Impact of antiretroviral and tuberculosis therapies on CD4+ and CD8+ HIV/M. tuberculosis-specific T-cell in co-infected subjects.

BACKGROUND: Human Immunodeficiency Virus (HIV) infection is a risk factor for tuberculosis (TB). Antiretroviral therapy (ART) changed HIV clinical management but it is still unclear how pre-existing HIV/Mycobacterium tuberculosis (Mtb)-specific CD4+ and CD8+ T-cells are restored. AIM: to evaluate the impact of ART and TB therapies on the functional and phenotypic profile of Mtb-specific antigen-response of CD4+ and CD8+ T-cells in prospectively enrolled HIV-TB co-infected patients. METHODS: ART-naïve HIV-infected patients, with or without active TB or latent TB infection (LTBI), were enrolled before and after starting ART and TB therapies. Peripheral blood mononuclear cells (PBMC) were stimulated overnight with Mtb and HIV antigens (GAG). Cytokine expression and phenotype profile were evaluated by flow cytometry. Cytomegalovirus (CMV) and staphylococcal enterotoxin B (SEB) were also used. RESULTS: The median of absolute number of CD4+ T-cells increased after ART and TB therapies in all groups analyzed, while the median of absolute number of CD8+ T-cells decreases in HIV and HIV-LTBI groups. Treatments significantly increased the frequency of Mtb-specific CD4+ T-cells in the HIV-LTBI (p = 0.015) with a rise of the central memory compartment. The magnitude of the CD4+ T-cell response to HIV-GAG significantly increased in active TB (p = 0.03), whereas the magnitude of CMV-specific CD4+ T-cell response decreased in all the groups. Similarly, the treatments increased the number of Mtb-specific CD8+ responders in both HIV-LTBI and HIV-TB groups, whereas the phenotype distribution was dependent on the antigens used and on the stage of infection/disease. CONCLUSIONS: After therapies the median of absolute number and the proportion of CD4+ T-cells increased in all groups whereas the median of absolute count and proportion of CD8+ T-cells decreased in the HIV and HIV-LTBI subjects. Interestingly, an increased frequency of CD4+ T-cell response to RD1 proteins in HIV-LTBI subjects was found. These results contribute to a better understanding of the effect of ART and TB therapies on the modulation of Mtb-specific CD4+ and CD8+ T-cells subsets.

Immune characterization of the HBHA-specific response in Mycobacterium tuberculosis-infected patients with or without HIV infection.

INTRODUCTION: RD1-based Interferon-γ Release Assays (IGRAs) cannot distinguish latent from active tuberculosis (TB) disease. Conversely, a positive response to heparin-binding haemagglutinin (HBHA)-based IGRAs, among TB-infected subjects, correlates with Mycobacterium tuberculosis (Mtb) containment and low risk of TB progression. The aim of this study was to characterize HBHA-immune responses in HIV-infected and uninfected subjects with active TB or latent TB infection (LTBI). METHODS: 49 subjects were prospectively enrolled: 22 HIV-uninfected (13 TB, 9 LTBI) and 27 HIV-infected (12 HIV-TB, 15 HIV-LTBI). Whole blood and peripheral blood mononuclear cells were stimulated with HBHA and RD1 antigens. Interferon (IFN)γ release was evaluated by ELISA whereas cytokine profile [IFNγ, tumor necrosis (TNF)α, interleukin (IL)2] and phenotype (CD45RA, CCR7) by flow cytometry. RESULTS: Among LTBI individuals, HBHA stimulation induced IFNγ release in all the HIV-uninfected, while, only 4/15 HIV-infected responded. Within the active TB, only 5/13 HIV-uninfected and 1/12 HIV-TB patients responded. Interestingly, by cytometry we showed that CD4+ T-cells response to HBHA was significantly impaired in the HIV-infected subjects with TB or LTBI compared to the HIV-uninfected subjects. The phenotype of HBHA-specific CD4 T-cells showed a predominantly central memory (CM) and effector memory (EM) phenotype without differences among the groups. Differently, HBHA-specific CD8+ T-cells, showed mainly a CM and naïve phenotype in LTBI group while TB, HIV-LTBI and HIV-TB groups were characterized by EM or terminally differentiated phenotypes. Interestingly, differently than what observed for RD1, the cytokine profile of HBHA-specific T-cells evaluated by cytometry showed that the CD4+ T-cells were mostly monofunctional. Conversely, CD8-specific T-cells were mostly monofunctional for both HBHA and RD1 stimulations. CONCLUSIONS: These results characterize the impact of HIV infection in CD4- and CD8-specific response to HBHA in both LTBI and TB patients. HIV infection impairs the CD4 response to HBHA and likely this may lead to an impairment of TB control.

Polyfunctional T-cells and effector memory phenotype are associated with active TB in HIV-infected patients.

OBJECTIVES: Polyfunctional T-cells associate with chronic viral infection control while their involvement in tuberculosis (TB) is unclear. We evaluated TB-specific polyfunctional T-cell response and memory status in antiretroviral treatment (ART)-naïve HIV-infected patients from a low TB-endemic country. METHODS: We prospectively enrolled HIV-infected patients, 12 with active TB (HIV-TB) and 15 with latent tuberculosis infection (LTBI). Peripheral blood cells were stimulated with TB antigens (RD1 proteins/peptides), HIV antigens, cytomegalovirus (CMV) and staphylococcal enterotoxin B (SEB) and analyzed by cytometry. RESULTS: The HIV-TB showed a higher frequency of polyfunctional CD4(+) T-cells in response to RD1 antigens than HIV-LTBI (p = 0.007). Among the CD8(+) T-cells, both groups showed a significantly higher frequency of RD1-specific monofunctional cells than polyfunctional cells (p = 0.03). Analyzing the cytokine profile, IFNγ(+) TNFα(+) CD4(+) T-cells associated with HIV-TB (p ≤ 0.02) whereas IL2(+) TNFα(+) associated with HIV-LTBI (p = 0.009). CD4(+) T-cell response presented an effector-memory status in HIV-TB (p = 0.007) and an effector-memory terminally-differentiated phenotype in HIV-LTBI (p = 0.03). CD8(+) T-cell response presented an effector status in HIV-LTBI (p = 0.02). No significant cytokine profile pattern associated with responses to the other stimuli tested. CONCLUSIONS: In HIV-infection, polyfunctional CD4(+) T-cell-response associates with active TB, characterized by a high proportion of IFNγ(+) TNFα(+) and an effector-memory phenotype.

The potential impact of routine testing of individuals with HIV indicator diseases in order to prevent late HIV diagnosis.

BACKGROUND: The aim of our work was to evaluate the potential impact of the European policy of testing for HIV all individuals presenting with an indicator disease, to prevent late diagnosis of HIV. We report on a retrospective analysis among individuals diagnosed with HIV to assess whether a history of certain diseases prior to HIV diagnosis was associated with the chance of presenting late for care, and to estimate the proportion of individuals presenting late who could have been diagnosed earlier if tested when the indicator disease was diagnosed. METHODS: We studied a large cohort of individuals newly diagnosed with HIV infection in 13 counselling and testing sites in the Lazio Region, Italy (01/01/2004-30/04/2009). Considered indicator diseases were: viral hepatitis infection (HBV/HCV), sexually transmitted infections, seborrhoeic dermatitis and tuberculosis. Logistic regression analysis was performed to estimate association of occurrence of at least one indicator disease with late HIV diagnosis. RESULTS: In our analysis, the prevalence of late HIV diagnosis was 51.3% (890/1735). Individuals reporting at least one indicator disease before HIV diagnosis (29% of the study population) had a lower risk of late diagnosis (OR = 0.7; 95%CI: 0.5-0.8) compared to those who did not report a previous indicator disease. 52/890 (5.8%) late presenters were probably already infected at the time the indicator disease was diagnosed, a median of 22.6 months before HIV diagnosis. CONCLUSIONS: Our data suggest that testing for HIV following diagnosis of an indicator disease significantly decreases the probability of late HIV diagnosis. Moreover, for 5.5% of late HIV presenters, diagnosis could have been anticipated if they had been tested when an HIV indicator disease was diagnosed.However, this strategy for enhancing early HIV diagnosis needs to be complemented by client-centred interventions that aim to increase awareness in people who do not perceive themselves as being at risk for HIV.

IFNγ/TNFα specific-cells and effector memory phenotype associate with active tuberculosis.

OBJECTIVES: Controversial results were reported on the role of polyfunctional T-cells in tuberculosis (TB). Our aim was to simultaneously characterize the Mycobacterium tuberculosis (Mtb)-specific immune response as cytokine production and memory phenotype by flow cytometry after in vitro stimulation with region of difference 1 ("RD1") recombinant proteins (ESAT-6 and CFP-10) in patients at different TB stage in a low TB endemic country. To assess the specificity of these findings, we evaluated the response to cytomegalovirus (CMV), an unrelated antigen. METHODS: We enrolled subjects with active TB, cured TB, latent TB infection (LTBI). Cytokine and phenotype profiles of T-cells from whole blood stimulated with "RD1" proteins and CMV were characterized by multi-parametric flow cytometry. RESULTS: Bifunctional IFNγ(+) TNFα(+) CD4(+) T-cells and effector memory phenotype significantly associated with active TB compared to the LTBI group (p = 0.008, at least p ≤ 0.009 respectively) whereas "RD1"-T-cell response in cured TB and LTBI was characterized by a central memory phenotype (at least p ≤ 0.013 and p ≤ 0.004 respectively vs active TB). In contrast, response to CMV antigen was not associated with a TB-specific status. CONCLUSION: We identified qualitative associations between Mtb-specific T-cell and TB status in terms of functional capacity and memory status. These immune correlates may be helpful to trace natural history of TB.

Neurocognitive performance and quality of life in patients with HIV infection.

We examined the relationship of HIV-related cognitive impairment and health-related quality of life (QoL). Subjects were administered measures of cognitive function (a battery of 17 neuropsychological tests) and of QoL (the MOS-HIV questionnaire). Study measures also included comprehensive clinical and neurological evaluation, laboratory testing, and brain imaging studies in patients with impaired neuropsychological evaluation. One-hundred and eleven subjects were examined. Cognitively impaired patients (33.3%) reported poorer QoL scores in all domains (p < 0.05): physical health summary score (PHS) (44.6 vs. 49.9), mental health summary score (MHS) (37.7 vs. 44.4), pain (67.6 vs. 79.4), physical functioning (75.9 vs. 87.7), role functioning (32.4 vs. 41.5), social functioning (70.3 vs. 83.5), mental health (48.2 vs. 61.0), energy (53.1 vs. 63.0), health distress (60.8 vs. 75.5), cognitive functioning (CF) (60.5 vs. 71.8), general health perceptions (29.2 vs. 43.4), and QoL (36.5 vs. 47.0). The number of altered neuropsychological tests correlated significantly with MHS (p < 0.001), PHS (p < 0.03), CF (p < 0.02), and QoL (p < 0.02) scores. A correlation between seven of seven neuropsychological measures exploring speed of mental processing, three of four exploring mental flexibility, four of six exploring memory, and two of two exploring fine motor functioning and MHS, PHS, CF, or QoL scores was also found. Poor performance on the Digit Symbol test was most strongly associated with poor MHS (OR 1.04, 95% CI 1.01-1.08, p < 0.009) and PHS (OR 1.04, 95% CI 1.01-1.08, p < 0.01) scores, controlling for CD4 count, previous AIDS diagnosis, receiving HAART, and drug abuse. Cognitive impairment is associated with poor QoL. People with more severe cognitive impairment have the highest probability of having a poor QoL. Cognitive impairment in any cognitive domain explored in our battery is also associated with poor QoL. Poor performance on the Digit Symbol Test is the strongest predictor of poor QoL.