Incomplete B-cell reconstitution in ART-treated people living with HIV is associated with EBV-linked lymphoma...

Despite the widespread use of antiretroviral therapy (ART), people living with HIV continue to exhibit persistent immune alterations. Among the most affected cell populations are B lymphocytes, which show disruptions in differentiation, class-switch recombination, and the development of immunological memory. However, the relationship between these abnormalities, Epstein-Barr virus (EBV) coinfection, and clinical outcomes across different stages of HIV disease remains poorly understood.

We analyzed 272 patients living with HIV from Hospital Universitario San Ignacio (Bogotá, Colombia), divided in four groups: clinical stage (S1, S2, S3 and lymphoma), clinical categories: AIDS-defining diseases, non-AIDS-defining diseases, and coinfections (CI), time on ART (<1 year, >1 year); and EBV coinfection. B lymphocyte subpopulations and immunoglobulin isotypes were quantified (next-generation flow cytometry). Cytokines (multiplex assays) and EBV viral load (quantitative PCR) were measured.

HIV progression was observed, associated with B cell compartment remodeling, characterized by depletion of naïve and memory B cells (smIgA1-2 and smIgG1-4) and an increase in immature/transitional cells and alterations in smIgM with isotype switching. These variations correlated negatively with clinical stage (ρ up to -0·43). The cytokine profile showed a persistent inflammatory signature (MIP-1β, G-CSF, FLT-3L, and IL-3). EBV coinfection intensified this phenotype, being associated with elevated levels of IL-6, IL-10, IL-15, TNF-α, and sCD40L, and with greater loss of memory cell subpopulations. Patients with AIDS-defining diseases and lymphomas exhibited the most profound alteration. Even after prolonged ART (>1 year), B cell reconstitution remained incomplete and biased toward immature phenotypes.

This study shows that recovery of the B cell compartment under ART is incomplete and functionally unbalanced. Humoral memory loss, bias toward immature phenotypes, and persistent inflammation create a state of dysregulation that is exacerbated by EBV coinfection, especially in advanced clinical stages. These immunological defects provide a basis for the pathogenesis of non-AIDS-defining diseases and Epstein-Barr-associated lymphomas. Our findings support the need to integrate advanced immunological assessments, including standardized flow cytometry, as a complement to CD4+ count and viral load, in order to more accurately characterize immune competence and anticipate clinical risks in people living with HIV.