Philippe Colson | Search PubMed

PubMed2025

Five-Year (2017-2022) Evolutionary Dynamics of Human Coronavirus HKU1 in Southern France With Emergence of Viruses Harboring Spike H512R Substitution.

HCoV-HKU1 diversity and evolution were scarcely studied. We performed next-generation sequencing (NGS) and analysis of HCoV-HKU1 genomes over 5 years. NGS used Illumina technology on NovaSeq 6000 following whole genome PCR amplification by an in-house set of primers designed using Gemi and PrimalScheme. Genome assembly and analyses used CLC Genomics, Mafft, BioEdit, Nextstrain, Nextclade, MEGA, and iTol bioinformatic tools. Spike molecular modeling and dynamics simulations used Molegro Molecular Viewer and Hyperchem programs. Twenty-eight PCR systems allowed obtaining 158 HCoV-HKU1 genomes including 69 and 89 of genotypes A and B, respectively. Both genotypes co-circulated during the study period but one predominated each year. A total of 1683 amino acid substitutions including 80 in ≥ 10 genomes were detected in genotype A relatively to a 2004 reference. H512R in spike, first detected in 2009 and reported as involved in antibody neutralization, was found in all genotype A, almost always with V387I and K478N, and was predicted here to significantly improve cellular TMPRSS2 protein binding. Also, 1802 amino acid substitutions including 64 in ≥ 10 genomes were detected in genotype B relatively to a 2005 reference. This study substantially expands the global set of HCoV-HKU1 genomes. Genomics with protein structural analyses contributed to our understanding of HCoV-HKU1 evolution.

Humans↗

PubMed2025

Fatal Hepatitis B Reactivation in Absence of Antibody to Hepatitis B Core Antigen in a Lymphoma Patient.

Reactivations of hepatitis B virus (HBV) infection in severely immunocompromised patients with serological profiles of past hepatitis B are non-exceptional and potentially severe or fatal events. The preventive and pre-emptive detection of this serological status is compromised in the absence of antibodies to hepatitis B core antigen (anti-HBc), observed in a very small number of cases of HBV infection. Here, we describe the case of a patient with a serological profile indicating a HBV vaccination although the patient did not report previous vaccination, following lymphoma and chemotherapy including rituximab. This patient presented HBV reactivation with appearance of hepatitis B surface antigen (HBsAg) but without appearance of anti-HBc, suggesting the absence of detectable anti-HBc in this patient at the stage of past infection. Next-generation sequencing provided the complete HBV genome, showing the presence of a mutation in HBsAg associated with immune escape but without the detection of mutations in the core gene previously described as significantly associated with the absence of anti-HBc. Nonetheless, W28* pre-core mutation was found, which was reported to enhance replication capacity in case of weak immune responses and suspected to promote HBV reactivation in association with immune escape mutations. Overall, this case highlights that negativity of anti-HBc cannot definitely rule out past HBV infection and the risk of HBV reactivation in immunocompromised patients in the context of treatment of hemopathies, and that it is difficult to assess such a risk and to prevent or monitor HBV reactivation in patients with past HBV infection but no detectable anti-HBc.

Female↗