MI2025 – Nguyen Thi Thu Hong

Title:
Antibody and T-cell Responses in Mpox Patients with Advanced HIV

Abstract:
In people with advanced HIV, mpox is associated with poor outcome. However, there has been no study assessing the immune response to monkeypox virus (MPXV) in this vulnerable group.

This work describes a viable methodology to move away from animal-derived antibodies in lateral flow immunoassays to sequence-defined, recombinant binders.
We enrolled PCR-confirmed mpox patients admitted to a tertiary referral hospital in Ho Chi Minh City, Vietnam, September 2022-May 2024. We collected clinical data and laboratory findings alongside longitudinal blood samples at enrolment, discharge, and 3 and 6 months post enrolment. T-cell responses against MPXV-CD4-P peptides were assessed using IFN-γ ELISpot and Intracellular Cytokines Staining (ICS) assays. IgG responses to MPXV E8 and A27 protein were measured using Luminex assay. Patients were divided into cases (advanced HIV, CD4+ <200 cells/µL), and controls (HIV-negative or HIV-positive with CD4+ ≥ 200 cells/µL).

A total of 32 mpox patients, aged 20-54 years, median: 32, were enrolled. 24 (75%) were men who have sex with men. None were vaccinated for mpox or had a tecovirimat prescription. HIV infection was documented in 25 (78%), including six with advanced HIV (CD4+ < 200 cells/ µL). Compared with the controls, mpox patients with advanced HIV had long hospital stay (days, median (range): 29 (17-59) vs 13 (6 - 16)), and high mortality (4/6, 67% vs. 0/26). In samples collected at enrolment, T-cell and IgG responses to MPXV were documented in 2/6 patients of the case group as compared to 25/26 (96.2%) of the controls, with both CD4+ and CD8+ T cells contributing to IFN-γ and TNF-α production. During follow up, both antibody and T-cell responses in the controls gradually declined but remained detectable up to 6 months. No follow-up samples available for analysis in advanced-HIV group.

Mpox patients with advanced HIV had poor immune response and extremely high mortality, emphasizing they need timely initiation of appropriate therapy.

Biography:
Hong joined the OUCRU team in 2015 and received her Master’s degree in Genetics in the same year. Her research focuses on applying next-generation sequencing (NGS)-based metagenomics pipelines for the detection and whole-genome sequencing of pathogens responsible for brain infections and hand, foot, and mouth disease in clinical samples. Since 2020, she has been actively involved in SARS-CoV-2 research, studying viral dynamics and immune responses in Vietnamese populations. Her work has contributed to a better understanding of the replicative potential of SARS-CoV-2 throughout the course of infection, informed outbreak response strategies, and explored viral evolution, importation, and circulation within Vietnam. She has also assessed T cell responses to SARS-CoV-2 and related sarbecoviruses with zoonotic potential. Currently, her research focuses primarily on T cell and antibody responses to Mpox and H5N1 viruses.