Cellular immune responses against natural human papillomavirus infections among men in Kisumu, Kenya.

Human papillomavirus (HPV) is associated with ano-genital and cervical cancer. Persistence of oncogenic HPV genotypes is a requirement for development and progression of malignancies. Although, >70% of women clear incident HPV infections, data on natural history and HPV immunology among men is limited. To evaluate cell-mediated immune responses to natural HPV infections among men, we assessed cytokine responses on PBMCs collected from men with persistent or cleared HPV. Men with HPV clearance and those with HPV persistence had increased odds (6-times and 3-times respectively) of mounting cytokine responses compared to HPV uninfected men. Th1 cytokines IFN-γ (5.1-fold) and IL-2 (4.2-fold) were significantly (p < 0.0001) upregulated among men with HPV clearance compared to HPV uninfected men. Among men with HPV clearance compared to those with persistent HPV infection, only IFN-γ (2.4–fold) and IL-2 (3.0–fold) were significantly (p < 0.0001) upregulated. Th1 cell-mediated cytokine response was associated with natural HPV clearance in men.