Investigation of atypical serological profiles for Epstein-Barr virus (EBV).

BACKGROUND: Commercial immunoassays that detect IgG and IgM directed toward VCA and IgG EBNA are used in combination to assess EBV immune status. However, this strategy does not always confirm/exclude recent/past EBV infection or absence of immunity. OBJECTIVES: The aim of our study was to perform complementary investigations on samples with atypical EBV serological profiles, in order to identify the clinical situation they correspond to. STUDY DESIGN: EBV serology was performed using EBV VCA IgM/IgG and EBNA IgG LXL® DiaSorin assay. Complementary investigations included ELISA IgM VCA, immunoblots, CMV IgM/IgG and CMV IgG avidity, and EBV PCR. RESULTS: In our study, 12810 EBV serological results were analyzed, and 3580 atypical profiles were detected (28 %). Among these latter, isolated VCA IgG represented 42.9 %, the three positive markers accounted for 29.1 %, isolated EBNA IgG represented 18.5 %, isolated VCA IgM accounted for 6.4 % and positive VCA IgM & positive EBNA IgG represented 3.1 %. VCA IgG detected alone were specific in 100 % cases and EBNA IgG detected alone were specific in 91.7 % cases. VCA IgM detected alone were false positive or due to a cross reaction with CMV in 52.8 % cases. The pattern positive VCA IgM and positive EBNA IgG correspond to a false positive in VCA IgM, EBNA IgG or both in 83.4 % cases. Positive EBV VCA IgM/IgG and EBNA IgG were unreliable to detect active EBV infection in 66.7 % cases. DISCUSSION: Atypical EBV serological profiles may correspond to several clinical situations and complementary investigations allow to determine the immune status in more than 98.5 % cases.

Evaluation of two commercial diagnostic methods for HHV-8 viral load assessment.

Objectives: Human herpesvirus-8 (HHV-8) can cause Kaposi's sarcoma or B lymphoproliferative disorders such as multicentric Castleman disease. Patient follow-up is based on assessing the HHV-8 viral load, which is usually achieved using real-time polymerase chain reaction (PCR). The HHV-8 Premix r-gene kit (BioMérieux) was used by some laboratories in the past, but BioMérieux ceased the production and distribution of this kit in 2021-2022. Other kits need to be tested so that they can be used for diagnostic purposes. Here we evaluated two commercial kits: HHV8 ELITe MGB Kit (ELITech) and Quanty HHV-8 (Clonit) and compared them with the HHV-8 Premix r-gene kit. Methods: We used whole blood samples that had previously been tested with the HHV-8 Premix r-gene kit for diagnostic purposes. Overall, 46 samples (37 HHV-8-positive and 9 HHV-8-negative) were tested with the ELITe MGB Kit and 37 (29 HHV-8-positive and 8 HHV-8-negative) with the Quanty HHV-8 kit. The different methods were compared using Bland-Altman and Passing-Bablok tests with Analyse-it software. Results: Qualitative results were concordant except for one HHV-8 low-positive sample that was found to be negative by the ELITe MGB Kit. The quantitative results were also concordant; both kits showed mean differences of 0.58 log10 copies/ml and 0.73 log10 copies/ml, respectively, compared to the Premix r-gene kit. Conclusions: Both the methods tested produced acceptable results and could be used for diagnostic purposes. It should be remembered that there is no international standard for HHV-8 quantification and that patients should always be followed using the same method.

Performance of the QIAprep& Viral RNA UM Kit assay (Qiagen), an automatable method for RT-qPCR detection of SARS-CoV-2 without RNA extraction.

We evaluated the performance of the QIAprep& Viral RNA UM Kit (Qiagen) for SARS-CoV-2 detection. It displayed specificity and sensitivity required for SARS-CoV-2 RNA detection from swab transport media without RNA extraction. This method identifies accurately patients at risk of transmission while saving time and cost of extraction.

Emergence of SARS-CoV-2 resistance mutations in a patient who received anti-SARS-COV2 spike protein monoclonal antibodies: a case report.

BACKGROUND: To manage severe or potentially severe cases of CoronaVirus Disease 2019 (COVID-19), therapeutic monoclonal antibodies targeting Spike protein of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) have been designed. It has been noted in vitro that upon exposure to these treatments, mutations could be selected. CASE PRESENTATION: We here report the case of an immunosuppressed patient infected with a B.1.1.7 variant, who received a combination of monoclonal antibodies, and subsequently selected mutations K417N, E484K and Q493R on Spike protein of SARS-CoV-2. CONCLUSIONS: Our case raises the importance of monitoring SARS-CoV-2 mutations in patients receiving monoclonal antibodies and having persistent excretion of the virus, in order to offer optimal management of their infection, and strengthen prevention measures to avoid subsequent transmission of these selected variants.

Variability in molecular characteristics of Hepatitis E virus quasispecies could modify viral surface properties and transmission.

Hepatitis E virus (HEV) usually causes self-limited liver diseases but can also result in severe cases. Genotypes 1 (G1) and 2 circulate in developing countries are human-restricted and waterborne, while zoonotic G3 and G4 circulating in industrialized countries preferentially infect human through consumption of contaminated meat. Our aims were to identify amino acid patterns in HEV variants that could be involved in pathogenicity or in transmission modes, related to their impact on antigenicity and viral surface hydrophobicity. HEV sequences from human (n = 37) and environmental origins (wild boar [n = 3], pig slaughterhouse effluent [n = 6] and urban wastewater [n = 2]) were collected for the characterization of quasispecies using ultra-deep sequencing (ORF2/ORF3 overlap). Predictive and functional assays were carried out to investigate viral particle antigenicity and hydrophobicity. Most quasispecies showed a major variant while a mixture was observed in urban wastewater and in one chronically infected patient. Amino acid signatures were identified, as a rabbit-linked HEV pattern in two infected patients, or the S68L (ORF2) / H81C (ORF3) residue mostly identified in wild boars. By comparison with environmental strains, molecular patterns less likely represented in humans were identified. Patterns impacting viral hydrophobicity and/or antigenicity were also observed, and the higher hydrophobicity of HEV naked particles compared with the enveloped forms was demonstrated. HEV variants isolated from human and environment present molecular patterns that could impact their surface properties as well as their transmission. These molecular patterns may concern only one minor variant of a quasispecies and could emerge under selective pressure.

Interpretation of single target positivity among SARS-CoV-2 RT-PCR result tests.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently emerged and is responsible for coronavirus disease 19 (COVID-19). Diagnostic tests have been developed, mainly based on reverse-transcriptase PCR (RT-PCR). Most RT-PCR assays target at least two SARS-CoV-2 genes. In some cases, only one target gene is detected; the interpretation of such cases remains unclear. Objectives: Our objective was to analyse one target positive (OPT) RT-PCR results, using two RT-PCR assays: the Xpert® Xpress SARS-CoV-2 (Cepheid diagnosis, "Cepheid") and the Cobas® 6800 SARS-CoV-2 Test (Roche Molecular Diagnostics, "Roche"). Methods: All SARS-CoV-2 RT-PCR results performed on respiratory samples with the Roche or the Cepheid tests, from 23rd March to 6th August 2020 were collected. A patient with an OPT result was classified as "probable COVID-19" if they met at least one of the three following criteria: (i) history of a two gene-positive SARS-CoV-2 RT-PCR result, (ii) anti-SARS-CoV-2 antibody (IgG) detection or (iii) compatible chest computed tomography scan (CT-scan). Results: A total of 18,630 and 1189 SARS-CoV-2 RT-PCR tests were performed with the Roche and Cepheid tests, respectively. Among the positive SARS-CoV-2 RT-PCR, 293 samples - corresponding to 264 patients - were OPT (11% of the positive samples). Of these patients, 180 (68%) had at least one of the three criteria listed above and were classified as probable COVID-19. Conclusions: Sixty-eight percent of the patients with an OPT result were classified as probable COVID-19 and are probably at a late stage of infection. Serology and imaging can be helpful to confirm diagnosis.

Stable prevalence of transmitted drug resistance mutations and increased circulation of non-B subtypes in antiretroviral-naive chronically HIV-infected patients in 2015/2016 in France.

OBJECTIVES: We estimated the prevalence of transmitted-drug-resistance-associated mutations (TDRAMs) in antiretroviral-naive chronically HIV-1-infected patients. PATIENTS AND METHODS: TDRAMs were sought in samples from 660 diagnosed HIV-1-infected individuals in 2015/2016 in 33 HIV clinical centres. Weighted analyses, considering the number of patients followed in each centre, were used to derive representative estimates of the percentage of individuals with TDRAMs. Results were compared with those of the 2010/2011 survey (n = 661) using the same methodology. RESULTS: At inclusion, median CD4 cell counts and plasma HIV-1 RNA were 394 and 350/mm3 (P = 0.056) and 4.6 and 4.6 log10 copies/mL (P = 0.360) in the 2010/2011 survey and the 2015/2016 survey, respectively. The frequency of non-B subtypes increased from 42.9% in 2010/2011 to 54.8% in 2015/2016 (P < 0.001), including 23.4% and 30.6% of CRF02_AG (P = 0.004). The prevalence of virus with protease or reverse-transcriptase TDRAMs was 9.0% (95% CI = 6.8-11.2) in 2010/2011 and 10.8% (95% CI = 8.4-13.2) in 2015/2016 (P = 0.269). No significant increase was observed in integrase inhibitor TDRAMs (6.7% versus 9.2%, P = 0.146). Multivariable analysis showed that men infected with the B subtype were the group with the highest risk of being infected with a resistant virus compared with others (adjusted OR = 2.2, 95% CI = 1.3-3.9). CONCLUSIONS: In France in 2015/2016, the overall prevalence of TDRAMs was 10.8% and stable compared with 9.0% in the 2010/2011 survey. Non-B subtypes dramatically increased after 2010. Men infected with B subtype were the group with the highest risk of being infected with a resistant virus, highlighting the need to re-emphasize safe sex messages.

The variability of hepatitis B envelope is associated with HBs antigen persistence in either chronic or acute HBV genotype A infection.

BACKGROUND: More than 240 million people are chronically infected by hepatitis B virus (HBV) worldwide. Envelope proteins play a crucial role in viral cellular entry and immune recognition. The loss of HBs antigen (HBsAg) correlated with a good clinical prognosis is rarely achieved with or without treatment (3-16%). OBJECTIVES: HBV envelope variability was investigated according to HBsAg persistence. STUDY DESIGN: The cohort consisted of 15 HBV genotype A-infected patients divided into "resolvers", with HBsAg clearance, and "non-resolvers", with HBsAg persistence and in subgroups: acute (n=5, AHBV) or chronic infection (n=4, CHBV) and HBV/HIV coinfection (n=6, CHBV/HIV). HBV S and preS sequences were studied by direct and ultra-deep sequencing. Amino acid sequences were analyzed with bioinformatics for predicted antigenicity. RESULTS: In S gene, the complexity was lower in AHBV than in chronic-infected patients (p=0.046). Major mutations, detected using direct sequencing, were more frequent in AHBV developing chronicity (p=0.01) than in AHBV resolvers. In the Major Hydrophilic Region, more frequent mutations were observed in non-resolvers versus resolvers (p=0.047) and non-resolvers tended to have more haplotypes with a reduced predicted antigenicity (p=0.07). Most of the mutations in preS/S region were found rather in epitopic than in non-epitopic areas (p=0.025). Interestingly, the mutation sY161F found in 3/8 non-resolvers was associated with a decrease in predicted antigenicity (28%; AnTheProt). CONCLUSIONS: HBsAg persistence was correlated with mutations and deletions in areas playing a key role in immune recognition. These data suggest that variability in HBV envelope could favor immune escape in various clinical settings of HBV genotype A-infected patients.

Impact of deletions and mutations in Hepatitis B virus envelope proteins on serological profile and clinical evolution.

The Hepatitis B virus (HBV) envelope glycoproteins are essential for viral entry into the hepatocyte and are also targets for host immune response. The study of these proteins could allow us to highlight molecular hot points influencing HBV fitness, which would subsequently modify the clinical evolution of the disease, both under anti-viral therapy or without treatment. The present short communication underlines the importance of the high variability in HBV envelope proteins, in regard with the literature and in our hands, for HBV-infected patients either on anti-HBV treatment or not. We report mutations in antigenic areas of S protein, i.e. CD8+/CD4+ T-cell epitopes and B-cell epitopes in the major hydrophilic region (MHR), such as sI126N and sG145R possibly involved in the rare coexisting Hepatitis B surface Antigen (HBsAg)/anti-HBs serological pattern. We mostly report serial mutations in preS region including preS1 deletion (aa 1-6, 31-71, 38-73, 72-104) and preS2 deletion (aa132-141) in patients with various clinical evolutions. Some of these viral envelope mutations, due to immune selection pressure, may result in a worsening of the hepatic disease.

Biochemical analysis of ascites fluid as an aid to etiological diagnosis: a series of 100 cases of nonimmune fetal ascites.

OBJECTIVE: The aim of this study is to analyze the contribution of biochemistry and cytology of fetal ascites fluid to the etiological diagnosis of ascites after ultrasonographic scan, maternal blood sampling, and fetal karyotyping. METHOD: This is a retrospective study of 100 consecutive cases of nonimmune fetal ascites in which ascites fluid was sampled. All women underwent referral ultrasound scan and fetal karyotyping. All cases of fetal ascites were studied by biochemistry (total protein, ß2 -microglobulin, IgM, gamma-glutamyl transpeptidase, aspartate aminotransferase, aminopeptidase M, and intestinal isoform of alkaline phosphatase) and cytology (lymphocyte count and vacuolated cells). RESULTS: The etiology of ascites was diagnosed at ultrasound scan in only 50% of cases. We observed significantly (P < 0.001) low levels of total protein in ascites of urinary origin, high levels of digestive enzymes in ascites of digestive origin, and high ß2 -microglobulin in infectious ascites. Vacuolated cells were observed in all ten storage metabolic diseases. CONCLUSION: Sampling of fetal ascites fluid for biochemical and cytological examination provides important additional information. We propose a two-step management: (1) detailed ultrasound scan examination, maternal blood analysis, and fetal karyotyping and (2) biochemical and cytological analyses. On the basis of such an approach, 63% and 96% of etiologies would have been identified in our series after the first and second steps, respectively. © 2014 John Wiley & Sons, Ltd.