Clinical characteristics of HIV-1-infected patients with high levels of plasma interferon-γ: a multicenter observational study.

BACKGROUND: Circulating interferon-γ (IFN-γ) concentration may be sustained at a high level regardless of the initiation of antiretroviral therapy (ART) in some patients with HIV-1 infection. In the present study, we examined the clinical characteristics of HIV-1-infected patients with high levels of plasma IFN-γ. METHODS: The study subjects were patients infected with HIV-1 who were either naïve to ART with CD4+ cell count > 200 cells/µL (n = 12), or had achieved viral suppression after ART for over a year (n = 188). The levels of plasma IFN-γ and interleukin-6 (IL-6) were measured by the enzyme-linked immunosorbent assay. Patients were divided into high IFN-γ and low IFN-γ groups based on a cutoff level of 5 pg/mL. RESULTS: The high IFN-γ group included 41 patients (21%). Compared to the patients on ART with low IFN-γ levels, those on ART in the high IFN-γ group were more likely to be younger than 50 years of age (P = 0.0051) and less likely to have dyslipidemia (P = 0.0476) or to be on a protease inhibitor (P = 0.0449). There was no significant difference between groups in the median increase of CD4+ cell counts from the initiation of ART for up to 3 years. However, after 4 years, the increase in CD4+ cell counts was significantly lower in the high IFN-γ group compared with that in the low IFN-γ group. There were no such significant differences between patients with low and high (> 2 pg/mL) levels of plasma IL-6. CONCLUSION: We concluded that HIV-1-infected patients with high levels of circulating IFN-γ did not have a higher rate of comorbidities related to immune activation. However, they exhibited lower CD4+ cell count recovery after 4 years of being on ART. This deficit could be a consequence of persistent immune activation.

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.