ANTIRETROVIRAL therapy (ART) reduces accelerated biological ageing in people with HIV by nearly 4 years, a major Swiss study presented at ESCMID Global 2026 on 20th April has found.
The Plasma Proteomic Ageing Clock
In the landmark study, researchers developed a plasma proteomic ageing clock (PAC) that estimates biological age, reflecting physiology over chronology, using patterns across hundreds of blood proteins.
The PAC was trained on 941 plasma samples from people with HIV receiving successful antiretroviral therapy and subsequently evaluated in 80 participants, who collectively contributed 294 longitudinal samples across viraemic pre-ART infection and suppressive post-ART phases.
It was then applied to participants in the Swiss HIV Cohort Study.
Biological Age During HIV Infection
During untreated HIV infections, the PAC estimated that people’s biological age was accelerated by a median of 10 years.
After an average 1.55 years of ART, researchers observed a significant mean reduction of 3.7 years in proteomic age.
Proteomic age continued to move closer to chronological age with longer ART exposure, suggesting ongoing biological recovery with sustained treatment.
Barry Ryan, lead author, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, said: “This research demonstrates the importance of early start and optimal adherence to ART.
“We’re extremely fortunate to have a unique group from the Swiss HIV Cohort Study who had samples collected for up to eight years before they started ART.
“With this group, we have measured the effect of untreated HIV infection and successful ART on telomere shortening, epigenetic ageing and now proteomic ageing.
“In each case we have shown that uncontrolled HIV infection is linked to faster ageing and that ART significantly slows this.”
Implications for HIV Treatment
Importantly, the reversal of proteomic age acceleration after ART was not significantly associated with CD4+ or CD8+ T-cell count recovery, suggesting that the reversal reflects broader inflammatory and innate immune remodelling rather than T-cell reconstitution alone.
Researchers called for external validation of the PAC in more diverse global populations and for proteome-wide feature attribution studies, to pinpoint the specific pathways driving HIV-related ageing biology.
Ryan added: “Our findings support the current consensus for starting ART promptly after HIV diagnosis.”
Reference
Ryan B et al. A plasma proteomic aging clock reflects reversal of accelerated aging in people with HIV under antiretroviral therapy. 2026. Oral presentation. ESCMID Global 2026, 17-21 April, 2026.
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