Background: Reemergence of human herpesvirus 8 (HHV-8)-induced Kaposi sarcoma (KS) in people living with HIV (PLWH) despite antiretroviral therapy (ART) poses a clinical challenge because they already have favorable CD4 T-cell numbers and undetectable viral loads. We observed that clinical presentation in PLWH on ART resembled classic KS found in older HIV-uninfected patients and hypothesized that immunosenescence may thus play a role in occurrence of KS on ART. We compared viral and immune factors implicated in the development of KS in ART-treated PLWH (HIV KS) and HIV-uninfected classic KS patients (cKS), compared to controls without KS (HIV Control, cControls respectively).

Methods: Plasma, peripheral blood mononuclear cell, and skin tissues were obtained from 11 HIV KS and 11 cKS patients and 2 groups of age-matched controls.

Results: HIV KS participants were younger than cKS (aged 53 vs 75 years). HHV-8 genotypes did not differ between groups. Despite the younger age and a lower CD4/CD8 ratio, activated, exhausted, and senescent T-cell frequencies were similar between HIV KS and cKS. Anti-HHV-8 immunoglobulin G levels were higher and circulating HHV-8 DNA lower in HIV KS compared with cKS. Circulating platelet-derived growth factors AA-BB and granulocyte colony-stimulating factors were higher in HIV KS We observed similar levels of HHV-8 DNA and PD-1 expression in skin lesions from HIV KS and cKS patients.

Conclusions: Altogether, early immune senescence could be involved in the development of KS in ART-treated PLWH. Higher anti-HHV-8 immunoglobulin G levels could be linked with lower circulating viral load. Such insights should help developing therapeutical strategies to prevent development and treat KS in PLWH on ART.