Human Immunodeficiency Virus (HIV)-Negative Men Who Have Sex With Men Have Higher CD8+ T-Cell Counts and Lower CD4+/CD8+ T-Cell Ratios Compared With HIV-Negative Heterosexual Men

Background. We previously reported T-cell senescence to be similar in people with human immunodeficiency virus (PWH) with suppressed viremia (predominantly men who have sex with men [MSM]) and human immunodeficiency virus (HIV)-negative otherwise comparable controls but greater than in healthy blood donors. This led us to compare CD4(+) and CD8(+) T-cell counts and CD4(+)/CD8(+) ratios between HIV-negative MSM and men who only have sex with women (MSW) and relate observed differences in behavioral factors and infectious exposures, including cytomegalovirus (CMV) infection. Methods. In 368 HIV-negative MSM and 72 HIV-negative MSW, T lymphocyte phenotyping was performed 3 times biennially. Baseline CMV serology and sexually transmitted infection (STI) incidence and/or STI seroprevalence, sexual, and substance-use behavior data were collected during study visits. Results. Men who have sex with men, compared with MSW, had higher CD8(+) counts (551 vs 437 cells/mm(3), P < .001), similar CD4(+) counts (864 vs 880 cells/mm(3), P = .5), and lower CD4(+)/CD8(+) ratios (1.84 vs 2.47, P < .001). Differences were most pronounced for MSM with >10 recent sex partners and partly explained by higher CMV seroprevalence in MSM. Conclusions. These findings suggest that factors other than HIV may, in both PWH and certain HIV-negative MSM, contribute to a low CD4(+)/CD8(+) ratio. Whether this, like in PWH, contributes to comorbidity risk in HIV-negative MSM requires further study.

Automated summary

In this study, it was found that compared to men who only have sex with women, men who have sex with men have higher CD8(+) counts and lower CD4(+)/CD8(+) ratios, with these differences partly explained by higher CMV seroprevalence.