Characterization of erythrovirus B19 genomes isolated in liver tissues from patients with fulminant hepatitis and biliary atresia who underwent liver transplantation

Beyond arboviruses: A multicenter study to evaluate differential diagnosis of rash diseases and acute febrile illness cases in Rio de Janeiro, Brazil

Introduction

A wide variety of viruses can cause rash diseases (RDs) or acute febrile illness (AFIs) in children, adolescents and adults; however, approximately 19% of RD cases and 40% of AFI cases remain without a defined etiology. Parvovirus B19 (B19V) and herpesvirus infection can also cause RD and/or AFI, and in some risk groups, these infections can become persistent (or latent) and may require hospital treatment. Since these infections do not have mandatory reporting, they can be hidden by other diseases, such as those caused by arboviruses (e.g., dengue virus). In this context, the aim of this study was to pursue the differential laboratory diagnoses of B19V and herpesvirus infections in patients with RD and AFI, without a defined etiology, seen in hospitals and/or reference centers for infectious diseases in Rio de Janeiro.

Methods

A total of 114 participants were enrolled in the study, including 54 children and 60 adults. B19V infection was assessed by real-time PCR (qPCR) and ELISA (anti-B19V IgM and IgG). EBV was assessed through qPCR, and betaherpesviruses (HCMV, HHV-6 and HHV-7) were assessed through multiplex qPCR. Sociodemographic and clinical data were obtained from the medical record data of these participants.

Results

The median age of children with RD was 2 years (interquartile range (IQR): 5), and 55.6% were male. Among adults with AFI, the median age was 38 years (IQR: 21), and 56.7% were female. Regarding RD patients, viral prevalence (and load) were 5.5%(104IU/mL), 3.4%(104IU/mL), 5.5%(104IU/mL) and 11.1%(105IU/mL) for B19V, EBV, HCMV and HHV-6 infection, respectively, and in AFI patients they were 6.6%(105IU/mL), 1.6%(103IU/mL), 3.3%(104IU/mL) for B19V, HCMV and HHV-6, respectively. HHV-7 was not detected in RD or AFI patients.

Conclusion

These results suggest the importance of including B19V and herpesviruses in the differential laboratory diagnoses for patients with RD and AFI, not only for epidemiological purposes but also for the proper management of the patient.

Persistence of Parvovirus B19 in liver from transplanted patients with acute liver failure

Aim: In this study, we investigated the presence of B19V in liver tissues from patients with acute liver failure (ALF) and evaluated the viral activity in infected liver. Methods: Serum and liver samples from 30 patients who underwent liver transplantation for ALF were investigated for B19V infection by real-time PCR, serological tests and examination of B19V mRNA (transcript) expression in the liver. Results: The serum and liver samples from seven patients were B19V DNA positive (10³-10⁵ copies/ml). Most of them presented detectable anti-B19V IgG, indicating persistent infection. B19V mRNA was detected in all patients, demonstrating intra-hepatic replication. Conclusion: B19V infection of the liver during the course of non-A-E ALF suggested a role of B19V, which produced the worst outcome in co-infected patients and in patients with cryptogenic ALF, in liver damage.

High prevalence of parvovirus B19 infection in patients with chronic kidney disease under hemodialysis: A multicenter study

OBJECTIVES

Parvovirus B19 (B19V) infection is commonly acute and self-limited, but in chronic kidney disease (CKD) patients under dialysis treatment, this infection could increase susceptibility to acute and chronic anemia. The aim of this study was to evaluate the frequency and risk of B19V infection among Brazilian CKD patients under dialysis.

METHODS

A study was conducted among 221 CKD patients and a control group of 142 blood donors. B19V infection was evaluated in serum samples by real-time PCR, and ELISA (anti-B19V IgM and IgG).

RESULTS

B19V DNA was detected in 65% (145/221) of CKD patients, which was significantly higher (p < 0.001) than in the blood donors (6.3%). Simultaneous detection of B19V IgG and viremia was shown in 40.3% of CKD patients, which was indicative of persistent B19V infection. CKD patients showed an increased risk of developing B19V infection (OR = 28.1, CI = 13.5-58.5, p = 0.001).

CONCLUSIONS

Despite an absence of clinical signs of B19V infection, these data highlight the importance of B19V infection in this high-risk population, since a persistent B19V infection could become clinically significant after renal transplant. Moreover, the persistent viremia should be considered as a potential risk, mainly because of the contamination of dialysis equipment.

Genetic diversity of primate erythroparvovirus 1 between 2009 and 2016: First report from Turkey

Parvovirus B19 (B19V) is one of the major viral pathogens that infect only human beings. This study's aim is to determine which genotypes of the B19V are present in Turkey and to perform a phylogenetic analysis. Twelve B19V positive serum specimens already diagnosed by real-time PCR amplifying a partial region of the NS gene were included in this study. The serological markers and viral loads of the patients were determined. The positivity of the specimens was confirmed using semi-nested PCR. To determine the genotype of the B19V, PCR-positive amplicons were sequenced directly and compared to GenBank-referenced strain sequences. The phylogeny of the 12 sequenced strains was constructed with the maximum likelihood method. Two different genotypes of B19V were identified in our study. Genotype 2 of B19V was not detected. All of the B19V genotype 1 sequences were clustered in the common genotype 1a cluster (10/12, 83.3%). The average quantification of the B19V strains was determined to be 2.1 × 10⁷ IU/ml. The nucleotide identities between our strains and those isolated in other countries were 85.8%-99.5%. Compared to the Turkish strains identified in our study, at the nucleotide level, the closest strains based on genotypes 3b and 1a were the Germany and Netherlands isolates respectively. This study was the first to provide the genotypic variation of B19V circulated in Turkey. We determined two distinct subtypes of B19V, including subtype 3b and 1a. While the genotype 1 is common all over the world, genotype 3 has begun to spread outside of Africa.

Parvovirus B19 Infection in a Fatal Case of Acute Liver Failure

B19V has been proposed as an etiologic agent for hepatitis, mainly in children, but this is a rare clinical occurrence. In this article, we report a case of non-A-E acute liver failure in an immunocompetent child with B19 infection. The clinical findings of severe anemia and pancytopenia combined with the detection of anti-B19 Immunoglobulin G (IgG), B19 DNA and B19 mRNA in liver indicate a persistent infection and suggest a diagnosis of parvovirus B19-associated acute liver failure.

Incidence and progression of Parvovirus B19 infection and molecular changes in circulating B19V strains in children with haematological malignancy: A follow up study

The present study was planned to estimate the incidence of human Parvovirus B19 infection and understand its progression in children suffering with hematological malignancy. The circulating B19V genotypes and viral mutations occurring in strains of B19V over one-year period were also studied. Children with malignancies were enrolled consecutively and were followed up for one-year period. Serum sample was collected at the time of enrolment and each follow up visit and was tested for anti B19V IgG and IgM as well as for B19V DNA. At least one B19V DNA positive sample from each patient was processed for sequencing. For patients positive for B19V DNA >1 time and at least 6 months apart, last positive sample from the same patient was also sequenced to study the nucleotide change over time. We have found very high incidence of B19V infection (100%) in the study population. All the patients tested positive for at least one B19V infection parameter (either antibodies or DNA) at least once, over one year of follow up. Cumulative percent positivity of anti B19V IgG, anti B19V IgM and B19V DNA was 85.3%, 45.2% and 72.1% respectively. Genotype 3b was reported, with occasional nucleotide change over one year period. DNA clearance was delayed in spite of appearance of IgG antibodies. Appearance of IgM class of antibodies was either delayed or absent. To conclude, children with haematological malignancies have high incidence of B19V infection with late and short lived serological response and persistence of DNA for long duration.

Surgical outcome and etiologic heterogeneity of infants with biliary atresia who received Kasai operation less than 60 days after birth: A retrospective study

This study aimed to analyze the impact of etiologic heterogeneity and operation age on prognosis of infants with biliary atresia (BA) who received Kasai operation prior to 60 days of age.From 2004 to 2010, 158 infants received Kasai operation before turning 60 days old. According to Davenport 2012 classifications, 4 groups of BA were defined: cystic BA, syndrome BA, and associated malformation, cytomegalovirus (CMV)-associated BA, and isolated BA. Native (autologous) liver survival rates and incidence of cholangitis 2 years after operation, as well as jaundice clearance rates 3 months after operation, were recorded.Although infants who received the operation between 51 and 60 days of age had a better jaundice clearance 3 months after operation and lower incidence of cholangitis as compared with those under 40 or between 41 and 50 days of age, there was no significant difference in survival rates. Among types of BA, infants with cystic BA had the best prognosis. In the syndrome BA and associated malformations group, as well as CMV-associated group, infants who received the operation early (<40 days of age) had a worse outcome as compared with those who received the operation between 41 and 50 days or 51 and 60 days of age.Both clinical etiologic heterogeneity and operation age may influence BA prognosis.

Cynomolgus monkeys (Macaca fascicularis) experimentally infected with B19V and hepatitis A virus: no evidence of the co-infection as a cause of acute liver failure

This study was conducted to analyse the course and the outcome of the liver disease in the co-infected animals in order to evaluate a possible synergic effect of human parvovirus B19 (B19V) and hepatitis A virus (HAV) co-infection. Nine adult cynomolgus monkeys were inoculated with serum obtained from a fatal case of B19V infection and/or a faecal suspension of acute HAV. The presence of specific antibodies to HAV and B19V, liver enzyme levels, viraemia, haematological changes, and necroinflammatory liver lesions were used for monitoring the infections. Seroconversion was confirmed in all infected groups. A similar pattern of B19V infection to human disease was observed, which was characterised by high and persistent viraemia in association with reticulocytopenia and mild to moderate anaemia during the period of investigation (59 days). Additionally, the intranuclear inclusion bodies were observed in pro-erythroblast cell from an infected cynomolgus and B19V Ag in hepatocytes. The erythroid hypoplasia and decrease in lymphocyte counts were more evident in the co-infected group. The present results demonstrated, for the first time, the susceptibility of cynomolgus to B19V infection, but it did not show a worsening of liver histopathology in the co-infected group.

Prevalence of human parvovirus B19, bocavirus, and PARV4 in blood samples from the general population of China and lack of a correlation between parvovirus and hepatitis B co-infection

Few comprehensive studies have investigated viraemia caused by human parvoviruses (HPAVs) in China. A total of 1626 of blood samples were collected from non-HBV and HBV infected Chinese subjects (adults, N = 1279; children, N = 347) from south-western and south-eastern China. DNA from three HPAVs was detected in blood samples using PCR-based assays. The epidemiological profiles and association with HBV co-infection were also analysed. Of the 1626 blood samples tested, 138 (8.49%) were found to exhibit HPAV viraemia, including 3.51% with B19, 3.75% with HBoV and 2.52% with PARV4. The presence of B19 DNA in both child and adult, as well as that of PARV4 DNA in adult,from the south-western region was significantly higher than that from the south-eastern region (P = 0.006 for B19 in children; P = 0.026 for B19 in adults; and P = 0.014 for PARV4 in adult).However, the frequency of HBoV DNA in adults from the south-western region was significantly lower than that observed in adults from the south-eastern region (P = 0.001). Furthermore, HBoV was more prevalence in male (4.9%) than in female (1.4%) individuals. In addition, no significant correlation between HBV and HPAV co-infection was found using serum samples from Chinese adults. In conclusions,the molecular prevalence of three HPAVs in blood samples exhibited variation among different populations depending on area, age and gender; No association between HPAV and HBV infection in adults was found. Our data provide a basis for improving blood safety and preventing HPAV infection in China.

Human parvovirus B19 induced apoptotic bodies contain altered self-antigens that are phagocytosed by antigen presenting cells

Human parvovirus B19 (B19V) from the erythrovirus genus is known to be a pathogenic virus in humans. Prevalence of B19V infection has been reported worldwide in all seasons, with a high incidence in the spring. B19V is responsible for erythema infectiosum (fifth disease) commonly seen in children. Its other clinical presentations include arthralgia, arthritis, transient aplastic crisis, chronic anemia, congenital anemia, and hydrops fetalis. In addition, B19V infection has been reported to trigger autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. However, the mechanisms of B19V participation in autoimmunity are not fully understood. B19V induced chronic disease and persistent infection suggests B19V can serve as a model for viral host interactions and the role of viruses in the pathogenesis of autoimmune diseases. Here we investigate the involvement of B19V in the breakdown of immune tolerance. Previously, we demonstrated that the non-structural protein 1 (NS 1) of B19V induces apoptosis in non-permissive cells lines and that this protein can cleave host DNA as well as form NS1-DNA adducts. Here we provide evidence that through programmed cell death, apoptotic bodies (ApoBods) are generated by B19V NS1 expression in a non-permissive cell line. Characterization of purified ApoBods identified potential self-antigens within them. In particular, signature self-antigens such as Smith, ApoH, DNA, histone H4 and phosphatidylserine associated with autoimmunity were present in these ApoBods. In addition, when purified ApoBods were introduced to differentiated macrophages, recognition, engulfment and uptake occurred. This suggests that B19V can produce a source of self-antigens for immune cell processing. The results support our hypothesis that B19V NS1-DNA adducts, and nucleosomal and lysosomal antigens present in ApoBods created in non-permissive cell lines, are a source of self-antigens.

Interclade recombination in porcine parvovirus strains

A detailed analysis of the Ns1/Vp1Vp2 genome region of the porcine parvovirus (PPV) strains isolated from vaccinated animals was performed. We found many inconsistencies in the phylogenetic trees of these viral isolates, such as low statistical support and strains with long branches in the phylogenetic trees. Thus, we used distance-based and phylogenetic methods to distinguish de facto recombinants from spurious recombination signals. We found a mosaic virus in which the Ns1 gene was acquired from one PPV clade and the Vp1Vp2 gene was acquired from a distinct phylogenetic clade. We also described the interclade mosaic structure of the Vp1Vp2 gene of a reference strain. If recombination is an adaptive mechanism over the course of PPV evolution, we would likely observe increasing numbers of chimeric strains over time. However, when the PPV sequences isolated from 1964 to 2011 were analysed, only two chimeric strains were detected. Thus, PPV recombination is an independent event, resulting from close contact between animals housed in high-density conditions.

Parvovirus B19 genotype specific amino acid substitution in NS1 reduces the protein's cytotoxicity in culture

A clinical association between idiopathic liver disease and parvovirus B19 infection has been observed. Fulminant liver failure, not associated with other liver-tropic viruses, has been attributed to B19 in numerous reports, suggesting a possible role for B19 components in the extensive hepatocyte cytotoxicity observed in this condition. A recent report by Abe and colleagues (Int J Med Sci. 2007;4:105-9) demonstrated a link between persistent parvovirus B19 genotype I and III infection and fulminant liver failure. The genetic analysis of isolates obtained from these patients demonstrated a conservation of key amino acids in the nonstructural protein 1 (NS1) of the disease-associated genotypes. In this report we examine a conserved residue identified by Abe and colleagues and show that substitution of isoleucine 181 for methionine, as occurs in B19 genotype II, results in the reduction of B19 NS1-induced cytotoxicity of liver cells. Our results support the hypothesis that in the setting of persistent B19 infection, direct B19 NS1-induced cytotoxicity may play a role in idiopathic fulminant liver failure.

Coinfection of parvovirus b19 with other hepatitis viruses leading to fulminant hepatitis of unfavorable outcome in children

Fulminant hepatic failure (FHF) associated with parvovirus B19 (B19) infection has a favorable prognosis in children. However, there is no data available to predict outcome in cases of FHF associated with hepatotropic virus coinfection. Clinical characteristics of 3 pediatric groups with FHF were compared and it was observed that B19 coinfection with other viruses adds to the severity of the disease and increases the probability of a fatal outcome.

HepG2 hepatocellular carcinoma cells are a non-permissive system for B19 virus infection

Parvovirus B19 has been associated with liver dysfunction and has been considered a potential aetiological agent of fulminant hepatitis and hepatitis-associated aplastic anaemia. The possible effects of B19 virus infection on the liver have been investigated using HepG2 hepatocellular carcinoma cells as a model system, but the reported results are inconsistent. To investigate this relationship further, this study followed the course of B19 virus infection of HepG2 cells in terms of viral DNA, RNA and protein production by quantitative PCR, RT-PCR and immunofluorescence assays. The data showed that B19 virus is able to bind and possibly enter HepG2 cells, but that viral genome replication or transcription is not supported and that viral proteins are not produced. As far as HepG2 cells can be considered a representative model system, any possible pathogenic role of B19 virus on the liver cannot be ascribed to infection or to a direct cytopathic effect on hepatocytes.

Detection of hepatitis A virus RNA from children patients with acute and fulminant hepatitis of unknown etiology in Vietnam: Genomic characterization of Vietnamese HAV strain

BACKGROUND

Although it is thought that Vietnam is a high endemic region of hepatitis A virus (HAV) infection, there is no report on genomic characterization of HAV spread in Vietnam. The purpose of the present paper was therefore to identify various virus infections from 33 children with acute or fulminant hepatitis of unknown etiology admitted to Children's Hospital No.1 in Ho Chi Minh City, Vietnam.

METHODS

Anti-HAV IgM and IgG were assayed by ELISA. Viral RNA and DNA were determined by PCR method. HAV genes isolated by PCR were sequenced and characterized by phylogenetic analysis.

RESULTS

Anti-HAV IgM was detected in 18 of 26 acute hepatitis (69.2%) and one of seven (14.3%) fulminant hepatitis patients. Furthermore, HAV-RNA in serum was identified in five of 26 acute (19.2%) and two of seven (28.6%) fulminant hepatitis patients, respectively, on nested reverse transcription-polymerase chain reaction. Among the seven HAV-RNA-positive patients tested, two (28.6%) were negative for anti-HAV IgM. We also obtained seven isolates containing the HAV genome with the viral protein 1 (VP1) region sequence. All Vietnamese HAV isolates formed a cluster and belonged to genotype IA according to phylogenetic analysis based on the short sequences of VP1-2A junction region.

CONCLUSION

HAV is an important agent with regard to fulminant hepatitis among children in Vietnam. To the authors' knowledge this is the first report on Vietnamese HAV strain confirmed on sequencing.