Clinical, immunological and treatment-related factors associated with normalised CD4+/CD8+ T-cell ratio: effect of naïve and memory T-cell subsets

A comprehensive analysis of the immune system in healthy Vietnamese people

Lifestyle, diet, socioeconomic status and genetics all contribute to heterogeneity in immune responses. Vietnam is plagued with a variety of health problems, but there are no available data on immune system values in the Vietnamese population. This study aimed to establish reference intervals for immune cell parameters specific to the healthy Vietnamese population by utilizing multi-color flow cytometry (MCFC). We provide a comprehensive analysis of total leukocyte count, quantitative and qualitative shifts within lymphocyte subsets, serum and cytokine and chemokine levels and functional attributes of key immune cells including B cells, T cells, natural killer (NK) cells and their respective subpopulations. By establishing these reference values for the Vietnamese population, these data contribute significantly to our understanding of the human immune system variations across diverse populations. These data will be of substantial comparative value and be instrumental in developing personalized medical approaches and optimizing diagnostic strategies for individuals based on their unique immune profiles.

Transcriptomic crosstalk between viral and host factors drives aberrant homeostasis of T-cell proliferation and cell death in HIV-infected immunological non-responders

BACKGROUND

Immunological non-responders (INRs) among people living with HIV have inherently higher mortality and morbidity rates. The underlying immunological mechanisms whereby failure of immune reconstitution occurs in INRs require elucidation.

METHOD

HIV-1 DNA and HIV-1 cell-associated RNA (CA-HIV RNA) quantifications were conducted via RT-qPCR. Transcriptome sequencing (RNA-seq), bioinformatics, and biological verifications were performed to discern the crosstalk between host and viral factors. Flow cytometry was employed to analyze cellular activation, proliferation, and death.

RESULTS

HIV-1 DNA and CA-HIV RNA levels were observed to be significantly higher in INRs compared to immunological responders (IRs). Evaluation of CD4/CD8 ratios showed a significantly negative correlation with HIV-1 DNA in IRs, but not in INRs. Bioinformatics analyses and biological verifications showed IRF7/INF-α regulated antiviral response was intensified in INRs. PBMCs of INRs expressed significantly more HIV integrase-mRNA (p31) than IRs. Resting (CD4+CD69- T-cells) and activated (CD4+CD69+ T-cells) HIV-1 reservoir harboring cells were significantly higher in INRs, with the co-occurrence of significantly higher cellular proliferation and cell death in CD4+ T-cells of INRs.

CONCLUSION

In INRs, the systematic crosstalk between the HIV-1 reservoir and host cells tends to maintain a persistent antiviral response-associated inflammatory environment, which drives aberrant cellular activation, proliferation, and death of CD4+ T-cells.

Impact of Latent M. tuberculosis Infection Treatment on Time to CD4/CD8 Recovery in Acute, Recent, and Chronic HIV Infection

INTRODUCTION

In people living with HIV, active and latent tuberculosis (TB) coinfections are associated with immune activation that correlate with HIV progression and mortality. We investigated the effect of initiating antiretroviral therapy (ART) during acute (AHI), recent (RHI), or chronic HIV infection (CHI) on CD4/CD8 ratio normalization and associated factors, the impact of latent TB infection treatment, and prior/concomitant TB diagnosis at the time of ART initiation.

METHODS

We included sex with men and transgender women individuals initiating ART with AHI, RHI and CHI between 2013 and 2019, from a prospective cohort in Brazil. We compared time from ART initiation to the first normal CD4/CD8 ratio (CD4/CD8 ≥1) using Kaplan-Meier curves and multivariable Cox proportional hazards models. Sociodemographic and clinical variables were explored. Variables with P -values <0.20 in univariable analyses were included in multivariable analyses.

RESULTS

Five hundred fifty participants were included, 11.8% classified as AHI and 6.4% as RHI, 46.7% with CHI-CD4 cell counts ≥350 cells/mm 3 and 35.1% with CHI-CD4 cell counts <350 cells/mm 3 . Time to normalization was shortest among AHI patients, followed by RHI and CHI individuals with higher baseline CD4. In the multivariable model, AHI was associated with a six-fold increased likelihood of achieving a CD4/CD8 ratio ≥1 (hazard ratio [HR]: 6.03; 95% confidence interval [CI]: 3.70 to 9.82; P < 0.001), RHI with HR: 4.47 (95% CI: 2.57 to 7.76; P < 0.001), and CHI CD4 ≥350 cells/mm 3 with HR: 1.87 (95% CI: 1.24 to 2.84; P = 0.003). Latent TB infection treatment was significantly associated with a higher likelihood of the outcome (HR: 1.79; 95% CI: 1.22 to 2.62; P = 0.003). Previous history or concomitant active TB at ART initiation was associated with a lower likelihood of the outcome (HR: 0.41; 95% CI: 0.16 to 1.02; P = 0.054).

CONCLUSIONS

Initiating ART early during AHI may offer an opportunity to mitigate immune damage. Efforts to implement HIV diagnosis and ART initiation during AHI are critical to amplify ART benefits.

CD4:CD8 Ratio and CD8 Cell Count and Their Prognostic Relevance for Coronary Heart Disease Events and Stroke in Antiretroviral Treated Individuals: The Swiss HIV Cohort Study

INTRODUCTION

HIV infection leads to a persistent expansion of terminally CD8 T cells and CD8 T suppressor cells, a marker of chronic immune activation leading to a low CD4:CD8 ratio that may persist in the presence of potent antiretroviral therapy and regained CD4 helper cells. It remains unclear whether a low CD4:CD8 ratio is associated with cardiovascular diseases.

METHODS

We conducted an observational cohort study to investigate the association of immune depression and activation as characterized by the proxy of the CD4:CD8 ratio on the hazard of coronary heart disease (CHD) and stroke among treated individuals living with HIV, while accounting for viral load and known risk factors for cardiovascular diseases and exposure to abacavir or protease inhibitors. We used Cox proportional hazard models with time-dependent cumulative and lagged exposures to account for time-evolving risk factors and avoid reverse causality.

RESULTS

CD4, CD8, and CD4:CD8 immunological markers were not associated with an increased hazard for CHD. CD8 cell count lagged at 12 months above 1000 cells per μL increased the hazard of stroke, after adjusting for sociodemographics, cardiovascular risk factors, and exposure to specific types of antiretroviral drugs.

CONCLUSIONS

This analysis of treated HIV-positive individuals within a large cohort with long-term follow-up does not provide evidence for a prognostic role of immune dysregulation regarding CHD. However, increased CD8 cell count may be a moderate risk factor for stroke. Early detection and treatment of HIV-positive individuals are crucial for an optimal immune restoration and a limited CD8 cells expansion.

Impact of age and gender disparity on CD4+ cell counts to control disease progression using specific HAART in HIV-1 positive patients: A case-control study

BACKGROUND

Highly Active Antiretroviral Therapy (HAART) is composed of several drugs in the antiretroviral class to better treat human immunodeficiency virus type 1 (HIV-1) patients. The estimation of CD4+ T cell counts and HIV-1 viral load in plasma is required to evaluate the treatment success of a specific HAART.

METHODOLOGY

The study included the effects of NRTIs (nucleoside reverse transcriptase inhibitors) and novel protease inhibitors (HAART) on normal control subjects and HIV-1 positive subjects from SGPGIMS, Lucknow, with different age groups and genders. Furthermore, the study was conducted by the estimation of HIV through ELISA, measurement of absolute CD4+ cell count, and the measurement of viral load through qRT-PCR. Furthermore, NRTIs (Retrovir and Epivir) were administered orally one tablet daily in the morning followed by newly FDA-approved protease inhibitors (fosamprenavir and darunavir) orally in the evening at the same dose. Furthermore, CD4+T cell counts and HIV-1 viral load were investigated and correlated in patients with different genders and age groups.

RESULT

Administration of NRTIs and novel protease inhibitors (HAART) in HIV patients had a significant effect on the CD4+ cell count in various age intervals among males and females. The mean comparison of viral load distribution based on gender in CD4 +ve patients in the case group exhibited a viral load higher in females compared to males, indicating a statistically significant difference between males and females (p<0.05). A notable association between virological and immunological parameters was observed with a reciprocal relationship between viral load and CD4 cell count in CD4 +ve patients, demonstrating multiple correlation coefficients with an R-value of 0.853.

CONCLUSION

The administration of specific HAART (NRTIs and novel protease inhibitors) in HIV patients had a notable improvement in the CD4+ cell count and viral load with significant age and gender disparity.

Predictive value of CD8+ T cell and CD4/CD8 ratio at two years of successful ART in the risk of AIDS and non-AIDS events

BACKGROUND

While increased CD8 counts and low CD4/CD8 ratio during treated HIV correlate with immunosenescence, their additional predictive values to identify individuals with HIV at higher risk of clinical events remain controversial.

METHODS

We selected treatment-naive individuals initiating ART from ACTG studies 384, 388, A5095, A5142, A5202, and A5257 who had achieved viral suppression at year 2. We examined the effect of CD8+ T cell counts and CD4/CD8 at year 2 on the probability of AIDS and serious non-AIDS events in years 3-7. We used inverse probability weighting methods to address informative censoring, combined with multivariable logistic regression models.

FINDINGS

We analyzed 5133 participants with a median age of 38 years; 959 (19%) were female, pre-ART median CD4 counts were 249 (Q1-Q3 91-372) cell/µL. Compared to participants with CD8 counts between 500/µL and 1499/µL, those with >1500/µL had a higher risk of clinical events during years 3-7 (aOR 1.75; 95%CI 1.33-2.32). CD4/CD8 ratio was not predictive of greater risk of events through year 7. Additional analyses revealed consistent CD8 count effect sizes for the risk of AIDS events and noninfectious non-AIDS events, but opposite effects for the risk of severe infections, which were more frequent among individuals with CD8 counts <500/µL (aOR 1.70; 95%CI 1.09-2.65).

INTERPRETATION

The results of this analysis with pooled data from clinical trials support the value of the CD8 count as a predictor of clinical progression. People with very high CD8 counts during suppressive ART might benefit from closer monitoring and may be a target population for novel interventions.

FUNDING

This research was supported by NIH/NIAID awards UM1 AI068634, UM1 AI068636, and UM1 AI106701 and Carlos III Health Institute and FEDER funds (BA21/00017 and BA21/00022).

Distinct effects of treatment with two different interferon-alpha subtypes on HIV-1-associated T-cell activation and dysfunction in humanized mice

OBJECTIVE

Interferon-alpha (IFN-α) has been associated with excessive immune activation and dysfunction during HIV-1 infection. However, evidence suggests specific IFN-α subtypes may be beneficial rather than detrimental. This study compared the effects of treatment with two different IFN-α subtypes on indicators of T-cell activation and dysfunction during HIV-1 infection.

DESIGN

Humanized mice were infected with HIV-1 for 5 weeks and then treated with two different IFN-α subtypes for an additional 3 weeks. Splenic T cells were assessed both immediately posttreatment and again 6 weeks after treatment cessation.

METHODS

HIV-1 infected triple-knockout bone marrow-liver-thymus mice received daily intraperitoneal injections of either IFN-α14 or the clinically approved subtype, IFN-α2. T cells were analysed directly ex vivo for indicators of activation and dysfunction or stimulated to determine their proliferative capacity and ability to produce functional mediators.

RESULTS

Unlike IFN-α2, IFN-α14 treatment reduced viremia and resulted in less activated CD4+ T cells and a lower naïve to effector CD8+ T-cell ratio. Despite exhibiting a reduced proliferative response, the frequency of CD8+ T cells from IFN-α14 treated mice that produced functional mediators and expressed markers of dysfunction was more similar to healthy controls than untreated and IFN-α2 treated mice. Frequencies of exhaustion marker expression remained higher in untreated and IFN-α2 treated mice 6 weeks posttreatment despite similar viral loads between groups at this timepoint.

CONCLUSIONS

Treatment with different IFN-α subtypes had distinctive effects on T cells during HIV-1 infection. IFN-α14 was associated with fewer indicators of T-cell dysfunction whereas IFN-α2 treatment had little impact.

A novel and efficient method to induce allospecific CD8+ memory T lymphocytes

The aim of the current study was to establish a simple method for effectively inducing memory T lymphocytes by the intraperitoneal injection of spleen lymphocytes into mice. In total, 75 mice were divided into the following groups: an injection group administered three doses of spleen lymphocytes (1 × 10⁶, 5 × 10⁶, and 1 × 10⁷ cells), a transplantation group in which a 0.25‐cm² skin section from C57BL/6 mice was transplanted onto the back of the recipient, and a control group in which an equal volume of phosphate‐buffered saline was injected. At 1, 2, or 3 months following transplantation, the following parameters were evaluated: quantity of T lymphocytes, percentage of cluster of differentiation 8⁺ (CD8⁺) memory T cells, and proliferation index of purified CD8⁺ memory T cells. No significant differences among groups were detected at 1 month (p > .05). However, the injection group administered 1 × 10⁶ cells exhibited the highest proportion of CD8⁺ memory T cells among all groups at 2 months, and the proportions of CD8⁺ T cells were higher in the three injection groups than in the skin transplantation and control groups at 3 months. The proportions of memory T cells were higher in the injection groups administered 5 × 10⁶ or 1 × 10⁷ cells than in the skin transplantation and control groups at 3 months. The newly established method effectively induces memory T lymphocytes via the intraperitoneal injection of spleen lymphocytes in vivo and has potential applications in the field of immunotherapy.

The effects of twenty-four nutrients and phytonutrients on immune system function and inflammation: A narrative review

BACKGROUND AND AIM

Recently, optimal immune function has become a primary focus of worldwide attention not only in the prevention of chronic disease but also as one strategy to reduce the severity of acute illness. Inflammation, a process largely controlled by the immune system, has long been studied and recognized for its role in chronic disease. Optimizing immune function or managing inflammation using individual nutrients and phytonutrients is not well understood by the average person. Thus, this narrative literature review summarizes many of the more recent findings about how certain nutrients and phytonutrients affect immune function and inflammation, and how they may best be utilized considering the growing worldwide interest in this topic.

METHODS

A comprehensive literature search of PubMed was performed to find clinical trials in humans that assessed the effect of nutrients and phytonutrients on immune function and inflammation, in individuals with acute and chronic health conditions, published in English between 2000 and 2020. Two independent reviewers evaluated the articles for their inclusion.

RESULTS

Eighty-seven articles were summarized in this narrative review. In total 24 nutrients and phytonutrients were included in the study, that is, acetyl-L-carnitine, Aloe vera polysaccharides, beta-glucans, bilberry, black seed oil, coenzyme Q10, curcumin (turmeric), frankincense, garlic, ginger, hydrolyzed rice bran, isoflavones, lipoic acid, mistletoe, N-acetyl cysteine, omega-3 fatty acids, resveratrol, selenium, shiitake mushroom and its derivatives, Vitamin B12, Vitamin C, Vitamin D3 (cholecalciferol), Vitamin E (d-alpha- and gamma-tocopherol), and zinc. Some of the noteworthy immune function and anti-inflammatory responses to these interventions included modulation of nuclear factor-Kappa B, tumor necrosis factor-a, interferon-g, interleukin-6, and CD4+ T cells, among others. These findings are not completely consistent or ubiquitous across all patient populations or health status.

CONCLUSIONS

Based on this review, many nutrients and phytonutrients are capable of significantly modulating immune function and reducing inflammation, according to multiple biomarkers in clinical trials in different populations of adults with varying health statuses. Thus, dietary supplementation may serve as an adjunct to conventional pharmaceutical or medical therapies, but evaluation of risks and benefits for each person and health status is necessary. Additional larger studies are also needed to investigate the safety and efficacy of nutritional compounds in various health conditions, with emphases on potential drug-supplement interactions and clinical endpoints.

RELEVANCE FOR PATIENTS

As demonstrated in the reviewed clinical trials, patients of various health challenges with a wide range of severity may benefit from select nutrients and phytonutrients to improve their immune function and reduce inflammation.

Immune recovery in HIV-1 infected patients with sustained viral suppression under long-term antiretroviral therapy in Ethiopia

BACKGROUND

There is very little data on long-term immune recovery responses in patients on suppressive antiretroviral therapy (ART) in the setting of sub-Saharan Africa (SSA). Thus, we sought to determine CD4+ T-cell, CD8+ T-cell and CD4/CD8 ratio responses in a cohort of HIV infected individuals on sustained suppressive ART followed up for more than a decade.

METHODS

The cohort comprised adult patients who started ART between 2001 and 2007 and followed for up to 14 years. Trends in median CD4+ T-cells, CD8+ T-cells and CD4/CD8 ratio were reviewed retrospectively. Poisson regression models were used to identify factors associated with achieving normalized T-cell biomarkers. Kaplan-Meier curves were used to estimate the probability of attaining normalized counts while on suppressive ART.

RESULTS

A total of 227 patients with a median duration of follow-up on ART of 12 (IQR: 10.5-13.0) years were included. CD4 cell count increased from baseline median of 138 cells (IQR: 70-202) to 555 cells (IQR: 417-830). CD4 cell increased continuously up until 5 years, after which it plateaued up until 14 years of follow up. Only 69.6% normalized their CD4 cell count within a median of 6.5 (IQR: 3.0-10.5) years. In addition, only 15.9% of the cohort were able to achieve the median reference CD4+ T-cell threshold count in Ethiopians (≈760 cells/μL). CD8+ T-cell counts increased initially until year 1, after which continuous decrease was ascertained. CD4/CD8 ratio trend revealed continuous increase throughout the course of ART, and increased from a median baseline of 0.14 (IQR: 0.09-0.22) to a median of 0.70 (IQR: 0.42-0.95). However, only 12.3% normalized their ratio (≥ 1.0) after a median of 11.5 years. In addition, only 8.8% of the cohort were able to achieve the median reference ratio of healthy Ethiopians.

CONCLUSION

Determination of both CD4+ and CD8+ T-cells, along with CD4/CD8 ratio is highly relevant in long-term follow-up of patients to assess immune recovery. Monitoring ratio levels may serve as a better biomarker risk for disease progression among patients on long-term ART. In addition, the findings emphasize the relevance of initiation of ART at the early stage of HIV-1 infection.

CD4+:CD8+ T Cell Ratio Normalization and the Development of AIDS Events in People with HIV Starting Antiretroviral Therapy

We identify factors associated with the normalization of the CD4+:CD8+ T cell ratio among UK Collaborative HIV Cohort study participants, and describe the association of the CD4+ and CD8+ T cell counts and the CD4+:CD8+ T cell ratio, with the risk of new AIDS events among individuals who achieve a suppressed viral load. Participants initiating combination antiretroviral therapy (cART) after 2006 with a CD4+:CD8+ T cell ratio <1, and viral suppression within 6 months were included. Cox proportional hazard models were used to examine associations with ratio normalization (ratio ≥1). Poisson regression models were used to investigate factors associated with the development of AIDS after viral load suppression. A total of 13,178 participants [median age: 37 (interquartile range: 31–44)] were followed for 75,336 person-years. Of the 4,042 (32.9%) who experienced ratio normalization, individuals with a high CD4+ T cell count [>500 vs. ≤200 cells/mm³, adjusted hazard ratio (95% confidence interval): 7.93 (6.97–9.01)], low CD8+ T cell count [>1,150 vs. ≤500 cells/mm³: 0.18 (0.16–0.21)], and low CD4+:CD8+ T cell ratio [>0.8 vs. <0.2: 12.36 (10.41–14.68)] at cART initiation were more likely to experience ratio normalization. Four hundred and nineteen people developed a new AIDS event. Most recent CD4+ T cell count [>500 vs. ≤200 cells/mm³: adjusted rate ratio 0.24 (0.16–0.34)] and CD4+:CD8+ T cell ratio [>0.8 vs. <0.2: 0.33 (0.21–0.52)] were independently associated with a new AIDS event. One third of study participants experienced ratio normalization after starting cART. CD4+ T cell count and CD4+:CD8+ T cell ratio are both individually associated with ratio normalization and the development of new AIDS events after cART.

Effects of first-line antiretroviral therapy on the CD4/CD8 ratio and CD8 cell counts in CoRIS: a prospective multicentre cohort study

BACKGROUND

A low CD4/CD8 ratio during antiretroviral therapy (ART) identifies people with heightened immunosenescence and increased risk of mortality. We aimed to assess the effects of integrase strand transfer inhibitor (INSTI)-based, protease inhibitor-based, or non-nucleoside reverse transcriptase inhibitor (NNRTI)-based first-line ART on long-term CD4/CD8 ratio recovery.

METHODS

This prospective cohort study included 13 026 individuals with HIV registered in the Spanish HIV Research Network (CoRIS) cohort recruited from 45 Spanish hospitals. We included HIV-positive people who started triple ART (two nucleoside reverse transcriptase inhibitors [NRTI] with a NNRTI, protease inhibitor, or INSTI) and had HIV RNA suppression within 48 weeks. We used piecewise linear mixed models adjusted for potential confounders to compare longitudinal changes in the CD4/CD8 ratio between people receiving three different types of ART. We used Cox proportional-hazard models to compare the times to CD4/CD8 normalisation between the treatment groups, using cutoff ratios of 0·4, 1·0, and 1·5.

FINDINGS

6804 individuals contributing 37 149 persons-years and 37 680 observations were analysed; median follow-up was 49 months (IQR 22-89). INSTI-based ART was associated with greater CD4/CD8 gain (change per year compared with INSTI was coefficient -0·07 [95% CI -0·08 to -0·06] for NNRTI and was -0·08 [-0·09 to -0·08] for protease inhibitors). Differences were observed from the first year of therapy and were driven by changes in both CD4 and CD8 cell counts. Subanalyses at different time periods suggested that these differences were driven by changes during the first year of ART without significant differences in the adjusted CD4/CD8 ratio trajectories after the second year of ART (change per year compared with INSTI was coefficient -0·03 [95% CI -0·05 to -0·13] for NNRTI and was -0·06 [95% CI -0·08 to -0·04] for protease inhibitors). Although no differences in the time until CD4/CD8 normalisation at a cutoff ratio of no less than 0·4 were reported between any of the groups, compared with the INSTI group, both the NNRTI and protease inhibitor groups showed lower rates of normalisation at cutoff ratios of 1·0 or more (adjusted hazard ratio 0·80 [95% CI 0·72-0·89] for the NNRTI group and 0·79 [0·69-0·89] for the protease inhibitor group), and 1·5 or more (0·79 [0·65-0·95] for the NNRTI group and 0·78 [0·64-0·97] for the protease inhibitor group). No differences were found between the different integrases in the time until CD4/CD8 normalisation. Subanalyses adjusted for the backbone NRTIs and allowing observations after virological failure yielded similar results.

INTERPRETATION

This study provides new evidence that reinforces the positioning of INSTI-based therapies as a first choice and underlines the importance of analysing the effects of therapeutic interventions on biomarkers linked with morbidity and mortality beyond the plasma HIV RNA and the CD4 cell counts.

FUNDING

Spanish AIDS Research Network (Instituto de Salud Carlos III), European Development Regional Fund "A way to achieve Europe".

Role of CD4/CD8 ratio on the incidence of tuberculosis in HIV-infected patients on antiretroviral therapy followed up for more than a decade

Background

The role of CD4/CD8 ratio on the incidence of tuberculosis (TB) in patients on antiretroviral therapy (ART) is unknown. Thus, we sought to determine whether the CD4/CD8 ratio was associated with development of TB in a cohort of HIV infected individuals on ART followed up for more than a decade in the setting of sub-Saharan Africa (SSA).

Methods

The cohort comprised adult patients who started ART between 2001 and 2007 and followed for up to 15 years. Clinical data were collected in retrospective manner. Patients with an AIDS defining illness or a CD4 count <200 cell/μL were started with a combination of ART. The participants have clinic visits every 6 months and/or as needed. Poisson regression models were used to identify factors associated with development of incident TB. Kaplan-Meier curves were used to estimate the probability of incident TB while on ART.

Results

A total of 347 patients with a median duration of follow-up on ART of 11.5 (IQR: 10.0–12.5) years were included. Incident TB developed in 47 patients during the 3259 person-years of follow-up, the majority (76.6%) occurred within five year of ART initiation. On univariate analysis, poor ART adherence (RR:2.57, 95% CI: 1.28–5.17), time-updated CD4 cell count of lower than 200 (RR: 4.86, 95%CI 2.33–10.15), or CD4 cell count between 200 and 500 (RR: 4.68, 95% CI: 2.17–10.09), time-updated CD8 cell count lower than 500 (RR: 2.83 95% CI 1.31–6.10), or CD8 cell count over 1000 (RR: 2.23, 95% CI: 1.12–4.45), time-updated CD4/CD8 ratio of less than 0.30 (RR: 6.00, 95% CI: 2.96–12.14), lack of normalization of CD4 T-cell count (RR: 6.13, 95% CI: 2.20–17.07), and virological failure (RR: 2.35 (95% CI: 1.17–4.71) were all associated with increased risk of incident TB. In multivariate analysis, however, time-updated CD4/CD8 ratio of less than 0.30 (adjusted RR: 4.08, 95% CI: 1.31–12.68) was the only factor associated with increased risk of developing incident TB (p = 0.015). Similar results were obtained in a sensitivity analysis by including only those virally suppressed patients (n = 233, 69% of all patients). In this group, CD4/CD8 ratio of less than 0.30 was associated with development of incident TB (adjusted RR: 4.02, 95% CI: 1.14–14.19, p = 0.031). Overall, the incidence rate of TB in patients with an updated CD4/CD8 ratio of less than 0.30 was more than 5-fold higher when compared with those with a ratio more than 0.45.

Conclusion

Low CD4/CD8 ratio is independently associated with an increased risk of incident TB despite viral suppression. CD4/CD8 ratio may serve as a biomarker for identifying patients at risk of TB in patients on ART in the setting of SSA.

Interferon lambda rs368234815 ΔG/ΔG is associated with higher CD4+:CD8+ T-cell ratio in treated HIV-1 infection

BACKGROUND

The objectives of this study were to investigate the relationships between polymorphisms at the interferon lambda (IFNL) locus and CD4⁺:CD8⁺ ratio normalisation in people living with HIV (PLWH) on effective antiretroviral therapy (ART); and to examine whether these polymorphisms influence the composition of T lymphocyte compartments in long-term treated HIV-1 infection.

METHODS

A cross-sectional study in PLWH enrolled into the Mater Immunology study. We performed IFNL genotyping on stored samples and evaluated the association of IFNL single-nucleotide polymorphisms (rs368234815 and rs12979860) with CD4⁺:CD8⁺ ratio normalization (> 1) and expanded CD4⁺ and CD8⁺ T-cell subsets; CD45RO⁺CD62L⁺ (central-memory), CD45RO⁺ CD62L^-(effector-memory) and CD45RO^-CD62L⁺ (naïve), using logistic and linear regression models, respectively.

RESULTS

190 ambulatory PLWH recruited to the main study, 143 were included in the analysis (38 had no stored DNA and 9 no T-lymphocyte subpopulation). Of 143 included, the median age (IQR) was 45(39-48) years, 64% were male and 66% were of Caucasian ethnicity. Heterosexual-contact (36%), injecting drug-use (33%) and men who have sex with men (24%) were the most presented HIV-transmission risk groups. The majority of subjects (90.2%) were on ART with 79% of the cohort having an undetectable HIV-RNA (< 40 copies/ml) and the time since ART initiation was 7.5 (3.7-10.4) year. rs368234815 and rs12979860 displayed similar allelic frequencies, with minor alleles ΔG and T representing 39% and 42%, respectively, of circulating alleles. rs368234815 ΔG/ΔG minor homozygotes were significantly associated with increased odds for attaining a normalised CD4⁺:CD8⁺ ratio compared to rs368234815 T/T major homozygotes in PLWH virologically suppressed on effective ART (OR = 3.11; 95% CI [1.01:9.56]). rs368234815 ΔG/ΔG homozygosity was also significantly associated with lower levels of CD4⁺ effector memory T-cells (regression coefficient: - 7.1%, p = 0.04) and CD8⁺ naïve T-cell subsets were significantly higher in HIV-1 mono-infected PLWH with rs368234815 ΔG/ΔG (regression coefficient: + 7.2%, p = 0.04).

CONCLUSIONS

In virally-suppressed, long-term ART-treated PLWH, rs368234815 ΔG/ΔG homozygotes were more likely to have attained normalisation of their CD4⁺:CD8⁺ ratio, displayed lower CD4⁺ effector memory and higher naive CD8⁺ T-cells. Further studies are needed to replicate our findings in other, larger and more diverse cohorts and to determine the impact of IFNL genetic-variation on CD4⁺:CD8⁺ ratio normalisation and clinical outcomes in PLWH.

Acute HIV Infection and CD4/CD8 Ratio Normalization After Antiretroviral Therapy Initiation

BACKGROUND

We estimated the effect of initiating virologically suppressive antiretroviral therapy (ART) during acute HIV infection versus chronic HIV infection (AHI vs. CHI) on CD4/CD8 ratio normalization.

SETTING

A prospective clinical cohort study.

METHODS

We included patients initiating ART with AHI and CHI between 2000 and 2015 and compared time from ART initiation to the first normal CD4/CD8 ratio (defined as CD4/CD8 ≥1) using Kaplan-Meier curves and multivariable Cox proportional hazards models. Patient time was censored at virologic failure, lost to follow-up, or death. We also characterized CD4, CD8, and CD4/CD8 trajectories over the first 3 years of ART.

RESULTS

The 1198 patients were 27% female and 60% African American, with a median age of 37 years (interquartile range 28-47) at ART initiation. The 83 AHI patients were more likely male, younger, and of white race, than CHI patients. After 2 years of suppressive ART, 70% of AHI patients achieved a normal CD4/CD8 ratio, compared to 6%-38% of CHI patients, with greater likelihood of normalization at higher baseline CD4 counts. Time to normalization was shortest among AHI patients, followed by CHI patients with higher baseline CD4. The adjusted hazard ratio for time to normalization for AHI patients compared to CHI patients with baseline CD4 >350 was 4.33 (95% CI: 3.16 to 5.93). Higher baseline CD4/CD8 ratio was also associated with time to normalization (adjusted hazard ratio 1.54; 1.46, 1.63, per 0.1 increase in ratio).

CONCLUSIONS

Initiating ART during AHI at higher baseline CD4 cell counts and CD4/CD8 ratios was associated with shorter time to CD4/CD8 ratio normalization.

Determinants of blood telomere length in antiretroviral treatment-naïve HIV-positive participants enrolled in the NEAT 001/ANRS 143 clinical trial

OBJECTIVES

Our aim was to investigate factors associated with baseline blood telomere length in participants enrolled in NEAT 001/ANRS 143, a randomized, open-label trial comparing ritonavir-boosted darunavir (DRV/r) plus raltegravir (RAL) with DRV/r plus tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in antiretroviral therapy (ART)-naïve HIV-positive adults.

METHODS

A cross-sectional study of 201 randomly selected participants who had stored samples available was carried out. We measured telomere length (i.e. the relative telomere length, calculated as the telomere to single copy gene ratio) at baseline with monochrome quantitative multiplex polymerase chain reaction (PCR). We used multivariable predictive linear regression to calculate mean differences and 95% confidence intervals (CIs) for the association between baseline telomere length and baseline characteristics.

RESULTS

The baseline characteristics of the 201 participants did not differ from those of the 805 participants in the parent trial population: 89% were male, the mean age was 39 years, 83.6% were Caucasian, 93% acquired HIV infection via sexual transmission, the mean estimated time since HIV diagnosis was 2.1 years, the mean HIV-1 RNA load was 4.7 log₁₀ HIV-1 RNA copies/mL, the mean nadir and baseline CD4 counts were 301 and 324 cells/μL, respectively, and the mean CD4:CD8 ratio was 0.4. In the univariate analysis, shorter telomere length was associated with older age (per 10 years) (P < 0.001), HIV-1 RNA ≥ 100 000 copies/mL (P = 0.001), CD4 count < 200 cells/μL (P = 0.037), lower CD4:CD8 ratio (P = 0.018), statin treatment (P = 0.004), and current alcohol consumption (P = 0.035). In the multivariable analysis, older age (P < 0.001) and HIV RNA ≥ 100 000 copies/mL (P = 0.054) were independently associated with shorter telomere length.

CONCLUSIONS

Both age and HIV RNA viral load correlated with shorter blood telomere length in untreated persons living with HIV. These results suggest that HIV infection and age have synergistic and independent impacts upon immunosenescence.

Enhancement of Macrophage Function by the Antimicrobial Peptide Sublancin Protects Mice from Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is the major pathogen responsible for community and hospital bacterial infections. Sublancin, a glucosylated antimicrobial peptide isolated from Bacillus subtilis 168, possesses antibacterial infective effects. In this study, we investigated the role and anti-infection mechanism of sublancin in a mouse model of MRSA-induced sublethal infection. Sublancin could modulate innate immunity by inducing the production of IL-1β, IL-6, TNF-α, and nitric oxide, enhancing phagocytosis and MRSA-killing activity in both RAW264.7 cells and mouse peritoneal macrophages. The enhanced macrophage function by the peptide in vitro correlated with stronger protective activity in vivo in the MRSA-invasive sublethal infection model. Macrophage activation by sublancin was found to be partly dependent on TLR4 and the NF-κB and MAPK signaling pathways. Moreover, oral administration of sublancin increased the frequencies of CD⁴⁺ and CD⁸⁺ T cells in mesenteric lymph nodes. The protective activity of sublancin was associated with in vivo augmenting phagocytic activity of peritoneal macrophages and partly improving T cell-mediated immunity. Macrophages thus represent a potentially pivotal and novel target for future development of innate defense regulator therapeutics against S. aureus infection.

The Novel Effects of a Hydrolyzed Polysaccharide Dietary Supplement on Immune, Hepatic, and Renal Function in Adults with HIV in a Randomized, Double-Blind, Placebo-Control Trial

The primary objective of the study was to evaluate the effects of a hydrolyzed polysaccharide, rice bran arabinoxylan compound (RBAC), on immune, hepatic, and renal function in HIV + individuals. A 6-month randomized double-blind placebo-controlled trial was utilized to conduct the intervention. Forty-seven HIV + individuals on stable antiretroviral therapy were enrolled and randomly assigned to one of the 2 study conditions (n = 22 RBAC and n = 25 placebo) and consumed 3 gram/day of either compound for 6 months. Participants were assessed at baseline and 3 and 6 months follow-up for CD4+ and CD8+, liver enzymes, and kidney function. No side effects were reported, and liver and kidney markers remained nearly completely within normal limits. The percentage change in CD4+ was similar for the placebo (+2.2%) and RBAC (+3.1%) groups at 6 months follow-up. The percentage change in CD8+ count significantly decreased from baseline to 6 months in the RBAC group (-5.2%), whereas it increased in the placebo group (+57.8%; p = 0.04). The CD4+/CD8+ ratio improved clinically in the RBAC group from 0.95 (SD = 0.62) at baseline to 1.07 (SD = 0.11) at 6 months, whereas it declined in the placebo group from 0.96 (SD = 0.80) at baseline to 0.72 (SD = 0.59) at 6 months. Our results showed a statistically significant decrease in CD8+ count and a clinically significant increase in CD4+/CD8+ ratio for the RBAC group compared to the placebo group. Thus, the results of this study suggest that the immunomodulatory and antisenescent activities of RBAC are promising for the HIV population.

Suboptimal Immune Reconstitution among HIV-Infected Saudi Patients following Successful Antiretroviral Treatment

Background and Objectives

Variations in immune reconstitution following antiretroviral treatment (ART) among HIV patients have previously been observed. This study aims at assessing immune reconstitution after successful ART among HIV-infected Saudi patients.

Methods

This retrospective study of 240 HIV-infected patients was performed between May 2010 and June 2015 in the HIV center at King Saud Hospital, Riyadh. Data were extracted for CD4, CD8 cell, and CD3/HLA-DR counts along with the viral load from patient records before and after four years of successful ART. The inclusion criterion was patients with CD4 reconstitution of either equal to or more than 400 cells/mm³ with an undetectable HIV viral load following ART. Based on their presentation, the HIV patients were grouped into early treatment (ET) and delayed treatment (DT) groups with CD4 counts of 200–350 cells/mm³ and less than 200 cells/mm³, respectively.

Findings

The pretreatment CD8+ counts of median 865 cells/mm³ (interquartile range (IQR) 774–1072) in the DT group declined to median 753 cells/mm³ (IQR 574–987; p < 0.0001). Moreover, there was a decline in CD8 counts from 703 cells/mm³ (IQR 655–747) to 620 cells/mm³ (IQR 563–645; p < 0.04) in the ET group after four years of successful ART. Pretreatment activation marker (CD3/HLA-DR+) expression of median 29% in the DT group declined to 22% and in the ET group from a median of 23% to 19% after treatment. The CD4/CD8 ratio in the DT group increased from 0.14 (IQR 0.09–0.88) to 0.71 (IQR 0.54–0.9) and from 0.42 (IQR 0.35–0.55) to 0.87 (IQR 0.71–0.98) in the ET group.

Conclusion

Immune reconstitution after successful ART among HIV-infected Saudi patients was associated with a CD8 T-cell population expansion with a suboptimal CD4/CD8 ratio and persistent immune activation. Early initiation of ART appears to favorably influence the CD4/CD8 ratio.

RETRACTED ARTICLE: The Novel Effects of a Hydrolyzed Polysaccharide Dietary Supplement on Immune, Hepatic, and Renal Function in Adults with HIV in a Randomized, Double-Blind Placebo-Control Trial

The primary objective of the study was to evaluate the effects of a hydrolyzed polysaccharide, rice bran arabinoxylan compound (RBAC), on immune, hepatic, and renal function in HIV + individuals. A six-month randomized double-blind placebo-controlled trial was utilized to conduct the intervention. Forty-seven HIV + participants on stable antiretroviral therapy were enrolled and randomly assigned to one of the two study conditions (n = 22 RBAC and n = 25 placebo) and consumed 3 gram/day of either compound for six months. Participants were assessed at baseline and 3 and 6 months follow-up for CD4+ and CD8+, liver enzymes, and kidney function. No side effects were reported, and liver and kidney markers nearly remained completely within normal limits. The percentage change in CD4+ was similar for the placebo (+2.2%) and RBAC (+3.1%) groups at 6 months follow-up. The percentage change in CD8+ count significantly decreased from baseline to 6 months in the RBAC group (-5.2%), whereas it increased in the placebo group (+57.8%; p = 0.04). The CD4+/CD8+ ratio improved clinically in the RBAC group from 0.95 (SD =0.62) at baseline to 1.07 (SD =0.11) at 6 months, whereas it declined in the placebo group from 0.96 (SD =0.80) at baseline to 0.72 (SD =0.59) at 6 months. Our results showed a statistically significant decrease in CD8+ count and a clinically significant increase in CD4+/CD8+ ratio for the RBAC group compared to the placebo group. Thus, the results of this study suggest that the immunomodulatory and antisenescent activities of RBAC are promising for the HIV population.

Absolute CD4+ T cell count overstate immune recovery assessed by CD4+/CD8+ ratio in HIV-infected patients on treatment

Objectives

To analyse the correlation and concordance between aCD4, CD4%, CD4/CD8, their intra-patient variability, and to compare the immune recovery (IR) rates based on the three parameters in HIV-infected patients after starting antiretroviral therapy.

Methods

From a prospectively followed cohort, patients who maintained HIV-RNA suppression in ≥95% of the determinations throughout the follow-up were selected. IR was defined as aCD4 >650/μl, CD4% ≥38% or CD4/CD8 ≥1.

Results

A total of 1164 patients with a median follow-up of 5 years were analysed. The increases in aCD4, CD4% and CD4/CD8 were highest during the first year and considerably lower thereafter regardless of baseline aCD4. The annual increases in aCD4 showed poor correlations with those of CD4% (r = 0.143–0.250) and CD4/CD8 (r = 0.101–0.192) but were high between CD4% and CD4/CD8 (r = 0.765–0.844; p<0.001). The median intra-annual coefficients of variation for aCD4, CD4/CD8 and CD4% were 12.5, 8.5 and 6.6, respectively. After five years, 66.7%, 41.6% and 42.1% of the patients reached aCD4 >650/μl, CD4% ≥38%, and CD4/CD8 ≥1, respectively, while only 31% achieved both aCD4 and CD4/CD8 target values.

Conclusions

The increases in aCD4 poorly correlate with those of CD4% and CD4/CD8. IR rates based on aCD4 significantly overstate those obtained by CD4% and CD4/CD8. CD4% and CD4/CD8 are more stable markers than aCD4 and should be taken into account to monitor the IR after treatment initiation.

CD4/CD8 ratio normalization rates and low ratio as prognostic marker for non-AIDS defining events among long-term virologically suppressed people living with HIV

Background

Immune restoration is often incomplete after ART in HIV patients, both quantitatively and qualitatively. We studied the incidence and probability of CD4/CD8 normalization in an adult Thai HIV cohort and explored the predictive value of the ratio for developing of non-AIDS defining events (NAEs).

Methods

We analyzed data from HIV-infected Thai adults between 1996 and 2017 in the HIV-NAT 006 prospective long-term cohort in Bangkok, Thailand. Normalization was defined as CD4/CD8 ratio ≥ 1 on two consecutive visits, and normalization probability was calculated using the Kaplan–Meier method. NAEs were a composite endpoint including cardiovascular or cerebrovascular diseases, chronic kidney diseases, non-AIDS defining malignancies and death. Multivariate Cox regression was used to evaluate demographic, disease and treatment characteristics associated with CD4/CD8 ratio normalization and NAEs.

Results

A total of 800 ART-naïve patients with baseline CD4/CD8 ratio of < 0.8 who started combination ART, and had sustained virological suppression were enrolled. Participants were on ART for a median of 8.9 years and virologically suppressed for 6.1 years. The probabilities of CD4/CD8 normalization at 2, 5 and 10 years after virological suppression were 5.1%, 18.6% and 39.1%, respectively. Factors associated with normalization in multivariate analysis were female sex (hazard ratio [HR]: 2.47, 95% CI 1.71–3.56, p < 0.001) and baseline CD4 counts ≥ 350 cells/mm³ (HR: 3.62, 95% CI 2.36–5.55), p < 0.001) vs. < 200 cells/mm³ as reference. The second analysis explored the predictive value of CD4/CD8 ratio for NAEs. Older age (HR: 1.09, 95% CI 1.05–1.13, p < 0.01) and current CD4/CD8 ratio < 0.3 (HR: 3.02, 95% CI 1.27–7.21, p = 0.01) or between 0.3 and 0.45 (HR: 2.03, 95% CI 1.03–3.98, p = 0.04) vs. > 0.45 were independently associated with higher risk of progression to NAEs in the multivariate analysis.

Conclusions

Our findings showed that complete immune recovery is uncommon in an Asian setting and earlier ART initiation at higher CD4 counts may have increased the ratio sooner. The findings demonstrate the use of CD4/CD8 ratio as a prognostic marker for clinical progression of NAEs.

Trial registration HIV-NAT 006 cohort, clinical trial number: NCT00411983

CD4+/CD8+ ratio restoration in long-term treated HIV-1-infected individuals

OBJECTIVES

A persistently low CD4/CD8 ratio despite virological control reflects a higher risk of morbidity in HIV-infected individuals. The objective of the study was to assess the probability and determinants of ratio restoration (≥1) during long-term combined antiretroviral therapy (cART).

DESIGN

Study cohort based on the French Hospital Database on HIV (ANRS CO4).

METHODS

Antiretroviral-naive HIV-1-infected individuals were included if they achieved virological control (plasma HIV RNA ≤ 500 copies/ml) within 9 months following cART, started between 2000 and 2010. Cumulative incidence of ratio restoration after virological control and predictive factors of such a favorable outcome were studied taking into account 'virological failure', 'loss to follow-up', and 'death' as competing risks for ratio restoration.

RESULTS

Among the 10012 individuals included, the probability of CD4/CD8 ratio restoration was 30% (95% confidence interval, 29-31) at 8 years, ranging from 17% (15 to 19) among individuals with AIDS, to 45% (41 to 50) in people with CD4 at least 500 cells/μl at cART introduction. The main factors associated with ratio restoration were cART started during primary HIV infection whatever the CD4 cell count, or starting at CD4 at least 500 cells/μl while not in primary HIV infection [subdistribution hazard ratio = 1.67 (95% confidence interval, 1.13-2.47) and 2.26 (1.92-2.66) respectively, compared with starting cART at 200-349 CD4 cells/μl], and starting cART in recent years [subdistribution hazard ratio = 2.38 (2.01-2.83) in 2009-2010, compared with 2000-2002]. Higher baseline CD8 cell count was negatively associated with ratio restoration.

CONCLUSION

At 8 years, only one-third of individuals achieved CD4/CD8 ratio restoration with sustained virological control. Treatment at the earliest stage, and starting cART in recent years appeared to be key determinants.

Brief Report: Enhanced Normalization of CD4/CD8 Ratio With Earlier Antiretroviral Therapy at Primary HIV Infection

Supplemental Digital Content is Available in the Text.

Background:

Total CD4⁺ T-cell counts predict HIV disease progression but do not necessarily reflect normalization of immune function. CD4/CD8 ratio is a marker of immune dysfunction, a prognostic indicator for non-AIDS mortality, and reflects viral reservoir size. Despite antiretroviral therapy (ART), recovery of CD4/CD8 ratio in chronic HIV infection is incomplete; we hypothesize enhanced CD4/CD8 ratio recovery with earlier treatment initiation in recently infected individuals.

Methods:

CD4⁺ count and CD4/CD8 ratio were analyzed using data from 2 cohorts: SPARTAC trial and the UK HIV Seroconverters Cohort where primary HIV infection (PHI) was defined as within 6 months from estimated date of infection. Using time-to-event methods and Cox proportional hazard models, we examined the effect of CD4/CD8 ratio at seroconversion on disease progression (CD4 <350 cells per cubic millimeter/ART initiation) and factors associated with time from ART initiation to CD4/CD8 normalization (ratio >1.0).

Findings:

Of 573 seroconverters, 482 (84%) had abnormal CD4/CD8 ratios at HIV seroconversion. Individuals with higher CD4/CD8 ratio at seroconversion were significantly less likely to reach the disease progression endpoint [adjusted hazard ratio (aHR) (95% CI) = 0.52 (0.32 to 0.82), P = 0.005]. The longer the interval between seroconversion and ART initiation [HR (95% CI) = 0.98 per month increase (0.97, 0.99), P < 0.001], the less likely the CD4/CD8 ratio normalization. ART initiation within 6 months from seroconversion was significantly more likely to normalize [HR (95% CI) = 2.47 (1.67 to 3.67), P < 0.001] than those initiating later.

Interpretation:

Most individuals presenting in PHI have abnormal CD4/CD8 ratios. The sooner the ART is initiated in PHI, the greater the probability of achieving normal CD4/CD8 ratio.

The CD4+ T-lymphocyte count is an important predictor for the prognosis of cryptococcosis

There is great heterogeneity of immunity among patients with cryptococcosis, and severe immunodeficiency can lead to negative clinical outcomes. Underlying disease is a poor surrogate for immune status and inferior in predicting an individual’s prognosis. This study was intended to determine whether T-lymphocyte subgroups would be more suitable indicators regarding the severity of infection and clinical outcomes of such patients. We retrieved clinical data on 101 patients with cryptococcosis and compared the validity of multiple parameters (underlying disease and T-lymphocyte subgroups) in predicting the severity of infection and clinical outcome in these patients. For patients with CD4⁺ T-lymphocyte counts lower than 400/μL, the odds ratio of disseminated cryptococcosis was 23.3 (P = 0.005). There was a moderate negative correlation between CD4⁺ T-cell count and Apache II score (−0.609, P < 0.001). Mortality among patients with low levels of CD4⁺ T lymphocytes was significantly higher than among those with normal levels (23.8% vs 5.3%, P = 0.016). However, the difference was not significant if the patients were grouped by underlying disease (P = 0.067). The CD4⁺ T-lymphocyte count in peripheral blood is a simple and more accurate biomarker for predicting severity of infection and clinical outcome in patients with cryptococcosis.

A decreasing CD4/CD8 ratio over time and lower CSF-penetrating antiretroviral regimens are associated with a higher risk of neurocognitive deterioration, independently of viral replication

Persistent immune activation is one of the suspected causes of HIV-associated neurocognitive disorders (HAND) in cART era. The CD4/CD8 ratio has been recently showed as a marker of immune activation and HAND. Our aim was to analyze if a decrease in the CD4/CD8 ratio over time could have an impact on neurocognitive deterioration. Randomly selected HIV-infected patients were followed for neuropsychological (NP) testing during a period of almost 2 years. Tests were adjusted for age, gender, and education. Patients were divided into 5 groups: normal tests (NT), neuropsychological deficit (ND, one impaired cognitive domain), asymptomatic neurocognitive disorders (ANI), mild neurocognitive disorders (MND), and HIV-associated dementia (HAD). Risk factors for neurocognitive deterioration were analyzed. Two hundred fifty-six patients underwent NP tests and 94 participated in the follow-up. The groups were comparable. Upon neuropsychological re-testing, six patients showed clinical improvement, 30 had worsened, and 58 were stable, resulting in 42 patients presenting with HAND (45 %). The majority of HAND cases consisted of ANI (26 %) and MND (16 %). In patients whose NP performance worsened, CPE 2010 score was lower at inclusion (7.13 vs 8.00, p = 0.003) and CD4/CD8 decrease more frequent (60 vs 31 %, p = 0.008) than in those who were stable or improved. Multivariate analysis confirmed these results. A decreasing CD4/CD8 ratio during a longitudinal follow-up of randomly selected HIV-infected patients and lower CSF-penetrating regimens were independently associated with cognitive decline. Monitoring trends in CD4/CD8 ratio could contribute to identifying patients at higher risk of neurocognitive deterioration.

CD4/CD8 ratio and CD8 counts predict CD4 response in HIV-1-infected drug naive and in patients on cART

Plasma HIV viral load is related to declining CD4 lymphocytes. The extent to which CD8 cells, in addition to RNA viral load, predict the depletion of CD4 cells is not well characterized so far. We examine if CD8 cell count is a prognostic factor for CD4 cell counts during an HIV infection.A longitudinal analysis is conducted using data from the Swiss HIV cohort study collected between January 2000 and October 2014. Linear mixed regression models were applied to observations from HIV-1-infected treatment naive patients (NAIVE) and cART-treated patients to predict the short-term evolution of CD4 cell counts. For each subgroup, it was quantified to which extent CD8 cell counts or CD4/CD8 ratios are prognostic factors for disease progression.In both subgroups, 2500 NAIVE and 8902 cART patients, past CD4 cells are positively (P < 0.0001) and past viral load is negatively (P < 0.0001) associated with the outcome. Including additionally past CD8 cell counts improves the fit significantly (P < 0.0001) and increases the marginal explained variation 31.7% to 40.7% for the NAIVE and from 44.1% to 50.7% for the cART group. The past CD4/CD8 ratio (instead of the past CD8 level) is positively associated with the outcome, increasing the explained variation further to 41.8% for NAIVE and 51.9% for cART.

Different impact of raltegravir versus efavirenz on CD4/CD8 ratio recovery in HIV-infected patients

OBJECTIVES

A low CD4/CD8 ratio during treated HIV identifies individuals with heightened immunoactivation and excess mortality. Whether ART regimens elicit distinct CD4/CD8 ratio recovery remains unknown. We aimed to compare the efficacy of an integrase inhibitor versus a non-nucleoside to normalize the CD4/CD8 ratio.

METHODS

We conducted a post hoc analysis of the STARTMRK study, a randomized, blinded, double-dummy Phase III trial of raltegravir versus efavirenz, and each in combination with tenofovir/emtricitabine, in treatment-naive HIV-infected adults. Blinding was maintained for the entire 5 year duration of the study. Kaplan-Meier methods for time-dependent variables were used to calculate the rates of CD4/CD8 normalization at different cut-offs and cumulative probabilities. Cox proportional hazard models were used to compare probabilities of CD4/CD8 normalization by treatment arm.

RESULTS

A total of 563 patients were analysed; 81% were males and the mean age (SD) was 37 (10) years. Raltegravir was associated with higher rates of CD4/CD8 ratio normalization at the >0.4 cut-off (median time to normalization = 56 versus 84 days; P = 0.048 by log-rank test). A Cox proportional hazard model stratified based on baseline CD4 counts showed an association between raltegravir and higher rates of CD4/CD8 ratio normalization (HR = 1.23; P = 0.02).

CONCLUSIONS

We herein show that normalization of the CD4/CD8 ratio above a clinically meaningful threshold may be dependent on the drug class used. Raltegravir showed faster CD4/CD8 ratio normalization compared with efavirenz, a finding with potential clinical implications. Whether other integrase inhibitors have a similar impact for this outcome remains to be explored.

Low CD4/CD8 Ratio Is Associated with Non AIDS-Defining Cancers in Patients on Antiretroviral Therapy: ANRS CO8 (Aproco/Copilote) Prospective Cohort Study

Objectives

To study the association between CD4/CD8 ratio and morbidity in HIV-infected patients on antiretroviral therapy (ART).

Methods

The APROCO/COPILOTE cohort enrolled patients initiating a protease inhibitor-containing ART in 1997–1999. The association between occurrence of first non AIDS-defining severe events (NADE) and time-dependent measures of immune restoration was assessed by 4 Cox models with different definitions of restoration, CD4+ cell counts (CD4), CD4/CD8 ratio, both CD4 and CD4/CD8 ratio, or a composite variable (CD4< 500/mm³, CD4 > 500/mm³ and CD4/CD8 ratio < 1, CD4 > 500/mm³ and CD4/CD8 ratio > 1). Models adjusted on baseline characteristics and time-dependent viral load were compared using Akaike Information Criterion.

Results

We included 1227 patients. Median duration of follow-up was 9.2 years (IQR: 4.2–11.4). Median CD4 was 530/mm³ at 9 years. Median CD4/CD8 ratio was 0.3 (IQR: 0.2–0.5) at baseline and 0.6 (IQR: 0.4–0.9) after 9 years. Incidence of first NADE was 7.4/100 person-years, the most common being bacterial infections (21%), cardiovascular events (14%) and cancers (10%). For both bacterial infections and cardiovascular events, the CD4/CD8 ratio did not add predictive information to the CD4 cell count. However, low CD4/CD8 ratio was the best predictor of non-AIDS cancers (adjusted HR = 2.13 for CD4/CD8 < 0.5; 95% CI = 1.32–3.44).

Conclusions

CD4/CD8 ratio remains < 1 in most HIV-infected patients despite long-term CD4+ cell counts restoration on ART. A CD4/CD8 ratio < 0.5 could identify patients who require a more intensive strategy of cancer prevention or screening.

CD4+/CD8+ ratio, age, and risk of serious noncommunicable diseases in HIV-infected adults on antiretroviral therapy

OBJECTIVE

In virologically suppressed HIV-infected adults, noncommunicable diseases (NCDs) have been associated with immune senescence and low CD4/CD8 lymphocyte ratio. Age differences in the relationship between CD4/CD8 ratio and NCDs have not been described.

DESIGN

Observational cohort study.

METHODS

We assessed CD4/CD8 ratio and incident NCDs (cardiovascular, cancer, liver, and renal diseases) in HIV-infected adults started on antiretroviral therapy between 1998 and 2012. Study inclusion began once patients maintained virologic suppression for 12 months (defined as baseline). We examined age and baseline CD4/CD8 ratio and used Cox proportional hazard models to assess baseline CD4/CD8 ratio and NCDs.

RESULTS

This study included 2006 patients. Low baseline CD4/CD8 ratio was associated with older age, male sex, and low CD4 lymphocyte counts. In models adjusting for CD4 lymphocyte count, CD4/CD8 ratio was inversely associated with age (P < 0.01). Among all patients, 182 had incident NCDs, including 46 with coronary artery disease (CAD) events. CD4/CD8 ratio was inversely associated with risk of CAD events [adjusted HR per 0.1 increase in CD4/CD8 ratio = 0.87, 95% confidence interval (CI): 0.76-0.99, P = 0.03]. This association was driven by those under age 50 years (adjusted HR 0.83 [0.70-0.97], P = 0.02) vs. those over age 50 years (adjusted HR = 0.96 [0.79-1.18], P = 0.71). CD4/CD8 ratio was not significantly associated with incident noncardiac NCDs.

CONCLUSIONS

Higher CD4/CD8 ratio after 1 year of HIV virologic suppression was independently predictive of decreased CAD risk, particularly among younger adults. Advanced immune senescence may contribute to CAD events in younger HIV patients on antiretroviral therapy.

The Impact of Sex Work Interruption on Blood-Derived T Cells in Sex Workers from Nairobi, Kenya

BACKGROUND

Unprotected sexual intercourse exposes the female genital tract (FGT) to semen-derived antigens, which leads to a proinflammatory response. Studies have shown that this postcoital inflammatory response can lead to recruitment of activated T cells to the FGT, thereby increasing risk of HIV infection.

OBJECTIVE

The purpose of this study was to evaluate the impact of sex work on activation and memory phenotypes of peripheral T cells among female sex workers (FSW) from Nairobi, Kenya.

SUBJECTS

Thirty FSW were recruited from the Pumwani Sex Workers Cohort, 10 in each of the following groups: HIV-exposed seronegative (at least 7 years in active sex work), HIV positive, and New Negative (HIV negative, less than 3 years in active sex work). Blood was obtained at three different phases (active sex work, abstinence from sex work-sex break, and following resumption of sex work). Peripheral blood mononuclear cells were isolated and stained for phenotypic markers (CD3, CD4, CD8, and CD161), memory phenotype markers (CD45RA and CCR7), activation markers (CD69, HLA-DR, and CD95), and the HIV coreceptor (CCR5). T-cell populations were compared between groups.

RESULTS

In HIV-positive women, CD8+CCR5+ T cells declined at the sex break period, while CD4+CD161+ T cells increased when returning to sex work. All groups showed no significant changes in systemic T-cell activation markers following the interruption of sex work, however, significant reductions in naive CD8+ T cells were noted. For each of the study points, HIV positives had higher effector memory and CD8+CD95+ T cells and lower naive CD8+ T cells than the HIV-uninfected groups.

CONCLUSIONS

Interruption of sex work had subtle effects on systemic T-cell memory phenotypes.

Elevation and persistence of CD8 T-cells in HIV infection: the Achilles heel in the ART era

Introduction

HIV infection leads to a disturbed T-cell homeostasis, featured by a depletion of CD4 T-cells and a persistent elevation of CD8 T-cells over disease progression. Most effort of managing HIV infection has been focused on CD4 T-cell recovery, while changes in the CD8 compartment were relatively underappreciated in the past.

Methods

A comprehensive literature review of publications in English language was conducted using major electronic databases. Our search was focused on factors contributing to CD8 T-cell dynamics in HIV infection and following antiretroviral therapy (ART).

Discussion

Normalization of CD8 counts is seldom observed even with optimal CD4 recovery following long-term treatment. Initiation of ART in primary HIV infection leads to enhanced normalization of CD8 count compared with long-term ART initiated in chronic infection. Importantly, such CD8 elevation in treated HIV infection is associated with an increased risk of inflammatory non-AIDS-related clinical events independent of CD4 T-cell recovery. The mechanisms underlying CD8 persistence remain largely unknown, which may include bystander activation, exhaustion and immunosenescence of CD8 T-cells. The information provided herein will lead to a better understanding of factors associated with CD8 persistence and contribute to the development of strategies aiming at CD8 normalization.

Conclusions

Persistence of CD8 T-cell elevation in treated HIV-infected patients is associated with an increased risk of non-AIDS-related events. Now that advances in ART have led to decreased AIDS-related opportunistic diseases, more attention has been focused on reducing non-AIDS events and normalizing persistent CD8 T-cell elevation.

Short Communication: p21/CDKN1A Expression Shows Broad Interindividual Diversity in a Subset of HIV-1 Elite Controllers

The p21/CDKN1A protein has been described in vitro as well as in a small subset of patients as a restriction factor for HIV infection. We evaluated p21/CDKN1A mRNA expression on CD4(+) T cells from HIV-infected individuals with two outcomes (18 elite controllers and 28 viremic progressors). Our results show broad interindividual variation in this factor, which is unrelated to the patient's phenotype. Considering the gene's genetic surroundings in chromosome 6, such as HLA genotype and single nucleotide polymorphisms (SNPs), there was a positive association with carrying HLA-B2705 alleles and the rs733590 SNP. Thus, this natural variation of p21/CDKN1A alone does not appear to be a prognostic indicator of effective viral control in vivo and other factors must be considered.

Normal T-cell activation in elite controllers with preserved CD4+ T-cell counts

BACKGROUND

HIV elite controllers suppress HIV viremia without antiretroviral therapy (ART), yet previous studies demonstrated that elite controllers maintain an activated T-cell phenotype. Chronic immune activation has detrimental consequences and thus ART has been advocated for all elite controllers. However, elite controllers are not a clinically homogenous group. Since CD4% is among the best predictors of AIDS-related events, in the current study, we assessed whether this marker can be used to stratify elite controllers needing ART.

METHODS

Sixteen elite controllers were divided into two groups based on CD4% (EC > 40% and EC ≤40%), and T-cell subsets were analyzed for markers of memory/differentiation (CD45RA, CCR7, CD28), activation (CD38/HLA-DR), immunosenescence (CD57), costimulation (CD73, CD28) and exhaustion (PD-1, CD160, Tim-3). Monocyte subsets (CD14, CD16) were also analyzed and sCD14 levels were quantified using ELISA.

RESULTS

In the EC group, expression of activation, exhaustion, and immunosensescence markers on T cells were significantly reduced compared with the EC group and similar to the seronegative controls. The EC group expressed higher levels of costimulatory molecules CD28 and CD73 and had lower levels of monocyte activation (HLA-DR expression) with a reduced frequency of inflammatory monocyte (CD14 CD16) subset. Furthermore, the EC group maintained a stable CD4% during a median follow-up of 6 years.

CONCLUSION

Elite controllers with preserved CD4T cells (EC) have normal T-cell and monocyte phenotypes and therefore may have limited benefit from ART. CD4% can be an important marker for evaluating future studies aimed at determining the need for ART in this group of individuals.

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”.

Neurocognitive decline in HIV patients is associated with ongoing T-cell activation in the cerebrospinal fluid

Objective

HIV-associated neurocognitive disorders (HAND) remain a challenge despite combination antiretroviral therapy (cART). Immune cell activation has been implicated to play a major role in the development of HAND.

Methods

In this study, we used multicolor flow cytometry on peripheral blood (PB) and cerebrospinal fluid (CSF) samples to determine the expression of HLA-DR and programmed death-1 (PD-1) on CD4+ and CD8+ T cells in patients with chronic HIV infection. Expression levels were correlated with HI virus load in PB and CSF, classification of HAND and severity of magnetic resonance imaging (MRI) signal abnormalities.

Results

In a cohort of 86 HIV patients we found that the grade of neurocognitive impairment and the severity of MRI signal abnormalities correlated with decreasing CD4/CD8-ratios and increased frequencies of HLA-DR expressing CD4+ and CD8+ T cells reaching the highest values in the CSF samples. Importantly, HLA-DR upregulation was still detectable in virologically suppressed HIV patients. Further, T-cell subpopulation analysis of 40 HIV patients showed a significant shift from naïve to effector memory (EM) T cells that was negatively correlated with the grade of neurocognitive impairment in the PB samples. Moreover, PD-1 was significantly increased on CD4+ memory T cells with highest levels on EM T cells in HIV patients with mild or severe neurocognitive alterations.

Interpretation

The CD4/CD8 ratio, the proportion of EM to naïve T cells and the immune activation profile of CD4+ and CD8+ T cells in PB and CSF might be useful parameters to monitor the efficacy of cART and to identify HIV patients at risk of further neurocognitive deterioration.

Second European Round Table on the Future Management of HIV: 10-11 October 2014, Barcelona, Spain

The Second European Round Table on the Future Management of HIV took place in Barcelona, 10-11 October 2014 and focused on the HIV-1 reservoir, strategies for HIV cure and primary HIV infection (PHI). Important issues in the HIV-1 reservoir research field are the validity of reservoir measurement techniques and the potential of new drugs to target latently infected cells. Current HIV-1 cure concepts are based on theoretical assumptions of biologically plausible mechanisms, supported by several clinical observations. Three main potential strategies are under investigation in order to achieve a sterilising cure or maintain HIV-1 remission: latency reversal resulting in antigen expression and viral cytolysis or immune targeted cell-death; immunological control of the reservoir; or replacement of the complete autologous haematopoietic and lymphoid stem-cell repertoire by transplantation. An interesting opportunity for restricting the size of the reservoir entails the early initiation of antiretroviral treatment (ART) during PHI. In terms of the reservoir, early treatment limits its size, alters its composition, and restricts the genetic variability of integrated proviral HIV-1 DNA. The challenges ahead involve the identification of patients undergoing seroconversion to HIV-1 and the prompt initiation of treatment. How the seemingly beneficial impact of early treatment will make cure more feasible, and whether the positive effects of the cure efforts outweigh the potentially negative impact of life-long ART, are important aspects of future collaborative research prospects.

CD4:CD8 ratio as a frontier marker for clinical outcome, immune dysfunction and viral reservoir size in virologically suppressed HIV-positive patients

Introduction

Absolute CD4 T cell count and plasma viral load have been established as predictors of HIV disease progression, and CD4 T cell count is used as an indicator for initiation of antiretroviral therapy. Following long-term therapy, patients generally present with significant CD4 T cell recovery contrasting with persistently elevated CD8 T cell counts, which leads to a partial restoration of CD4:CD8 ratio. This review focuses on the relevance of the CD4:CD8 ratio on clinical outcomes, immune dysfunction and HIV reservoir size in long-term treated patients.

Method

We conducted a comprehensive literature review of publications in English language using major electronic databases. Our search was focused on factors contributing to CD4:CD8 T cell ratio and clinical outcome in adult HIV-positive patients in the context of treated infection.

Discussion

Low CD4:CD8 ratio has been linked to ageing and acts as a predictor of mortality in the general population. This ratio may represent the combined effects of inflammation and immunological changes called “inflammaging.” Although the mechanisms underlying partial correction of the CD4:CD8 ratio and persistently elevated CD8 T cell count in long-term treated patients remain poorly understood, it has been recently indicated that patients with optimal CD4 T cell recovery and low CD4:CD8 ratio still harbour increased immune activation, an immune senescent phenotype and have a higher risk of non-AIDS morbidity and mortality. This review reconsiders CD4:CD8 ratio in the light of advances in the understanding of immune dysfunction and examines its pathophysiological features and implications on clinical outcome and HIV reservoir size in long-term treated HIV-positive adults.

Conclusion

The CD4:CD8 ratio can contribute to the immunological evaluation of treated patients in a long-term follow-up and may be applied for monitoring both immune dysfunction and viral reservoir size in immune-based clinical trials.

CD4/CD8 ratio normalisation and non-AIDS-related events in individuals with HIV who achieve viral load suppression with antiretroviral therapy: an observational cohort study

BACKGROUND

In patients with HIV, immune reconstitution after antiretroviral therapy (ART) is often incomplete. We assessed the probability of patients reaching a CD4/CD8 ratio of 1 or more after the start of ART and its association with the onset of non-AIDS-defining events and death.

METHODS

We did an analysis of the ICONA cohort, which recruited treatment-naive patients with HIV in Italy. We included participants in the cohort who started ART, reached an undetectable viral load (≤80 copies per mL), and had a CD4/CD8 ratio of less than 0·8 at the time of an undetectable viral load. We defined ratio normalisation in patients as two consecutive values of 1 or more. We used Kaplan-Meier curves to estimate the cumulative probability of ratio normalisation. We then used Poisson regression models to identify factors independently associated with normalisation and with progression to non-AIDS-defining events or death.

FINDINGS

We included 3236 participants, enrolled between Jan 22, 1997, and Feb 25, 2013. At the start of ART, median CD4/CD8 ratio in our population was 0·39 (IQR 0·26-0·55). 458 (14%) patients reached a CD4/CD8 ratio of 1 or more; the estimated probability of normalisation was 4·4% (95% CI 3·7-5·2) by 1 year from baseline, 11·5% (10·2-13·0) by 2 years, and 29·4% (26·7-32·4) by 5 years. Factors associated with normalisation were high pre-ART CD4 cell counts, a high CD4/CD8 ratio at baseline, and negative cytomegalovirus serological findings. The incidence rate of non-AIDS-defining events for patients with a CD4/CD8 ratio of less than 0·30 (4·2 per 100 patient-years, 95% CI 3·4-5·3) was double that for those with a ratio of 0·30-0·45 (2·3, 2·1-2·5) or more than 0·45 (2·2, 1·7-2·9). A ratio of less than 0·30 was independently associated with an increased risk of non-AIDS-defining events or death compared with one of more than 0·45.

INTERPRETATION

Few patients had normalised CD4/CD8 ratios, even though they had viral suppression. Low ratios were associated with increased risk of serious events and deaths. The CD4/CD8 ratio could be used by clinicians to identity patients at risk of non-AIDS-related events.

FUNDING

AbbVie, Bristol-Myers Squibb, Gilead, Janssen, Merck Sharp & Dohme, ViiV Italy.