, their aetiology is unknown. Along with other predisposing factors, the viral association of lymphomas, such as Epstein-Barr virus (EBV) and Burkitt and Hodgkin lymphomas, is well-established. Modern molecular biology techniques have enabled the discovery of novel human viruses, exemplified by the protoparvovirus cutavirus (CuV), associated with cutaneous T-cell lymphoma. These findings, and the anatomical location of the sinonasal tract with its rich microbiome and infectious agents, justify in-depth studies among SL.

METHODS

We analysed the presence of 20 viruses of Orthoherpesviridae, Parvoviridae, and Polyomaviridae by qPCR in 24 SL tumours. We performed RNAscope in situ hybridisation (RISH) to localize the viruses. Parvovirus-specific IgG was analysed by enzyme immunoassay and targeted next-generation sequencing (NGS) was applied to detect CuV in plasma.

RESULTS

We detected viral DNA in 15/24 (63%) tumours; nine of EBV, six of human herpesvirus (HHV) -7, four each of HHV-6B and parvovirus B19, two of cytomegalovirus, and one each of CuV and Merkel-cell polyomavirus. We found tumours with up to four viruses per tumour, and localized CuV and EBV DNAs by RISH. Two of the ten plasma samples exhibited CuV IgG, and one plasma sample demonstrated CuV viremia by NGS.

CONCLUSION

Viruses were frequent findings in SL. The EBV detection rate was high in diffuse large B-cell lymphoma, and co-detections with other viruses were prevalent.

Viral DNA in submandibular gland tissue with an inflammatory disorder

Background

The etiology behind different types of chronic sialadenitis (CS), some of which exhibit IgG4 overexpression, is unknown. Further, IgG4-related disease (IgG4-RD) commonly affects the submandibular gland, but its relationship to IgG4-overexpressing CS, and the antigen triggering IgG4 overexpression, remain unknown.

Materials and Methods

By qPCR, we assessed the presence of 21 DNA-viruses causing IgG4 overexpression in submandibular gland tissue from patients with IgG4-positive and IgG4-negative CS. Healthy submandibular glands and glands with sialolithiasis without CS were used as controls. We examined the distribution of HHV-7, HHV-6B and B19V DNA, within virus PCR-positive tissues with RNAscope in-situ hybridization (RISH).

Results

We detected DNA from seven viruses in 48/61 samples. EBV DNA was more prevalent within the IgG4-positive samples (6/29; 21%) than the IgG4-negative ones (1/19; 5.3%). B19V DNA was more prevalent within the IgG4-negative samples (5/19; 26%) than the IgG4-positive ones (4/29; 14%). The differences in virus prevalence were not statistically significant. Of the IgG4-RD samples (n = 3) one contained HHV-6B DNA. RISH only showed signals of HHV-7.

Conclusions

None of the studied viruses are implicated as triggering IgG4-overexpression in CS. Although our results do not confirm viral etiology in the examined conditions, they provide valuable information on the prevalence of viruses in both diseased and healthy submandibular gland tissue.

Molecular investigation of some DNA viruses in mucosal melanoma: Case-control study

The association between viral infections and both cutaneous and mucosal melanoma (MM) has not been fully investigated. Here, we assessed the prevalence of the DNA of a broad range of viruses in 31 MMs and 15 biopsies of healthy mucosa (HM) using molecular methods. The parvoviruses CuV and B19V, herpesviruses HSV1, HSV2, EBV, HHV6, and HHV8, polyomavirus MCPyV, and α-HPVs were not detected, or rarely found, in MMs, and in HM, of the digestive, respiratory, and female genital tract. The overall prevalence of β-HPV in MMs was not significantly higher compared to that in HM (70.9% and 53.3% respectively; p = 0.514). However, the number of MMs positive for β-HPV types belonging to Species 3 and 5 and for some viral types belonging to Species 1, 2, 3, and 5 were significantly higher compared with HM (p < 0.05). Moreover, compared to HM, the MM samples contained a significantly higher number of β-HPV types, mainly belonging to Species 1, 3, and 5 (p < 0.05). Our data, although suggesting a role for certain β-HPV types in MM oncogenesis, require additional investigation in larger populations to support this hypothesis.

Herpesviruses, polyomaviruses, parvoviruses, papillomaviruses, and anelloviruses in vestibular schwannoma

Etiology of vestibular schwannoma (VS) is unknown. Viruses can infect and reside in neural tissues for decades, and new viruses with unknown tumorigenic potential have been discovered. The presence of herpesvirus, polyomavirus, parvovirus, and anellovirus DNA was analyzed by quantitative PCR in 46 formalin-fixed paraffin-embedded VS samples. Five samples were analyzed by targeted next-generation sequencing. Viral DNA was detected altogether in 24/46 (52%) tumor samples, mostly representing anelloviruses (46%). Our findings show frequent persistence of anelloviruses, considered normal virome, in VS. None of the other viruses showed an extensive presence, thereby suggesting insignificant role in VS.

Prevalence, Cell Tropism, and Clinical Impact of Human Parvovirus Persistence in Adenomatous, Cancerous, Inflamed, and Healthy Intestinal Mucosa

Parvoviruses are single-stranded DNA viruses, infecting many animals from insects to humans. Human parvovirus B19 (B19V) causes erythema infectiosum, arthropathy, anemia, and fetal death, and human bocavirus (HBoV) 1 causes respiratory tract infections, while HBoV2-4 are enteric. Parvoviral genomes can persist in diverse non-permissive tissues after acute infection, but the host-cell tropism and the impact of their tissue persistence are poorly studied. We searched for parvoviral DNA in a total of 427 intestinal biopsy specimens, as paired disease-affected and healthy mucosa, obtained from 130 patients with malignancy, ulcerative colitis (UC), or adenomas, and in similar intestinal segments from 55 healthy subjects. Only three (1.6%) individuals exhibited intestinal HBoV DNA (one each of HBoV1, 2, and 3). Conversely, B19V DNA persisted frequently in the intestine, with 50, 47, 31, and 27% detection rates in the patients with malignancy, UC, or adenomas, and in the healthy subjects, respectively. Intra-individually, B19V DNA persisted significantly more often in the healthy intestinal segments than in the inflamed colons of UC patients. The highest loads of B19V DNA were seen in the ileum and colon specimens of two healthy individuals. With dual-RNAscope in situ hybridization and immunohistochemistry assays, we located the B19V persistence sites of these intestines in mucosal B cells of lymphoid follicles and vascular endothelial cells. Viral messenger RNA transcription remained, however, undetected. RNA sequencing (RNA-seq) identified 272 differentially expressed cellular genes between B19V DNA-positive and -negative healthy ileum biopsy specimens. Pathway enrichment analysis revealed that B19V persistence activated the intestinal cell viability and inhibited apoptosis. Lifelong B19V DNA persistence thus modulates host gene expression, which may lead to clinical outcomes.

Detection of Low-Copy Human Virus DNA upon Prolonged Formalin Fixation

Formalin fixation, albeit an outstanding method for morphological and molecular preservation, induces DNA damage and cross-linking, which can hinder nucleic acid screening. This is of particular concern in the detection of low-abundance targets, such as persistent DNA viruses. In the present study, we evaluated the analytical sensitivity of viral detection in lung, liver, and kidney specimens from four deceased individuals. The samples were either frozen or incubated in formalin (±paraffin embedding) for up to 10 days. We tested two DNA extraction protocols for the control of efficient yields and viral detections. We used short-amplicon qPCRs (63–159 nucleotides) to detect 11 DNA viruses, as well as hybridization capture of these plus 27 additional ones, followed by deep sequencing. We observed marginally higher ratios of amplifiable DNA and scantly higher viral genoprevalences in the samples extracted with the FFPE dedicated protocol. Based on the findings in the frozen samples, most viruses were detected regardless of the extended fixation times. False-negative calls, particularly by qPCR, correlated with low levels of viral DNA (<250 copies/million cells) and longer PCR amplicons (>150 base pairs). Our data suggest that low-copy viral DNAs can be satisfactorily investigated from FFPE specimens, and encourages further examination of historical materials.

The Human Bone Marrow Is Host to the DNAs of Several Viruses

The long-term impact of viruses residing in the human bone marrow (BM) remains unexplored. However, chronic inflammatory processes driven by single or multiple viruses could significantly alter hematopoiesis and immune function. We performed a systematic analysis of the DNAs of 38 viruses in the BM. We detected, by quantitative PCRs and next-generation sequencing, viral DNA in 88.9% of the samples, up to five viruses in one individual. Included were, among others, several herpesviruses, hepatitis B virus, Merkel cell polyomavirus and, unprecedentedly, human papillomavirus 31. Given the reactivation and/or oncogenic potential of these viruses, their repercussion on hematopoietic and malignant disorders calls for careful examination. Furthermore, the implications of persistent infections on the engraftment, regenerative capacity, and outcomes of bone marrow transplantation deserve in-depth evaluation.

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 activates in vitro normal human dermal fibroblasts: a possible implication in skin fibrosis and systemic sclerosis

OBJECTIVE

Fibrosis is the most characteristic pathological hallmark of SSc, a connective tissue disease characterized by vascular and immunological abnormalities, inflammation and enhanced extracellular matrix production, leading to progressive fibrosis of skin and internal organs. We previously demonstrated that parvovirus B19 (B19V) can infect normal human dermal fibroblasts (NHDFs) and that B19V persists in SSc fibroblasts. In this study, we investigated whether parvovirus B19V is able to activate in vitro NHDFs and to induce in these cells some phenotypic features similar to that observed in the SSc fibroblasts.

METHODS

We preliminarily analysed the time course of B19V infection in cultured NHDFs, then we investigated the ability of B19V to induce cell migration, invasive phenotype and mRNA expression of some profibrotic and/or proinflammatory genes.

RESULTS

We confirmed our previous findings that B19V infects NHDFs, but the infection is not productive. After incubation with B19V, NHDFs showed a significant increase of both migration and invasiveness, along with mRNA expression of different profibrotic genes (α-SMA, EDN-1, IL-6, TGF-β1 receptors 1 and 2, Col1α2), some genes associated with inflammasome platform (AIM2, IFI16, IL-1β, CASP-1) and genes for metalloprotease (MMP 2, 9 and 12).

CONCLUSION

These data suggest that B19V can activate dermal fibroblasts and may have a role in the pathogenesis of fibrosis. B19V-induced fibroblast migration and invasiveness could be due to the B19V-associated MMP9 overexpression and activation. Moreover, the up-regulation of MMP12, typical of SSc, could link the B19V infection of fibroblasts to the anti-angiogenic process.

Intratonsillar detection of 27 distinct viruses: A cross-sectional study

Palatine tonsils have been observed to harbor several distinct respiratory and herpesviruses in separate studies. In this study, the presence of these viruses in palatine tonsils was comprehensively studied in both children and adults. A cross-sectional analysis of 181 patients (median age 22 years; range, 2.6-66) operated for a benign tonsillar disease was conducted. Real-time polymerase chain reaction was performed to detect 27 distinct viruses in all: eight human herpesviruses, 16 respiratory viruses, parvo B19, and polyoma BK/JC viruses. Clinical characteristics of the patients and underlying conditions were evaluated. In total, 92% of patients had virus detected in tonsils (Epstein-Barr virus 72%, human herpesvirus 7, and 6B 54% and 16%, respectively, enterovirus 18%, parvovirus B19 7% and the rest <4%). No herpes simplex virus 2, varicella zoster virus, polyoma JC virus, parainfluenza-, metapneumo-, or coronaviruses were found. Enterovirus was more common in children and was frequently observed in the presence of HHV6B. None of the viruses showed a positive association to the tonsillar disease. Respiratory symptoms were not associated with the prevalence of viruses. This study comprehensively reports a cross-sectional view of intratonsillar virus infections in elective tonsillectomy patients in a wide age range cohort. Tonsils are a major virus reservoir for distinct herpes and respiratory viruses without a positive association with tonsillar disease or respiratory symptoms.

Cutavirus DNA in Malignant and Nonmalignant Skin of Cutaneous T-Cell Lymphoma and Organ Transplant Patients but Not of Healthy Adults

BACKGROUND

Three new parvoviruses of Protoparvovirus genus, bufavirus (BuV), tusavirus (TuV), and cutavirus (CuV), have recently been discovered in diarrheal stools. CuV was further detected in a proportion of cutaneous T-cell lymphoma (CTCL)/mycosis fungoides skin samples and in one melanoma.

PATIENTS AND METHODS

With novel multiplex quantitative polymerase chain reaction and antibody assays, we studied 3 patient groups for BuV, TuV, and CuV DNA and immunoglobulin G (IgG): CTCL patients, immunosuppressed solid-organ transplant recipients, and immunocompetent healthy adults.

RESULTS

CuV DNA was detected in skin biopsies of 4/25 (16.0%) CTCL and 4/136 (2.9%) transplant patients but not in any of 159 skin samples of 98 healthy adults. The dermal CuV-DNA prevalence was significantly higher in CTCL patients than in the other subjects. CuV DNA was further detected in healthy skin of 4 organ transplant recipients, 2 of whom also had CuV-positive skin carcinomas. One CTCL patient harbored CuV DNA in both malignant (CTCL, melanoma) and nonmalignant skin and sentinel lymph nodes but not in his prostate. The CuV IgG seroprevalences were among CTCL patients 9.5% (4/42), transplant recipients 6.5% (8/124), and healthy adults 3.8% (3/78). BuV and TuV DNAs were absent and antibodies infrequent in all cohorts. Parvoviral antibodies were shown to persist for ≥20 years and dermal CuV DNA for 4 years. All 3 CuV-DNA-positive patients, with both biopsies and sera available, were CuV-IgG positive.

CONCLUSION

Our results suggest that dermal CuV DNA carriage is associated with CTCL. Any putative roles of CuV in the carcinogenesis must be determined in forthcoming studies.

The landscape of persistent human DNA viruses in femoral bone

The imprints left by persistent DNA viruses in the tissues can testify to the changes driving virus evolution as well as provide clues on the provenance of modern and ancient humans. However, the history hidden in skeletal remains is practically unknown, as only parvovirus B19 and hepatitis B virus DNA have been detected in hard tissues so far. Here, we investigated the DNA prevalences of 38 viruses in femoral bone of recently deceased individuals. To this end, we used quantitative PCRs and a custom viral targeted enrichment followed by next-generation sequencing. The data was analyzed with a tailor-made bioinformatics pipeline. Our findings revealed bone to be a much richer source of persistent DNA viruses than earlier perceived, discovering ten additional ones, including several members of the herpes- and polyomavirus families, as well as human papillomavirus 31 and torque teno virus. Remarkably, many of the viruses found have oncogenic potential and/or may reactivate in the elderly and immunosuppressed individuals. Thus, their persistence warrants careful evaluation of their clinical significance and impact on bone biology. Our findings open new frontiers for the study of virus evolution from ancient relics as well as provide new tools for the investigation of human skeletal remains in forensic and archaeological contexts.

Alphatorquevirus is the most prevalent virus identified in blood from a matched maternal-infant preterm cohort

Objective: To determine the prevalence of virus in a previously uncharacterized matched maternal-infant preterm cohort and test if viral presence or viral load correlate with histologic chorioamnionitis, spontaneous preterm labor or pre-eclampsia.Study Design: Using qRT-PCR/qPCR we tested plasma or whole blood samples from 56 matched maternal and premature infant dyads for: adenovirus, anellovirus (alphatorquevirus and betatorquevirus), cytomegalovirus (CMV), Epstein-Barr virus (EBV), enterovirus, human herpesvirus 6 (HHV6), parechovirus, and parvovirus B19.Result: Viral detection was more common in maternal samples 29/56 (52%) than in cord blood from their infants (4/56 (7%)) (p ≤ .0001). No significant difference in viral load or viral prevalence was identified between pregnancies with and without histologic chorioamnionitis, spontaneous preterm labor or pre-eclampsia.Conclusion: Despite frequent detection of virus in maternal samples, virus was less frequently detected in the infants. Additionally, there was no association of presence or quantity of virus in maternal blood with histologic chorioamnionitis, spontaneous preterm labor or pre-eclampsia in this small, but well-defined cohort. Future studies are necessary to further characterize the role of virus in placental inflammatory states and pregnancy outcomes.

Performance of Zika Assays in the Context of Toxoplasma gondii, Parvovirus B19, Rubella Virus, and Cytomegalovirus (TORCH) Diagnostic Assays

Infections during pregnancy that may cause congenital abnormalities have been recognized for decades, but their diagnosis is challenging. This was again illustrated with the emergence of Zika virus (ZIKV), highlighting the inherent difficulties in estimating the extent of pre- and postnatal ZIKV complications because of the difficulties in establishing definitive diagnoses. We reviewed the epidemiology, infection kinetics, and diagnostic methods used for Toxoplasma gondii, parvovirus B19, rubella virus, and cytomegalovirus (TORCH) infections and compared the results with current knowledge of ZIKV diagnostic assays to provide a basis for the inclusion of ZIKV in the TORCH complex evaluations. Similarities between TORCH pathogens and ZIKV support inclusion of ZIKV as an emerging TORCH infection. Our review evaluates the diagnostic performance of various TORCH diagnostic assays for maternal screening, fetal screening, and neonatal screening. We show that the sensitivity, specificity, and positive and negative predictive value of TORCH complex pathogens are widely variable, stressing the importance of confirmatory testing and the need for novel techniques for earlier and accurate diagnosis of maternal and congenital infections. In this context it is also important to acknowledge different needs and access to care for different geographic and resource settings.

Newly detected DNA viruses in juvenile nasopharyngeal angiofibroma (JNA) and oral and oropharyngeal squamous cell carcinoma (OSCC/OPSCC)

PURPOSE

Approximately 20% of cancers are estimated to have a viral etiology. We aimed to investigate whether DNA of 8 human parvoviruses [bocavirus 1-4 (HBoV1-4), parvovirus B19 (B19V), protoparvoviruses (bufa-, tusa-, and cutavirus)] and 13 human polyomaviruses (HPyV) can be detected in oropharyngeal and oral cavity squamous cell carcinoma (OPSCC/OSCC), and in juvenile nasopharyngeal angiofibroma (JNA) tissue samples.

METHODS

Fresh samples of seven JNA tissues and ten paired tissues of OSCC/OPSCC tumor and adjacent healthy tissues were collected. DNA extraction and real-time PCRs were performed to detect HBoV1-4, B19V, bufa- tusa- and cutavirus, and HPyV genomes.

RESULTS

JNA specimens were negative for all parvoviruses tested, whereas one JNA sample was Merkel cell polyomavirus (MCPyV) DNA positive. The OSCC/OPSCC samples were negative for the human protoparvoviruses, HBoV1-4, and all human polyomaviruses, except for one patient that was MCPyV DNA positive in both healthy and tumor tissues. Seven OSCC/OPSCC patients were positive for B19V DNA, three of them in both healthy and cancerous tissues and three in only healthy tissues. Three of the B19V DNA-positive patients harbored viral genotype 1, three genotype 2, and one genotype 3B.

CONCLUSIONS

These are the first reports of MCPyV and B19V DNA being detected in JNA and OPSCC. The significance of viral DNA positivity is unclear. B19V DNA is known to remain in the tissues lifelong, however, it is of interest that there are some patients with B19 DNA in healthy tissue, but not in the corresponding cancer tissue.

Occurrence of newly discovered human polyomaviruses in skin of liver transplant recipients and their relation with squamous cell carcinoma in situ and actinic keratosis - a single-center cohort study

To date 14 human polyomaviruses (HPyVs) have been identified. The newly found HPyVs have not been examined with regard to post-transplant skin carcinogenesis. To determine the occurrences in skin and possible pathological associations of the HPyVs, we studied their genoprevalences in squamous cell carcinoma (SCC) in situ or actinic keratosis and benign skin in liver transplant recipients (LiTRs); and of healthy skin in immunocompetent adults. We used highly sensitive and specific HPyV PCRs of two types. Overall, Merkel cell polyomavirus (MCPyV), human polyomavirus 6 (HPyV6), human polyomavirus 7 (HPyV7), trichodysplasia spinulosa polyomavirus (TSPyV), and Lyon IARC polyomavirus (LIPyV) were found in 58/221 (26.2%) skin biopsies. MCPyV DNA was detected in 5/14 (35.7%) premalignant vs. 32/127 (25.2%) benign skin of LiTRs, and in 12/80 (15%) healthy skin of immunocompetent adults, with no statistically significant difference in viral DNA prevalence or load. TSPyV DNA was found in a single skin lesion. LIPyV, HPyV6 and HPyV7 DNAs occurred exclusively in benign skin. Overall, the viral findings in premalignant versus benign skin were alike. The occurrences of HPyVs in skin of LiTRs and immunocompetent individuals speak against a role for any of the 14 HPyVs in SCC development.

Digital polymerase chain reaction technology - recent advances and future perspectives

Digital polymerase chain reaction (dPCR) technology has remained a "hot topic" in the last two decades due to its potential applications in cell biology, genetic engineering, and medical diagnostics. Various advanced techniques have been reported on sample dispersion, thermal cycling and output monitoring of digital PCR. However, a fully automated, low-cost and handheld digital PCR platform has not been reported in the literature. This paper attempts to critically evaluate the recent developments in techniques for sample dispersion, thermal cycling and output evaluation for dPCR. The techniques are discussed in terms of hardware simplicity, portability, cost-effectiveness and suitability for automation. The present paper also discusses the research gaps observed in each step of dPCR and concludes with possible improvements toward portable, low-cost and automatic digital PCR systems.

Molecular prevalence of parvovirus B19 among HIV1-infected patients in Iran

Background: Different outcomes of parvovirus B19 (B19V) infection in immunocompromised patients, including HIV1-infected persons, may be life-threatening. Considering the hematologic disorders associated with B19V infection, this study aimed to investigate the prevalence of B19V infection among HIV1-infected individuals in Iran.

Methods: Serum samples from 100 HIV1-infected patients were analyzed for B19 viral DNA using real-time PCR assay. COBAS TaqMan HIV-1 test was performed for quantitative measurements of HIV-1 RNA in the patients’ sera.

Results: Real-time PCR analysis revealed that 10 out of 100 cases (10%) were positive for B19V infection. Across various age groups, the B19V infection was more prevalent among patients within the age range of 21-40 years. Higher prevalence of B19V infection was observed among HIV1-infected patients with a viral load of higher than 400 copies/mL.

Conclusion: Despite limitations, this study may set the stage for further evaluations with larger sample sizes to elucidate the potential role of B19V in hematologic disorders, which may result in exacerbation of the disease in HIV1-infected patients. Moreover, as it has been shown that B19V infection can be treated using intravenous immunoglobulin (IVIG) therapy, available treatments may help improve the quality of life in HIV-infected persons.

Human parvovirus B19 and parvovirus 4 among Iranian patients with hemophilia

Background

Human parvovirus B19 (B19V) is one of the smallest DNA viruses and shows great resistance to most disinfectants. Therefore, it is one of the common contaminant pathogens present in blood and plasma products. Parvovirus 4 (PARV4) is a newly identified parvovirus, which is also prevalent in parenteral transmission. In this study, we aimed to evaluate the prevalence of B19V and PARV4 DNA among patients with hemophilia in Birjand County in eastern Iran.

Methods

This was a cross-sectional epidemiological study comprising nearly all people with hemophilia in this region. Whole blood samples were taken after patient registration and sent for plasma isolation. After nucleic acid extraction, B19V was detected with real-time polymerase chain reaction, PARV4 DNA was then detected using sensitive semi-nested PCR.

Results

In total, there were 86 patients with hemophilia, with mean age 28.5±1.5 years. Of these, 90.7% were men and 9.3% women; 84.9% had hemophilia A and 7.0% had hemophilia B. We found 11 patients (12.8%) were positive for B19V DNA and 8 were positive (9.3%) for PARV4 DNA. The prevalence of B19V was higher in middle-aged groups rather than younger people, whereas PARV4 infection was more common in younger patients (P <0.05).

Conclusion

There was a high prevalence of B19V and PARV4 infection in this high-risk group of patients with hemophilia. Due to the clinical significance of the B19 virus, imposing more precautionary measures for serum and blood products is recommended.

Parvovirus B19 infection in pregnancy-awareness and opportunities

Parvovirus B19 (B19V) is a human pathogenic virus associated with a wide range of clinical conditions. In pregnancy, B19V poses a potential hazard to the fetus as crossing the placental barrier and infecting erythroid progenitor cells in bone marrow and liver, it blocks fetal erythropoiesis leading to profound anemia, hydrops and/or fetal death. The virus is not regarded as a teratogen, however more scientific awareness is emerging on mechanisms and consequences of intrauterine infection and possible sequelae in the neonatal development. Reliable diagnostic procedures and fetal management strategies, including intrauterine transfusion, are established. In spite of being a recognized fetotropic agent possibly leading to fetal loss, testing for B19V is not routinely included in preconception or antenatal screenings, possibly delaying the management of B19V-complicated pregnancies. Continuous advances in B19V research will provide for better diagnostic methods and algorithms, as well as for the development of effective prophylactic interventions and novel therapeutic options.

Simultaneous detection and differentiation of human parvovirus B19 and human parvovirus 4 by an internally controlled multiplex quantitative real-time PCR

Human parvovirus B19 (B19V) and human parvovirus 4 (PARV4) are two parvoviruses known to infect humans and transmit through blood and plasma derived medicinal products (PDMPs). Inactivation of the two parvoviruses has proven to be difficult and nucleic acid testing (NAT) would be an efficient means to exclude viruses. In this study, an internally controlled multiplex quantitative real-time PCR (qPCR) assay for B19V and PARV4 simultaneous detection and quantification was established and evaluated. The optimized multiplex qPCR assay allowed for simultaneous detection of all of the genotypes (1-3) of B19V and PARV4, with equal limit of quantification (LOQ) of 5 copies/μL, rather than other blood-borne viruses. It had a wide dynamic range of reliable amplification linearity of at least 8 orders of magnitude. Low standard deviations (SD) of quantification cycle (Cq) values and low coefficients of variation (CV) of copy numbers for both B19V and PARV4 suggested a high level of repeatability and reproducibility for the multiplex qPCR assay. This multiplex qPCR assay can be served as a readily applicable approach to screen plasma units intended for further manufacturing into PDMPs to reduce the risk of parvoviruses infection by such products and may also be useful for the detection of B19V/PARV4 co-infection or co-existence.

Extinct type of human parvovirus B19 persists in tonsillar B cells

Parvovirus B19 (B19V) DNA persists lifelong in human tissues, but the cell type harbouring it remains unclear. We here explore B19V DNA distribution in B, T and monocyte cell lineages of recently excised tonsillar tissues from 77 individuals with an age range of 2–69 years. We show that B19V DNA is most frequent and abundant among B cells, and within them we find a B19V genotype that vanished from circulation >40 years ago. Since re-infection or re-activation are unlikely with this virus type, this finding supports the maintenance of pathogen-specific humoral immune responses as a consequence of B-cell long-term survival rather than continuous replenishment of the memory pool. Moreover, we demonstrate the mechanism of B19V internalization to be antibody dependent in two B-cell lines as well as in ex vivo isolated tonsillar B cells. This study provides direct evidence for a cell type accountable for B19V DNA tissue persistence.

The cell type that hosts parvovirus B19 (B19V) DNA lifelong is currently unknown. Here, the authors identify tonsillar B cells as a reservoir, detect an extinct B19V type in older adults, supporting a long-term association, and show that B19V uptake into B cells is antibody dependent.

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.

Parvovirus B19

Primary parvovirus B19 infection is an infrequent, but serious and treatable, cause of chronic anemia in immunocompromised hosts. Many compromised hosts have preexisting antibody to B19 and are not at risk. However, upon primary infection, some patients may be able to mount a sufficient immune response to terminate active parvovirus B19 infection of erythroid precursors. The most common consequence of B19 infection in the compromised host is pure red-cell aplasia, resulting in chronic or recurrent anemia with reticulocytopenia. Anemia persists until neutralizing antibody is either produced by the host or passively administered. Parvovirus B19 should be suspected in compromised hosts with unexplained or severe anemia and reticulocytopenia, or when bone-marrow examination shows either giant pronormoblasts or absence of red-cell precursors. Diagnosis is established by detection of B19 DNA in serum in the absence of IgG antibody to B19. In some cases, IgG antibody is detected but is not neutralizing. Anti-B19 IgM may or may not be present. Therapy includes any or all of the following: red-cell transfusion, adjustment in medications to restore or improve the patient’s immune system, and administration of intravenous immunoglobulin (IVIG). Following treatment, patients should be closely monitored, especially if immunosuppression is unchanged or increased. Should hematocrit trend downward and parvovirus DNA trend upward, the therapeutic options above should be revisited. In a few instances, monthly maintenance IVIG may be indicated. Caregivers should be aware that B19 variants, though rarely encountered, can be missed or under-quantitated by some real-time polymerase-chain reaction methods.

Bones hold the key to DNA virus history and epidemiology

DNA in human skeletal remains represents an important historical source of host genomic information and potentially of infecting viruses. However, little is known about viral persistence in bone. We searched ca. 70-year-old long bones of putative Finnish casualties from World War II for parvovirus B19 (B19V) DNA, and found a remarkable prevalence of 45%. The viral sequences were exclusively of genotypes 2 (n = 41), which disappeared from circulation in 1970´s, or genotype 3 (n = 2), which has never been reported in Northern Europe. Based on mitochondrial and Y-chromosome profiling, the two individuals carrying B19V genotype 3 were likely from the Soviet Red Army. The most recent common ancestor for all genotypes was estimated at early 1800s. This work demonstrates the forms of B19V that circulated in the first half of the 20^th century and provides the first evidence of the suitability of bone for exploration of DNA viruses.