Similar Immunological Profiles Between African Endemic and Human Immunodeficiency Virus Type 1-Associated Epidemic Kaposi Sarcoma (KS) Patients Reveal the Primary Role of KS-Associated Herpesvirus in KS Pathogenesis.

Background: Kaposi sarcoma (KS)-associated herpesvirus (KSHV) is etiologically linked to all KS forms, but mechanisms underlying KS development are unclear. The incidence of KS in human immunodeficiency virus type 1-infected (HIV-1+) individuals implicates immune dysregulation; however, the lack of characterization of KSHV immune responses in endemic KS makes the role of HIV-1 unclear. The study objective was to investigate the HIV-1 and KSHV roles in viral nucleic acid detection, antibody responses, and cytokine responses in polymerase chain reaction-confirmed epidemic KS and endemic KS patients and non-cancer controls from sub-Saharan Africa.

Methods: KSHV viral DNA (vDNA), total anti-KSHV antibody, KSHV neutralizing antibody (nAb), and cytokines were quantified.

Results: KSHV vDNA was detectable in tumors but variably in plasma and peripheral blood mononuclear cells. Consistent with elevated antibody-associated cytokines (interleukin [IL] 6, IL-5, and IL-10), nAb titers were higher in epidemic KS and endemic KS patients than in controls (P < .05). Despite HIV-1 coinfection in epidemic KS, nAb titers were similar between epidemic KS and endemic KS patients (P = 0.3).

Conclusions: Similarities in antibody and cytokine responses between epidemic and endemic KS patients suggest that KSHV drives KS pathogenesis, whereas HIV-1 exacerbates it.