Abstract
Polyfunctional T-cells have been related with control of human chronic viral infections such as HIV. Contrasting findings have been reported in tuberculosis (TB) and HIV-TB co-infection.
Aims: To evaluate in HIV-infected patients naïve to antiretroviral treatment (ART) the latent tuberculosis infection (LTBI) prevalence ad to analyze the cytokine profile and memory status of TB antigen-response.
Methods: prospective enrollment of ART-naïve HIV-infected patients without active TB (74) or with active TB (HIV-TB) (12). PBMC-stimulation with TB antigens (RD1 proteins and peptides), cytometric analysis of cytokines (IFNγ, IL2, TNFα) and phenotype (CD45RA, CCR7).
Results:Among the HIV-infected patients, 15 (20%) resulted QFT-IT positive and defined as LTBI. HIV-TB group showed higher frequency of polyfunctional CD4+ T-cells in response to RD1 antigens than HIV-LTBI (p=0.007). Among the CD8+ T-cell, the frequency of monofunctional cells was significantly higher than polyfunctional cells in HIV-TB and HIV-LTBI (p=0.03, p=0.03). Analizing the cytokine profile, IFNγ+ TNFα+ CD4+ T-cells associated with HIV-TB (p=0.01) whereas IL2+ TNFα+ associated with HIV-LTBI (p= 0.009). The CD4+ T-cell-response showed an effector-memory (EM) status in HIV-TB (p=0.007) and an effector-memory terminally differentiated (E) phenotype in HIV-LTBI (p=0.03). The CD8+ T-cell-response showed an E status in HIV-LTBI (p=0.02).
Conclusion: This study highlights the plasticity of the response to TB antigens in ART-naïve HIV-infected patients, with a polyfunctional CD4+ T-cell-response associated with active TB and characterized by a high proportion of IFNγ+ TNFα+ and EM status.
- © 2014 ERS