External Validation of LCR1-LCR2, a Multivariable Hepatocellular Carcinoma Risk Calculator, in a Multiethnic Cohort of Patients With Chronic Hepatitis B.

Background And Aims: The liver cancer risk test (LCR1-LCR2) is a multianalyte blood test combining proteins involved in liver cell repair (apolipoprotein A1, haptoglobin), hepatocellular carcinoma (HCC) risk factors (gender, age, gamma glutamyl transpeptidase), a marker of fibrosis (alpha2-macroglobulin), and alpha-fetoprotein, a specific marker of HCC. The aim was to externally validate LCR1-LCR2 in hepatitis B.

Methods: Preincluded patients were from the Hepather cohort, a multicenter, multiethnic prospective study in 6071 patients.

Validation of the Performance of A1HPV6, a Triage Blood Test for the Early Diagnosis and Prognosis of SARS-CoV-2 Infection.

Background And Aims: Apolipoprotein A1 (A1) and haptoglobin (HP) serum levels are associated with the spread and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We have constructed and validated a multivariable risk calculator (A1HPV6) integrating A1, HP, alpha2-macroglobulin, and gamma glutamyl transferase to improve the performances of virological biomarkers.

Methods: In a prospective observational study of hospitalized patients with nonsevere SARS-CoV-2 infection, A1HPV6 was constructed in 127 patients and validated in 116.

Accuracy assessment of total or IgG Immunoglobulin to hepatitis A virus tests around immunity threshold.

Background: Anti-hepatitis A virus (HAV) antibody titers at 20 IU/L are assumed to correlate with protection against HAV challenge.

Methods: We examined the accuracy and precision of currently in use immunoassays for total or anti-HAV IgG determination, by repeated testing of dilutions of the international anti-HAV standard, within a 10-50 IU/mL concentration range.

Results And Conclusion: Eight immunoassays were evaluated.

External validation of LCR1-LCR2, a multivariable HCC risk calculator, in patients with chronic HCV.

Background & Aims: The Liver Cancer Risk test algorithm (LCR1-LCR2) is a multianalyte blood test combining proteins involved in liver cell repair (apolipoprotein-A1 and haptoglobin), known hepatocellular carcinoma (HCC) risk factors (sex, age, and gamma-glutamyl transferase), a marker of fibrosis (alpha2-macroglobulin) and alpha-fetoprotein (AFP), a specific marker of HCC. The aim was to externally validate the LCR1-LCR2 in patients with chronic HCV (CHC) treated or not with antivirals.

Methods: Pre-included patients were from the Hepather cohort, a multicentre prospective study in adult patients with CHC in France.

Performance of 30 commercial SARS-CoV-2 serology assays in testing symptomatic COVID-19 patients.

We report evaluation of 30 assays' (17 rapid tests (RDTs) and 13 automated/manual ELISA/CLIA assay (IAs)) clinical performances with 2594 sera collected from symptomatic patients with positive SARS-CoV-2 rRT-PCR on a respiratory sample, and 1996 pre-epidemic serum samples expected to be negative. Only 4 RDT and 3 IAs fitted both specificity (> 98%) and sensitivity (> 90%) criteria according to French recommendations. Serology may offer valuable information during COVID-19 pandemic, but inconsistent performances observed among the 30 commercial assays evaluated, which underlines the importance of independent evaluation before clinical implementation.

Performance of serum apolipoprotein-A1 as a sentinel of Covid-19.

Background: Since 1920, a decrease in serum cholesterol has been identified as a marker of severe pneumonia. We have assessed the performance of serum apolipoprotein-A1, the main transporter of HDL-cholesterol, to identify the early spread of coronavirus disease 2019 (Covid-19) in the general population and its diagnostic performance for the Covid-19.

Methods: We compared the daily mean serum apolipoprotein-A1 during the first 34 weeks of 2020 in a population that is routinely followed for a risk of liver fibrosis risk in the USA (212,297 serum) and in France (20,652 serum) in relation to a local increase in confirmed cases, and in comparison to the same period in 2019 (266,976 and 28,452 serum, respectively).

High clustering of acute HCV infections and high rate of associated STIs among Parisian HIV-positive male patients.

Background: Increasing incidence of hepatitis C virus (HCV) infection in human immunodeficiency virus (HIV)-positive men having sex with men (MSM) has been described in recent years. Phylogenetic analyses of acute HCV infections were undertaken to characterize the dynamics during the epidemic in Paris, and associated sexually transmitted infections (STIs) were evaluated.

Methods: Sanger sequencing of polymerase gene was performed.

Net emergence of substitutions at position 28 in NS5A of hepatitis C virus genotype 4 in patients failing direct-acting antivirals detected by next-generation sequencing.

More data on resistance of HCV genotype (GT) 3 and 4 to direct-acting antivirals (DAAs) are still needed. Here we investigated the presence of resistance-associated substitutions (RASs) pre- and post-treatment and their emergence under DAAs in HCV GT3- and GT4-infected patients failing DAA regimens by next-generation sequencing (NGS). Sanger sequencing and NGS were performed on NS5B and NS5A in plasma samples prior to and post treatment of 13 patients.

Chronic hepatitis E in a heart transplant patient: sofosbuvir and ribavirin regimen not fully effective.

Hepatitis E virus (HEV) can induce chronic infections in the case of immunosuppression, which are sometimes not cured with ribavirin. Furthermore, sofosbuvir is a highly potent inhibitor of HCV polymerase and was shown to inhibit HEV genotype-3 replication in vitro. We report here the outcome of sofosbuvir/ribavirin therapy on a chronic HEV infection in a heart transplant recipient non-responder to ribavirin.

Multicenter comparison of the new Cobas 6800 system with Cobas Ampliprep/Cobas TaqMan and Abbott RealTime for the quantification of HIV, HBV and HCV viral load.

Background: The new Roche Cobas 6800 platform (C6800) has been recently introduced for viral load (VL) measurement.

Objectives: Comparing C6800 to Cobas Ampliprep/Cobas TaqMan v2.0 (CAP/CTM) for the quantification of HIV, HBV and HCV viremia, and to the Abbott RealTime assay (ABB) for HCV quantification.

Hepatitis E infection in patients with severe alcoholic hepatitis: is there a place for systematic screening?

Background: One study has suggested that markers of acute hepatitis E virus (HEV) infection are present in 3.6% of patients with severe alcoholic hepatitis (AH). However, validation of these preliminary results is lacking, as well as the impact of HEV infection on the 6-month survival.

Coexistence of circulating HBsAg and anti-HBs antibodies in chronic hepatitis B carriers is not a simple analytical artifact and does not influence HBsAg quantification.

Background: Presence at the same time of HBsAg and anti-HBs antibodies (HBsAg/Ab) is an entity sometimes encountered in chronic hepatitis B (CHB) carriers.

Objectives: This study was designed to characterize such serological profiles and to assess the reliability of serological marker quantification by three commercially available assays in this setting.

Study Design: Among 2578 CHB identified patients, 129 (5%) had an HBsAg/Ab profile as determined by Abbott Architect.

Performance of the DiaSorin LIAISON(®) anti-HBs II for the detection of hepatitis B surface antibodies: comparison with the Abbott Architect anti-HBs assay.

Background: Detection of hepatitis B virus (HBV) surface antibodies (anti-HBs) is required in order to evaluate the response to hepatitis B vaccination and to optimize post-exposure monitoring. The widespread use of vaccines has highlighted the need for accurate and consistent quantification, yielding comparable quantitative results.

Objectives: This study assessed the adequacy of DiaSorin LIAISON(®) anti-HBs II assay in detecting anti-HBs antibodies and determined the correlation with Abbott Architect anti-HBs quantification.

Impact of hepatitis B virus genotypes and surface antigen variants on the performance of HBV real time PCR quantification.

Quantitative PCR assays used to monitor hepatitis B virus (HBV) load differ in their ability to detect different HBV variants. This study evaluated the performance of the Abbott RT PCR assay for quantitating DNA from different HBV genotypes and from HBV variants bearing HBsAg gene mutations. The study was performed on a randomly-selected sample with a viral load >6logIU/mL for each genotype and on 25 HBsAg variants.

A two adenine insertion polymorphism in the 3' untranslated region of factor VII gene is associated with peripheral arterial disease but not with venous thrombosis. Results of case-control studies.

Polymorphic variants of genes encoding blood coagulation proteins have been extensively studied as risk factors for venous or arterial thrombosis A variation in the 3' untranslated region (UTR) involved in the post-transcriptional regulation of factor VII (FVII) gene has been recently identified, a two adenine insertion/deletion at nucleotide 11293. In this study, we investigated its effect on the risk of thrombosis in the frame of two case-control studies, including patients suffering from peripheral arterial disease (PAD) or venous thromboembolic (VTE) disease. The 3'UTR FVII gene polymorphism was investigated i) in 181 patients who had symptomatic atherosclerotic disease of the lower limbs, ii) in 178 patients who had had at least one episode of objectively diagnosed deep venous thrombosis and iii) in controls matched for age and sex.

Recurrence of a Phe31Ser mutation in the Gla domain of blood coagulation factor X, in unrelated Algerian families: a founder effect?

The presence of gene lesions in blood coagulation factor X (FX) was investigated in eight FX-deficient patients with severe bleeding symptoms, originating from five unrelated Algerian families (FX coagulant activity <1%, FX antigen ranging from 2% to 16%). A missense mutation (p.Phe31Ser) in the Gla domain was found in homozygous form for all patients but one, who is a compound heterozygote for the Phe31Ser mutation and for a non-sense mutation, Tyr130Term in EGF-2 domain.

The natural mutation by deletion of Lys9 in the thrombin A-chain affects the pKa value of catalytic residues, the overall enzyme's stability and conformational transitions linked to Na+ binding.

The catalytic competence of the natural thrombin mutant with deletion of the Lys9 residue in the A-chain (deltaK9) was found to be severely impaired, most likely due to modification of the 60-loop conformation and catalytic triad geometry, as supported by long molecular dynamics (MD) simulations in explicit water solvent. In this study, the pH dependence of the catalytic activity and binding of the low-molecular mass inhibitor N-alpha-(2-naphthylsulfonyl-glycyl)-4-amidinophenylalanine-piperidine (alpha-NAPAP) to the wild-type (WT) and deltaK9 thrombin forms were investigated, along with their overall structural stabilities and conformational properties. Two ionizable groups were found to similarly affect the activity of both thrombins.

The P303T mutation in the human factor VII (FVII) gene alters the conformational state of the enzyme and causes a severe functional deficiency.

We report the results of in vitro expression and biochemical characterization of the naturally occurring type II mutation Pro303Thr (P303T) in the factor VII (FVII) gene. Recombinant activated mutated FVII (FVIIa303T), compared with the activated wild-type FVII (FVIIaWT), showed reduced amidase activity toward synthetic substrates, especially when the observed reduced binding affinity for human soluble tissue factor (TF) (K(d) from 4.4 nmol/l for FVIIaWT to 17.

A natural prothrombin mutant reveals an unexpected influence of A-chain structure on the activity of human alpha-thrombin.

We have recently identified in two unrelated patients with bleeding tendency a homozygous mutation causing a deletion of one of the two contiguous Lys(9)/Lys(10) residues in the A-chain of alpha-thrombin (DeltaK9). We used in vitro expression analysis to clarify the role of the deletion of Lys(9) or Lys(10) in the thrombin function. The k(cat)/K(m) value of the hydrolysis by DeltaK9 of the synthetic substrate Phe-Pip-Arg-p-nitroanilide (where Pip represents l-pipecolyl) and fibrinopeptide A was 18- and 60-fold lower, respectively, compared with wild type (WT).