Background: Mechanisms underlying Kaposi sarcoma (KS) development are unclear. The high incidence of KS in HIV-1+ individuals implicates immune dysregulation in epidemic KS (EpKS) development. In African endemic KS (EnKS), the immune response is uncharacterized. Aim: The aim was to assess a comparative quantification between newly diagnosed Tanzanian EpKS and EnKS patients, and asymptomatic controls. We also report the first comparison of KSHV NAb prevalence and titer between EpKS and EnKS patients. Methods: To compare innate and adaptive immune responses, we recruited histologically confirmed Tanzanian EpKS and EnKS patients, as well as noncancer controls. After differential detection of KSHV nucleic acids in tissues, neutralizing antibody (NAb), levels of cytokines/chemokines, and T-cell differentiation subsets were quantified. The Mann-Whitney U-test was used to assess median differences between groups. All tests were 2-tailed and P-values < 0.05 were considered significant. Results: A total of 180 patients have been recruited in this study. In addition, a comparable 25 EpKS and 10 EnKS as well as 10 noncancer controls were recruited for this study. KSHV was significantly more frequently detected in EpKS patients than in EnKS. While all EpKS, and some EnKS patients mounted NAb responses, the EpKS patients had higher prevalence and titer of NAb compared with EnKS patients ( P = 0.001). Levels of the cytokines IP-10 and IL-10 were higher in EpKS vs EnKS patients ( P = 0.006 and P = 0.005 respectively), whereas, IL-4 was lower in EpKS vs EnKS patients ( P = 0.004). The levels of all 14 cytokines/chemokines measured were comparable between EnKS patients and HIV− controls ( P < .05 ). The distribution of CD4+ and CD8+ T-cells was similar between EpKS and EnKS such as naive and effector T-cells were depleted while central memory T-cells were elevated in both KS forms. Conclusion: The detection of similar abnormalities in T-cell differentiation subsets in both EpKS and EnKS as compared with controls, suggests that KSHV-induced T-cell dysfunction plays a major role in the disease, and that HIV-1 coinfection is only exacerbating and accelerating KSHV pathogenesis and KS development.
Compartmentalized T cell profile in the lungs of patients with HIV-1-associated pulmonary Kaposi sarcoma
