The absence of CD4+ T cell count recovery despite receipt of virologically suppressive highly active antiretroviral therapy: clinical risk, immunological gaps, and therapeutic options

Physical Activity as an Adjunct Treatment for People Living with HIV?

This review evaluates physical activity as a candidate for an adjunct treatment, in conjunction with antiretroviral therapy (ART), for people living with HIV (PLWH). Evidence is summarized that chronic, non-resolving inflammation (a principal feature of immune system dysfunction) and a dysfunctional state of the gut environment are key factors in HIV infection that persist despite treatment with ART. In addition, evidence is summarized that regular physical activity may restore normal function of both the immune system and the gut environment and may thereby ameliorate symptoms and non-resolving inflammation-associated comorbidities that burden PLWH. Physicians who care for PLWH could thus consider incorporating physical activity into treatment plans to complement ART. It is also discussed that different types of physical activity can have different effects on the gut environment and immune function, and that future research should establish more specific criteria for the design of exercise regimens tailored to PLWH.

Immune reconstitution efficacy after combination antiretroviral therapy in male HIV-1 infected patients with homosexual and heterosexual transmission

We aimed to explore the impact of sexual transmission modes on immune reconstitution after combined antiretroviral therapy (cART). We have retrospectively analyzed longitudinal samples from 1557 treated male patients with virological suppression (HIV-1 RNA<50 copies/ml) for at least 2 years. Both heterosexuals (HET) and men who have sex with men (MSM) patients showed an increasing annual trend in CD4⁺ T cell counts after receiving cART (HET, β: 23.51 (cell/µl)/year, 95% CI: 16.70 to 30.31; MSM, β: 40.21 (cell/µl)/year, 95% CI: 35.82 to 44.61). However, the CD4⁺ T cell recovery rate was much lower in HET patients than MSM patients, determined by both the generalized additive mixed model (P < 0.001) and generalized estimating equations (P = 0.026). Besides HIV-1 subtypes, baseline CD4⁺ T cell counts and age at cART initiation, HET was an independent risk factor for immunological non-responders (adjusted OR: 1.73; 95% CI: 1.28 to 2.33). HET was also associated with lower probability of achieving conventional immune recovery (adjusted HR: 1.37; 95%CI: 1.22 to 1.67) and optimal immune recovery (adjusted HR: 1.48, 95%CI: 1.04-2.11). Male HET patients might have poorer immune reconstitution ability even after effective cART. Early initiation of cART after diagnosis and clinical monitoring for male HET patients should be highly emphasized.

CD4+ T lymphocyte recovery in the modern antiretroviral therapy era: Toward a new threshold for defining immunological non-responders

Introduction

Despite the high level of efficacy of modern antiretroviral therapy (ART) in reducing HIV viremia and the control of viral replication, some people living with HIV (PLWH) do not recover their CD4+ T cell count.

Methods

To evaluate the frequency and predictive factors of discordant immune responses, we performed a retrospective cohort study of 324 antiretroviral-naïve PLWH who initiated first-line ART between 2008 and 2018 and maintained HIV RNA &lt; 50 copies/ml during 36 months of follow-up. PLWH were defined as immunological non-responders (INRs) when CD4+ T cell count was &lt; 20% compared with baseline (INR20%), or &lt; 500 cells/mm3 (INR500) or &lt; 200 cells/mm3 (INR200) at 36 months.

Results

The prevalence of INR20%, INR500, and INR200 was 12.5%, 34.6%, and 1.5%, respectively. After adjustment for possible confounders, CD4 nadir showed a significant association with all INR definitions, with lower values predicting INR500 (aOR 0.98, 95% CI 0.98–0.99, p &lt; 0.001) and INR200 (aOR 0.98, 95% CI 0.95–1.01, p = 0.096). Moreover, a higher baseline CD4/CD8 ratio was inversely related to the probability of being INR500 (OR 0.03, 95% CI 0.01–0.12, p &lt; 0.001) and INR200 (OR 0.002, 95% CI 18–7–67.72, p = 0.255). By contrast, INR20% had a higher CD4 nadir and CD4/CD8 ratio than other INRs, suggesting the identification of an heterogenous population with such definition.

Discussion

The present study highlights how INR200 has become rare in the contemporary ART era, and about one-third of PLWH meet the criteria for INR500. Overcoming the threshold of 500 CD4/mm3 could be an appropriate definition of immune response, in contrast with the older definitions of INR200 and INR20%. Early diagnosis and rapid treatment initiation, before CD4 counts and the CD4/CD8 ratio begin to decline, are critical for achieving an optimal immune response.

Immunovirological discordance among people living with human immunodeficiency virus at a center in Western India: A retrospective study

Background and Objectives

Treatment of people living with human immunodeficiency virus (HIV) (PLHIV) is monitored using plasma HIV viral load levels and CD4 counts. Patients with either immunological nonresponse (virological suppression achieved) or virological nonresponse (immune reconstitution achieved) are termed as having a discordant response. These patients are at higher risk for acquired immunodeficiency syndrome (AIDS)-related infections/diseases/neoplasms, non-AIDS-related illnesses (cardiovascular, neurological, renal, hepatic diseases), and all-cause death. This study was conducted to assess the prevalence of immunovirological discordance among PLHIV after completion of at least 1 year of combination antiretroviral therapy (cART) at an antiretroviral therapy (ART) plus center in India and analyze contributory factors.

Methods

The study was a retrospective study of PLHIV receiving cART at the ART plus clinic in Western India from January 18 to December 21. Four hundred and ninety-six patients were studied based on sample size calculated and assessed for CD4 and viral load response at 0, 6, and 12 months of ART.

Results

Of the 496 patients, 48 patients (9.7%) had immunovirological discordance. Out of them, 36 patients (75%) had a virological response (immunological nonresponse) and 12 (25%) patients had an immunological response (virological nonresponse). The factors contributing to immunological nonresponse were as follows - low baseline CD4 levels (<100 cells) (36.1%), adherence <95% (33.3%), presence of opportunistic infections (16.6%), and failure on first-line therapy (11.1%). Other factors noted included higher baseline viral load (2.7%), chronic kidney disease (5.5%), and chronic hepatitis B virus co-infection (5.5%). Virological nonresponse was associated with poor adherence to therapy <95% (33%) and failure of first-line regimen (33%). Opportunistic infections were noted among 33% of patients and 8.3% of patients were found to have higher baseline viral load.

Interpretation and Conclusion

Immunovirological discordance is an important factor influencing response to cART and is associated with many complications such as AIDS and non-AIDS-related events and even death. Improved adherence and timely identification and management of opportunistic infections are measures that are beneficial in reducing the incidence of immunovirological discordance.

Probiotic effects on immunity and microbiome in HIV-1 discordant patients

Background

Some HIV-1 infected patients are unable to completely recover normal CD4+ T-cell (CD4+) counts after achieving HIV-1 suppression with combined Antiretroviral Therapy (cART), hence being classified as immuno-discordant. The human microbiome plays a crucial role in maintaining immune homeostasis and is a potential target towards immune reconstitution.

Setting

RECOVER (NCT03542786) was a double-blind placebo-controlled clinical trial designed to evaluate if the novel probiotic i3.1 (AB-Biotics, Sant Cugat del Vallès, Spain) was able to improve immune reconstitution in HIV-1 infected immuno-discordant patients with stable cART and CD4+ counts <500 cells/mm3. The mixture consisted of two strains of L. plantarum and one of P. acidilactici, given with or without a fiber-based prebiotic.

Methods

71 patients were randomized 1:2:2 to Placebo, Probiotic or probiotic + prebiotic (Synbiotic), and were followed over 6 months + 3-month washout period, in which changes on systemic immune status and gut microbiome were evaluated. Primary endpoints were safety and tolerability of the investigational product. Secondary endpoints were changes on CD4+ and CD8+ T-cell (CD8+) counts, inflammation markers and faecal microbiome structure, defined by alpha diversity (Gene Richness), beta diversity (Bray-Curtis) and functional profile. Comparisons across/within groups were performed using standard/paired Wilcoxon test, respectively.

Results

Adverse event (AE) incidence was similar among groups (53%, 33%, and 55% in the Placebo, Probiotic and Synbiotic groups, respectively, the most common being grade 1 digestive AEs: flatulence, bloating and diarrhoea. Two grade 3 AEs were reported, all in the Synbiotic group: abdominal distension (possibly related) and malignant lung neoplasm (unrelated), and 1 grade 4 AE in the Placebo: hepatocarcinoma (unrelated). Synbiotic exposure was associated with a higher increase in CD4+/CD8+ T-cell (CD4/CD8) ratio at 6 months vs baseline (median=0.76(IQR=0.51) vs 0.72(0. 45), median change= 0.04(IQR=0.19), p = 0.03). At month 9, the Synbiotic group had a significant increase in CD4/CD8 ratio (0.827(0.55) vs 0.825(0.53), median change = 0.04(IQR=0.15), p= 0.02) relative to baseline, and higher CD4+ counts (447 (157) vs. 342(73) counts/ml, p = 0.03), and lower sCD14 values (2.16(0.67) vs 3.18(0.8), p = 0.008) than Placebo. No effect in immune parameters was observed in the Probiotic arm. None of the two interventions modified microbial gene richness (alpha diversity). However, intervention as categorical variable was associated with slight but significant effect on Bray-Curtis distance variance (Adonis R2 = 0.02, p = 0.005). Additionally, at month 6, Synbiotic intervention was associated with lower pathway abundances vs Placebo of Assimilatory Sulphate Reduction (8.79·10^-6 (1.25·10^-5) vs. 1.61·10^-5 (2.77·10^-5), p = 0.03) and biosynthesis of methionine (2.3·10^-5 (3.17·10^-5) vs. 4·10^-5 (5.66·10^-5), p = 0.03) and cysteine (1.83·10^-5 (2.56·10^-5) vs. 3.3·10^-5 (4.62·10^-5), p = 0.03). At month 6, probiotic detection in faeces was associated with significant decreases in C Reactive Protein (CRP) vs baseline (11.1(22) vs. 19.2(66), median change= -2.7 (13.2) ug/ml, p = 0.04) and lower IL-6 values (0.58(1.13) vs. 1.17(1.59) ug/ml, p = 0.02) when compared with samples with no detectable probiotic. No detection of the probiotic was associated with higher CD4/CD8 ratio at month 6 vs baseline (0.718(0.57) vs. 0.58(0.4), median change = 0.4(0.2), p = 0.02). After washout, probiotic non-detection was also associated with a significant increase in CD4+ counts (457(153) vs. 416(142), median change = 45(75), counts/ml, p = 0.005) and CD4/CD8 ratio (0.67(0.5) vs 0.59(0.49), median change = 0.04 (0.18), p = 0.02).

Conclusion

A synbiotic intervention with L. plantarum and P. acidilactici was safe and led to small increases in CD4/CD8 ratio and minor reductions in sCD14 of uncertain clinical significance. A probiotic with the same composition was also safe but did not achieve any impact on immune parameters or faecal microbiome composition.

Evaluation of antiretroviral therapy effect and prognosis between HIV-1 recent and long-term infection based on a rapid recent infection testing algorithm

Early diagnosis of HIV-1 infection and immediate initiation of combination antiretroviral therapy (cART) are important for achieving better virological suppression and quicker immune reconstitution. However, no serological HIV-1 recency testing assay has been approved for clinical use, and the real-world clinical outcomes remain to be explored for the subjects with HIV-1 recent infection (RI) or long-term infection (LI) when antiretroviral therapy is initiated. In this study, a HIV-1 rapid recent-infection testing strip (RRITS) was developed and incorporated into the recent infection testing algorithms (RITAs) to distinguish HIV-1 RI and LI and to assess their clinical outcomes including virological response, the recovery of CD4+ T-cell count and CD4/CD8 ratio and the probability of survival. We found that the concordance between our RRITS and the commercially available LAg-Avidity EIA was 97.13% and 90.63% when detecting the longitudinal and cross-sectional HIV-1 positive samples, respectively. Among the 200 HIV-1 patients analyzed, 22.5% (45/200) of them were RI patients and 77.5% (155/200) were chronically infected and 30% (60/200) of them were AIDS patients. After cART, 4.1% (5/155) of the LI patients showed virological rebound, but none in the RI group. The proportion of CD4+ T-cell count >500 cells/mm3 was significantly higher in RI patients than in LI after 2 years of cART with a hazard ratio (HR) of 2.6 (95% CI: 1.9, 3.6, p < 0.0001) while the probability of CD4/CD8 = 1 was higher in RI than in LI group with a HR of 3.6 (95% CI: 2.2, 5.7, p < 0.0001). Furthermore, the immunological recovery speed was 16 cells/mm3/month for CD4+ T-cell and 0.043/month for the ratio of CD4/CD8 in the RI group, and was bigger in the RI group than in the LI patients (p < 0.05) during the 1st year of cART. The survival probability for LI patients was significantly lower than that for RI patients (p < 0.001). Our results indicated that RRITS combined with RITAs could successfully distinguish HIV-1 RI and LI patients whose clinical outcomes were significantly different after cART. The rapid HIV-1 recency test provides a feasible assay for diagnosing HIV-1 recent infection and a useful tool for predicting the outcomes of HIV-1 patients.

Decreased CD73+ Double-Negative T Cells and Elevated Level of Soluble CD73 Correlated With and Predicted Poor Immune Reconstitution in HIV-Infected Patients After Antiretroviral Therapy

Although extensive use of antiretroviral therapy (ART) has made great progress in controlling HIV replication and improving CD4+ T cell recovery, the immune reconstitution remained insufficient in some patients, who were defined as poor immunological responders (PIRs). These PIRs were at a high risk of AIDS-related and non-AIDS complications, resulting in higher morbidity and mortality rate. Thus, it is a major challenge and urgently needed to distinguish PIRs early and improve their immune function in time. Immune activation is a key factor that leads to impaired immune reconstitution in people living with HIV (PLWH) who are receiving effective ART. Double negative T cells (DNT) were reported to associate with the control of immune activation during HIV infection. However, the precise mechanisms by which DNT cells exerted their suppressive capacity during HIV infection remained puzzled. CD73, both a soluble and a membrane-bound form, display immunosuppressive effects through producing adenosine (ADO). Thus, whether DNT cells expressed CD73 and mediated immune suppression through CD73-ADO pathway needs to be investigated. Here, we found a significant downregulation of CD73 expression on DNT cells in treatment-naïve PLWH (TNs) compared to healthy controls, accompanied with increased concentration of sCD73 in plasma. Both the frequency of CD73+ DNT cells and the level of plasma sCD73 recovered after ART treatment. However, PIRs showed decreased percentage of CD73+ DNT cells compared to immunological responders (IRs). The frequency of CD73+ DNT cells was positively correlated with CD4+ T cell count and CD4/CD8 ratio, and negatively correlated with immune activation in PLWH. The level of sCD73 also showed a negative correlation to CD4+ T cell count and CD4/CD8 ratio. More importantly, in the present cohort, a higher level of sCD73 at the time of initiating ART could predict poor immune reconstitution in PLWH after long-term ART. Our findings highlighted the importance of CD73+ DNT cells and sCD73 in the disease progression and immune reconstitution of PLWH, and provided evidences for sCD73 as a potential biomarker of predicting immune recovery.

Determinants of suboptimal immune recovery among a Chinese Yi ethnicity population with sustained HIV suppression

Objectives

Despite sustained viral suppression with effective antiretroviral therapy (ART), HIV-infected patients with suboptimal immune recovery are still at high risk of both non-AIDS-related and AIDS-related events. The aim of this study was to investigate determinants potentially associated with suboptimal CD4 + T cell count recovery during free ART with sustained viral suppression among an HIV-infected Yi ethnicity population in Liangshan Prefecture, an area in China with high HIV prevalence.

Methods

This retrospective study included HIV-infected Yi adults (≥ 18 years and baseline CD4 + T cell count less than 500 cells/μL) for whom ART supported by National Free Antiretroviral Treatment Program was initiated between January 2015 and December 2018 in Zhaojue County, Liangshan Prefecture. Virological suppression (viral load < 50 copies/mL) was achieved within 12 months after ART initiation, and sustained virological suppression was maintained. Multivariate log-binomial regression analysis was used to assess determinants of suboptimal immune recovery.

Results

There were 140 female and 137 male patients in this study, with a mean age of 36.57 ± 7.63 years. Most of the Yi patients were infected through IDU (48.7%) or heterosexual contact (49.8%), and the anti-HCV antibody prevalence was high (43.7%, 121/277). Of the 277 patients with a mean ART duration of 3.77 ± 1.21 years, complete immune recovery occurred in only 32.9%. The baseline CD4 + T cell count in patients with suboptimal and intermediate immune recovery was 248.64 ± 108.10 and 288.59 ± 108.86 cells/μL, respectively, which was much lower than the baseline 320.02 ± 123.65 cells/μL in patients who achieved complete immune recovery (p < 0.001). Multivariable analysis demonstrated that low pre-ART CD4 + cell count and coinfection with HCV were associated with immune recovery of the HIV patients.

Conclusions

Our study suggests that for HIV-infected Yi patients in Liangshan Prefecture, prompt ART initiation after diagnosis of HIV infection should be applied, and curative HCV treatment should be given to patients with HCV/HIV coinfection to improve the immunological effectiveness of ART.

Trial registration None

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07113-y.

Leptin Promotes Greater Ki67 Expression in CD4+ T Cells From Obese Compared to Lean Persons Living With HIV

While antiretroviral therapy (ART) has proven effective in suppressing viremia and disease progression among people living with human immunodeficiency virus (HIV; PLWH), suboptimal CD4+ T cell reconstitution remains a major obstacle in nearly 30% of ART-treated individuals. Epidemiological studies demonstrate that obesity, or a body mass index (BMI) ≥ 30 kg/m2, is positively correlated with greater CD4+ T cell recovery in PLWH on ART. Leptin is a known immunomodulator that is produced in proportion to fat mass and is increased in obese individuals, including PLWH. We hypothesized that CD4+ T cells from obese PLWH have increased cell proliferation and cytokine production compared to cells from lean PLWH, potentially modulated by differential effects of leptin signaling. To test this hypothesis, peripheral blood mononuclear cells from obese and lean PLWH with long-term virologic suppression on the same ART regimen were pretreated with recombinant leptin and then stimulated with anti-CD3/CD28 or PMA/ionomycin to measure Ki67 expression, leptin receptor (LepR) surface expression and cytokine production. In the absence of leptin, Ki67 expression and IL-17A production were significantly higher in CD4+ T cells from obese compared to lean PLWH. However, LepR expression was significantly lower on CD4+ T cells from obese compared to lean PLWH. After leptin treatment, Ki67 expression was significantly increased in CD4+ T cells from obese PLWH compared to the lean participants. Leptin also increased IL-17A production in CD4+ T cells from obese healthy controls. In contrast, leptin decreased IL-17A production in CD4+ T cells from both obese and lean PLWH. Combined, these results demonstrate that obesity is associated with greater CD4+ T cell proliferation among PLWH, and that higher circulating leptin levels in obesity may contribute to improved CD4+ T reconstitution in PLWH initiating ART.

Identification of Diagnostic Markers Correlated With HIV+ Immune Non-response Based on Bioinformatics Analysis

Background: HIV-infected immunological non-responders (INRs) are characterized by their inability to reconstitute CD4⁺ T cell pools after antiretroviral therapy. The risk of non-AIDS-related diseases in INRs is increased, and the outcome and prognosis of INRs are inferior to that of immunological responders (IRs). However, few markers can be used to define INRs precisely. In this study, we aim to identify further potential diagnostic markers associated with INRs through bioinformatic analyses of public datasets.

Methods: This study retrieved the microarray data sets of GSE106792 and GSE77939 from the Gene Expression Omnibus (GEO) database. After merging two microarray data and adjusting the batch effect, differentially expressed genes (DEGs) were identified. Gene Ontology (GO) resource and Kyoto Encyclopedia of Genes and Genomes (KEGG) resource were conducted to analyze the biological process and functional enrichment. We performed receiver operating characteristic (ROC) curves to filtrate potential diagnostic markers for INRs. Gene Set Enrichment Analysis (GSEA) was conducted to perform the pathway enrichment analysis of individual genes. Single sample GSEA (ssGSEA) was performed to assess scores of immune cells within INRs and IRs. The correlations between the diagnostic markers and differential immune cells were examined by conducting Spearman’s rank correlation analysis. Subsequently, miRNA-mRNA-TF interaction networks in accordance with the potential diagnostic markers were built with Cytoscape. We finally verified the mRNA expression of the diagnostic markers in clinical samples of INRs and IRs by performing RT-qPCR.

Results: We identified 52 DEGs in the samples of peripheral blood mononuclear cells (PBMC) between INRs and IRs. A few inflammatory and immune-related pathways, including chronic inflammatory response, T cell receptor signaling pathway, were enriched. FAM120AOS, LTA, FAM179B, JUN, PTMA, and SH3YL1 were considered as potential diagnostic markers. ssGSEA results showed that the IRs had significantly higher enrichment scores of seven immune cells compared with IRs. The miRNA-mRNA-TF network was constructed with 97 miRNAs, 6 diagnostic markers, and 26 TFs, which implied a possible regulatory relationship.

Conclusion: The six potential crucial genes, FAM120AOS, LTA, FAM179B, JUN, PTMA, and SH3YL1, may be associated with clinical diagnosis in INRs. Our study provided new insights into diagnostic and therapeutic targets.

CTN 328: immunogenicity outcomes in people living with HIV in Canada following vaccination for COVID-19 (HIV-COV): protocol for an observational cohort study

INTRODUCTION

Most existing vaccines require higher or additional doses or adjuvants to provide similar protection for people living with HIV (PLWH) compared with HIV-uninfected individuals. Additional research is necessary to inform COVID-19 vaccine use in PLWH.

METHODS AND ANALYSIS

This multicentred observational Canadian cohort study will enrol 400 PLWH aged >16 years from Montreal, Ottawa, Toronto and Vancouver. Subpopulations of PLWH of interest will include individuals: (1) >55 years of age; (2) with CD4 counts <350 cells/mm3; (3) with multimorbidity (>2 comorbidities) and (4) 'stable' or 'reference' PLWH (CD4 T cells >350 cells/mm3, suppressed viral load for >6 months and <1 comorbidity). Data for 1000 HIV-negative controls will be obtained via a parallel cohort study (Stop the Spread Ottawa), using similar time points and methods. Participants receiving >1 COVID-19 vaccine will attend five visits: prevaccination; 1 month following the first vaccine dose; and at 3, 6 and 12 months following the second vaccine dose. The primary end point will be the percentage of PLWH with COVID-19-specific antibodies at 6 months following the second vaccine dose. Humoral and cell-mediated immune responses, and the interplay between T cell phenotypes and inflammatory markers, will be described. Regression techniques will be used to compare COVID-19-specific immune responses to determine whether there are differences between the 'unstable' PLWH group (CD4 <350 cells/mm3), the stable PLWH cohort and the HIV-negative controls, adjusting for factors believed to be associated with immune response. Unadjusted analyses will reveal whether there are differences in driving factors associated with group membership.

ETHICS AND DISSEMINATION

Research ethics boards at all participating institutions have granted ethics approval for this study. Written informed consent will be obtained from all study participants prior to enrolment. The findings will inform the design of future COVID-19 clinical trials, dosing strategies aimed to improve immune responses and guideline development for PLWH.

TRIAL REGISTRATION NUMBER

NCT04894448.

Increased homeostatic cytokines and stability of HIV-infected memory CD4 T-cells identify individuals with suboptimal CD4 T-cell recovery on-ART

Clinical outcomes are inferior for individuals with HIV having suboptimal CD4 T-cell recovery during antiretroviral therapy (ART). We investigated if the levels of infection and the response to homeostatic cytokines of CD4 T-cell subsets contributed to divergent CD4 T-cell recovery and HIV reservoir during ART by studying virologically-suppressed immunologic responders (IR, achieving a CD4 cell count >500 cells/μL on or before two years after ART initiation), and virologically-suppressed suboptimal responders (ISR, did not achieve a CD4 cell count >500 cells/μL in the first two years after ART initiation). Compared to IR, ISR demonstrated higher levels of HIV-DNA in naïve, central (CM), transitional (TM), and effector (EM) memory CD4 T-cells in blood, both pre- and on-ART, and specifically in CM CD4 T-cells in LN on-ART. Furthermore, ISR had higher pre-ART plasma levels of IL-7 and IL-15, cytokines regulating T-cell homeostasis. Notably, pre-ART PD-1 and TIGIT expression levels were higher in blood CM and TM CD4 T-cells for ISR; this was associated with a significantly lower fold-changes in HIV-DNA levels between pre- and on-ART time points exclusively on CM and TM T-cell subsets, but not naïve or EM T-cells. Finally, the frequency of CM CD4 T-cells expressing PD-1 or TIGIT pre-ART as well as plasma levels of IL-7 and IL-15 predicted HIV-DNA content on-ART. Our results establish the association between infection, T-cell homeostasis, and expression of PD-1 and TIGIT in long-lived CD4 T-cell subsets prior to ART with CD4 T-cell recovery and HIV persistence on-ART.

Determinants of suboptimal CD4+ T cell recovery after antiretroviral therapy initiation in a prospective cohort of acute HIV-1 infection

Introduction

Up to 30% of individuals treated with antiretroviral therapy (ART) during chronic HIV fail to recover CD4 counts to >500 cells/mm³ despite plasma viral suppression. We investigated the frequency and associations of suboptimal CD4 recovery after ART started during acute HIV infection (AHI).

Methods

Participants who started ART in Fiebig I to V AHI with ≥48 weeks of continuous documented HIV‐RNA < 50 copies/mL were stratified by CD4 count at latest study visit to suboptimal immune recovery (SIR; CD4 < 350 cells/mm³), intermediate immune recovery (IIR; 350 ≤ CD4 < 500) and complete immune recovery (CIR; CD4 ≥ 500). Clinical and laboratory parameters were assessed at pre‐ART baseline and latest study visit. Additional inflammatory and neurobehavioral endpoints were examined at baseline and 96 weeks.

Results

Of 304 participants (96% male, median 26 years old) evaluated after median 144 (range 60 to 420) weeks of ART initiated at median 19 days (range 1 to 62) post‐exposure, 3.6% (n = 11) had SIR and 14.5% (n = 44) had IIR. Pre‐ART CD4 count in SIR compared to CIR participants was 265 versus 411 cells/mm³ (p = 0.002). Individuals with SIR or IIR had a slower CD4 rate of recovery compared to those with CIR. Timing of ART initiation by Fiebig stage did not affect CD4 count during treatment. Following ART, the CD8⁺T cell count (p = 0.001) and CD4/CD8 ratio (p = 0.047) were lower in SIR compared to CIR participants. Compared to the CIR group at week 96, the combined SIR and IIR groups had higher sCD14 (p = 0.008) and lower IL‐6 (p = 0.04) in plasma, without differences in neuropsychological or psychiatric indices.

Conclusions

Despite immediate and sustained treatment in AHI, suboptimal CD4 recovery occurs uncommonly and is associated with low pre‐ART CD4 count as well as persistent low CD8 count and CD4/CD8 ratio during treatment.

IFNL4 Genotype Does Not Associate with CD4 T-Cell Recovery in People Living with Human Immunodeficiency Virus

Immune non-responders (INRs) are people with HIV infection who fail to restore their CD4 T-cell counts in spite of prolonged virologic suppression, a condition associated with higher rates of all-cause mortality. The mechanisms of immune non-response are not entirely clear. We used existing clinical and genetic data from AIDS Clinical Trials Group clinical trials to ask whether an IFNL4 single-nucleotide polymorphism, shown to be associated with outcomes for other infectious diseases, correlated with immune non-response for HIV. Analysis of data from 426 participants with clearly defined CD4 T-cell recovery phenotypes, including 88 INRs with CD4 < 200 cells/mm³ after 2 years of suppressive antiretroviral therapy, did not identify an association of IFNL4 genotype with immune non-response. Thus, the IFNL4 genotype is unlikely to influence immunologic recovery.

Altered gut microbiota correlate with different immune responses to HAART in HIV-infected individuals

Background

Although gut microbiota dysbiosis has been reported in HIV infected individuals recently, the relationship between the gut microbiota and immune activation in patients with different immune responses to highly active antiretroviral therapy (HAART) is still not well understood. Gut microbiota and immune activation were studied in 36 non-HIV-infected subjects (healthy controls) and 58 HIV-infected individuals, including 28 immunological responders (IR) and 30 immunological non-responders (INR) (≥500 and < 200 CD4+ T-cell counts/μl after 2 years of HIV-1 viral suppression respectively) without comorbidities.

Results

Metagenome sequencing revealed that HIV-infected immunological responders and immunological non-responders could not recover completely from the gut microbiota dysbiosis. At a 97% similarity level, the relative abundances of Fusobacterium, Ruminococcus gnavus and Megamonas were greater, whereas Faecalibacterium, Alistipes, Bifidobacterium, Eubacterium rectale and Roseburia were more depleted in the IR and INR groups than those in the healthy controls. Ruminococcaceae and Alistipes were positively correlated with nadir and current CD4+ T-cell counts, but negatively correlated with CD8 + CD57+ T-cell counts. Inflammation markers and translocation biomarkers (LPS) levels were positively correlated with the abundances of genera Ruminococcus and Fusobacterium but were negatively correlated with the genus Faecalibacterium. The relative abundances of Escherichia-Shigella and Blautia were significantly higher in the IR than those in the INR group. Escherichia-Shigella were negatively correlated with the CD4/CD8 ratio but positively correlated with the amount of CD8 + CD57+ T-cells. Roseburia and Blautia were negatively associated with nadir CD4+ T-cell and positively associated with CD8 + CD57+ T-cell counts.

Conclusions

Gut microbiota dysbiosis may be one of the factors contributing to different immune responses and treatment outcomes to HAART.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-020-02074-1.

The Impact of microRNA Regulation on Immune Recovery in HIV-1-Infected Patients Treated during Acute Infection: A Pilot Study

microRNAs (miRNAs) are small noncoding RNAs involved in a large range of cellular activities and can be used as biomarkers and indicators for diagnosis. We investigated the alterations in miRNA profiles in immune reconstituted vs. nonimmune reconstituted HIV-1-infected individuals to assess the association between miRNAs and the occurrence of immunological nonresponses, with the aim of searching for miRNA-based biomarkers for these HIV-1-infected individuals. Thirteen immunological responders (IRs) and 12 immunological nonresponders (INRs) were recruited, and RNA was collected from the plasma samples of the 25 HIV-1-infected individuals at both baseline and after 24 months of maintaining virological suppression (VS). Next-generation sequencing was used to detect miRNAs and evaluate the expression differences in miRNAs between IR and INR patients and between baseline and after 24 months of maintaining VS. Samples from 13 IRs and 11 INRs were successfully sequenced. The horizontal comparison of differentially expressed miRNAs between the groups and the longitudinal comparison of differentially expressed miRNAs between baseline and after 24 months of maintaining VS showed that a large proportion of miRNAs in INRs are downregulated compared to the levels in IRs. We also found that the miRNA let-7d-5p was downregulated in 9 INRs but only in 2 IRs by more than 2-fold. The difference was significant. In summary, these results demonstrate for the first time that a large proportion of miRNAs are downregulated in INRs compared with IRs, and the miRNA let-7d-5p is a potential biomarker for INRs.

Mesenchymal stromal cells in human immunodeficiency virus-infected patients with discordant immune response: Early results of a phase I/II clinical trial

Between 15% and 30% of HIV‐infected subjects fail to increase their CD4⁺ T‐cell counts despite continuous viral suppression (immunological nonresponders [INRs]). These subjects have a higher morbidity and mortality rate, but there are no effective treatments to reverse this situation so far. This study used data from an interrupted phase I/II clinical trial to evaluate safety and immune recovery after INRs were given four infusions, at baseline and at weeks 4, 8, and 20, with human allogeneic mesenchymal stromal cells from adipose tissue (Ad‐MSCs). Based on the study design, the first 5 out of 15 INRs recruited received unblinded Ad‐MSC infusions. They had a median CD4⁺ nadir count of 16/μL (range, 2‐180) and CD4⁺ count of 253 cells per microliter (171‐412) at baseline after 109 (54‐237) months on antiretroviral treatment and 69 (52‐91) months of continuous undetectable plasma HIV‐RNA. After a year of follow‐up, an independent committee recommended the suspension of the study because no increase of CD4⁺ T‐cell counts or CD4⁺/CD8⁺ ratios was observed. There were also no significant changes in the phenotype of different immunological lymphocyte subsets, percentages of natural killer cells, regulatory T cells, and dendritic cells, the inflammatory parameters analyzed, and cellular associated HIV‐DNA in peripheral blood mononuclear cells. Furthermore, three subjects suffered venous thrombosis events directly related to the Ad‐MSC infusions in the arms where the infusions were performed. Although the current study is based on a small sample of participants, the findings suggest that allogeneic Ad‐MSC infusions are not effective to improve immune recovery in INR patients or to reduce immune activation or inflammation. ClinicalTrials.gov identifier: NCT0229004. EudraCT number: 2014‐000307‐26.

Characteristics of suboptimal immune response after initiating antiretroviral therapy among people living with HIV with a pre-treatment CD4 T cell count <200 ​cells/mm3 in Thailand

Background

Complete recovery of the CD4 T cell count is uncommon among chronically HIV-infected individuals with very low pre-treatment CD4 count. We studied the prevalence of chronically immune recovery and its associated factors including immune characteristics chronic HIV-infected Thais.

Methods

Treatment-naïve participants (n ​= ​375) from the HIV-NAT 006 cohort with a pre-treatment CD4 T cell count after initiating antiretroviral therapy (ART) and having achieved a suppressed viremia (HIV-RNA level ​< ​400 copies/mL) were retrospectively followed at the Thai Red Cross AIDS Research Centre, Bangkok, Thailand. Suboptimal immune recovery (SIR) was defined as having a CD4⁺ T cell count <200 ​cells/mm³ for 3 years after ART initiation. A case-control sub-study matched for age, sex and pre-ART CD4 T cell count was conducted to compare immunological characteristics between SIR (n ​= ​17) and non-SIR (n ​= ​24) participants. Immunological biomarkers such as interleukin-7 (IL-7) and soluble CD14 (sCD14) and other covariates including cytomegalovirus (CMV) DNA level, baseline hemoglobin level, hepatitis B and C co-infections, and T cell subsets associated with immune activation and exhaustion were evaluated.

Results

Among 375 participants with pre-ART CD4 T cell counts < 200 ​cells/mm³, the prevalence of SIR was 39.7%, 19.7% and 7.7% at years 1, 2 and 3 after starting ART, respectively. In a multivariate analysis, a pre-ART CD4 T cell count ≤100 ​cells/mm³ (adjusted odds ratio [aOR] 9.45, 95% CI 2.92–30.61, p ​< ​0.001), older age (aOR 1.07, 95% CI 1.01–1.13, p ​= ​0.029) and baseline HIV-RNA level (aOR 0.36, 95% CI 0.21–0.59, p ​< ​0.001) were independently associated with SIR at year 3 after ART initiation. In the matched case-control sub-study (cases ​= ​17, controls ​= ​24), there was a higher prevalence of hepatitis C co-infection (18.8% vs. 0%, p ​= ​0.05), lower sCD14 levels (mean, 6.23 vs. 6.27 log₁₀ ​pg/mL, p ​= ​0.04), lower CD8 T cell counts (mean, 514 vs. 876, p ​= ​0.0003), lower CD4/CD8 T cell ratio (mean, 0.27 vs. 0.41, p ​= ​0.01) and higher expression of PD1 on CD8⁺ T cells (74.2% vs. 65.1%, p ​= ​0.02) observed in SIR participants compared to their non-SIR counterparts at year 3 after ART initiation.

Conclusions

Nearly 10% of the study participants who had achieved virological suppression failed to recover a CD4 T cell count > 200 cells/mm³ after 3 years of ART which was with a very low pre-ART CD4 T cell count and older age. The long-term clinical outcomes of SIR participants need to be further explored.

Signature genes associated with immunological non-responsiveness to anti-retroviral therapy in HIV-1 subtype-c infection

Objective

HIV-infected individuals undergoing therapy may show an immunological-discordant response to therapy, with poor CD4⁺ T cells recovery, despite viral suppression below the detection limit. The present study was carried out to delineate the underlying molecular mechanisms of immunological non-responsiveness to HIV therapy.

Design

We conducted microarray-based whole gene expression profiles of 30 subjects infected with HIV-1 subtype C, in peripheral blood to discern the signature genes associated with immunological non-responsiveness. After a thorough analysis and comparison of gene-expression profiles, microarray data was validated via qRT-PCR approach.

Results

Overall, we found 10 genes significantly up-regulated and 60 genes down-regulated (≥2-fold change) in immunological non-responders as compared to responders. Based on these results and pathway analysis of the protein-protein interaction, 20 genes were shortlisted for validation in human infected cases. We found statistically significant differences in expression levels of twelve genes IL-1α, IL-1β, IL-7R, TNF-α, FoxP3, PDCD5, COX7B, SOCS1, SOCS3, RPL9, RPL23, and LRRN3 respectively among immunological non-responders compared to therapy responders, confirming their an intimate relationship with immunological responsiveness to therapy.

Conclusions

Altogether, microarray and qRT-PCR validation results indicated that the aberrant expression of key genes involved in the regulation of T cell homeostasis, immune activation, inflammatory cytokine production, apoptosis, and immune-regulatory processes are possibly associated with immunological non-responsiveness in HIV-1 C infected individuals on ART.

Incomplete immune reconstitution in HIV/AIDS patients on antiretroviral therapy: Challenges of immunological non-responders

The morbidity and mortality of HIV type-1 (HIV-1)-related diseases were dramatically diminished by the grounds of the introduction of potent antiretroviral therapy, which induces persistent suppression of HIV-1 replication and gradual recovery of CD4⁺ T-cell counts. However, ∼10-40% of HIV-1-infected individuals fail to achieve normalization of CD4⁺ T-cell counts despite persistent virological suppression. These patients are referred to as "inadequate immunological responders," "immunodiscordant responders," or "immunological non-responders (INRs)" who show severe immunological dysfunction. Indeed, INRs are at an increased risk of clinical progression to AIDS and non-AIDS events and present higher rates of mortality than HIV-1-infected individuals with adequate immune reconstitution. To date, the underlying mechanism of incomplete immune reconstitution in HIV-1-infected patients has not been fully elucidated. In light of this limitation, it is of substantial practical significance to deeply understand the mechanism of immune reconstitution and design effective individualized treatment strategies. Therefore, in this review, we aim to highlight the mechanism and risk factors of incomplete immune reconstitution and strategies to intervene.

Risk Factors for Low CD4+ Count Recovery Despite Viral Suppression Among Participants Initiating Antiretroviral Treatment With CD4+ Counts > 500 Cells/mm3: Findings From the Strategic Timing of AntiRetroviral Therapy (START) Trial

BACKGROUND

Low CD4 recovery among HIV-positive individuals who achieve virologic suppression is common but has not been studied among individuals initiating treatment at CD4 counts of >500 cells/mm.

SETTING

United States, Africa, Asia, Europe and Israel, Australia, Latin America.

METHODS

Among participants randomized to immediate antiretroviral therapy (ART) in the Strategic Timing of AntiRetroviral Therapy trial, low CD4 recovery was defined as a CD4 increase of <50 cells/mm from baseline after 8 months despite viral load of ≤200 copies/mL. Risk factors for low recovery were investigated with logistic regression.

RESULTS

Low CD4 recovery was observed in 39.7% of participants. Male sex [odds ratio (OR), 1.53; P = 0.007], lower screening CD4 cell counts (OR, 1.09 per 100 fewer cells/mm; P = 0.004), higher baseline CD8 cell counts (OR, 1.05 per 100 more cells/mm; P < 0.001), and lower HIV RNA levels (OR, 1.93 per log10 decrease; P < 0.001) were associated with low CD4 recovery. D-dimer had a quadratic association with low CD4 recovery, with lowest odds occurring at 0.32 μg/mL. At lower HIV RNA levels, the odds of low CD4 recovery were elevated across the levels of screening CD4 count; but at higher HIV RNA levels, the odds of low CD4 recovery were higher among those with lower vs. higher screening CD4.

CONCLUSIONS

Low CD4 recovery is frequent among participants starting ART at high CD4 counts. Risk factors include male sex, lower screening CD4 cell counts, higher CD8 cell counts, and lower HIV RNA levels. More follow-up is required to determine the impact of low CD4 recovery on clinical outcomes.

Lymphocyte homeostasis is maintained in perinatally HIV-infected patients after three decades of life

Background

While immunosenescence, defined as reduced production of new lymphocytes, restriction of T-cell receptor repertoire and telomeres shortening, has been extensively evaluated in HIV-infected children and adults, no data about these parameters are available in perinatally-infected patients with very long-lasting HIV infection.

Methods

We compared thymic and bone marrow output, telomere length (measured by Real-Time PCR) and T-cell receptor repertoire (determined by spectratyping) of 21 perinatally HIV-infected subjects (with a median of 27 years of infection) with those of 19 age-matched non-perinatally HIV-infected patients and 40 healthy controls. All patients received a combined antiretroviral therapy.

Results

While thymic and bone marrow output were not different among the analyzed groups, telomere length in peripheral blood cells and T-cell receptor diversity were significantly lower in HIV-perinatally and non-perinatally infected individuals compared to healthy controls.

Conclusions

In HIV-infected subjects, a normal thymic output together with a reduced telomere length and a restricted T-cell receptor repertoire could be explained by the shift of newly produced cells into memory subsets. This phenomenon may allow to control viral infection and maintain peripheral homeostasis.

Enhanced IFN-γ, but not IL-2, response to Mycobacterium tuberculosis antigens in HIV/latent TB co-infected patients on long-term HAART

BACKGROUND

HIV-infected individuals with latent TB infection are at increased risk of developing active TB. HAART greatly reduces the incidence rate of TB in HIV-infected patients and reconstitutes Mycobacterium tuberculosis (M. tuberculosis)-specific immune response in the first 12 months of therapy. The durability of the anti-mycobacterial immune restoration after a year of HAART however remains less investigated.

METHOD

A cross-sectional study was conducted to evaluate M. tuberculosis-specific functional immune responses in HIV/latent TB co-infected patients who were on HAART for at least 1.5 up to 9 years as compared to HAART-naïve patients. Three-hundred sixteen HIV-infected patients without active TB were screened by tuberculin skin testing for M. tuberculosis infection and peripheral blood mononuclear cells (PBMCs) were isolated from 61 HIV/latent TB co-infected patients (30 HAART-naïve and 31 HAART-treated). IFN-γ and IL-2 ELISPOT as well as CFSE cell proliferation assays were performed after stimulation with M. tuberculosis antigens PPD and ESAT-6.

RESULT

The median frequency of PPD and ESAT-6 specific IFN-γ secreting cells was significantly higher in the HAART-treated patients as compared to HAART-naïve patients, p = 0.0021 and p = 0.0081 respectively. However, there was no significant difference in the median frequency of IL-2 secreting cells responding to PPD (p = 0.5981) and ESAT-6 (p = 0.3943) antigens between HAART-naïve and-treated groups. Both IFN-γ and IL-2 responses were independent of CD4+ T cell count regardless of the HAART status. Notably, the frequency of PPD and ESAT-6 specific IL-2 secreting cells was positively associated with CD4+ T cell proliferation while inversely correlated with duration of HAART, raising the possibility that M. tuberculosis-specific IL-2 response that promote the antigen-specific CD4+ T cell proliferation diminish with time on antiretroviral therapy in HIV/latent TB co-infected patients.

CONCLUSION

This study shows an increased M. tuberculosis-specific IFN-γ, but not IL-2, response in HIV/latent TB co-infected patients with long-term HAART, consistent with only partial immune restoration. Future studies should, therefore, be done to prospectively define the rate and extent to which functional immune responses to M. tuberculosis are restored after long-term HAART.

Genetic and clinical predictors of CD4 lymphocyte recovery during suppressive antiretroviral therapy: Whole exome sequencing and antiretroviral therapy response phenotypes

Increase of peripheral blood CD4 lymphocyte counts is a key goal of combined antiretroviral therapy (cART); most, but not all, recipients respond adequately and promptly. A small number of studies have examined specific genetic factors associated with the extent of CD4 recovery. We report a genome-wide examination of factors that predict CD4 recovery in HIV-infected women. We identified women in in a cohort study who were on cART with viral load below 400 copies, and drew racially and ethnically matched samples of those with good CD4 response over 2 years or poor response. We analyzed the exomes of those women employing next generation sequencing for genes associated with CD4 recovery after controlling for non-genetic factors identified through forward stepwise selection as important. We studied 48 women with good CD4 recovery and 42 with poor CD4 recovery during virologically-suppressive cART. Stepwise logistic regression selected only age as a statistically significant (p<0.05) non-genetic predictor of response type (each additional year of age reduced the odds of good recovery by 11% (OR = 0.89, CI = 0.84–0.96, p = 0.0009). After adjustment for age and genomic estimates of race and ethnicity, 41 genes harbored variations associated with CD4 recovery group (p≤0.001); 5 of these have been previously reported to be associated with HIV infection, 4 genes would likely influence CD4 homeostasis, and 13 genes either had known functions or were members of product families that had functions for which interactions with HIV or effects on lymphocyte homeostasis were biologically plausible. Greater age was the strongest acquired factor that predicted poor CD4 cell recovery. Sequence variations spanning 41 genes were independently predictive of CD4 recovery. Many of these genes have functions that impact the cell cycle, apoptosis, lymphocyte migration, or have known interactions with HIV. These findings may help inform new hypotheses related to responses to HIV therapy and CD4 lymphocyte homeostasis.

CD4 count recovery and associated factors among individuals enrolled in the South African antiretroviral therapy programme: An analysis of national laboratory based data

Background

We describe CD4 count recovery among HIV positive individuals who initiated antiretroviral therapy (ART) with and without severe immune suppression using complete laboratory data from South Africa’s national HIV treatment programme between 2010 and 2014 and discuss implications for CD4 count monitoring.

Methods

Retrospective analysis of routinely collected laboratory data from South Africa’s National Health Laboratory Service (NHLS). A probabilistic record linkage algorithm was used to create a cohort of HIV positive individuals who initiated ART between 2010 and 2014 based on timing of CD4 count and viral load measurements. A CD4 count < 50 copies/μl at ART initiation was considered severe immunosuppression. A multivariable piecewise mixed-effects linear regression model adjusting for age, gender, year of starting ART, viral suppression in follow up and province was used to predict CD4 counts during follow up.

Results

1,070,900 individuals had evidence of starting ART during 2010–2014 and met the criteria for inclusion in the cohort -46.6% starting ART with CD4 < 200 cells/μl and 10.1% with CD4 < 50 cells/ μl. For individuals with CD4 counts < 200 cells/μl, predicted CD4 counts > 200 cells/μl, >350 cells/μl and >500 cells/μl corresponded with mean follow up durations of 1.5 years (standard deviation [s.d] 1.1), 1.9years (s.d 1.2) and 2.1 years (s.d 1.3 years). For those with CD4 counts < 50 cells/μl, predicted CD4 count above these threshold corresponded with mean follow up durations of 2.5 years (s.d 0.9 years), 4.4 years (s.d 0.4 years) and 5.0 years (s.d 0.1years) for recovery to the same thresholds. CD4 count recovery varied mostly with duration on ART, CD4 count at the start of ART and gender.

Conclusion

For individuals starting with ART with severe immunosuppression, CD4 recovery to 200cells/μl did not occur or took longer than 12 month for significant proportions. CD4 monitoring and interventions recommended for advanced HIV disease should continue until full recovery.

Genetic variation in CCR2 and CXCL12 genes impacts on CD4 restoration in patients initiating cART with advanced immunesupression

OBJECTIVE

We investigated the association of genetic polymorphisms in chemokine and chemokine receptor genes with poor immunological recovery in HIV patients starting combined antiretroviral therapy (cART) with low CD4 T-cell counts.

METHODS

A case-control study was conducted in 412 HIV-infected patients starting cART with CD4 T-cell count <200 cells/μL and successful viral control for two years. CD4 count increase below 200 cells/μL after two years on cART was used to define INR (immunological non-responder) patients. Polymorphisms in CXCL12, CCL5 and CCR2 genes were genotyped using sequenom's MassARRAY platform.

RESULTS

Thirty two percent (134/412) of patients were classified as INR. After adjusting by age, route of HIV infection, length of infection before cART and viral hepatitis coinfection, CCR2 rs1799864-AG genotype was significantly associated with INR status (OR [95% CI]: 1.80 [1.04-3.11]; p = 0.04), and CXCL12 rs1801157-TT genotype showed a trend (OR [95% CI]: 2.47 [0.96-6.35]; p = 0.06).

CONCLUSIONS

CCR2 rs1799864-AG or CXCL12 rs1801157-TT genotypes influence on the probability of poor CD4 recovery in the population of HIV patients starting cART with low CD4 counts. Genotyping of these polymorphisms could be used to estimate the risk of poor CD4 restoration, mainly in patients who are diagnosed late in the course of infection.

Effect of early highly active antiretroviral therapy on viral suppression among newly diagnosed men who have sex with men living with human immunodeficiency virus in Xi'an, China

BACKGROUND

The number of men who have sex with men (MSM) living with human immunodeficiency virus (HIV) in China has increased rapidly and thus immediate highly active antiretroviral therapy (HAART) after diagnosis was implemented as a strategy to reduce the HIV transmission.

METHODS

MSM who were diagnosed with HIV and received HAART between 2013 to 2015 in Xi'an were divided into three groups (>350, 200-350, and <200 cell/μL) according to their baseline CD4+ T cell count. The time of follow-up was calculated from the first date of receiving HAART to December 31, 2016. The CD4+ T cell count was detected with 1 week before or after HAART. The plasma viral loads were tested after 1, 2, and 3 years of treatment.

RESULTS

Of 1442 subjects who received HAART, 690 (47.9%) cases were in >350 cell/μL group, whereas 400 (27.7%) cases and 352 (24.4%) cases were in the 200-350 cell/μL group and <200 cell/μL group, respectively. After 1 year of treatment, the viral suppression rate in the <200 cell/μL group was 91.1%, which was significantly lower than the other two groups. The logistic regression results show that the >350 cell/μL group and 200-350 cell/μL group predicted higher viral suppression rates.

CONCLUSIONS

Baseline CD4+ T cell count more than 350 cell/μL can improve viral suppression among MSM living with HIV. Furthermore, to reduce the transmission risk, the treatment compliance of people living with HIV with high CD4+ T cell levels should be improved, and their diagnosis to the treatment time should be decreased.

Continued Decay of HIV Proviral DNA Upon Vaccination With HIV-1 Tat of Subjects on Long-Term ART: An 8-Year Follow-Up Study

Introduction: Tat, a key HIV virulence protein, has been targeted for the development of a therapeutic vaccine aimed at cART intensification. Results from phase II clinical trials in Italy (ISS T-002) and South Africa (ISS T-003) indicated that Tat vaccination promotes increases of CD4⁺ T-cells and return to immune homeostasis while reducing the virus reservoir in chronically cART-treated patients. Here we present data of 92 vaccinees (59% of total vaccinees) enrolled in the ISS T-002 8-year extended follow-up study (ISS T-002 EF-UP, ClinicalTrials.gov NCT02118168). Results: Anti-Tat antibodies (Abs) induced upon vaccination persisted for the entire follow-up in 34/92 (37%) vaccinees, particularly when all 3 Ab classes (A/G/M) were present (66% of vaccinees), as most frequently observed with Tat 30 μg regimens. CD4⁺ T cells increased above study-entry levels reaching a stable plateau at year 5 post-vaccination, with the highest increase (165 cells/μL) in the Tat 30 μg, 3 × regimen. CD4⁺ T-cell increase occurred even in subjects with CD4⁺ nadir ≤ 250 cells/uL and in poor immunological responders and was associated with a concomitant increase of the CD4⁺/CD8⁺ T-cell ratio, a prognostic marker of morbidity/mortality inversely related to HIV reservoir size. Proviral DNA load decreased over time, with a half-life of 2 years and an estimated 90% reduction at year 8 in the Tat 30 μg, 3 × group. In multivariate analysis the kinetic and amplitude of both CD4⁺ T-cell increase and proviral DNA reduction were fastest and highest in subjects with all 3 anti-Tat Ab classes and in the 30 μg, 3 × group, irrespective of drug regimens (NNRTI/NRTI vs. PI). HIV proviral DNA changes from baseline were inversely related to CD4⁺/CD8⁺ T-cell ratio and CD4⁺ T-cell changes, and directly related to the changes of CD8⁺ T cells. Further, HIV DNA decay kinetics were inversely related to the frequency and levels of intermittent viremia. Finally, Tat vaccination was similarly effective irrespective of the individual immunological status or HIV reservoir size at study entry. Conclusions: Tat immunization induces progressive immune restoration and reduction of virus reservoirs above levels reached with long-term cART, and may represent an optimal vaccine candidate for cART intensification toward HIV reservoirs depletion, functional cure, and eradication strategies.

Thymic Function as a Predictor of Immune Recovery in Chronically HIV-Infected Patients Initiating Antiretroviral Therapy

Poor immunological responders (PIR) are HIV-infected patients with virologic suppression upon antiretroviral therapy (ART) but persistently low CD4⁺ T cell counts. Early identification of PIR is important given their higher morbimortality compared to adequate immune responders (AIR). In this study, 33 patients severely lymphopenic at ART onset, were followed for at least 36 months, and classified as PIR or AIR using cluster analysis grounded on their CD4⁺ T cell count trajectories. Based on a variety of immunological parameters, we built predictive models of PIR/AIR outcome using logistic regression. All PIR had CD4⁺ T cell counts consistently below 500 cells/μL, while all AIR reached this threshold. AIR showed a higher percentage of recent thymic emigrants among CD4⁺ T cells; higher numbers of sj-TRECs and greater sj/β TREC ratios; and significant increases in thymic volume from baseline to 12 months of ART. We identified mathematical models that correctly predicted PIR/AIR outcome after 36 months of therapy in 77-87% of the cases, based on observations made until 2-6 months after ART onset. This study highlights the importance of thymic activity in the immune recovery of severely lymphopenic patients, and may help to select the patients that will benefit from closer follow-up or novel therapeutic approaches.

Predictors of CD4 cell recovery following initiation of antiretroviral therapy among HIV-1 positive patients with well-estimated dates of seroconversion

OBJECTIVES

To investigate factors that predict speed of recovery and long-term CD4 cell count in HIV-1 seroconverters initiating combination antiretroviral therapy (cART), and to quantify the influence of very early treatment initiation. We make use of all pre-treatment CD4 counts, because analyses using only a single observation at initiation may be subject to biases.

METHODS

We used data from the CASCADE (Concerted Action on SeroConversion to AIDS and Death in Europe) multinational cohort collaboration of HIV-1 seroconverters. We analysed pre- and post-treatment data of patients with seroconversion dates estimated January 2003-March 2014 (n = 7600 for primary analysis) using a statistical model in which the characteristics of recovery in CD4 counts are determined by multiple predictive factors. Secondary analyses were performed incorporating uncertainty in the exact timing of seroconversion to allow more precise estimation of the benefit of very early treatment initiation.

RESULTS

'True' CD4 count at cART initiation was the strongest predictor of CD4 count beyond 3 years on cART. Allowing for lack of complete certainty in the date of seroconversion, CD4 recovery was more rapid for patients in whom treatment was initiated within 4 months. For a given CD4 count, higher viral load (VL) at initiation was strongly associated with higher post-treatment CD4 recovery. For other patient and drug characteristics, associations with recovery were statistically significant but small in magnitude.

CONCLUSIONS

CD4 count at cART initiation is the most important factor in predicting post-treatment recovery, but VL provides substantial additional information. If cART is initiated in the first 4 months following seroconversion, recovery of CD4 counts appears to be more rapid.

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.

Combining CD4 recovery and CD4: CD8 ratio restoration as an indicator for evaluating the outcome of continued antiretroviral therapy: an observational cohort study

OBJECTIVES

Immune recovery following highly active antiretroviral therapy (HAART) is commonly assessed by the degree of CD4 reconstitution alone. In this study, we aimed to assess immune recovery by incorporating both CD4 count and CD4:CD8 ratio.

DESIGN

Observational cohort study SETTING AND PARTICIPANTS: Clinical data from Chinese HIV-positive patients attending the largest HIV service in Hong Kong and who had been on HAART for ≥4 years were accessed.

MAIN OUTCOME MEASURES

Optimal immune outcome was defined as a combination of a CD4 count ≥500/μL and a CD4:CD8 ratio ≥0.8.

RESULTS

A total of 718 patients were included for analysis (6353 person-years). At the end of year 4, 318 out of 715 patients achieved CD4 ≥500/μL, of which only 33% (105 out of 318) concurrently achieved CD4:CD8 ratio ≥0.8. Patients with a pre-HAART CD8 ≤800/μL (428 out of 704) were more likely to be optimal immune outcome achievers with CD4 ≥500/μL and CD4:CD8 ratio ≥0.8, the association of which was stronger after adjusting for pre-HAART CD4 counts. In a multivariable logistic model, optimal immune outcome was positively associated with male gender, younger pre-HAART age and higher pre-HAART CD4 count, longer duration of HAART and pre-HAART CD8 ≤800/μL. Treatment regimen and cumulative viral loads played no significant role in the pattern of immune recovery.

CONCLUSIONS

A combination of CD4 count and CD4:CD8 ratio could be a useful approach for the characterisation of treatment outcome over time, on top of monitoring CD4 count alone.

Brief Report: A High Rate of β7+ Gut-Homing Lymphocytes in HIV-Infected Immunological Nonresponders is Associated With Poor CD4 T-Cell Recovery During Suppressive HAART

Supplemental Digital Content is Available in the Text.

Objective:

Correlation between GALT homing markers on lymphocytes and the low blood CD4 T-cell reconstitution in immunological nonresponders (INRs) has been studied.

Design:

Thirty-one INRs, 19 immunological responders (IRs), and 12 noninfected controls were enrolled in this study. INRs were defined by an undetectable plasma viral load RNA less than 40 copies per milliliter and CD4⁺ T-cell count <500 cells per cubic milliliter in at least 3 years.

Methods:

A complete peripheral and mucosal lymphocyte immunophenotyping was performed on these patients with a focus on the CCR9, CCR6, and α4β7 gut-homing markers.

Results:

A highly significant upregulation of α4β7 on INRs peripheral lymphocytes compared with that of IRs has been observed. This upregulation impacts different lymphocyte subsets namely CD4⁺, CD8⁺, and B lymphocytes. The frequency of β7⁺ Th17 and Treg cells are increased compared with IRs and healthy controls. The frequency of β7⁺ CD8⁺ T cells in the blood is negatively correlated with integrated proviral DNA in rectal lymphoid cells in contrast to β7⁺ CD4⁺ T cells associated with HIV integration.

Conclusions:

Alteration of lymphocyte homing abilities would have deleterious effects on GALT reconstitution and could participate to HIV reservoir constitution. These results emphasize the great interest to consider α4β7-targeted therapy in INR patients to block homing of lymphocytes and/or to directly impair gp120-α4β7 interactions.

CD161 Expression on Mucosa-Associated Invariant T Cells is Reduced in HIV-Infected Subjects Undergoing Antiretroviral Therapy Who Do Not Recover CD4+ T Cells

Background:

Mucosa-associated invariant T (MAIT) cells are a recently identified class of innate-like T cells that are involved in the mucosal immune response. MAIT cells are characterized by expression of TCR Vα7.2 and CD161. In HIV infection, there is a profound early loss of MAIT cells from the circulation that never fully recovers, even after prolonged viral control with antiretroviral therapy (ART).

Methods:

We analyzed PBMCs from fresh whole blood from HIV-negative or ART-treated HIV-positive donors with full (Immune Success) or impaired (Immune Failure) CD4⁺ T- cell recovery by flow cytometry for T-cell markers, TCR Vα7.2, and CD161. The PBMCs were cultured with or without TCR-mediated stimulation, and CD161 expression was assessed on Vα7.2⁺ T cells. Interferon-γ (IFNγ) production was assessed by intracellular cytokine staining.

Results:

We found a decrease in the percentage of CD3⁺ T cells that expressed CD161 and the percentage of Vα7.2⁺ T cells that expressed CD161, in HIV-infected individuals. We also found a significant increase in the percentage of T cells that were Vα7.2⁺CD161- in immune failure compared to controls, accompanied by an increase in the percentage of Vα7.2⁺CD161- T cells that express CD8⁺ in donors with immune failure, but not immune success. After TCR stimulation in vitro, Vα7.2⁺ T cells reduced expression of CD161, yet Vα7.2⁺ CD161- cells from immune failure donors retained the ability to express IFNγ on stimulation.

Conclusions:

Our findings suggest that in immune failure patients, the reduction in peripheral MAIT cells is due, at least in part, to a loss in CD161 expression, and is not merely the result of trafficking into mucosal tissues or cell death. These CD161- cells retain their function.

Uniquely altered transcripts are associated with immune preservation in HIV infection

The mechanisms underlying host HIV control hold much promise in the search for a functional HIV cure. We investigated the host genomic signatures in elite controllers or rapid progressors following recent infection and the correlates of immune reconstitution during combination antiretroviral therapy. We characterized the HIV-specific longitudinal host transcriptional response of peripheral blood mononuclear cells from elite controllers, rapid progressors, immune responders and non-responders using a RT-qPCR array in a cohort of recently HIV-infected Brazilian individuals. The elite controllers expressed unique transcripts early in infection that were closely associated with specialized cross-presentation between XCR1+ DCs and antigen-specific CD8+ T cells (XCL1). The natural suppression of HIV was also associated with the highly functional co-expression of cytokines and chemokines (CCL2, TNF and IL-10) concomitant with the maintenance of important anti-inflammatory and anticoagulant properties (Antithrombin III). Immune responders exhibited exclusively upregulated mRNAs possibly related to stem cell mobilization before combination antiretroviral therapy (neutrophil elastase). Our longitudinal approach to gene expression permitted us to discover previously unrecognized determinants that contribute to natural or antiretroviral-mediated HIV-1 immune control.

Impact of probiotic Saccharomyces boulardii on the gut microbiome composition in HIV-treated patients: A double-blind, randomised, placebo-controlled trial

Dysbalance in gut microbiota has been linked to increased microbial translocation, leading to chronic inflammation in HIV-patients, even under effective HAART. Moreover, microbial translocation is associated with insufficient reconstitution of CD4+T cells, and contributes to the pathogenesis of immunologic non-response. In a double-blind, randomised, placebo-controlled trial, we recently showed that, compared to placebo, 12 weeks treatment with probiotic Saccharomyces boulardii significantly reduced plasma levels of bacterial translocation (Lipopolysaccharide-binding protein or LBP) and systemic inflammation (IL-6) in 44 HIV virologically suppressed patients, half of whom (n = 22) had immunologic non-response to antiretroviral therapy (<270 CD4+Tcells/μL despite long-term suppressed viral load). The aim of the present study was to investigate if this beneficial effect of the probiotic Saccharomyces boulardii is due to modified gut microbiome composition, with a decrease of some species associated with higher systemic levels of microbial translocation and inflammation. In this study, we used 16S rDNA gene amplification and parallel sequencing to analyze the probiotic impact on the composition of the gut microbiome (faecal samples) in these 44 patients randomized to receive oral supplementation with probiotic or placebo for 12 weeks. Compared to the placebo group, in individuals treated with probiotic we observed lower concentrations of some gut species, such as those of the Clostridiaceae family, which were correlated with systemic levels of bacterial translocation and inflammation markers. In a sub-study of these patients, we observed significantly higher parameters of microbial translocation (LBP, soluble CD14) and systemic inflammation in immunologic non-responders than in immunologic responders, which was correlated with a relative abundance of specific gut bacterial groups (Lachnospiraceae genus and Proteobacteria). Thus, in this work, we propose a new therapeutic strategy using the probiotic yeast S. boulardii to modify gut microbiome composition. Identifying pro-inflammatory species in the gut microbiome could also be a useful new marker of poor immune response and a new therapeutic target.

Plasma Metabolomics Biosignature According to HIV Stage of Infection, Pace of Disease Progression, Viremia Level and Immunological Response to Treatment

BACKGROUND

We evaluated plasma samples HIV-infected individuals with different phenotypic profile among five HIV-infected elite controllers and five rapid progressors after recent HIV infection and one year later and from 10 individuals subjected to antiretroviral therapy, five of whom were immunological non-responders (INR), before and after one year of antiretroviral treatment compared to 175 samples from HIV-negative patients. A targeted quantitative tandem mass spectrometry metabolomics approach was used in order to determine plasma metabolomics biosignature that may relate to HIV infection, pace of HIV disease progression, and immunological response to treatment.

RESULTS

Twenty-five unique metabolites were identified, including five metabolites that could distinguish rapid progressors and INRs at baseline. Severe deregulation in acylcarnitine and sphingomyelin metabolism compatible with mitochondrial deficiencies was observed. β-oxidation and sphingosine-1-phosphate-phosphatase-1 activity were down-regulated, whereas acyl-alkyl-containing phosphatidylcholines and alkylglyceronephosphate synthase levels were elevated in INRs. Evidence that elite controllers harbor an inborn error of metabolism (late-onset multiple acyl-coenzyme A dehydrogenase deficiency [MADD]) was detected.

CONCLUSIONS

Blood-based markers from metabolomics show a very high accuracy of discriminating HIV infection between varieties of controls and have the ability to predict rapid disease progression or poor antiretroviral immunological response. These metabolites can be used as biomarkers of HIV natural evolution or treatment response and provide insight into the mechanisms of the disease.

Antiretroviral therapy suppressed participants with low CD4+ T-cell counts segregate according to opposite immunological phenotypes

Supplemental Digital Content is available in the text

Background:

The failure to increase CD4⁺ T-cell counts in some antiretroviral therapy suppressed participants (immunodiscordance) has been related to perturbed CD4⁺ T-cell homeostasis and impacts clinical evolution.

Methods:

We evaluated different definitions of immunodiscordance based on CD4⁺ T-cell counts (cutoff) or CD4⁺ T-cell increases from nadir value (ΔCD4) using supervised random forest classification of 74 immunological and clinical variables from 196 antiretroviral therapy suppressed individuals. Unsupervised clustering was performed using relevant variables identified in the supervised approach from 191 individuals.

Results:

Cutoff definition of CD4⁺ cell count 400 cells/μl performed better than any other definition in segregating immunoconcordant and immunodiscordant individuals (85% accuracy), using markers of activation, nadir and death of CD4⁺ T cells. Unsupervised clustering of relevant variables using this definition revealed large heterogeneity between immunodiscordant individuals and segregated participants into three distinct subgroups with distinct production, programmed cell-death protein-1 (PD-1) expression, activation and death of T cells. Surprisingly, a nonnegligible number of immunodiscordant participants (22%) showed high frequency of recent thymic emigrants and low CD4⁺ T-cell activation and death, very similar to immunoconcordant participants. Notably, human leukocyte antigen - antigen D related (HLA-DR) PD-1 and CD45RA expression in CD4⁺ T cells allowed reproducing subgroup segregation (81.4% accuracy). Despite sharp immunological differences, similar and persistently low CD4⁺ values were maintained in these participants over time.

Conclusion:

A cutoff value of CD4⁺ T-cell count 400 cells/μl classified better immunodiscordant and immunoconcordant individuals than any ΔCD4 classification. Immunodiscordance may present several, even opposite, immunological patterns that are identified by a simple immunological follow-up. Subgroup classification may help clinicians to delineate diverse approaches that may be needed to boost CD4⁺ T-cell recovery.

Combined models for pre- and post-treatment longitudinal biomarker data: an application to CD4 counts in HIV-patients

BACKGROUND

There has been some debate in the literature as to whether baseline values of a measurement of interest at treatment initiation should be treated as an outcome variable as part of a model for longitudinal change or instead used as a predictive variable with respect to the response to treatment. We develop a new approach that involves a combined statistical model for all pre- and post-treatment observations of the biomarker of interest, in which the characteristics of response to treatment are treated as a function of the 'true' value of the biomarker at treatment initiation.

METHODS

The modelling strategy developed is applied to a dataset of CD4 counts from patients in the UK Register of HIV Seroconverters (UKR) cohort who initiated highly active antiretroviral therapy (HAART). The post-HAART recovery in CD4 counts for each individual is modelled as following an asymptotic curve in which the speed of response to treatment and long-term maximum are functions of the 'true' underlying CD4 count at initiation of HAART and the time elapsed since seroconversion. Following previous research in this field, the models developed incorporate non-stationary stochastic process components, and the possibility of between-patient differences in variability over time was also considered.

RESULTS

A variety of novel models were successfully fitted to the UKR dataset. These provide reinforcing evidence for findings that have previously been reported in the literature, in particular that there is a strong positive relationship between CD4 count at initiation of HAART and the long-term maximum in each patient, but also reveal potentially important features of the data that would not have been easily identified by other methods of analysis.

CONCLUSION

Our proposed methodology provides a unified framework for the analysis of pre- and post-treatment longitudinal biomarker data that will be useful for epidemiological investigations and simulations in this context. The approach developed allows use of all relevant data from observational cohorts in which many patients are missing pre-treatment measurements and in which the timing and number of observations vary widely between patients.

Responsiveness to IL-7 but not to IFN-α is diminished in CD4+ T cells from treated HIV infected patients who experience poor CD4+ T-cell recovery

OBJECTIVE

To assess CD4 T-cell responsiveness to IL-7 and IFN-α in HIV-infected patients who experience poor recovery of CD4 T-cell counts during therapy (immune failure patients).

DESIGN

Responses to IL-7 and IFN-α were compared between HIV-infected immune failure (CD4 cell counts <379 cells/μl) patients and immune success (CD4 cell counts >500 cells/μl) as well as healthy control patients.

METHODS

Flow cytometry was used to assess peripheral blood mononuclear cells for IL-7-induced proliferation, CD25 expression, and signaling (signal transducer and activator of transcription 5 phosphorylation and Akt phosphorylation) in CD4 T cells. Freshly isolated cells were characterized by expression of IL-7Rα (CD127) among CD4 T-cell maturation subsets by flow cytometry and sorted CD3 T cells were assessed for expression of IFN-α and interferon stimulated genes (2'-5'-oligoadenylate synthetase-1 and myxovirus resistance A protein) by quantitative real-time PCR. Responses to IFN-α were assessed by induction of signal transducer and activator of transcription 1 phosphorylation and inhibition of IL-7-induced CD4 T-cell proliferation.

RESULTS

IL-7-induced proliferation and CD25 expression were decreased in CD4 T cells from immune failure patients. CD127 expressing CD4 T cells were decreased, whereas expression of 2'-5'-oligoadenylate synthetase-1, myxovirus resistance A protein, and IFN-α mRNA were increased in total CD3 T cells from immune failure patients. CD127 expression correlated with CD25 induction but not proliferation, whereas T-cell IFN-α mRNA was associated with reduced proliferation in CD4 T cells from immune failure patients. IFN-α-mediated induction of signal transducer and activator of transcription 1 phosphorylation and inhibition of proliferation were not diminished in CD4 T cells from immune failure patients.

CONCLUSION

IL-7 responsiveness is impaired in immune failure patients and may be related to expression of CD127 and IFN-α.

Frequency and impact of suboptimal immune recovery on first-line antiretroviral therapy within the International Epidemiologic Databases to Evaluate AIDS in East Africa

OBJECTIVE

To describe patterns of suboptimal immune recovery (SO-IR) and associated HIV-related-illnesses during the first 5 years following first-line antiretroviral therapy (ART) initiation across seven ART sites in East Africa.

DESIGN

Retrospective analysis of data from seven ART clinical sites (three Uganda, two Kenya and two Tanzania).

METHODS

SO-IR was described by proportions of ART-treated adults with CD4 cell counts less than 200, less than 350 and less than 500 cells/μl. Kaplan-Meier survival analysis techniques were used to assess predictors of SO-IR, and incident rates of HIV-related illnesses at CD4 cell counts less than 200, 200-350, 351-499, and >500 cells/μl, respectively.

RESULTS

Overall 80 843 adults initiated non-nucleoside reverse transcriptase inhibitor-based first-line ART; 65% were women and median CD4 cell count was 126 [interquartile range (IQR), 52-202] cells/μl. Cumulative probability of SO-IR <200 cells/μl, <350 cells/μl and <500 cells/μl, after 5 years, was 11, 38 and 63%, respectively. Incidence of HIV-related illnesses was higher among those with CD4 cell counts less than 200 and 200-350 cells/μl, than those who achieved CD4 counts above these thresholds. The most common events, at CD4 < 200 cells/μl, were pulmonary tuberculosis [incident rate 15.98 (15.47-16.51)/100 person-years at risk (PYAR), oral candidiasis [incident rate 12.5 (12.03-12.94)] and herpes zoster [incident rate 6.30 (5.99-6.64)] events/100 PYAR. With attainment of a CD4 cell count level 200-350 cells/μl, there was a substantial reduction in events/100 PYAR - by 91% to 1.45 (1.29-1.63) for TB, by 94% to 0.75 (0.64-0.89) for oral candidiasis, by 84% to 0.99 (0.86-1.14) for Herpes Zoster, and by 78% to 1.22 (1.07-1.39) for chronic diarrhea. The incidence of all events decreased further with CD4 counts above these thresholds.

CONCLUSION

Around 40% of adults initiated on ART have suboptimal immune recovery with CD4 counts <350 cells/μl after five years. Such patients will require closer monitoring for both HIV-related and non-HIV-related clinical events.

Inflammation Perturbs the IL-7 Axis, Promoting Senescence and Exhaustion that Broadly Characterize Immune Failure in Treated HIV Infection

BACKGROUND

HIV-infected patients who fail to normalize CD4 T cells despite suppressive antiretroviral therapy have impaired immune homeostasis: diminished naive T-cell numbers, elevated T-cell turnover, senescence, and inflammation.

METHODS

Blood samples from immune failures (n = 60), immune successes (n = 20), and healthy controls (n = 20) were examined for plasma interleukin (IL)-7 levels, for cellular expression of the IL-7Rα chain (CD127), for the exhaustion and senescence markers programed death 1 (PD-1) and CD57, and for the survival factor Bcl2. Because both inflammatory and homeostatic cytokines can induce T-cell cycling, we also examined the effects of these mediators on exhaustion and senescence markers.

RESULTS

Plasma levels of IL-7 were elevated and both CD4 and CD8 T-cell CD127 expression was decreased in immune failure. Plasma levels of IL-7 correlated directly with naive CD4 T-cell counts in immune success and inversely with T-cell cycling (Ki67) in healthy controls and immune success, but not in immune failure. CD4 T-cell density of PD-1 was increased and Bcl2+ CD4 T cells were decreased in immune failure but not in immune success, whereas the proportion of T cells expressing CD57 was increased in immune failure. PD-1 and CD57 were induced on CD4 but not CD8 T cells by stimulation in vitro with inflammatory IL-1β or homeostatic (IL-7) cytokines.

CONCLUSIONS

Perturbation of the IL-7/IL-7 receptor axis, increased T-cell turnover, and increased senescence may reflect dysregulated responses to both homeostatic and inflammatory cytokines in immune failure patients.

Mortality According to CD4 Count at Start of Combination Antiretroviral Therapy Among HIV-infected Patients Followed for up to 15 Years After Start of Treatment: Collaborative Cohort Study

BACKGROUND

CD4 count at start of combination antiretroviral therapy (ART) is strongly associated with short-term survival, but its association with longer-term survival is less well characterized.

METHODS

We estimated mortality rates (MRs) by time since start of ART (<0.5, 0.5-0.9, 1-2.9, 3-4.9, 5-9.9, and ≥10 years) among patients from 18 European and North American cohorts who started ART during 1996-2001. Piecewise exponential models stratified by cohort were used to estimate crude and adjusted (for sex, age, transmission risk, period of starting ART [1996-1997, 1998-1999, 2000-2001], and AIDS and human immunodeficiency virus type 1 RNA at baseline) mortality rate ratios (MRRs) by CD4 count at start of ART (0-49, 50-99, 100-199, 200-349, 350-499, ≥500 cells/µL) overall and separately according to time since start of ART.

RESULTS

A total of 6344 of 37 496 patients died during 359 219 years of follow-up. The MR per 1000 person-years was 32.8 (95% confidence interval [CI], 30.2-35.5) during the first 6 months, declining to 16.0 (95% CI, 15.4-16.8) during 5-9.9 years and 14.2 (95% CI, 13.3-15.1) after 10 years' duration of ART. During the first year of ART, there was a strong inverse association of CD4 count at start of ART with mortality. This diminished over the next 4 years. The adjusted MRR per CD4 group was 0.97 (95% CI, .94-1.00; P = .054) and 1.02 (95% CI, .98-1.07; P = .32) among patients followed for 5-9.9 and ≥10 years, respectively.

CONCLUSIONS

After surviving 5 years of ART, the mortality of patients who started ART with low baseline CD4 count converged with mortality of patients with intermediate and high baseline CD4 counts.

Discordant Immune Response with Antiretroviral Therapy in HIV-1: A Systematic Review of Clinical Outcomes

Background

A discordant immune response (DIR) is a failure to satisfactorily increase CD4 counts on ART despite successful virological control. Literature on the clinical effects of DIR has not been systematically evaluated. We aimed to summarise the risk of mortality, AIDS and serious non-AIDS events associated with DIR with a systematic review.

Methods

The protocol is registered with the Centre for Review Dissemination, University of York (registration number CRD42014010821). Included studies investigated the effect of DIR on mortality, AIDS, or serious non-AIDS events in cohort studies or cohorts contained in arms of randomised controlled trials for adults aged 16 years or older. DIR was classified as a suboptimal CD4 count (as defined by the study) despite virological suppression following at least 6 months of ART. We systematically searched PubMed, Embase, and the Cochrane Library to December 2015. Risk of bias was assessed using the Cochrane tool for assessing risk of bias in cohort studies. Two authors applied inclusion criteria and one author extracted data. Risk ratios were calculated for each clinical outcome reported.

Results

Of 20 studies that met the inclusion criteria, 14 different definitions of DIR were used. Risk ratios for mortality in patients with and without DIR ranged between 1.00 (95% CI 0.26 to 3.92) and 4.29 (95% CI 1.96 to 9.38) with the majority of studies reporting a 2 to 3 fold increase in risk.

Conclusions

DIR is associated with a marked increase in mortality in most studies but definitions vary widely. We propose a standardised definition to aid the development of management options for DIR.

HIV-Tat immunization induces cross-clade neutralizing antibodies and CD4(+) T cell increases in antiretroviral-treated South African volunteers: a randomized phase II clinical trial

BACKGROUND

Although combined antiretroviral therapy (cART) has saved millions of lives, it is incapable of full immune reconstitution and virus eradication. The transactivator of transcription (Tat) protein is a key human immunodeficiency virus (HIV) virulence factor required for virus replication and transmission. Tat is expressed and released extracellularly by infected cells also under cART and in this form induces immune dysregulation, and promotes virus reactivation, entry and spreading. Of note, anti-Tat antibodies are rare in natural infection and, when present, correlate with asymptomatic state and reduced disease progression. This suggested that induction of anti-Tat antibodies represents a pathogenesis-driven intervention to block progression and to intensify cART. Indeed Tat-based vaccination was safe, immunogenic and capable of immune restoration in an open-label, randomized phase II clinical trial conducted in 168 cART-treated volunteers in Italy. To assess whether B-clade Tat immunization would be effective also in patients with different genetic background and infecting virus, a phase II trial was conducted in South Africa.

METHODS

The ISS T-003 was a 48-week randomised, double-blinded, placebo-controlled trial to evaluate immunogenicity (primary endpoint) and safety (secondary endpoint) of B-clade Tat (30 μg) given intradermally, three times at 4-week intervals, in 200 HIV-infected adults on effective cART (randomised 1:1) with CD4(+) T-cell counts ≥200 cells/µL. Study outcomes also included cross-clade anti-Tat antibodies, neutralization, CD4(+) T-cell counts and therapy compliance.

RESULTS

Immunization was safe and well-tolerated and induced durable, high titers anti-Tat B-clade antibodies in 97 % vaccinees. Anti-Tat antibodies were cross-clade (all vaccinees tested) and neutralized Tat-mediated entry of oligomeric B-clade and C-clade envelope in dendritic cells (24 participants tested). Anti-Tat antibody titers correlated positively with neutralization. Tat vaccination increased CD4(+) T-cell numbers (all participants tested), particularly when baseline levels were still low after years of therapy, and this had a positive correlation with HIV neutralization. Finally, in cART non-compliant patients (24 participants), vaccination contained viral load rebound and maintained CD4(+) T-cell numbers over study entry levels as compared to placebo.

CONCLUSIONS

The data indicate that Tat vaccination can restore the immune system and induces cross-clade neutralizing anti-Tat antibodies in patients with different genetic backgrounds and infecting viruses, supporting the conduct of phase III studies in South Africa. Trial registration ClinicalTrials.gov NCT01513135, 01/23/2012.

A case report of immunosuppression-related Kaposi's sarcoma after autologous stem cell transplantation

BACKGROUND

Kaposi's sarcoma (KS) is a tumor formed by angioproliferations driven by Human herpes virus 8 also known as Kaposi's sarcoma-associated herpes virus (KSHV). It is best known as an acquired immune deficiency syndrome (AIDS) defining illness that may be fatal. There are only a few reports of KS after hematopoietic cell transplantation (HCT). This is the first case describing the disappearance of KS with immune recovery after autologous HCT.

CASE PRESENTATION

We present the case of a 61-year-old male heterosexual patient of Moroccan origin treated for primary mediastinal non-Hodgkin lymphoma. Because of refractory disease he received multiple lines of chemotherapy prior to autologous HCT. After the second course of low-dose bis-chloroethylnitrosourea, etoposide, cytarabine, melphalan (BEAM) the patient developed several round blue skin lesions. A biopsy was performed, showing many small vessels and positive immune histochemical staining for Human herpes virus 8 (HHV-8), confirming diagnosis of KS. Human immunodeficiency virus testing was negative and work-up showed that there were no visceral lesions. When KS are limited to the skin, prognosis is usually better. The extensive chemotherapy resulted in an important immunosuppression; on day 105 after autologous HCT CD4(+) count was 82/mm(3). Since KS were limited to the skin and attributed to severe immune suppression a watchful waiting strategy was adopted even though in the first months after autologous HCT new skin lesions appeared. With immune recovery (CD4(+) count > 200/mm(3)) 277 days after transplant, skin lesions faded.

CONCLUSION

Kaposi's sarcoma remains a rare tumor that should be thought of in any patient whose immunity is down. If immune recovery is expected and disease is limited to the skin, a watchful waiting strategy can be more rewarding than intensive chemotherapy.

Impact of HIV on the severity of influenza

Despite current antiretroviral therapy, HIV/AIDS is one of the most prelevant problems in healthcare worldwide. Similarly, influenza viruses are causes of epidemics outbreaks. HIV-infected patients are considered a high risk group for severe influenza infection, although several recent observational studies suggest that not all HIV-infected patients are equally susceptible to complications and that these patients should be stratified by their immunodeficiency status and other factors (such as smoking or comorbidities). Here, we have compiled the most recent data on the impact that HIV has on influenza infection.

Dissecting How CD4 T Cells Are Lost During HIV Infection

Although the replicative life cycle of HIV within CD4 T cells is understood in molecular detail, less is known about how this human retrovirus promotes the loss of CD4 T lymphocytes. It is this cell death process that drives clinical progression to acquired immune deficiency syndrome (AIDS). Recent studies have highlighted how abortive infection of resting and thus nonpermissive CD4 T cells in lymphoid tissues triggers a lethal innate immune response against the incomplete DNA products generated by inefficient viral reverse transcription in these cells. Sensing of these DNA fragments results in pyroptosis, a highly inflammatory form of programmed cell death, that potentially further perpetuates chronic inflammation and immune activation. As discussed here, these studies cast CD4 T cell death during HIV infection in a different light. Further, they identify drug targets that may be exploited to both block CD4 T cell demise and the chronic inflammatory response generated during pyroptosis.