Inflammation and microbial translocation measured prior to combination antiretroviral therapy (cART) and long-term probability of clinical progression in people living with HIV.

BACKGROUND: Despite the effectiveness of cART, people living with HIV still experience an increased risk of serious non-AIDS events, as compared to the HIV negative population. Whether pre-cART microbial translocation (MT) and systemic inflammation might predict morbidity/mortality during suppressive cART, independently of other known risk factors, is still unclear. Thus, we aimed to investigate the role of pre-cART inflammation and MT as predictors of clinical progression in HIV+ patients enrolled in the Icona Foundation Study Cohort. METHODS: We included Icona patients with ≥2 vials of plasma stored within 6 months before cART initiation and at least one CD4 count after therapy available. Circulating biomarker: LPS, sCD14, EndoCab, hs-CRP. Kaplan-Meier curves and Cox regression models were used. We defined the endpoint of clinical progression as the occurrence of a new AIDS-defining condition, severe non-AIDS condition (SNAEs) or death whichever occurred first. Follow-up accrued from the data of starting cART and was censored at the time of last available clinical visit. Biomarkers were evaluated as both binary (above/below median) and continuous variables (logescale). RESULTS: We studied 486 patients with 125 clinical events: 39 (31%) AIDS, 66 (53%) SNAEs and 20 (16%) deaths. Among the analyzed MT and pro-inflammatory markers, hs-CRP seemed to be the only biomarker retaining some association with the endpoint of clinical progression (i.e. AIDS/SNAEs/death) after adjustment for confounders, both when the study population was stratified according to the median of the distribution (1.51 mg/L) and when the study population was stratified according to the 33% percentiles of the distribution (low 0.0-1.1 mg/L; intermediate 1.2-5.3 mg/L; high > 5.3 mg/L). In particular, the higher the hs-CRP values, the higher the risk of clinical progression (p = 0.056 for median-based model; p = 0.002 for 33% percentile-based model). CONCLUSIONS: Our data carries evidence for an association between the risk of disease progression after cART initiation and circulating pre-cART hs-CRP levels but not with levels of MT. These results suggest that pre-therapy HIV-driven pro-inflammatory milieu might overweight MT and its downstream immune-activation.

Disseminated cytomegalovirus disease after bendamustine: a case report and analysis of circulating B- and T-cell subsets.

BACKGROUND: Bendamustine, used for the treatment of indolent B-cell non-Hodgkin lymphoma and chronic lymphocytic leukemia, is known to cause prolonged myelosuppression and lymphocytopenia and has been associated with the risk of developing serious and fatal infections. While reports of localized CMV infections in asymptomatic patients exist, disseminated CMV disease has not been described. CASE PRESENTATION: We report the first case of disseminated CMV infection in a 75-year-old male diagnosed with lymphoplasmacytic lymphoma/Waldenström macroglobulinemia with massive bone marrow infiltration. Despite 6-cycle R-bendamustine chemotherapy resulted in a good partial response, the patient developed persistent fever and severe weight loss. Analysis of cerebrospinal fluid and peripheral blood revealed the presence of CMV-DNA, while the fundus oculi examination revealed bilateral CMV retinitis. Treatment with induction and maintenance drugs was complicated by neutropenia and deterioration of renal function with electrolyte imbalance. From an immunological standpoint, we observed a profound imbalances in phenotype and function of B- and T-cell subsets, with a high proportion of circulating total, activated CD69+ and CD80+ B-cells, a low γ/δ T-cell frequency with a high proportion of CD69- and CD38-expressing cells, and hyperactivated/exhausted CD4+ and CD8+ T-cell phenotypes unable to face CMV challenge. CONCLUSIONS: We hereby describe a severe form of disseminated CMV disease after R-bendamustine treatment. Our observations strongly support the careful clinical monitoring of CMV reactivation/infection in oncologic patients undergoing this therapeutic regimen.

Pre-ART HIV-1 DNA in CD4+ T cells correlates with baseline viro-immunological status and outcome in patients under first-line ART.

Objectives: We evaluated the association between pre-ART HIV DNA and HIV-infected participant characteristics at baseline as well as with their response to first-line ART. Methods: Four hundred and thirty-three patients from the ICONA cohort, starting first-line ART after the year 2000, were analysed. Pre-ART HIV DNA was quantified with the modified COBAS TaqMan HIV-1 Test and normalized by CD4+ T cells. Linear correlation between pre-ART HIV DNA and other continuous markers (HIV RNA, CD4 count, markers of inflammation and coagulation) at baseline was evaluated by means of Pearson correlation coefficient and a linear regression model. Survival analyses and Cox regression models were used to study the association between pre-ART HIV DNA and time to viro-immunoclinical events. Results: Pre-ART HIV DNA [median (IQR): 10 702 (3397-36 632) copies/106 CD4+ T cells] was correlated with pre-ART HIV RNA [R2 = +0.44, (P < 0.0001)], CD4+ T cells [R2 = -0.58, (P < 0.0001)] and CD4/CD8 ratio [R2 = -0.48, (P < 0.0001)], while weaker correlations were observed with CD8+ T cells (R2 = -0.20, P = 0.01), IL-6 (R2 = +0.16, P = 0.002) and soluble CD14 (R2 = +0.09, P = 0.05). Patients with higher pre-ART HIV DNA showed lower rate and delayed virological response (defined as HIV RNA ≤50 copies/mL), compared with those having lower HIV DNA (67.2% for >10 000, 81.1% for 1000-10 000 and 86.4% for 10-1000 copies/106 CD4+ T cells; P = 0.0004). Higher pre-ART HIV DNA was also correlated with increased risk of virological rebound (defined as HIV RNA >50 copies/mL) by 24 months (17.2% for >10 000, 7.4% for 1000-10 000 and 4.3% for 10-1000 copies/106 CD4+ T cells; P = 0.0048). Adjusted HRs of all virological rebound definitions confirmed these findings (P ≤ 0.02). Conclusions: Pre-ART HIV DNA, along with HIV RNA and CD4+ T cell count, should be considered as a new staging marker to better identify people at lower (or higher) risk of viral rebound following achievement of virological suppression (≤50 copies/mL).

Is weak CD4+ gain in the course of suppressive combination antiretroviral therapy for HIV infection a current clinical challenge? A case report and brief review of the literature.

BACKGROUND: Individuals lacking immune recovery during suppressive cART will still represent a clinical issue in the years to come, given the high proportion of HIV-infected subjects introducing therapy late in the course of disease. Understanding the mechanisms underlying poor CD4+ T-cell gain is crucial for the correct clinical management of individuals in this context. CASE PRESENTATION: An HIV-infected subject with poor CD4+ T-cell gain in the course of suppressive antiretroviral therapy was extensively investigated to identify the mechanisms behind inadequate CD4+ reconstitution. In particular, we studied the phenotype of circulating T-cells, interleukin-7 signaling in peripheral blood and bone marrow, gut function and microbial translocation markers as well as the composition of the faecal microbiota. Numerous therapeutic interventions ranging from antiretroviral therapy intensification to immunotherapy and anti-hepatitis C virus treatment were also employed in order to target the possible causes of poor immune-recovery. CONCLUSIONS: Poor CD4+ T-cell gain on suppressive antiretroviral therapy is multifactorial and thus represents a clinical challenge. Clinicians should investigate subjects' immune profile as well as possible causes of chronic antigenic stimulation for the administration of the most appropriate therapeutic strategies in this setting.

Cross-clade ultrasensitive PCR-based assays to measure HIV persistence in large-cohort studies.

UNLABELLED: A small pool of infected cells persists in HIV-infected individuals receiving antiretroviral therapy (ART). Here, we developed ultrasensitive assays to precisely measure the frequency of cells harboring total HIV DNA, integrated HIV DNA, and two long terminal repeat (2-LTR) circles. These assays are performed on cell lysates, which circumvents the labor-intensive step of DNA extraction, and rely on the coquantification of each HIV molecular form together with CD3 gene sequences to precisely measure cell input. Using primary isolates from HIV subtypes A, B, C, D, and CRF01_A/E, we demonstrate that these assays can efficiently quantify low target copy numbers from diverse HIV subtypes. We further used these assays to measure total HIV DNA, integrated HIV DNA, and 2-LTR circles in CD4(+) T cells from HIV-infected subjects infected with subtype B. All samples obtained from ART-naive subjects were positive for the three HIV molecular forms (n = 15). Total HIV DNA, integrated HIV DNA, and 2-LTR circles were detected in, respectively, 100%, 94%, and 77% of the samples from individuals in which HIV was suppressed by ART. Higher levels of total HIV DNA and 2-LTR circles were detected in untreated subjects than individuals on ART (P = 0.0003 and P = 0.0004, respectively), while the frequency of CD4(+) T cells harboring integrated HIV DNA did not differ between the two groups. These results demonstrate that these novel assays have the ability to quantify very low levels of HIV DNA of multiple HIV subtypes without the need for nucleic acid extraction, making them well suited for the monitoring of viral persistence in large populations of HIV-infected individuals. IMPORTANCE: Since the discovery of viral reservoirs in HIV-infected subjects receiving suppressive ART, measuring the degree of viral persistence has been one of the greatest challenges in the field of HIV research. Here, we report the development and validation of ultrasensitive assays to measure HIV persistence in HIV-infected individuals from multiple geographical regions. These assays are relatively inexpensive, do not require DNA extraction, and can be completed in a single day. Therefore, they are perfectly adapted to monitor HIV persistence in large cohorts of HIV-infected individuals and, given their sensitivity, can be used to monitor the efficacy of therapeutic strategies aimed at interfering with HIV persistence after prolonged ART.

Role of in vitro stimulation with lipopolysaccharide on T-cell activation in HIV-infected antiretroviral-treated patients.

We investigated the effect of LPS in vitro stimulation on T-cell activation in HIV-infected patients with different CD4+ recovery on HAART. PBMCs from 30 HIV-positive, HAART-treated, aviremic individuals with different CD4+ reconstitution (Low Responders: CD4+ < 350/µL; Intermediate Responders: CD4+ 350-599/µL; High Responders: CD4+ ≥ 600/µL) were cultured with LPS and the proportion of HLA-DR/CD38- and Ki67-expressing CD4+/CD8+ T-cells was measured (flow cytometry). Upon LPS stimulation, significantly higher CD4+ and CD8+HLA-DR+ cells were shown in LR and IR versus HIV-negative controls. While no differences in the proportion of LPS-stimulated CD4+CD38+ cells were recorded amongst HIV-positive subgroups, CD8+CD38+ cells were more elevated in patients with lower CD4+ recovery on HAART (i.e., LR and IR). Upon in vitro LPS stimulation, HLA-DR and CD38 expression on T-cells are differentially regulated. While HLA-DR induction reflects impaired CD4+ reconstitution on HAART, cell-surface CD38 expression is increased only on CD8+ T-cells, allowing to speculate that the sole induction of CD38 on CD4+ cells may not be sufficient to depict LPS-driven immune activation in HIV.

Long-Term Suppressive cART Is Not Sufficient to Restore Intestinal Permeability and Gut Microbiota Compositional Changes.

Background: We explored the long-term effects of cART on markers of gut damage, microbial translocation, and paired gut/blood microbiota composition, with a focus on the role exerted by different drug classes. Methods: We enrolled 41 cART naïve HIV-infected subjects, undergoing blood and fecal sampling prior to cART (T0) and after 12 (T12) and 24 (T24) months of therapy. Fifteen HIV-uninfected individuals were enrolled as controls. We analyzed: (i) T-cell homeostasis (flow cytometry); (ii) microbial translocation (sCD14, EndoCab, 16S rDNA); (iii) intestinal permeability and damage markers (LAC/MAN, I-FABP, fecal calprotectin); (iv) plasma and fecal microbiota composition (alpha- and beta-diversity, relative abundance); (v) functional metagenome predictions (PICRUSt). Results: Twelve and twenty four-month successful cART resulted in a rise in EndoCAb (p = 0.0001) and I-FABP (p = 0.039) vis-à-vis stable 16S rDNA, sCD14, calprotectin and LAC/MAN, along with reduced immune activation in the periphery. Furthermore, cART did not lead to substantial modifications of microbial composition in both plasma and feces and metabolic metagenome predictions. The stratification according to cART regimens revealed a feeble effect on microbiota composition in patients on NNRTI-based or INSTI-based regimens, but not PI-based regimens. Conclusions: We hereby show that 24 months of viro-immunological effective cART, while containing peripheral hyperactivation, exerts only minor effects on the gastrointestinal tract. Persistent alteration of plasma markers indicative of gut structural and functional impairment seemingly parallels enduring fecal dysbiosis, irrespective of drug classes, with no effect on metabolic metagenome predictions.

Predictors of low ovarian reserve in cART-treated women living with HIV.

ABSTRACT: Ovarian dysfunction and lower circulating anti-Müllerian hormone (AMH) feature women living with HIV (WLWH). Because treated human immunodeficiency virus (HIV) infection is characterized by a pro-inflammatory/oxidative phenotype resulting in residual comorbidity, we sought to investigate possible associations between plasma AMH and markers of inflammation, immune activation/senescence/exhaustion, oxidative stress as well as comorbidities in a cohort of combined anti-retroviral therapy (cART)-treated WLWH versus age-matched HIV-uninfected, healthy women.Eighty WLWH on effective cART aged 25 to 50 years and 66 age-matched healthy women were enrolled. We measured: plasma AMH, IL-6, reactive oxygen species modulator 1 (ROMO1) (ELISA); plasma tumor necrosis factor α, IL-10, soluble vascular cell adhesion molecule 1, osteopontin (Luminex); CD4/CD8 activation (CD38/CD69), apoptosis (CD95), exhaustion (PD1), maturation (CD45RA/CD45R0/CD127/CCR7), recent thymic emigrants (CD31/CD103) (flow cytometry). Mann Whitney and chi-squared tests were used. Univariate and multivariate logistic regression analyses were used to assess factors associated with low AMH (≤1 ng/mL).Compared to healthy women, WLWH were more frequently non-Caucasian, drug/alcohol abusers, with history of late menarche, lower hormonal contraceptive use, with higher gravidity and lower parity. WLWH showed significantly lower AMH (P = .004) as well as higher ROMO1 (P = .0003) and tumor necrosis factor α (P < .0001). The multivariate analyses revealed ROMO1 (adjusted odds ratio [AOR]: 1.42, P = .03) and HIV infection (AOR: 8.1, P = .0001) as independently associated with low AMH. The logistic regression model with both HIV status and ROMO1 (a marker of oxidative stress) confirmed HIV as the only predictor of low AMH (AOR: 17, P = .0003).Despite effective cART, WLWH showed lower AMH compared to age-matched peers, indicating pre-mature ovarian ageing. Both HIV and oxidative stress are independently associated with low AMH, emphasizing the impact of HIV-associated oxidative stress on reproductive aging.

Biomarkers of aging in HIV: inflammation and the microbiome.

PURPOSE: HIV-infected subjects present increased levels of inflammatory cytokines and T cell activation in the peripheral blood despite suppressive combination antiretroviral therapy which renders them susceptible to premature aging. The purpose of the present work was to review existing evidence on the ways in which the anatomical and microbiological abnormalities of the gastrointestinal tract can represent a major cause of organ disease in HIV infection. METHODS: We conducted a systematic review of the Pubmed database for articles published from 2014 to 2018. We included studies on inflammatory/activation biomarkers associated with cardiovascular and bone disease, neurocognitive impairment and serious non-AIDS events in HIV-infected subjects. We also included researches which linked peripheral inflammation/activation to the anatomical, immune and microbiological alterations of the gastrointestinal tract. RESULTS: Recent literature data confirm the association between non-infectious comorbidities and inflammation in HIV infection which may be driven by gastrointestinal tract abnormalities, specifically microbial translocation and dysbiosis. Furthermore, there is mounting evidence on the possible role of metabolic functions of the microbiota in the pathogenesis of premature aging in the HIV-infected population. CONCLUSIONS: Biomarkers need to be validated for their use in the management of HIV infection. Compounds which counteract microbial translocation, inflammation and dysbiosis have been investigated as alternative therapeutic strategies in viro-suppressed HIV-infected individuals, but appear to have limited efficacy, probably due to the multifactorial pathogenesis of non-infectious comorbidities in this setting.

Mucosal cell populations may contribute to peripheral immune abnormalities in HIV-infected subjects introducing cART with moderate immune-suppression.

HIV infection causes the progressive depletion of CD4+ T-lymphocytes and profound modifications of T-cell homeostasis, which persist despite virologically-suppressive treatment and have been linked to a worse clinical outcome. Enduring alterations of the gastrointestinal tract may represent the underlying pathogenic mechanisms of these phenomena. Twenty-six HIV-infected subjects were assessed over a 12-month period following the introduction of antiretroviral therapy. 18 uninfected individuals were enrolled as controls. Parameters of peripheral T-cell homeostasis (activation, maturation), gastrointestinal function (microbial translocation, gut inflammation, fecal microbiota composition) and mucosal immunity (CD4+CCR6+CD161+, CD4+CCR9+α4ß7+, stem cell memory CD4+/CD8+ T-cells) were assessed. CD4+CCR6+CD161+ cells were depleted in HIV-infected untreated subjects and maintained significantly lower levels compared to controls, despite the introduction of effective antiviral treatment. The frequency of gut-homing CD4+CCR9+α4ß7+ cells was also impaired in untreated infection and correlated with the HIV RNA load and CD4+HLADR+CD38+; during therapy, we observed a contraction of this pool in the peripheral blood and the loss of its correlation with antigenic exposure/immune activation. A partial correction of the balance between stem cell memory pools and T-cell homeostasis was registered following treatment. In HIV-infected subjects with moderate immune-suppression, antiretroviral therapy has a marginal impact on mucosal immune populations which feature distinctive kinetics in the periphery, possibly reflecting their diverse recruitment from the blood to the mucosa. The persistent defects in mucosal immunity may fuel peripheral T-cell abnormalities through diverse mechanisms, including the production of IL-17/IL-22, cellular permissiveness to infection and regulation of T-lymphocyte maturation.

Association Between Impaired Vα7.2+CD161++CD8+ (MAIT) and Vα7.2+CD161-CD8+ T-Cell Populations and Gut Dysbiosis in Chronically HIV- and/or HCV-Infected Patients.

Both HIV and HCV infections feature increased microbial translocation (MT) and gut dysbiosis that affect immune homeostasis and disease outcome. Given their commitment to antimicrobial mucosal immunity, we investigated mucosal-associated invariant T (MAIT) cells and Vα7.2+CD161- T-cell frequency/function and their possible associations with MT and gut dysbiosis, in chronic HIV and/or HCV infections. We enrolled 56 virally infected (VI) patients (pts): 13 HIV+ on suppressive cART (HIV-RNA < 40cp/ml), 13 HCV+ naive to DAA (direct-acting antiviral) anti-HCV agents; 30 HCV+/HIV+ on suppressive cART and naive to anti-HCV. 13 age-matched healthy controls (HC) were enrolled. For Vα7.2+CD161++ and Vα7.2+CD161-CD8+ T cells we assessed: activation (CD69), exhaustion (PD1/CD39), and cytolytic activity (granzymeB/perforin). Following PMA/ionomycin and Escherichia coli stimulation we measured intracellular IL17/TNFα/IFNγ. Markers of microbial translocation (Plasma LPS, 16S rDNA, EndoCAb and I-FABP) were quantified. In 5 patients per group we assessed stool microbiota composition by 16S targeted metagenomics sequencing (alpha/beta diversity, relative abundance). Compared to controls, virally infected pts displayed significantly lower circulating Vα7.2+CD161++CD8+ MAIT cells (p = 0.001), yet expressed higher perforin (p = 0.004) and granzyme B (p = 0.002) on CD8+ MAIT cells. Upon E. coli stimulation, the residual MAIT cells are less functional particularly those from HIV+/HCV+ patients. Conversely, in virally infected pts, Vα7.2+CD161-CD8+ cells were comparable in frequency, highly activated/exhausted (CD69+: p = 0.002; PD-1+: p = 0.030) and with cytolytic potential (perforin+: p < 0.0001), yet were poorly responsive to ex vivo stimulation. A profound gut dysbiosis characterized virally infected pts, especially HCV+/HIV+ co-infected patients, delineating a Firmicutes-poor/Bacteroidetes-rich microbiota, with significant associations with MAIT cell frequency/function. Irrespective of mono/dual infection, HIV+ and HCV+ patients display depleted, yet activated/cytolytic MAIT cells with reduced ex vivo function, suggesting an impoverished pool, possibly due to continuous bacterial challenge. The MAIT cell ability to respond to bacterial stimulation correlates with the presence of Firmicutes and Bacteroidetes, possibly suggesting an association between gut dysbiosis and MAIT cell function and posing viral-mediated dysbiosis as a potential key player in the hampered anti-bacterial MAIT ability.

Reduction of Immune Activation and Partial Recovery of Staphylococcal Enterotoxin B-Induced Cytokine Production After Switching to an Integrase Strand Transfer Inhibitor-Containing Regimen: Results from an Observational Cohort Study.

BACKGROUND AND OBJECTIVE: Despite integrase strand transfer inhibitor (INSTI)-containing regimens now being considered a preferred option for both initial therapy and switching strategies in virologically suppressed patients, their effects on lymphocyte phenotypes and functions in the course of effective combination antiretroviral therapy (cART) are still unclear. Thus, we investigated the effect of a 24-week elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/c/FTC/TDF) regimen on the T cell compartment and HIV reservoirs in HIV-infected patients switching from a suppressive protease inhibitor-based regimen. METHODS: Thirty HIV-positive patients receiving suppressive tenofovir disoproxil fumarate/emtricitabine (TDF + FTC) (for a median of 5 years) in association with either darunavir/ritonavir (DVR/r) (47%) or atazanavir/ritonavir (ATV/r) (53%) were followed up for 24 weeks after switching to EVG/c/FTC/TDF. At baseline (week 0 [W0]) and after 12 (W12) and 24 (W24) weeks we analyzed HLA-DR (human leukocyte antigen-DR isotype)/CD38/Ki67/CCR7 (C-C chemokine receptor type 7)/CD45RA/CD127/PD-1 (programmed cell death-1) on CD4/CD8, interferon (IFN)-γ/interleukin (IL)-2 after HIV/Staphylococcal enterotoxin B (SEB) exposure (flow cytometry); total, integrated, and unintegrated HIV-DNA; and residual low-level HIV viremia (quantitative polymerase chain reaction [qPCR]). RESULTS: While EVG/c/FTC/TDF introduction resulted in a stable CD4+ and CD8+ count, residual low-level HIV-RNA viremia, and HIV reservoirs, we observed a significant reduction in both activated CD4+ (p = 0.016) and CD8+ (p = 0.048) T cells, coupled with an increase in IL-2 and IFN-γ release by CD4+ and CD8+ effector memory T cells, and a decrease in cytokine production by terminally differentiated CD8+ T cells following SEB exposure. Furthermore, the magnitude of the reduction of activated HLA-DR + CD38 + CD8+ T cells (r = - 0.63, p = 0.014) inversely correlates with the amount of total HIV-DNA at W24. CONCLUSIONS: Our data show a favorable effect of EVG/c/FTC/TDF switch to preserve immune activation-driven damage to T cell homeostasis, restore the multifunctional properties of effector T cells, and possibly contain cell-associated HIV viral burden in already virologically suppressed patients.

Brief Report: Soluble CD163 in CMV-Infected and CMV-Uninfected Subjects on Virologically Suppressive Antiretroviral Therapy in the ICONA Cohort.

AIMS: To contribute to the understanding of the role played by cytomegalovirus (CMV) in sustaining monocyte/macrophage-mediated immune activation in antiretroviral therapy treated HIV-infected subjects. DESIGN AND METHODS: We selected 23 CMV-uninfected and 46 CMV-infected HIV+ subjects, matched for age, CD4 nadir, HIV infection duration, and viral hepatitis serostatus. All subjects were on successful antiretroviral therapy since at least 1 year. A group of 16 healthy donors with similar age and sex was also included. Plasma levels of tumor necrosis factor-alpha, interleukin-6, sCD163, sCD14, and CMV immunoglobulin G levels were measured in duplicate with human enzyme-linked immunosorbent assay kits. RESULTS: We found significantly higher sCD163 plasma levels in HIV+CMV+ compared with HIV+CMV- subjects and healthy donors. This augmentation was confirmed also when subjects positive for hepatitis C virus-Ab were excluded from analysis. Interestingly, a correlation between anti-CMV immunoglobulin G levels and sCD163, tumor necrosis factor-alpha, interleukin-6, and sCD14 in HIV+CMV+ subjects was found. CONCLUSIONS: CMV coinfection could be a major driver of monocyte/macrophage activation in virally suppressed HIV+ individuals and might explain the increased risk of non-AIDS morbidity/mortality in HIV/CMV-coinfected subjects.

Clinical and viro-immunological correlates of HIV associated neurocognitive disorders (HAND) in a cohort of antiretroviral-naïve HIV-infected patients.

The multifactorial pathogenesis of HIV-associated neurocognitive disorders may explain the inconsistent association between neurocognitive impairment and cerebrospinal fluid (CSF) HIV RNA. Clinical and viro-immunological (CSF and plasma HIV RNA, CSF/plasma HIV RNA ratio, circulating T-cell phenotypes) parameters were investigated in 155 HIV-infected, antiretroviral-naïve, asymptomatic study participants undergoing a neuropsychological evaluation. HIV associated neurocognitive disorders (HAND) was independently associated with AIDS events and a CSF/plasma ratio of at least one, after adjustment for CD4 nadir of less than 200 cells/mmc, suggesting a role for active central nervous system (CNS) viral replication in the pathogenesis of neurocognitive impairment.

Stimulation of PBMC and Monocyte-Derived Macrophages via Toll-Like Receptor Activates Innate Immune Pathways in HIV-Infected Patients on Virally Suppressive Combination Antiretroviral Therapy.

In HIV-infected, combination antiretroviral therapy (cART)-treated patients, immune activation and microbial translocation persist and associate with inadequate CD4 recovery and morbidity/mortality. We analyzed whether alterations in the toll-like receptor (TLR) pathway could be responsible for the immune hyperactivation seen in these patients. PBMC/monocyte-derived macrophages (MDMs) of 28 HIV+ untreated and 35 cART-treated patients with HIV-RNA < 40 cp/mL [20 Full Responders (FRs): CD4 ≥ 350; 15 Immunological Non-Responders (INRs): CD4 < 350], as well as of 16 healthy controls were stimulated with a panel of TLR agonists. We measured: CD4/CD8/CD14/CD38/HLA-DR/Ki67/AnnexinV/CD69/TLR4/8 (Flow Cytometry); PBMC expression of 84 TLR pathway genes (qPCR); PBMC/MDM cytokine release (Multiplex); and plasma lipopolysaccharide (LPS)/sCD14 (LAL/ELISA). PBMC/MDM from cART patients responded weakly to LPS stimulation but released high amounts of pro-inflammatory cytokines. MDM from these patients were characterized by a reduced expression of HLA-DR+ MDM and failed to expand activated HLA-DR+ CD38+ T-lymphocytes. PBMC/MDM from cART patients responded more robustly to ssRNA stimulation; this resulted in a significant expansion of activated CD38 + CD8 and the release of amounts of pro-inflammatory cytokines comparable to those seen in untreated viremic patients. Despite greater constitutive TLR pathway gene expression, PBMC from INRs seemed to upregulate only type I IFN genes following TLR stimulation, whereas PBMC from full responders showed a broader response. Systemic exposure to microbial antigens drives immune activation during cART by triggering TLRs. Bacterial stimulation modifies MDM function/pro-inflammatory profile in cART patients without affecting T-lymphocytes; this suggests translocating bacteria as selective stimulus to chronic innate activation during cART. High constitutive TLR activation is seen in patients lacking CD4 recovery, suggesting an exhausted immune milieu, anergic to further antigen encounters.

Impaired gut junctional complexes feature late-treated individuals with suboptimal CD4+ T-cell recovery upon virologically suppressive combination antiretroviral therapy.

OBJECTIVE: HIV-infected individuals with incomplete CD4⁺ T-cell recovery upon combination antiretroviral therapy (cART) display high levels of immune activation and microbial translocation. However, whether a link exists between gut damage and poor immunological reconstitution remains unknown. DESIGN: Cross-sectional study of the gastrointestinal tract in late cART-treated HIV-infected individuals: 15 immunological nonresponders (CD4⁺ <350 cells/µl and/or delta CD4⁺ change from baseline <30%); 15 full responders (CD4⁺ >350 cells/µl and/or delta CD4⁺ change from baseline >30%). METHODS: We assessed gut structure (junctional complex proteins in ileum and colon) and function (small intestine permeability/damage and microbial translocation parameters). The composition of the fecal microbiome and the size of the HIV reservoir in the gut and peripheral blood were investigated as possible mechanisms underlying mucosal impairment. RESULTS: Markers of intestinal permeability, damage, systemic inflammation, and microbial translocation were comparable in all study individuals, yet the expression of junctional complex proteins in gut biopsies was significantly lower in HIV-infected patients with incomplete CD4⁺ restoration and negatively correlated with markers of CD4⁺ reconstitution. Electron microscopy revealed dilated intercellular spaces in individuals lacking immunological response to cART, yet not in patients displaying CD4⁺ T-cell recovery. Analysis of the fecal microbiome revealed an overall outgrowth of Bacteroides-Prevotella spp. with no differences according to CD4⁺ T-cell reconstitution. Interestingly, HIV reservoirs in peripheral CD4⁺ T cells and intestinal tissue negatively correlated with immune recovery. CONCLUSION: These observations establish gut damage and the size of the HIV reservoir as features of deficient immunological response to cART and provide new elements for interventional strategies in this setting.

Invariant natural killer T (iNKT) cells in HAART-treated, HIV-positive patients with bone and cardiovascular impairment.

BACKGROUND: Invariant Natural Killer T (iNKT) cells represent a determinant in the course of infections and diseases, however, their role in the pathogenesis of non-infectious co-morbidities in HIV-positive patients is unknown. METHODS: Flow cytometry was used to investigate iNKT cell frequency, phenotype and function in HIV-infected patients on HAART with bone and/or cardiovascular disorders and in HIV-positive controls free from co-morbidities. RESULTS: iNKT cells from subjects with bone and cardiovascular impairment expressed high levels of CD161 and predominantly secreted TNF. iNKT cells from individuals with bone disease alone did not show any distinctive phenotypical or functional characteristics. The functional capacity of iNKT cells in patients with cardiovascular disorder was impaired with no cytokine release upon stimulation. CONCLUSION: iNKT cells may have a role in non-infectious co-morbidities in treated HIV disease, possibly through the exacerbation of inflammation. Further studies are needed to investigate iNKT cells in the pathogenesis of non-communicable disorders in HIV infection.