Cross-sectional and longitudinal investigation of human herpesvirus 8 seroprevalence in HIV-1-infected individuals in Osaka, Japan.

Introduction: High human herpesvirus 8 (HHV-8) seroprevalence has been reported in men who have sex with men (MSM) and are infected with HIV-1. However, it is unclear when they become infected with HHV-8. Thus, we conducted cross-sectional and longitudinal investigations of HHV-8 seroprevalence in HIV-1-infected individuals in Osaka, Japan.

Patients And Methods: Plasma was collected from 121 individuals infected with HIV-1 and the anti-HHV-8 antibody titer was measured using an enzyme-linked immunosorbent assay with whole virus lysate. Subjects were classified into those with and without a past medical history of HHV-8-associated disease; the latter group was then classified into 3 subgroups based on the assumed route of HIV-1 infection: blood products, homosexual contact, and other routes. HHV-8 seroprevalence was compared among the groups and measured again approximately 3 years after the baseline measurement. The relationship between HHV-8 seropositivity and possible associated factors was also investigated.

Results: All 15 subjects with HHV-8-associated disease were seropositive, and all 11 subjects in the blood product group were seronegative. In the MSM group, 25 (30%) of 79 subjects were HHV-8 seropositive and, in the non-MSM group, 1 (6%) of 16 subjects was (p < 0.0001). In the longitudinal investigation, seroconversion was observed in 10 (19%) of 52 subjects in the MSM group who were seronegative at baseline. A correlation was observed between seroconversion and symptomatic syphilis (p = 0.0432).

Conclusions: HHV-8 seropositivity and seroconversion rates were high in HIV-1-infected MSM, suggesting that, currently, HHV-8 is an epidemic pathogen in this population.