Chronic immune activation and decreased CD4 cell counts associated with hepatitis C infection in HIV-1 natural viral suppressors

IFIH1 (MDA5) is required for innate immune detection of intron-containing RNA expressed from the HIV-1 provirus

Intron-containing RNA expressed from the HIV-1 provirus activates type 1 interferon in primary human blood cells, including CD4+ T cells, macrophages, and dendritic cells. To identify the innate immune receptor required for detection of intron-containing RNA expressed from the HIV-1 provirus, a loss-of-function screen was performed with short hairpin RNA-expressing lentivectors targeting twenty-one candidate genes in human monocyte-derived dendritic cells. Among the candidate genes tested, only knockdown of XPO1 (CRM1), IFIH1 (MDA5), or MAVS prevented activation of the interferon-stimulated gene ISG15. The importance of IFIH1 protein was demonstrated by rescue of the knockdown with nontargetable IFIH1 coding sequence. Inhibition of HIV-1-induced ISG15 by the IFIH1-specific Nipah virus V protein, and by IFIH1-transdominant 2-CARD domain-deletion or phosphomimetic point mutations, indicates that IFIH1 (MDA5) filament formation, dephosphorylation, and association with MAVS are all required for innate immune activation in response to HIV-1 transduction. Since both IFIH1 (MDA5) and DDX58 (RIG-I) signal via MAVS, the specificity of HIV-1 RNA detection by IFIH1 was demonstrated by the fact that DDX58 knockdown had no effect on activation. RNA-Seq showed that IFIH1 knockdown in dendritic cells globally disrupted the induction of IFN-stimulated genes by HIV-1. Finally, specific enrichment of unspliced HIV-1 RNA by IFIH1 (MDA5), over two orders of magnitude, was revealed by formaldehyde cross-linking immunoprecipitation (f-CLIP). These results demonstrate that IFIH1 is the innate immune receptor for intron-containing RNA from the HIV-1 provirus and that IFIH1 potentially contributes to chronic inflammation in people living with HIV-1, even in the presence of effective antiretroviral therapy.

Human Immunodeficiency Virus-1 Drug Resistance Mutations in Iranian Treatment-experienced Individuals

BACKGROUND

Human immunodeficiency virus-1 infection still remains a global health threat. While antiretroviral therapy is the primary treatment option, concerns about the emergence of drug-resistance mutations and treatment failure in HIV-infected patients persist.

OBJECTIVE

In this study, we investigated the development of drug resistance in HIV-1-infected individuals receiving antiretroviral therapy for 6-10 years.

METHODS

In this cross-sectional study, we evaluated 144 people living with HIV-1 who had received antiretroviral therapy for at least 6 years. Plasma specimens were collected, and the HIV-1 viral load and drug-resistance mutations were assessed using molecular techniques.

RESULTS

The demographic and epidemiological characteristics of the participants were also analyzed: Twelve [8.3%) of the studied patients showed a viral load over 1000 copies per/mL, which indicates the suboptimal response to antiretroviral therapy. Significant correlations were found between viral load and CD4 count, as well as epidemiological factors, such as vertical transmission, history of imprisonment, and needle stick injuries. Drug resistance mutations were detected in 10 (83.3%) of patients who failed on antiretroviral therapy, with the most common mutations observed against nucleoside reverse transcriptase inhibitors (5 (41.7%)) and non-nucleoside reverse transcriptase inhibitors (9 (75%)). Phylogenetic analysis revealed that 12 patients who failed treatment were infected with CRF35_AD.

CONCLUSION

Our study provides important insights into the characteristics and development of drug resistance in HIV-1-infected individuals receiving long-term antiretroviral therapy in Iran. The findings underline the need for regular viral load monitoring, individualized treatment selection, and targeted interventions to optimize treatment outcomes and prevent the further spread of drug-resistant strains.

IFIH1 (MDA5) is required for innate immune detection of intron-containing RNA expressed from the HIV-1 provirus

Antiretroviral therapy (ART) suppresses HIV-1 viremia and prevents progression to AIDS. Nonetheless, chronic inflammation is a common problem for people living with HIV-1 on ART. One possible cause of inflammation is ongoing transcription from HIV-1 proviruses, whether or not the sequences are competent for replication. Previous work has shown that intron-containing RNA expressed from the HIV-1 provirus in primary human blood cells, including CD4+ T cells, macrophages, and dendritic cells, activates type 1 interferon. This activation required HIV-1 rev and was blocked by the XPO1 (CRM1)-inhibitor leptomycin. To identify the innate immune receptor required for detection of intron-containing RNA expressed from the HIV-1 provirus, a loss-of-function screen was performed with shRNA-expressing lentivectors targeting twenty-one candidate genes in human monocyte derived dendritic cells. Among the candidate genes tested, only knockdown of XPO1 (CRM1), IFIH1 (MDA5), or MAVS prevented activation of the IFN-stimulated gene ISG15. The importance of IFIH1 protein was demonstrated by rescue of the knockdown with non-targetable IFIH1 coding sequence. Inhibition of HIV-1-induced ISG15 by the IFIH1-specific Nipah virus V protein, and by IFIH1-transdominant inhibitory CARD-deletion or phosphomimetic point mutations, indicates that IFIH1 filament formation, dephosphorylation, and association with MAVS, are all required for innate immune activation in response to HIV-1 transduction. Since both IFIH1 and DDX58 (RIG-I) signal via MAVS, the specificity of HIV-1 RNA detection by IFIH1 was demonstrated by the fact that DDX58 knockdown had no effect on activation. RNA-Seq showed that IFIH1-knockdown in dendritic cells globally disrupted the induction of IFN-stimulated genes. Finally, specific enrichment of unspliced HIV-1 RNA by IFIH1 was revealed by formaldehyde crosslinking immunoprecipitation (f-CLIP). These results demonstrate that IFIH1 is required for innate immune activation by intron-containing RNA from the HIV-1 provirus, and potentially contributes to chronic inflammation in people living with HIV-1.

Impact of treatment with direct-acting antivirals on inflammatory markers and autoantibodies in HIV/HCV co-infected individuals

HCV infection could have extrahepatic manifestations due to an aberrant immune response. HCV/HIV co-infection increases such persistent immune activation. Aim of the present study is to describe the evolution of inflammatory markers used in clinical practice, mixed cryoglobulinemia (MC) and autoantibody reactivity in co-infected individuals who achieved sustained virological response (SVR) after DAA treatment. This prospective, observational study included all HIV/HCV co-infected subjects who started any DAA regimen from 2015 to 2020. Samples for laboratory measurements (ferritin, C reactive protein, C3 and C4 fractions, rheumatoid factor, MC, anti-thyroglobulin Ab, anti-thyroid peroxidase Ab, ANCA, ASMA, anti-LKM, anti-DNA, AMA, ANA, T CD4+ and CD8+ cell count, and CD4/CD8 ratio) were collected at baseline, after 4 weeks, at end of treatment, and at SVR12. The analysis included 129 individuals: 51.9% with a F0-F3 fibrosis and 48.1% with liver cirrhosis. Cryocrit, C3 fraction, and rheumatoid factor significantly improved at week 4; ferritin, anti-thyroglobulin Ab, and C4 fraction at EOT; total leukocytes count at SVR12. MC positivity decreased from 72.8% to 35.8% (p < .001). T CD4+ cell slightly increased at SVR12, but with an increase also in CD8+ resulting in stable CD4/CD8 ratio. Autoantibody reactivity did not change significantly. ANA rods and rings positivity increased from 14.8% to 28.6% (p = .099): they were observed in three subjects without exposure to RBV. DAA therapy may lead to improvement in inflammatory markers and MC clearance but without significant changes in autoantibodies reactivity and CD4/CD8 ratio over a follow up of 12 weeks.

Immunological and Clinical Impact of DAA-Mediated HCV Eradication in a Cohort of HIV/HCV Coinfected Patients: Monocentric Italian Experience

HCV treatment became available for all infected patients regardless of their comorbidities, especially for HIV coinfected subjects, leading to an improvement in both clinical and immunological conditions. We retrospectively analyzed a cohort of HIV/HCV coinfected patients treated with DAA therapies; data regarding epidemiological, viral-immunological, and hepatic parameters before and after DAA administration have been collected. Drug-drug interactions between DAA and both antiretroviral therapy and non-ART-drugs were also evaluated; the study showed the efficacy of DAA schedules in HCV eradication also for HIV/HCV patients with multiple comorbidities and assuming many different drugs. Principal issues are still represented by drug interactions, pill burden, and patients' compliance. These concerns have to be taken into account, especially in HIV patients for whom the immunological state and ART interactions should always be considered.

Post-migration acquisition of HIV: Estimates from four European countries, 2007 to 2016

BackgroundThe assumption that migrants acquire human immunodeficiency virus (HIV) before migration, particularly those from high prevalence areas, is common.AimWe assessed the place of HIV acquisition of migrants diagnosed in four European countries using surveillance data.MethodsUsing CD4+ T-cell count trajectories modelled to account for seroconversion bias, we estimated infection year of newly HIV-diagnosed migrants residing in the United Kingdom (UK), Belgium, Sweden and Italy with a known arrival year and CD4+ T-cell count at diagnosis. Multivariate analyses identified predictors for post-migration acquisition.ResultsBetween 2007 and 2016, migrants constituted 56% of people newly diagnosed with HIV in the UK, 62% in Belgium, 72% in Sweden and 29% in Italy. Of 23,595 migrants included, 60% were born in Africa and 70% acquired HIV heterosexually. An estimated 9,400 migrants (40%; interquartile range (IQR): 34-59) probably acquired HIV post-migration. This proportion was similar by risk group, sex and region of birth. Time since migration was a strong predictor of post-migration HIV acquisition: 91% (IQR: 87-95) among those arriving 10 or more years prior to diagnosis; 30% (IQR: 21-37) among those 1-5 years prior. Younger age at arrival was a predictor: 15-18 years (81%; IQR: 74-86), 19-25 years (53%; IQR: 45-63), 26-35 years (37%; IQR: 30-46) and 36 years and older (25%; IQR: 21-33).ConclusionsMigrants, regardless of origin, sex and exposure to HIV are at risk of acquiring HIV post-migration to Europe. Alongside accessible HIV testing, prevention activities must target migrant communities.

Impact of first-line antiretroviral therapy regimens on the restoration of the CD4/CD8 ratio in the CNICS cohort

BACKGROUND

The CD4/CD8 ratio is an indicator of immunosenescence and a predictor of all-cause mortality in HIV-infected patients. The effects of different ART regimens on CD4/CD8 ratio recovery remain unclear.

METHODS

Clinical cohort study of ART-treated patients from the CFAR Network of Integrated Clinical Systems (CNICS). We included ART-naive adults with HIV infection who achieved undetectable HIV RNA during the first 48 weeks of treatment and had additional follow-up 48 weeks after virological suppression (VS). Primary endpoints included increase in CD4/CD8 ratio at both timepoints and secondary endpoints were CD4/CD8 ratio recovery at cut-offs of ≥0.5 or ≥1.0.

RESULTS

Of 3971 subjects who met the study criteria, 1876 started ART with an NNRTI, 1804 with a PI and 291 with an integrase strand transfer inhibitor (INSTI). After adjusting for age, sex, race, year of entry, risk group, HCV serostatus, baseline viral load and baseline CD4/CD8 ratio, subjects on an NNRTI showed a significantly greater CD4/CD8 ratio gain compared with those on a PI, either 48 weeks after ART initiation or after 48 weeks of HIV RNA VS. The greater CD4/CD8 ratio improvement in the NNRTI arm was driven by a higher decline in CD8 counts. The INSTI group showed increased rates of CD4/CD8 ratio normalization at the ≥1.0 cut-off compared with the PI group.

CONCLUSIONS

NNRTI therapy was associated with a greater increase in the CD4/CD8 ratio compared with PIs. NNRTI- and INSTI-based first-line ART were associated with higher rates of CD4/CD8 ratio normalization at a cut-off of 1.0 than a PI-based regimen, which might have clinical implications.

The impact of DAA-mediated HCV eradication on CD4+ and CD8+ T lymphocyte trajectories in HIV/HCV coinfected patients: Data from the ICONA Foundation Cohort

HCV infection has been hypothesized as a contributor of poor CD4⁺ recovery in patients living with HIV (PLWHIV). Aim of this study was to evaluate CD4⁺ , CD8⁺ cells and CD4/CD8 ratio trends before and after HCV treatment with direct acting agents (DAA) in PLWHIV. HIV/HCV patients enrolled in ICONA and HepaICONA cohorts with HIV-RNA≤50 copies/ml who achieved a sustained viral response after DAA treatment were studied. A linear regression model was used to investigate CD4⁺ , CD8⁺ and CD4/CD8 changes 12 months before and after DAA treatment. A total of 939 HIV/HCV patients were included, 225 (24.0%) female, median age: 53 years (IQR 50-56). At DAA initiation, CD4⁺ T cell count was <350 cells/mm³ in 164 patients (17.5%), and 246 patients (26.2%) had liver stiffness>12.5 kPa. Trends of CD4⁺ and CD4/CD8 ratio were similar before and after DAA in all study populations (CD4⁺ change +17.6 cells/mm³ (95%CI -33.5; 69.4, p = 0.494); CD4/CD8 change 0.013 (95%CI -0.061; 0.036, p = 0.611). However, patients treated with ribavirin (RBV)-free DAA showed a significant decrease in CD8⁺ cells (-204.3 cells/mm³ , 95%CI -375.0;-33.4, p = 0.019), while patients treated with RBV experienced CD8⁺ cell increase (+141.2 cells/mm³ , 95%CI 40.3; 242.1, p = 0.006). In conclusion, HCV eradication following DAA treatment does not seem to have an impact on CD4⁺ T cell recovery in PLWHIV. However, a fast decline of CD8⁺ T cells has been observed in patients treated without RBV, suggesting a favourable effect of HCV clearance on the general state of immune activation.

A Comparative Study of Different Joint Modeling Approaches for HIV/AIDS Patients in Southern Iran

Background:

The prevalence of HIV/AIDS has been increasing in Iran, especially amongst the young population, recently. The joint model (JM) is a statistical method that represents an effective strategy to incorporate all information of repeated measurements and survival outcomes simultaneously. In many theoretical studies, the population under the study were heterogeneous. This study aimed at comparing three approaches by considering heterogeneity in the patients.

Methods:

This study was conducted on 750 archived files of patients infected with HIV in Fars Province, southern Iran, from 1994 to 2017. Proposed Approach (PA), Joint Latent Class Models (JLCM), and Separated Approach (SA) were compared to evaluate the influence covariates on the longitudinal and time-to-event outcomes in the heterogeneous HIV/AIDS patients.

Results:

Gender (P<0.001) and HCV (P<0.01) were two significant covariates in the classification of HIV/AIDS patients. Time had a significant effect on CD4 (P<0.001) in both classes in the three approaches. In PA and SA, females had higher CD4 than males (P<0.001) in the first class. In JLCM, females had higher CD4 than males (P<0.01) in both classes. The patients with higher Hgb had also higher CD4 (P<0.001) in both classes in the three approaches. HCV reduced the CD4 significantly in both classes in PA (P<0.05) and SA (P<0.001). Within the survival sub-model, HCV reduced survival rate significantly in the second class in PA (P<0.05), JLCM (P<0.01) and SA (P<0.001).

Conclusion:

PA was an appropriate approach for joint modeling longitudinal and survival outcomes for this heterogeneous population.

Antiretroviral Treatment for HIV Elite Controllers?

In most HIV-infected persons, the natural history of untreated infection is one of sustained viremia, progressive CD4 T cell depletion with resultant morbidity and mortality. The advent of effective combination antiretroviral therapy (ART) that controls HIV replication has altered this landscape dramatically. Yet a rare population of HIV-infected persons-elite controllers (EC)-can control HIV replication such that plasma levels of virus are "undetectable" without ART. The EC phenotype is heterogeneous, with some subjects durably controlling the virus-persistent elite controllers-and some eventually losing viral control-transient elite controllers. Overall, EC tend to have robust HIV-specific T cell responses and in some cases, mainly in transient elite controllers, elevated activation and inflammation indices that diminish with ART suggesting that endogenous defenses against this persistent pathogen come at the cost of heightened activation/inflammation. A limited data set suggests that cardiovascular disease risk as well as the occur-rence of other morbid events may be greater in the overall EC population than in treated HIV infection. ART in EC decreases activation indices but does not appear to increase circulating CD4 T cell numbers nor do we know if it alters clinical outcomes. Thus, it is difficult to recommend or discourage a decision to start ART in the EC population but the authors lean toward treatment particularly in those EC whose activation indices are high and those who are progressively losing circulating CD4 T cell numbers. Biomarkers that can reliably predict loss of virologic control and immune failure are needed.

γδ T-cell subsets in HIV controllers: potential role of Tγδ17 cells in the regulation of chronic immune activation

OBJECTIVES

HIV controllers (HICs) are rare HIV-infected individuals able to maintain undetectable viremia in the absence of antiretroviral treatment. Although HIV-specific cytotoxic T cells have been well deciphered in HIC, γδ T lymphocytes remain largely uncharacterized. The aim of this study was to analyse phenotypic and functional characteristics of γδ T cells and their relationship with immune activation, which remains abnormally elevated and associated with comorbidities in HICs.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from 16 HICs, 16 patients with untreated chronic HIV infection (UT-CHI) and 20 healthy donors. Surface marker expression and cytokine production by γδ T cells were analysed by flow cytometry.

RESULTS

Despite normal frequencies of total γδ T cells, the Vδ2/Vδ2 ratio was significantly reduced in HIC, albeit to a lesser extent than UT-CHI patients. Of note, nine HICs showed elevated Vδ2 γδ T cells, as patients with UT-CHI, which was associated with higher CD8 T-cell activation. Interleukin (IL)-17-production by γδ T cells (Tγδ17) was better preserved in HIC than in UT-CHI patients. Proportion of total γδ T cells positively correlated with CD8 T-cell activation and HIV-DNA, IP-10 and sCD14 levels. Conversely, Tγδ17 cells negatively correlated with CD8 T-cell activation and plasma sCD14 levels. Moreover, transforming growth factor (TGF)-β producing Vδ2 T cells were as dramatically depleted in HIC as in UT-CHI patients.

CONCLUSION

The relative preservation of IL-17-producing γδ T cells in HIC and their negative association with immune activation raise the hypothesis that Tγδ17 cells - potentially through prevention of microbial translocation - may participate in the control of chronic systemic immune activation.

Characteristics of treatment-naïve HBV-infected individuals with HIV-1 coinfection: A cross-sectional study from South India

Purpose

Human immunodeficiency virus-1 (HIV-1) and hepatitis B virus (HBV) coinfection has become a major health problem across the globe. The increased life expectancy of HIV-1 patients due to antiretroviral therapy has led to the emergence of liver disease as a major mortality factor among them. The purpose of the study was to examine the baseline characteristics of HBV in treatment-naïve HBV/HIV coinfection from southern India compared to monoinfected individuals.

Materials and Methods

The study was cross sectional in design, and samples were examined from 80 HIV-1, 70 HBV and 35 HBV/HIV-coinfected individuals using chemiluminescent microparticle immunoassay, real-time polymerase chain reaction and flow cytometry assays.

Results

There was a significant increase in HBV DNA (P = 0.0001), higher hepatitis B e antigen percentage difference (P = 0.027) and lower CD4 counts (P = 0.01) among the HBV/HIV-coinfected individuals, but no difference in the HIV-1 viral load compared to HIV-1-monoinfected individuals. Also, the aspartate aminotransferase levels, prothrombin time and the international normalised ratio were significantly high among coinfected individuals.

Conclusion

These findings conclude that HIV-1 coinfection can have serious implications on the outcome of HBV-related liver disease. To the contrary, HBV infection had no consequence on the progression of HIV-1 disease but distinctly lowered CD4+ T-cells.

Influence of Injection Drug Use-Related HIV Acquisition on CD4 Response to First Antiretroviral Therapy Regimen Among Virally Suppressed Individuals

BACKGROUND

The inflammatory effects of injection drug use (IDU) may result in an impaired immune response to antiretroviral therapy (ART). We examined CD4 response to first ART regimen among individuals in routine HIV care, stratified by IDU-related HIV acquisition.

SETTING

Cohort study including patients who initiated ART between 2000 and 2015 in the Johns Hopkins HIV Clinic.

METHODS

We followed individuals from ART initiation until death, loss to follow-up, loss of viral load suppression (<500 copies/mL), or administrative censoring. We described CD4 trajectories after ART initiation using inverse probability weighted quantile regression models with restricted cubic splines for time. Weights accounted for differences in baseline characteristics of persons comparing those with IDU-related HIV acquisition to those with other HIV acquisition risks (non-IDU) and possible nondifferential censoring due to death, loss to follow-up, or loss of viral load suppression. We also examined CD4 response by strata of CD4 at ART initiation (≤200, 201-350, >350).

RESULTS

Of 1244 patients initiating ART, 30.4% were IDU. Absolute CD4 cell difference at the 50th percentile comparing IDU with non-IDU was -25 cells [95% confidence interval (CI): -63 to 35], -66 cells (95% CI: -141 to 16), and -91 cells (95% CI: -190 to -5) at 2, 4, and 6 years after ART initiation, respectively. Results were similar (non-IDU with slightly higher CD4 count, but not statistically significant differences) at other percentiles and stratified by baseline CD4.

CONCLUSIONS

CD4 recovery after ART initiation was similar for IDU and non-IDU, conditional on consistent viral load suppression.

Elevated liver stiffness is linked to increased biomarkers of inflammation and immune activation in HIV/hepatitis C virus-coinfected patients

OBJECTIVES

Immune dysregulation is a hallmark of HIV and hepatitis C virus (HCV) infections. We aimed to evaluate the relationship between liver stiffness measurement (LSM) and biomarkers of T-cell activation, bacterial translocation, inflammation, endothelial dysfunction, and coagulopathy in HIV/HCV-coinfected patients.

DESIGN

Cross-sectional study.

METHODS

We studied 238 HIV/HCV-coinfected patients, 32 healthy controls, and 39 HIV-monoinfected patients. Patients were stratified according to LSM into four groups: less than 12.5, 12.5-25, 25-40, and more than 40 kPa. T-cell subsets were measured using flow cytometry and plasma biomarkers using immunoassays.

RESULTS

HIV/HCV-coinfected patients had higher biomarker levels of immune activation in peripheral blood [T-cell activation (CD4CD38 and CD8CD38), bacterial translocation (soluble CD14), inflammation [IL-1b, IL-6, IL-8, IL-18, IFN-γ-inducible protein 10 (IP-10)] endothelial dysfunction [soluble vascular cell adhesion molecule 1 (sVCAM1), soluble intercellular cell adhesion molecule 1 (sICAM1), and soluble tumor necrosis factor receptor 1 (sTNFR1)], and coagulopathy (plasminogen activator inhibitor-1)] than healthy controls and HIV-monoinfected patients. Moreover, in HIV/HCV-coinfected patients, a direct relationship between LSM and immune activation [T-cell activation (CD8CD38 bacterial translocation (lipopolysaccharide), inflammation (IL-8, IP-10), endothelial dysfunction (sVCAM1, sICAM1, and sTNFR1), and coagulopathy (D-dimer)] was found. Subsequently, patients were stratified into different fibrosis stages, finding that patients with cirrhosis who had LSM at least 40 kPa showed higher biomarker values of immune activation [T-cell activation (CD4CD38 and CD8CD38), bacterial translocation (lipopolysaccharide), inflammation (IL-8, IL-6, IP-10), endothelial dysfunction (sVCAM1, sICAM1, and sTNFR1), and coagulopathy (D-dimer)] than patients from the other three groups (<12.5, 12.5-25, and 25-40 kPa).

CONCLUSION

T-cell activation, bacterial translocation, inflammation, endothelial dysfunction, and coagulopathy increased with the severity of liver fibrosis in HIV/HCV-coinfected patients, particularly in patients who had LSM at least 40 kPa.

Class-modeling analysis reveals T-cell homeostasis disturbances involved in loss of immune control in elite controllers

BACKGROUND

Despite long-lasting HIV replication control, a significant proportion of elite controller (EC) patients may experience CD4 T-cell loss. Discovering perturbations in immunological parameters could help our understanding of the mechanisms that may be operating in those patients experiencing loss of immunological control.

METHODS

A case-control study was performed to evaluate if alterations in different T-cell homeostatic parameters can predict CD4 T-cell loss in ECs by comparing data from EC patients showing significant CD4 decline (cases) and EC patients showing stable CD4 counts (controls). The partial least-squares-class modeling (PLS-CM) statistical methodology was employed to discriminate between the two groups of patients, and as a predictive model.

RESULTS

Herein, we show that among T-cell homeostatic alterations, lower levels of naïve and recent thymic emigrant subsets of CD8 cells and higher levels of effector and senescent subsets of CD8 cells as well as higher levels of exhaustion of CD4 cells, measured prior to CD4 T-cell loss, predict the loss of immunological control.

CONCLUSIONS

These data indicate that the parameters of T-cell homeostasis may identify those EC patients with a higher proclivity to CD4 T-cell loss. Our results may open new avenues for understanding the mechanisms underlying immunological progression despite HIV replication control, and eventually, for finding a functional cure through immune-based clinical trials.

Pulmonary disease in HIV-infected adults in the era of antiretroviral therapy

: HIV in the antiretroviral therapy era is characterized by multimorbidity and the frequent occurrence of HIV-associated non-AIDS chronic health conditions. Respiratory symptoms and chronic pulmonary diseases, including chronic obstructive pulmonary disease, asthma, and cardiopulmonary dysfunction, are among the conditions that may present in persons living with HIV. Tobacco smoking, which is disproportionately high among persons living HIV, strongly contributes to the risk of pulmonary disease. Additionally, features associated with and at times unique to HIV, including persistent inflammation, immune cell activation, oxidative stress, and dysbiosis, may also contribute. This review summarizes the available literature regarding epidemiology of and risk factors for respiratory symptoms and chronic pulmonary disease in the current era.

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.

Residual Immune Activation and Latency

The introduction of combination antiretroviral therapy (cART) in the 1990s has dramatically changed the course of HIV infection, decreasing the risk for both AIDS- and non-AIDS-related events. Cancers, cardiovascular disease (CVD), liver and kidney disease, neurological disorders and frailty have become of great importance lately in the clinical management as they represent the principal cause of death in people living with HIV who receive cART (Kirk et al. in Clin Infect Dis 45(1):103-10, 2007; Strategies for Management of Antiretroviral Therapy Study et al. N Engl J Med 355(22):2283-2296, 2006; Ances et al. J Infect Dis 201(3):336-340, 2010; Desquilbet et al. J Gerontol A Biol Sci Med Sci 62(11):1279-1286, 2007; Lifson et al. HIV Clin Trials 9(3):177-185, 2008). Despite the undeniable achievements of cART, we are now faced with its limitations: a considerable proportion of individuals, referred as to immunological non-responders, fails to reconstitute the immune system despite optimal treatment and viral suppression (Kelley et al. Clin Infect Dis 48(6):787-794, 2009; Robbins et al. Clin Infect Dis 48(3):350-361, 2009) and remains at high risk for opportunistic infections and non-AIDS-related events (Strategies for Management of Antiretroviral Therapy Study et al. N Engl J Med 355(22):2283-2296, 2006). Moreover, the generalized state of immune activation and inflammation, linked to serious non-AIDS events, persists despite successful HIV suppression with cART. Finally, the current strategies have so far failed to eradicate the virus, and inflammation appears a driving force in viral persistence. In the light of all this, it is of fundamental importance to investigate the pathophysiological processes that link incomplete immune recovery, immune activation and HIV persistence to design targeted therapies that could impact on the three.

Over-expression of CD8+ T-cell activation is associated with decreased CD4+ cells in patients seeking treatment of Alcohol Use Disorder

INTRODUCTION

Harmful alcohol consumption may have an impact on the adaptive immune system through an imbalance in T cell subpopulations and changes in cell activation. We aimed to analyze profiles of CD4 and CD8T cell activation in patients with alcohol use disorder (AUD).

METHODS

We used a cross-sectional study with patients seeking treatment of the disorder. Blood samples for immunophenotyping were obtained at admission. Profiles of T cell activation were defined: (I) CD38⁺/HLA-DR⁺, (II) CD38⁺/HLA-DR^-, (III) CD38^-/HLA-DR⁺, (IV) CD38^-/HLA-DR^- and compared with healthy controls. We calculated a CD8⁺ T cell activation indicator (AI) that was defined as the quotient of non-activated cells (CD38^-/HLA-DR^-) and activated cells (CD38⁺/HLA-DR⁺).

RESULTS

60 patients were eligible (83%M); median age was 49 years [IQR: 44-54] and alcohol consumption was 145g/day [IQR: 90-205]. Mean±SD of CD38⁺/HLA-DR^- was 50.3±50.6 cells/μL in patients and 33.5±24.5 cells/μL in controls (p=0.03), for the CD38^-/HLA-DR⁺ it was 61±62.2 cells/μL in patients and 21.2±17.3 cells/μL in controls (p<0.001) and for the CD38⁺/HLA-DR⁺ it was 20.2±15.6 cells/μL in patients and 10.8±10.3 cells/μL in controls (p<0.001). In patients, an inverse correlation was observed between absolute number and percentage of CD4⁺ T cells, and the percentage of CD38⁺/HLA-DR⁺CD8⁺ T cells (r=0.37, p=0.003; r=0.2, p=0.086, respectively).

CONCLUSIONS

Patients with AUD have an increased expression of immune activation with respect to healthy individuals. This excess of activated CD8⁺ T cells correlates with the absolute CD4⁺ T cells.

Long-term follow-up of elite controllers: Higher risk of complications with HCV coinfection, no association with HIV disease progression

To estimate the effect of hepatitis C virus (HCV) coinfection on the development of complications and progression of human immunodeficiency virus (HIV) disease among HIV-infected elite controllers.Single-center retrospective cohort. Kaplan-Meier methods, prevalence ratios, and Cox proportional-hazards models were used.In all, 55 HIV-infected elite controllers were included in this study. Among them, 45% were HIV/HCV coinfected and 55% were HIV mono-infected. Median follow-up time for the cohort was 11 years. Twenty-five patients experienced a complication and 16 lost elite controller status during the study period. HCV coinfected patients were 4.78 times (95% confidence interval 1.50-15.28) more likely to develop complications compared with HIV mono-infected patients. There was no association between HCV coinfection status and loss of elite control (hazard ratio 0.75, 95% confidence interval 0.27-2.06).Hepatitis C virus coinfection was significantly associated with the risk of complications even after controlling for sex, injecting drug use, and older age. HCV coinfected patients had higher levels of cellular activation while also having similar levels of lipopolysaccharide and soluble CD14. HCV coinfection was not associated with loss of elite controller status. Taken together, this suggests that HCV coinfection does not directly affect HIV replication dynamics or natural history, but that it may act synergistically with HIV to produce a greater number of associated complications. Continued follow-up will be needed to determine whether HCV cure through the use of direct-acting antivirals among HIV/HCV coinfected elite controllers will make the risk for complications among these patients similar to their HIV mono-infected counterparts.

Virologic and immunologic aspects of HIV-hepatitis C virus coinfection

HIV/hepatitis C virus (HCV) coinfection is estimated to affect 2 million individuals globally. The acceleration of HCV-associated complications, particularly hepatic fibrosis, because of HIV coinfection has been well established, whereas the impact of HCV on HIV progression remains unclear. In this review, we summarize the current evidence on the impact of coinfection on the transmission and clinical progression of each infection. We focus on the virological and immunological alterations that contribute to HIV and HCV pathogenesis in coinfection and also review the disease-modifying effects of antiretroviral therapy as they pertain to HCV.

Evaluation of immunological indices in HIV-infected patients with chronic hepatitis C in Kazakhstan

Aim

To evaluate immunological indices in HIV-infected patients with chronic hepatitis C (CHC) who are injecting drug users.

Materials and methods

The study examined 38 patients coinfected with HIV and CHC who were injecting drug users and 36 patients with HIV/CHC who were not injecting drug users. In the study of immune status, the relative and absolute numbers of CD3+, CD4+, CD8+, CD16+, and CD20+ cells were determined by means of flow cytofluorometry of “FACSCount” using monoclonal antibodies of the company Becton Dickinson. The level of circulating immune complexes in blood serum was determined by means of precipitation in polyethylene glycol solution.

Results

It was found that T-cell immunodeficiency was developing in patients coinfected with HIV and CHC. T-cell immunodeficiency was characterized by a decrease in the number of T-helpers, mainly for injecting drug users. At the same time, patients coinfected with HIV and CHC experienced markedly elevated levels of circulating immune complexes, mainly among injecting drug users. The evaluation of immunogram indices in injecting drug users coinfected with HIV and CHC, depending on the stage of HIV infection, revealed a greater degree of immune-suppression of T-helper cells in clinical stage III.

Conclusion

Our comprehensive immunological study of patients coinfected with HIV and CHC revealed a pronounced dysfunction of the immune system. The comparison of the immune system indices in patients with HIV/CHC showed a more pronounced T-cell suppression in injecting drug users than in patients with HIV/CHC but who were not injecting drug users.

Analysis of Non-AIDS-Defining Events in HIV Controllers

BACKGROUND

Human immunodeficiency virus (HIV) controllers have the striking ability to maintain viremia at extremely low or undetectable levels without antiretroviral treatment. Even though these patients have been widely studied, information about clinical outcomes, especially concerning to non-AIDS-defining events (nADEs), is scarce. We have analyzed the frequency and rate of nADEs and their associated factors in a large multicenter HIV controller cohort.

METHODS

Data on nADEs were recorded for 320 HIV controllers within the multicenter Spanish AIDS Research Network HIV Controllers Cohort (ECRIS). Percentages and crude incidence rates (CIRs) per 100 person-years of follow-up (PYFU) were calculated for the entire follow-up period and for 2 separate periods: the period under control and the period after loss of control. These rates were compared with those for 632 noncontrollers. Demographic and immunological data collected from the controllers were included in a multivariate model to assess factors that were independently associated with nADEs in HIV controllers.

RESULTS

HIV controllers experience nADEs, albeit at lower rates than patients who do not spontaneously control the virus (1.252 [95% confidence interval {CI}, .974-1.586] per 100 PYFU and 2.481 [95% CI, 2.153-2.845] per 100 PYFU, respectively; P < .001). Hepatitis C virus (HCV) coinfection was the main factor associated with nADEs in all of the studied periods. Although hepatic events were the most prevalent, they represented only approximately 30% of the total events. CIRs of cardiovascular events increased in the post-loss-of-control period.

CONCLUSIONS

HCV/HIV coinfection was the main factor associated with hepatic and extrahepatic nADEs in HIV controllers. The eradication of HCV infection may ameliorate the presence of comorbidities in these patients.

Dominant enrichment of phenotypically activated CD38(+) HLA-DR(+) CD8(+) T cells, rather than CD38(+) HLA-DR(+) CD4(+) T cells, in HIV/HCV coinfected patients on antiretroviral therapy

HIV infection may enhance immune-activation, while little is known regarding the role of HCV infection. This study investigates the impact of HCV in HIV coinfected patients with undetectable viraemia under HAART on the levels of peripheral T cell's immune-activation. We determined T lymphocytes subsets to characterize immune-activation defined as CD38 and/or HLA-DR expression in chronic monoinfected HCV, HIV, and HIV/HCV coinfected subjects. One hundred and fifty six patients were divided into three groups: (i) 77 HIV+ patients; (ii) 50 HCV+ patients; and (iii) 29 coinfected HIV/HCV patients. The level of CD4(+) was significantly higher in HCV+ than in HIV+ or in coinfected HIV/HCV subjects. The frequencies of CD4(+) CD38(+) /HLA-DR(-) , CD4(+) CD38(-) /HLA-DR(+) and CD4(+) CD38(+) /HLA-DR(+) in HIV+ patients were comparable to those measured in coinfected patients, but statistically higher than those observed in HCV+ subjects. The percentage of CD8(+) was comparable in HIV-1+ patients and coinfected HIV/HCV but the results obtained in both groups were significantly higher compared to the results obtained in HCV patients. The level of CD8(+) CD38(+) /HLA-DR(-) showed values lower in HIV+ patients than in that monoinfected HCV and coinfected HIV/HCV patients. The frequencies of CD8(+) CD38(-) /HLA-DR(+) were higher in HIV+ patients compared to HCV+ and coinfected HIV/HCV patients. HIV/HCV coinfected group showed highest levels of CD8(+) CD38(+) /HLA-DR(+) . HIV plays a pivotal role to determine the immune activation in the host. The role of HCV needs of further investigations but our data show that HCV mainly influences the immune-activation of the pool of CD8, but also probably plays a supporting additive effect on CD4 immune-activation. J. Med. Virol. 88:1347-1356, 2016. © 2016 Wiley Periodicals, Inc.

Clinical and demographic factors associated with low viral load in early untreated HIV infection in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

A small subset of HIV-positive adults have low HIV RNA in the absence of therapy, sometimes for years. Clinical factors associated with low HIV RNA in early infection have not been well defined.

METHODS

We assessed factors associated with low plasma HIV RNA level at study entry in the Strategic Timing of AntiRetroviral Treatment (START) trial. All START participants had a baseline HIV RNA assessment within 60 days prior to randomization. The key covariables considered for this analysis were race, and hepatitis B virus (HBV) and hepatitis C virus (HCV) status. We assessed factors associated with HIV RNA ≤ 50 and ≤ 400 HIV-1 RNA copies/mL using logistic regression. Because of the strong association between region of randomization and baseline low HIV RNA, analyses were stratified by region.

RESULTS

We found that, of 4676 eligible participants randomized in START with a baseline HIV RNA assessment, 113 (2.4%) had HIV RNA ≤ 50 copies/mL at baseline, and a further 257 (5.5%) between 51 and 400 copies/mL. We found that HIV exposure routes other than male homosexual contact, higher high-density lipoprotein (HDL) cholesterol levels, higher CD4 cell counts, and higher CD4:CD8 ratio were associated with increased odds of low HIV RNA. HCV antibody positivity was borderline statistically significantly associated with low HIV RNA. Race and HBV surface antigen positivity were not significantly associated with low HIV RNA.

CONCLUSIONS

In a modern cohort of individuals with early untreated HIV infection, we found that HIV exposure routes other than male homosexual contact and higher HDL cholesterol were associated with increased odds of low HIV RNA.

Antiretroviral Regimens and CD4/CD8 Ratio Normalization in HIV-Infected Patients during the Initial Year of Treatment: A Cohort Study

Background

As CD4/CD8 ratio inversion has been associated with non-AIDS morbidity and mortality, predictors of ratio normalization after cART need to be studied. Here, we aimed to investigate the association of antiretroviral regimens with CD4/CD8 ratio normalization within an observational cohort.

Methods

We selected, from a French cohort at the Nice University Hospital, HIV-1 positive treatment-naive patients who initiated cART between 2000 and 2011 with a CD4/CD8 ratio <1. Association between cART and ratio normalization (>1) in the first year was assessed using multivariate logistic regression models. Specific association with INSTI-containing regimens was examined.

Results

567 patients were included in the analyses; the median CD4/CD8 ratio was 0.36. Respectively, 52.9%, 29.6% and 10.4% initiated a PI-based, NNRTI-based or NRTI-based cART regimens. About 8% of the population started an INSTI-containing regimen. 62 (10.9%) patients achieved a CD4/CD8 ratio ≥1 (N group). cART regimen was not associated with normalization when coded as PI-, NNRTI- or NRTI-based regimen. However, when considering INSTI-containing regimens alone, there was a strong association with normalization [OR, 7.67 (2.54–23.2)].

Conclusions

Our findings suggest an association between initiation of an INSTI-containing regimen and CD4/CD8 ratio normalization at one year in naïve patients. Should it be confirmed in a larger population, it would be another argument for their use as first-line regimen as it is recommended in the recent update of the “Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents”.

Immunologic and Virologic Progression in HIV Controllers: The Role of Viral "Blips" and Immune Activation in the ANRS CO21 CODEX Study

Some HIV controllers (HICs) experience CD4+T cell count loss and/or lose their ability to control HIV. In this study, we investigated the rate of immunologic and/or virologic progression (ImmP/VirP) and its determinants in the ANRS CO21/CODEX cohort. Immunologic progression was defined as a lasting fall in CD4+T cell count below 350/mm(3) or more than 200/mm(3) with a baseline count below 600/mm(3). Virologic progression was defined as a HIV viral load (VL) above 2000 copies/mL on two consecutive determinations. Clinical characteristics, immune activation, ultrasensitive HIV VL and total HIV DNA were analyzed. Disease progression was observed in 15 of the 217 patients followed up between 2009 and 2013 (ImmP, n = 10; VirP, n = 5). Progressors had higher ultrasensitive HIV RNA levels at inclusion (i.e. 1-2 years before progression) than non-progressors. ImmP had also lower CD4+T cell nadir and CD4+T cell count at inclusion, and VirP had higher HIV DNA levels in blood. T cell activation and IP10 levels at inclusion were significantly higher in ImmP than in non-progressors. In summary, the lasting loss of CD4+T cells, residual HIV replication and basal levels of immune activation appear to be major determinants of progression in HICs. These factors should be considered for adjusting their follow-up.

Association of chronic hepatitis C infection with T-cell phenotypes in HIV-negative and HIV-positive women

BACKGROUND

Hepatitis C virus (HCV) viremia is thought to have broad systemic effects on the cellular immune system that go beyond its impact on just those T cells that are HCV specific. However, previous studies of chronic HCV and circulating T-cell subsets (activation and differentiation phenotypes) in HIV negatives used general population controls, rather than a risk-appropriate comparison group. Studies in HIV positives did not address overall immune status (total CD4⁺ count).

METHODS

We used fresh blood from HIV-positive and at-risk HIV-negative women, with and without chronic HCV, to measure percentages of activated CD4⁺ and CD8⁺ T cells, Tregs, and T-cell differentiation phenotypes (naive, central memory, effector memory (EM), and terminally differentiated effector). This included 158 HIV negatives and 464 HIV positives, of whom 18 and 63, respectively, were HCV viremic.

RESULTS

In multivariate models of HIV negatives, HCV viremia was associated with 25% fewer naive CD4⁺ (P = 0.03), 33% more EM CD4⁺ (P = 0.0002), and 37% fewer central memory CD8⁺ (P = 0.02) T cells. Among HIV positives, we observed only 1 of these 3 relationships: higher percentage of EM CD4⁺ among HCV viremic women. Furthermore, the association with EM CD4⁺ among HIV positives was limited to individuals with diminished immune status (total CD4⁺ count ≤500 cells/μL), as were associations of HCV viremia with higher percentages of activated CD4⁺ and Tregs. Among HIV positives with high CD4⁺ count, no significant associations were observed.

CONCLUSIONS

These data suggest that HCV viremia in HIV negatives is associated with accelerated T-cell differentiation, but among HIV positives, the impact of HCV viremia is less straightforward and varies by total CD4v count.

Joint modeling of HIV data in multicenter observational studies: A comparison among different approaches

Disease process over time results from the combination of event history information and longitudinal process. Commonly, separate analyses of longitudinal and survival outcomes are performed. However, discharging the dependence between these components may cause misleading results. Separate analyses are difficult to interpret whenever one deals with observational retrospective multicenter cohort studies where the biomarkers are poorly monitored over time, while the survival component may be affected by several sources of bias, such as multiple endpoints, multiple time-scales, and informative censoring. We discuss how joint modeling of longitudinal and survival data represents an effective strategy to incorporate all information simultaneously and to provide valid and efficient inferences, thus allowing to produce a better insight into the biological mechanisms underlying the phenomenon under study. Accounting for the whole dynamics of the disease process is crucial in retrospective longitudinal studies. In this work, we present different approaches for modeling longitudinal and time-to-event data, retrieved from 648 HIV-infected patients enrolled in the Italian cohort of the CASCADE (Concerted Action on SeroConversion to AIDS and Death in Europe) study, one of the largest AIDS collaborative cohort studies. In particular, we evaluate CD4 lymphocyte evolution over time (from the date of seroconversion) and overall survival, CD4 being one of the most important immunologic biomarker for HIV progression. Besides a standard separate modeling approach, we consider two alternative joint models: the traditional joint model and the joint latent class mixed model. Advantages and disadvantages of the different approaches are discussed. To compare the performances of these models, cross-validation procedures are also performed.

Hepatitis C virus infection in patients with HIV-1: epidemiology, natural history and management

Hepatitis C virus (HCV)-related liver diseases have contributed to increased morbidity and mortality in HIV-1-infected individuals in the era of effective antiretroviral therapy. HCV transmission patterns have changed among the HIV co-infected population during the last decade, with acute HCV infection emerging worldwide. HIV infection accelerates the progression of HCV-related liver diseases and consequently cirrhosis, liver failure, and hepatocellular carcinoma. However, the current standard treatment of HCV infection with pegylated interferon plus ribavirin results in only a limited viral response. Furthermore, cumbersome pill regimens, antiretroviral related hepatotoxicity, and drug interactions of HCV and HIV regimens complicate therapy strategies. Fortunately, in the near future, new direct-acting anti-HCV agents will widen therapeutic options for HCV/HIV co-infection. Liver transplantation is also gradually accepted as a therapeutic option for end stage liver disease of HCV/HIV co-infected patients.

HIV infection is associated with diffusing capacity impairment in women

Respiratory dysfunction is common with HIV infection, but few studies have directly assessed whether HIV remains an independent risk factor for pulmonary function abnormalities in the antiretroviral therapy era. Additionally, few studies have focused on pulmonary outcomes in HIV+ women. We tested associations between risk factors for respiratory dysfunction and pulmonary outcomes in 63 HIV+ and 36 HIV-uninfected women enrolled in the Women's Interagency HIV Study. Diffusing capacity (DL(CO)) was significantly lower in HIV+ women (65.5% predicted vs. 72.7% predicted, P = 0.01), and self-reported dyspnea in HIV+ participants was associated with both DL(CO) impairment and airflow obstruction. Providers should be aware that DL(CO) impairment is common in HIV infection, and that either DL(CO) impairment or airflow obstruction may cause respiratory symptoms in this population.

Characterization of CD4⁺ T-cell immune activation and interleukin 10 levels among HIV, hepatitis C virus, and HIV/HCV-coinfected patients

BACKGROUND

HIV/hepatitis C virus (HCV)-coinfected patients have accelerated liver disease compared with HCV monoinfection. In HIV-positive patients with viral suppression, data comparing inflammatory cytokines and immune activation between HIV/HCV coinfection with chronic hepatitis C (CHC) to HIV/HCV-seropositive patients with cleared HCV are limited.

METHODS

Fifty-nine age- and sex-matched patients were stratified: (1) HIV monoinfection (n = 15); (2) HCV monoinfection with CHC (n = 15); (3) HIV/HCV coinfection with CHC (n = 14); and (4) HIV/HCV seropositive with cleared HCV (n = 15). All HIV-positive patients had undetectable HIV viremia, and median CD4 was 420 cells per microliter. Liver fibrosis was assessed in each subject using transient elastography. Cells were collected for CD4 and CD8 immune activation (CD38/HLA-DR) markers via flow cytometry and plasma for luminex-multiplex cytokine assays.

RESULTS

CD38⁺HLA-DR⁺ expression on CD4⁺ T cells was significantly increased in HIV/HCV coinfection with CHC (7%) versus HCV monoinfection (4%) (P = 0.012). CD4⁺ total HLA-DR⁺ expression was significantly increased in HIV/HCV coinfection with CHC (43%) versus HIV monoinfection (31%) (P = 0.010) and HIV/HCV seropositive with cleared HCV (38%) (P = 0.046). Total CD4⁺CD38⁺ and CD4⁺CD38⁺HLA-DR⁻ expression was significantly higher in HIV monoinfection (23% and 18%) than HCV moninfection (13%, P = 0.002% and 9%, P = 0.001, respectively). Interleukin 10 levels were significantly lower in HIV monoinfection versus HIV/HCV coinfection with CHC (P = 0.0002). In multivariate analysis, severe fibrosis was associated with lower expression of CD4⁺CD38⁺HLA-DR⁺ and CD4⁺ total CD38⁺ than mild-moderate fibrosis (P = 0.03 and 0.03, respectively).

CONCLUSIONS

CD4 immune activation with HLA-DR⁺ expression in HIV/HCV coinfection with well-controlled HIV may arise from chronic HCV viremia. Conversely, CD4⁺CD38⁺ expression may be driven by underlying HIV infection. CD4 immune activation was unexpectedly found to be associated with decreased liver fibrosis.

CD4/CD8 ratio is a promising candidate for non-invasive measurement of liver fibrosis in chronic HCV-monoinfected patients

The extent of liver fibrosis is an important factor in prognosis and clinical decision-making in chronic hepatitis C virus (HCV) infection. We investigated CD4/CD8 ratio in HCV-monoinfected and HIV/HCV-coinfected patients, in order to reveal its relation with liver fibrosis. CD4/CD8 ratio in the peripheral blood was assessed by flow cytometry in a cohort of 19 HCV-monoinfected, 14 HIV/HCV-coinfected, ten HIV-monoinfected patients and 15 healthy controls. Liver fibrosis was assessed by transient elastography (n = 25) or by liver biopsy (n = 8). Coinfection with HIV was associated with decreased CD4/CD8 ratios in chronic HCV-infected patients, despite adequate antiretroviral treatment. Furthermore, HCV-monoinfected patients with F3-F4 liver fibrosis demonstrated much lower CD4/CD8 ratios than patients with F0-F2 fibrosis (1.4 versus 2.5, p = 0.023). Similarly, we observed a strong negative correlation between the CD4/CD8 ratio and liver stiffness measured by transient elastography (R = -0.78, p = 0.0006). ROC analysis revealed that CD4/CD8 ratio as a non-invasive marker for fibrosis is very promising (area under the curve 0.8). Although our study was performed with a relatively small number of patients, our findings suggest that the CD4/CD8 ratio is a promising candidate for non-invasive evaluation of liver fibrosis in HCV-monoinfected patients.

Blunted response to combination antiretroviral therapy in HIV elite controllers: an international HIV controller collaboration

Objective

HIV “elite controllers” (ECs) spontaneously control viral load, but some eventually require combination antiretroviral treatment (cART), due to a loss of viral control or a decline in CD4 T-cell counts. Here we studied the CD4 T-cell count dynamics after cART initiation among 34 ECs followed in U.S. and European cohorts, by comparison with chronically viremic patients (VIRs).

Methods

ECs were defined as patients with at least ≥5 viral load (VL) measurements below 400 copies/mL during at least a 5-year period despite never receiving ART and were selected from the French ANRS CO18 cohort, the U.S. SCOPE cohort, the International HIV Controllers study and the European CASCADE collaboration. VIRs were selected from the ANRS COPANA cohort of recently-diagnosed (<1 year) ART-naïve HIV-1-infected adults. CD4 T-cell count dynamics after cART initiation in both groups were modelled with piecewise mixed linear models.

Results

After cART initiation, CD4 T-cell counts showed a biphasic rise in VIRs with: an initial rapid increase during the first 3 months (+0.63/month), followed by +0.19/month. This first rapid phase was not observed in ECs, in whom the CD4Tc count increased steadily, at a rate similar to that of the second phase observed in VIRs. After cART initiation at a CD4 T-cell count of 300/mm³, the estimated mean CD4 T-cell gain during the first 12 months was 139/mm³ in VIRs and 80/mm³ in ECs (p = 0.048).

Conclusions

cART increases CD4 T-cell counts in elite controllers, albeit less markedly than in other patients.

Increased expression of intrinsic antiviral genes in HLA-B*57-positive individuals

The genetic background of HIV-1-infected subjects, particularly the HLA class I haplotype, appears to be critical in determining disease progression rates, thought to be a result of the role of HIV-1-specific CD8(+) T cell responses. The HLA-B*57 allele is strongly associated with viremic suppression and slower disease progression. However, there is considerable heterogeneity in HIV-1 disease progression rates among HLA-B*57-positive subjects, suggesting that additional factors may help to contain viral replication. In this report, we investigated the association between host restriction factors, other established immunological parameters, and HLA type in HIV-1-seronegative individuals. Our results demonstrate that healthy, uninfected HLA-B*57-positive individuals exhibit significantly higher gene-expression levels of host restriction factors, such as APOBEC3A, APOBEC3B, BST-2/tetherin, and ISG15. Interestingly, HLA-B*57 individuals have significantly lower CD4(+) T cell frequencies but harbor slightly more activated CD4(+) T cells compared with their HLA-B*35 counterparts. We detected significant correlations between CD4(+) T cell activation and expression of several APOBEC3 family members, BST-2/tetherin, SAMHD1, and TRIM5α in HLA-B*57-positive individuals. To our knowledge, this is the first report showing distinct associations between host restriction factors and HLA class I genotype. Our results provide insights into natural protection mechanisms and immunity against HIV-1 that fall outside of classical HLA-mediated effects.

Altered T-cell subsets in HIV-1 natural viral suppressors (elite controllers) with hepatitis C infection

We have established a cohort of 64 Natural Viral Suppressors (NVS) (similar to Elite Controllers/Elite Suppressors), 30 of which have chronic hepatitis C virus (HCV). We investigated T-cell phenotypic changes in association with HCV infection. NVS without HCV and normal controls had similar T-cell phenotypes. However, NVS with HCV had lower naive cell proportions (CD4 and CD8) compared with NVS without HCV (P = 0.0008 and P = 0.02) or normal controls (P = 0.0163 and P = 0.017). These results and previously reported data suggest that HCV coinfection increases immune activation and T-cell disturbances. Any associated T-cell functional changes or potential clinical consequences need further study.

Natural killer cells in HIV controller patients express an activated effector phenotype and do not up-regulate NKp44 on IL-2 stimulation

Control of HIV replication in elite controller (EC) and long-term nonprogressor (LTNP) patients has been associated with efficient CD8(+)cytotoxic T-lymphocyte function. However, innate immunity may play a role in HIV control. We studied the expression of natural cytotoxicity receptors (NKp46, NKp30, and NKp44) and their induction over a short time frame (2-4 d) on activation of natural killer (NK) cells in 31 HIV controller patients (15 ECs, 16 LTNPs). In EC/LTNP, induction of NKp46 expression was normal but short (2 d), and NKp30 was induced to lower levels vs. healthy donors. Notably, in antiretroviral-treated aviremic progressor patients (TAPPs), no induction of NKp46 or NKp30 expression occurred. More importantly, EC/LTNP failed to induce expression of NKp44, a receptor efficiently induced in activated NK cells in TAPPs. The specific lack of NKp44 expression resulted in sharply decreased capability of killing target cells by NKp44, whereas TAPPs had conserved NKp44-mediated lysis. Importantly, conserved NK cell responses, accompanied by a selective defect in the NKp44-activating pathway, may result in lack of killing of uninfected CD4(+)NKp44Ligand(+) cells when induced by HIVgp41 peptide-S3, representing a relevant mechanism of CD4(+) depletion. In addition, peripheral NK cells from EC/LTNP had increased NKG2D expression, significant HLA-DR up-regulation, and a mature (NKG2A-CD57(+)killer cell Ig-like receptor(+)CD85j(+)) phenotype, with cytolytic function also against immature dendritic cells. Thus, NK cells in EC/LTNP can maintain substantially unchanged functional capabilities, whereas the lack of NKp44 induction may be related to CD4 maintenance, representing a hallmark of these patients.

Future directions: lung aging, inflammation, and human immunodeficiency virus

Chronic lung diseases, including chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH), are unusually prevalent among persons infected with human immunodeficiency virus (HIV). Often these disease states are identified at younger ages than would be expected in the general population. Recent epidemiologic, basic scientific, and cross-sectional clinical data have implicated immune dysfunction and cellular senescence as potential drivers of advanced presentations of age-related diseases in HIV-infected persons. This article describes how HIV-associated COPD and PH may fit into a paradigm of immunosenescence, and outlines the hypothesized associations among chronic HIV infection, immune dysfunction and senescence, and cardiopulmonary outcomes.

Understanding and controlling chronic immune activation in the HIV-infected patients suppressed on combination antiretroviral therapy

Combination antiretroviral therapy (cART) has resulted in tremendous gains in survival among HIV-infected patients, but as a group those who achieve undetectable viral loads on cART experience a greater degree of immune activation and inflammation than the general population. HIV-infected patients continue to experience premature immune senescence with earlier and more frequent non-AIDS events compared to HIV-uninfected individuals. Chronic immune activation during suppressive cART derives from a variety of sources mediated by cytokines, chemokines, coagulation, microbial translocation, immune regulators and T(effector) cell activation abnormalities, among others. Current investigational strategies to control immune activation target potential causes of persistently heightened immune activation during cART such as microbial translocation, co-infections, and comorbidities or mediators along a common final pathway. Although several interventions have shown promise in vitro or in preliminary clinical trials, no intervention has sufficient evidence for routine use, making control of immune activation during cART an unmet need.