Serum Retinol-Binding Protein-4 Levels Are Increased in HIV-Infected Subjects with Metabolic Syndrome Receiving Highly Active Antiretroviral Therapy

Metabolic syndrome is an important long term complication in chronic asymptomatic HIV-infected subjects under highly active antiretroviral therapy (HAART), because it can contribute to morbidity and mortality via cardiovascular disease (CVD). Therefore, a predictive marker for early detection of metabolic syndrome may be necessary to prevent CVD in HIV-infected subjects. Retinol-binding protein-4 (RBP-4) has been shown to be associated with metabolic syndrome in various non-HIV-infected populations. We performed a cross-sectional study to evaluate whether serum RBP-4 levels are correlated with metabolic syndrome in HIV-infected subjects receiving HAART. In total, 98 HIV-infected Koreans who had been receiving HAART for at least 6 months were prospectively enrolled. Metabolic syndrome was diagnosed according to the Adult Treatment Panel III criteria, and serum RBP-4 concentrations were measured using human RBP-4 sandwich enzyme-linked immunosorbent assay. Serum RBP-4 levels were significantly higher in HIV-infected subjects receiving HAART with metabolic syndrome (n=33, 33.9±7.7 µg/mL) than in those without it (n=65, 29.9±7.2 µg/mL) (p=0.012). In multivariate linear regression analysis, the number of components of metabolic syndrome presented and waist circumference were independently, significantly correlated with RBP-4 (p=0.018 and 0.030, respectively). In conclusion, we revealed a strong correlation between RBP-4 and the number of components of metabolic syndrome in HIV-infected subjects receiving HAART.     

The Role of Plasmacytoid and Myeloid Dendritic Cells in Induction of Asthma in a Mouse Model and the Effect of a TLR9 Agonist on Dendritic Cells

Purpose

To determine the role of plasmacytoid dendritic cells (pDC) and myeloid dendritic cells (mDC) in priming effector T cells to induce allergy, and to evaluate the effect of immunostimulatory sequences (ISS, TLR9 agonist) on dendritic cells.

Methods

Cultured mDC and pDC with/without ISS were injected intratracheally into sensitized Balb/C mice. Mice were sacrificed, and then pulmonary function tests, bronchoalveolar lavage (BAL), cell counts, and cytokine levels were evaluated. Migration of dendritic cells was also evaluated after ISS administration.

Results

In mice injected with mDC, airway hyperresponsiveness, eosinophil counts, and Th2 cytokine levels in BAL increased with increasing numbers of mDC injected. However, in mice injected with pDC, none of these changed, suggesting poor priming of T cells by pDC. In addition, mDC pulsed with ISS inhibited asthmatic reactions, and ISS administration inhibited migration of DC to the lung.

Conclusions

We suggest that pDC played a limited role in priming T cells in this asthma model and that mDC played a major role in inducing asthma. In addition, ISS inhibited migration of DC to the lung.     

Effect of Highly Active Antiretroviral Therapy (HAART) and Hepatitis C Co-Infection on Hyperlipidemia in HIV-Infected Patients: A Retrospective Longitudinal Study

Abstract

Background: Lipid abnormalities are among the most frequent treatment-limiting adverse events during HAART in HIV-infected individuals. Lipid disturbances have also been associated with hepatitis C virus (HCV) chronic infection in HIV-uninfected participants. HAART-induced lipid abnormalities may then have peculiar features in HIV-HCV co-infected individuals. Purpose: To estimate the prevalence and incidence rates of hypertriglyceridemia and hypercholesterolemia and to identify associated factors in a large clinic population of HIV patients after HAART has been initiated. Design: We performed a retrospective longitudinal follow-up study in a large cohort of HIV patients on their first HAART. Patients and Method: The clinical databases of two major clinical centers in Italy participating in the MASTER study were merged. Treatment-emerging metabolic disorders in patients on their first HAART regimen (PI-based or NNRTI-based) who were stable for at least 4 months were prospectively analyzed by baseline parameters, drug regimens, and viroimmunological outcome of therapy. Follow-up was continued for 24 months or until drug discontinuation, whichever came first. Results: Two hundred and eighty two (282) HIV-infected patients undergoing HAART (203 PI + 79 NNRTI; 65 including stavudine [d4T]) met inclusion criteria and were enrolled in the study from 1997 to 2002. Mean follow-up was 18.5 ± 6.7 months. After HAART had been initiated, a statistically significant mean increase in total cholesterol over time was observed in comparison to baseline (p < .0001), without difference between treatment groups (PI vs. NNRTI, with or without d4T). In the univariate analysis, predictive factors for HAART-induced hypercholesterolemia were baseline total plasma cholesterol and triglycerides values and CD4+ cell count differential increase over time, while a negative correlation was found with zalcitabine-including regimens and baseline HCV seropositivity. At multivariate analysis, only high baseline total plasma cholesterol and triglycerides values retained their predictive value and baseline HCV seropositivity was significantly associated with lower increase in total cholesterol values under HAART, regardless of treatment groups (p < .001). Conclusion: HCV co-infection is an independent factor preventing the emergence of treatment-limiting total cholesterol increase under any HAART regimen, possibly reflecting impaired total cholesterol synthesis in the liver or total cholesterol hypercatabolism. On the contrary, no HCV influence on triglycerides plasma levels was noted. Our data do not suggest any favoring role of specific treatment or drugs (PI and/or d4T) on total cholesterol and triglycerides increase under HAART.     

Dendritic Cell Numbers in the Blood of HIV-1 Infected Patients Before and After Changes in Antiretroviral Therapy

Antigen presenting dendritic cells (DCs) can serve as sites for HIV replication and as vehicles for transmission of the virus to T cells. It is known that the numbers of DCs in blood is reduced during HIV-1 infection. Here we monitored the two major subsets of blood DCs in 12 individuals undergoing a change, primarily initiation, of highly active antiretroviral therapy. The numbers of plasmacytoid DCs were reliably higher on therapy, although in the 1–3 month interval we followed, these numbers did not return to those seen in HIV uninfected controls. An increase in plasmacytoid DCs was accompanied by an increase in IFN- production in response to a standard challenge in culture with UV-inactivated herpes simplex virus. The levels of myeloid DCs also demonstrated an increase while on HAART, and these numbers become comparable to the HIV uninfected controls. The numbers of plasmacytoid and myeloid DCs varied inversely with the levels of plasma HIV viremia. These longitudinal studies extend prior work showing that virus infection with HIV leads to a decrease in the number of dendritic cells in blood, and that this can be reversed at least in part by therapy.     

Relationship Between Low Bone Mineral Density and Highly Active Antiretroviral Therapy Including Protease Inhibitors in HIV-Infected Patients

Abstract

Purpose: The objectives of this study were to determine the prevalence of osteopenia and the factors associated with its presence in HIV-infected patients under highly active antiretroviral therapy (HAART) and to assess the changes of bone mineral density (BMD) in a population followed prospectively. Method: BMD was assessed by dual-energy X-ray absorptiometry (DEXA) scans at the lumbar spine and at the femoral neck in 78 HIV-infected patients who had previously received HAART as the first antiretroviral regimen and in 11 antiretroviral-naive HIV-infected patients. BMD measurements were repeated in 70 treated patients who had completed 1 year of follow-up. Results: Thirty-seven (42%) patients showed osteopenia at any localization. The prevalence of osteopenia in PI-naive patients was 23% versus 49% in individuals who had received PI at any moment [p = .001; adjusted odds ratio (95% CI) = 0.11 (0.02-0.48)]. The frequency of osteopenia was significantly higher among men than among women [50% vs. 17%; p = .016; adjusted OR (95% CI) = 12.1 (2.22-66.20)]. The level of plasma albumin was independently associated with osteopenia [adjusted OR (95% CI) per each g/dL of plasma albumin decrease 2.55 (1.18-10)]. In patients in whom a second DEXA was done, no significant changes in BMD were found. Conclusion: The prevalence of osteopenia in HIV-infected patients on HAART is high. Loss of BMD is associated with PI therapy, low plasma albumin level, and male sex. Osteopenia does not progress after 1 year of continued HAART.     

Body Mass Index and CD4+ T-Lymphocyte Recovery in HIV-Infected Men with Viral Suppression on Antiretroviral Therapy

Abstract

Purpose: To better characterize the relationship between body mass index (BMI) and CD4+ T-lymphocyte recovery in HIV disease.Methods: We analyzed the association between baseline BMI and CD4+ T-lymphocyte increases, as well as the association between BMI and immune activation (CD38 and HLA-DR co-expression on CD4+ and CD8+ T-lymphocytes), in male HIV-infected patients who achieved viral suppression on antiretroviral therapy (ART).Results: Baseline BMI predicted change in CD4+ T-lymphocyte count at weeks 96 ( P = .03, n = 461) and 144 ( P = .005, n = 357) but not at week 48 ( P = .38, n = 558). Relative to men with a normal BMI, overweight and obese men had increases at week 144 that were 35 and 113 cells/ mm³ higher, respectively, while underweight men had CD4+ T-lymphocyte increases that were 94 cells/mm³ lower. No significant correlations between baseline BMI and cellular immune activation were seen.Conclusions: BMI predicts CD4+ T-lymphocyte gains in men started on ART.     

HIV-infected cells are major inducers of plasmacytoid dendritic cell interferon production, maturation, and migration

Plasmacytoid dendritic cells (PDC), natural type-1 interferon (IFN) producing cells, could play a role in the innate anti-HIV immune response. Previous reports indicated that PDC IFN production is induced by HIV. Our results show a more robust IFN induction when purified PDC (>95%) were exposed to HIV-infected cells. This effect was not observed with non-viable cells, DNA, and RNA extracted from infected cells, and viral proteins. The response was blocked by anti-CD4 and neutralizing anti-gp120 antibodies as well as soluble CD4. IFN induction by HIV-infected cells was also prevented by low-dose chloroquine, which inhibits endosomal acidification. PDC IFN release resulted in reduced HIV production by infected CD4+ cells, supporting an anti-HIV activity of PDC. Stimulated CD4+ cells induced PDC activation and maturation; markers for PDC migration (CCR7) were enhanced by HIV-infected CD4+ cells only. This latter finding could explain the decline in circulating PDC in HIV-infected individuals.     

Comparison of Prognostic Importance of Latest CD4+ Cell Count and HIV RNA Levels in Patients with Advanced HIV Infection on Highly Active Antiretroviral Therapy

Abstract

The comparative prognostic importance of latest plasma HIV RNA levels (viral loads) and CD4+ cell counts among patients prescribed highly active antiretroviral therapy (HAART) has not been well characterized. Method: We assessed the prognostic value of latest CD4+ cell counts and latest viral loads for progression to AIDS or death and explored their interaction among 432 HIV-infected persons with advanced HIV who were prescribed a protease inhibitor (PI) as their first HAART regimen. Results: Pre-HAART median CD4+ cell count and viral load were 41 cells/mm³ and 126,331 copies/mL, respectively. After 12 months of HAART, the median CD4+ cell count was 154 cells/mm³; 39% of patients had a viral load of 400 copies/mL or lower. Over a median follow-up of 33 months, 109 (25%) of the 432 patients experienced an AIDS event or died. The hazard ratio for AIDS or death for those with latest CD4+ cell count <50 cells/mm³ versus ≥200 cells/mm³ was 13.9 (95% CI 6.5 to 29.7) without adjustment for latest viral load measurements and 9.5 (95% CI 4.0 to 22.5) after adjustment for latest viral load. In contrast, the hazard ratio for AIDS or death for those with viral load ≥100,000 versus <400 copies/mL was 4.2 (95% CI 2.3 to 7.7) without adjustment for latest CD4+ level and 1.2 (95% CI 0.6 to 2.4) with adjustment for latest CD4+ cell count. Conclusion: We conclude that when latest CD4+ cell count and viral load are considered separately, both are significantly related to AIDS or death; when these markers are jointly considered, the association of viral load with AIDS or death is substantially diminished. Latest CD4+ levels are more strongly related to AIDS or death than latest viral load levels in patients on HAART.     

Effect of Antiretroviral Therapy and Hepatitis C Co-infection on Changes in Lipid Levels in HIV-Infected Patients 48 Weeks After Initiation of Therapy

Abstract

Hepatitis C virus (HCV) commonly co-infects HIV-infected individuals. Antiretroviral therapy (ART) is associated with elevated serum lipid levels, and HCV infection is associated with low serum lipid levels. Fasting lipid levels were investigated in 1,434 ART-naïve HIV-infected people participating in the AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trials (ALLRT) protocol who prospectively initiated ART with ≥3 agents. Subjects with elevated liver-associated enzymes (>5 × ULN) were excluded. Demographics, body mass index, HCV status, CD4 cell count, HIV RNA, liver enzymes, lipid levels, and glucose were assessed before and following 48 weeks of ART. HCV-positive subjects (n = 160; 11%) were older, more likely to be Black, have a history of intravenous drug use (IDU), have higher baseline liver-associated enzyme levels than the HCV-negative group (p < .001 for each), and to have diabetes at baseline (5% vs. 2%, p = .07). Lipid levels rose in both groups following ART, and the differences were not significant except that HDL levels increased significantly more in the HCV-positive group (p = .006). In summary, HCV infection did not appear to provide significant protection against ART-induced hyperlipidemia in this cohort of HIV-infected subjects prospectively enrolled in ART trials, although HDL levels rose to a greater degree.     

Plasmacytoid dendritic cell and functional HIV Gag p55‐specific T cells before treatment interruption can inform set‐point plasma HIV viral load after treatment interruption in chronically suppressed HIV‐1+ patients

The identification of immune correlates of HIV control is important for the design of immunotherapies that could support cure or antiretroviral therapy (ART) intensification-related strategies. ART interruptions may facilitate this task through exposure of an ART partially reconstituted immune system to endogenous virus. We investigated the relationship between set-point plasma HIV viral load (VL) during an ART interruption and innate/adaptive parameters before or after interruption. Dendritic cell (DC), natural killer (NK) cell and HIV Gag p55-specific T-cell functional responses were measured in paired cryopreserved peripheral blood mononuclear cells obtained at the beginning (on ART) and at set-point of an open-ended interruption from 31 ART-suppressed chronically HIV-1⁺ patients. Spearman correlation and linear regression modeling were used. Frequencies of plasmacytoid DC (pDC), and HIV Gag p55-specific CD3⁺ CD4⁻ perforin⁺ IFN-γ⁺ cells at the beginning of interruption associated negatively with set-point plasma VL. Inclusion of both variables with interaction into a model resulted in the best fit (adjusted R² = 0·6874). Frequencies of pDC or HIV Gag p55-specific CD3⁺ CD4⁻ CSFE^lo CD107a⁺ cells at set-point associated negatively with set-point plasma VL. The dual contribution of pDC and anti-HIV T-cell responses to viral control, supported by our models, suggests that these variables may serve as immune correlates of viral control and could be integrated in cure or ART-intensification strategies.     

Lower CD4+ T Lymphocyte Nadirs May Indicate Limited Immune Reconstitution in HIV-1 Infected Individuals on Potent Antiretroviral Therapy: Analysis of Immunophenotypic Marker Results of AACTG 5067

Background: Although initiation of potent antiretroviral therapy (ART) has significantly improved immune perturbations in individuals with AIDS, it is unclear which factors are most important in determining the degree of immune reconstitution.Methods: Whole blood was analyzed at baseline and week 12 in six groups of subjects (n = 81): those with acute or following immune reconstitution after Pneumocystis jirovecii (previously known as Pneumocystis carinii) pneumonia (PcP) (two groups) and cytomegalovirus (CMV) retinitis (two groups), HIV-infection without AIDS (one group), and healthy volunteers (one group). Absolute CD4+ and CD8+ T lymphocytes, naíve (CD45RA+) and memory (CD45RO+) CD4+ T lymphocytes and percentages of activated CD8+ T lymphocytes (CD8+/CD38+/HLA-DR), and CD28 expression on CD4+ and CD8+ T lymphocytes were enumerated.Results: The reconstituted CMV group, which had a history of a lower CD4+ T lymphocyte nadir compared to the reconstituted PcP group (15 cells/mm³ versus 48 cells/mm³; p = .013), had significantly lower absolute CD4+, CD8+ and naíve CD4+ T lymphocytes and a trend toward lower memory CD4+ T lymphocytes compared to the reconstituted PcP group. Moreover, no difference was noted between the reconstituted groups in the proportion of subjects with undetected HIV-1 RNA. The reconstituted subjects had significantly lower absolute CD4+, memory CD4+ and naíve CD4+ T lymphocytes than the HIV-positive controls and a significantly higher percentage of activated CD8+ T lymphocytes with a lower percentage of CD8+CD28 expression than the HIV-negative controls.Conclusion: The association of CD4+ T lymphocyte nadir with the extent of immune reconstitution in HIV-infected individuals suggests that HIV-1 may cause irreparable immune system damage despite potent ART.     

Low-level HIV infection of plasmacytoid dendritic cells: onset of cytopathic effects and cell death after PDC maturation

Plasmacytoid dendritic cells (PDC), the natural type-1 interferon (IFN) producing cells, are part of the innate immune defense against human immunodeficiency virus (HIV). PDC numbers are reduced in advanced stages of infection. These cells can be infected in vivo by HIV since highly purified PDC showed evidence of infectious HIV. Moreover, when PDC derived from uninfected donors were exposed to high-titered HIV isolates, productive infection occurred although with low-level replication. Using real-time amplification, PDC and unstimulated CD4+ cells were found equally susceptible to HIV infection; however, HIV replication was considerably limited in the PDC. Virus replication was enhanced after PDC treatment with CD40L and antibodies against IFN-alpha, most likely reflecting the reduction in IFN-alpha activity. On maturation, the infected PDC showed multinuclear cell syncytia formation and death. These findings indicate that PDC can be reservoirs for HIV dissemination and that HIV infection of PDC can contribute to their decline.     

Omega-3 Fatty Acids and Hypertriglyceridemia in HIV-Infected Subjects on Antiretroviral Therapy: Systematic Review and Meta-analysis

Abstract

Purpose: Antiretroviral therapy (ART) changed the course of AIDS. However, it has been associated with chronic metabolic complications including hypertriglyceridemia. The aim of this systematic review is to evaluate the effects of marine omega-3 fatty acids in triglycerides concentrations of HIV-infected subjects on ART.Methods: Thirty-three articles were found in a PubMed search; 6 met the inclusion criteria, and 4 of them were considered of adequate quality and included. Meta-analysis with fixed effects was performed and weighted mean differences (WMD; 95% CI) were described.Results: The overall reduction of triglycerides concentrations after 8 to 16 weeks of treatment with 900 to 3360 mg omega-3/day was WMD -80.34 mg/dL (95% CI, -129.08 to -31.60). Short-term (4 to 8 weeks) and a long-term (12 to 16 weeks) interventions were associated with a WMD -134.36 mg/dL (95% CI, -208.04 to -60.69) and WMD -54.09 mg/dL (95% CI, -115.77 to 7.59), respectively. The pooled result of studies with mean triglycerides ≥300 mg/dL at baseline and 1800 to 2900 mg omega-3/day was WMD -129.72 mg/dL (95% CI, -206.54 to -52.91).Conclusion: Different doses of omega-3 fatty acids significantly reduce triglycerides concentrations, confirming the potential applicability of this nutrient on the management of hypertriglyceridemia in HIV-infected subjects on ART.     

Kinetics of Lymphokine Production in HIV+ Patients Treated with Highly Active Antiretroviral Therapy and Interleukin 2

This study presents the kinetics of CD4/CD25 cell numbers, serum sCD25 levels, and intracellular production and release of interleukin-2 (IL-2) and interleukin-16 (IL-16) in 11 HIV+ patients treated with six cycles of highly active antiretroviral therapy (HAART) plus six MUI of subcutaneous IL-2 compared to 10 HIV+ patients treated with HAART alone. IL-2 therapy induced moderate effects on CD4 T cell recovery and increased CD4/CD25+ cells and sCD25 levels after 2 weeks, while intracellular and secreted IL-2 was reduced and IL-16 was increased at the same time point. After 24 weeks, while HAART-treated patients had increased IL-2 production, in IL-2 treated patients, cytokine production was unaltered compared to pretreatment values. Decreased in vitro IL-2 production may depend on a feedback inhibition by IL-2 infusion. Because of its known antiviral effects, the increased IL-16 production seen after 2 weeks in IL-2-treated individuals may produce beneficial effects on HIV disease. The kinetics of cytokine production may serve to define better the use IL-2 in clinical trials.     

Effect of Interleukin-28B Polymorphism on Interleukin-28 Expression and Immunological Recovery amongst HIV-1-Infected Individuals Following Antiretroviral Therapy

Purpose: Type III interferon is well known to have diverse antiviral and immunomodulatory activities. Studies describing the association of interleukin (IL)-28 polymorphisms in treatment-experienced HIV participants are limited. This study was aimed to determine the association of IL-28B gene polymorphisms with immunological recovery in HIV patients on 6–9 months of antiretroviral therapy (ART). Methods: Eighty treatment-naive HIV patients were recruited, of which 48 patients were followed up after 6–9 months of ART. Whole blood samples were collected before and after 6–9 months of ART. CD4, CD8 and CD3 counts were enumerated flow cytometry. IL-28B polymorphisms (rs12979860 and rs8099917) were profiled by polymerase chain reaction (PCR)-restriction fragment length polymorphism. The IL-28 mRNA and plasma HIV-1 viral load were estimated using real-time PCR and plasma IL-28 level by ELISA. Results: The CD4, CD4/CD3%, IL-28 mRNA and reversal of CD4/CD8 ratio were significantly increased following 6–9 months of ART (P < 0.01). The rs12979860 CC genotype and rs12979860:rs8099917 (CC: TT) haplotype showed significant association with higher CD4+ T-cell count amongst treatment-naive HIV-infected individuals (P < 0.05). In addition, there was a significant association of rs12979860 CC genotype with increase in CD4/CD3% following 6–9 months of ART. IL-28 mRNA showed correlation with the HIV-1 viral load, and there was a significant increase in the IL-28 mRNA expression following 6–9 months of ART. Conclusion: Our preliminary findings suggest that IL-28 polymorphisms could influence both immunological recovery and therapeutic response in HIV infection. Hence, functional studies are warranted to understand the mechanistic basis of IL-28-mediated host genetic influence on HIV therapeutic response.     

The Relationship of CCR5 Antagonists to CD4+ T-Cell Gain: A Meta-Regression of Recent Clinical Trials in Treatment-Experienced HIV-Infected Patients

Abstract

Purpose: Lower CD4+ T-cell counts are related to increased morbidity and mortality despite virologic suppression. CCR5 antagonists are associated with robust CD4+ T-cell responses. We examined the relationship of CCR5 antagonists to CD4+ T-cell gains. Design: Meta-regression of recent phase 2–3 trials evaluating new antiretroviral agents in treatment-experienced subjects. Methods: We analyzed the relationship of CCR5 antagonists to CD4+ T-cell count increase 24 weeks after initiating the new regimen using a linear model with generalized estimating equations controlling for differing rates of virologic suppression. Each treatment group was treated as a data point weighted by sample size. Results: We included 46 treatment groups from 17 trials (11 groups from 5 trials used CCR5 antagonists). Controlling for average baseline HIV-1 RNA and proportion of subjects achieving HIV-1 RNA <50 copies/mL, use of a CCR5 antagonist was associated with an additional significant CD4+ T-cell gain of +30/μL (95% CI, 19–42) at 24 weeks compared to treatment groups not using a CCR5 antagonist. Conclusions: Use of a CCR5 antagonist was associated with an enhanced CD4+ T-cell count response independent of virologic suppression. This observation supports further evaluation of CCR5 antagonists in patients with discordant immunologic and virologic responses to ART.     

Dendritic cells,T cells and their interaction in rheumatoid arthritis

Dendritic cells (DCs) are the key professional antigen-presenting cells which bridge innate and adaptive immune responses, inducing the priming and differentiation of naive to effector CD4⁺ T cells, the cross-priming of CD8⁺ T cells and the promotion of B cell antibody responses. DCs also play a critical role in the maintenance of immune homeostasis and tolerance. DC–T cell interactions underpin the generation of an autoimmune response in rheumatoid arthritis (RA). Here we describe the function of DCs and review evidence for DC and T cell involvement in RA pathogenesis, in particular through the presentation of self-peptide by DCs that triggers differentiation and activation of autoreactive T cells. Finally, we discuss the emerging field of targeting the DC–T cell interaction for antigen-specific immunotherapy of RA.