Definition of Immunological Nonresponse to Antiretroviral Therapy: A Systematic Review

Application of Digital Tools and Artificial Intelligence to the Myasthenia Gravis Core Examination

Background

Advances in video image analysis and artificial intelligence provide the opportunity to transform the approach to patient evaluation through objective digital evaluation.

Objectives

We assessed ability to quantitate Zoom video recordings of a standardized neurological examination the myasthenia gravis core examination (MG-CE), which had been designed for telemedicine evaluations.

Methods

We used Zoom (Zoom Video Communications) videos of patients with myasthenia gravis undergoing the MG-CE. Computer vision in combination with artificial intelligence methods were used to build algorithms to analyze videos with a focus on eye or body motions. For the assessment of examinations involving vocalization, signal processing methods were developed, including natural language processing. A series of algorithms were built that could automatically compute the metrics of the MG-CE.

Results

Fifty-one patients with MG with videos recorded twice on separate days and 15 control subjects were assessed once. We were successful in quantitating lid, eye, and arm positions and as well as well as develop respiratory metrics using breath counts. Cheek puff exercise was found to be of limited value for quantitation. Technical limitations included variations in illumination, bandwidth, and recording being done on the examiner side, not the patient.

Conclusions

Several aspects of the MG-CE can be quantitated to produce continuous measures via standard Zoom video recordings. Further development of the technology offer the ability for trained, non-physician, health care providers to perform precise examination of patients with MG outside the clinic, including for clinical trials.

Plain Language Summary

Advances in video image analysis and artificial intelligence provide the opportunity to transform the approach to patient evaluation. Here, we asked whether video recordings of the typical telemedicine examination for the patient with myasthenia gravis be used to quantitate examination findings? Despite recordings not made for purpose, we were able to develop and apply computer vision and artificial intelligence to Zoom recorded videos to successfully quantitate eye muscle, facial muscle, and limb fatigue. The analysis also pointed out limitations of human assessments of bulbar and respiratory assessments. The neuromuscular examination can be enhanced by advance technologies, which have the promise to improve clinical trial outcome measures as well as standard care.

Enhanced immune reconstitution with albuvirtide in HIV-infected immunological non-responders

Background

Incomplete immune recovery in people living with HIV/AIDS (PLWHA) remains an important clinical challenge with the lack of an effective strategy currently available to restore their T-cell immune response. This study aimed to evaluate the effect of Albuvirtide (ABT) on immune recovery in immunological non-responders (INRs) and attempted to explore potential mechanisms of ABT on the functionality of immune cells.

Methods

In this prospective, open-label, controlled clinical study, participants with incomplete immune reconstitution (continuous ART over 5 years and CD4+T lymphocyte absolute count of <500 cells/µl or ART for 2-5 years and CD4+T cell count of <200 cells/µl with undetectable viral load) were received intensive treatment with ABT or maintained on the original ART regimen at a ratio of 1:1. Immune response and safety were examined within 24 weeks. In the cytological study, T subsets, cell apoptosis and cell autophagy were analyzed using immunofluorescence staining and flow cytometry from 25 blood specimens.

Results

Both groups (n=25 each) were comparable in age, gender, and ART duration. At week 12, CD4+T cell count increased significantly in the intensive ABT group compared with control group (the change from baseline in CD4+T cell count: 45 vs. -5 cells/µL, p<0.001). After ABT discontinuation, CD4+T cell counts remained significantly higher in the intensive ABT group at week 24 (55 vs. -5 cells/µL, p=0.012). In laboratory analysis, naïve CD4+ T cell amounts were lowest among participants with unsatisfactory immune response (uIR) to ABT (p=0.001). The proportion of caspase 3+CD45RA+CD31+CD4+ T cells was significantly lower in participants with satisfactory immune response (sIR) to ABT (p<0.05).

Conclusion

Significant CD4+T cell count increase suggests ABT enhances immune function in INRs which may be attributed to its antiviral properties as well as its ability to increase thymic cell output and decrease cell apoptosis.

HIV-Induced Thymic Insufficiency and Aging-Related Immunosenescence on Immune Reconstitution in ART-Treated Patients

The mechanisms underlying unsatisfactory immune reconstitution in HIV-1 positive patients under ART have not been fully elucidated, even after years of investigation. Thus, this study aimed to assess the correlation between age and thymic production profile, and its influence on inadequate immunological recovery. Here, 44 ART-treated patients with undetectable plasma HIV-1 load (<40 copies/mL) were classified as 31 immunological responders (IR) and 13 immunological non-responders (INR), according to their CD4+ T-cell count after 18 months of ART. The thymic function was assessed by identifying recent thymic emigrants (RTEs) CD4+ T cells (CD4+/CD45RA+CD31+) in PBMCs using flow cytometry. Clinical data were also analyzed from medical records. The INR group showed a higher age at ART initiation (41 ± 3.0) compared to the IR (33.7 ± 2.1) group (p = 0.041). Evaluating RTE CD4+ T-cells, we observed a lower percentage in the INR group (19.5 ± 6.3) compared to the IR group (29.9 ± 11.5) (p = 0.012). There was a strong negative correlation between age at ART initiation and RTE CD4+ T-cells in INRs (r = -0.784, p = 0.004). Our study has highlighted the thymic insufficiency and aging-related immunosenescence with unsatisfactory immunological recovery during ART in HIV-1 positive patients.

HIV immunological non-responders are characterized by extensive immunosenescence and impaired lymphocyte cytokine production capacity

Introduction

Immunological non-responders (INR) are people living with HIV (PLHIV) who fail to fully restore CD4+ T-cell counts despite complete viral suppression with antiretroviral therapy (ART). INR are at higher risk for non-HIV related morbidity and mortality. Previous research suggest persistent qualitative defects.

Methods

The 2000HIV study (clinical trials NTC03994835) enrolled 1895 PLHIV, divided in a discovery and validation cohort. PLHIV with CD4 T-cell count <350 cells/mm3 after ≥2 years of suppressive ART were defined as INR and were compared to immunological responders (IR) with CD4 T-cell count >500 cells/mm3. Logistic and rank based regression were used to analyze clinical data, extensive innate and adaptive immunophenotyping, and ex vivo monocyte and lymphocyte cytokine production after stimulation with various stimuli.

Results

The discovery cohort consisted of 62 INR and 1224 IR, the validation cohort of 26 INR and 243 IR. INR were older, had more advanced HIV disease before starting ART and had more frequently a history of non-AIDS related malignancy. INR had lower absolute CD4+ T-cell numbers in all subsets. Activated (HLA-DR+, CD38+) and exhausted (PD1+) subpopulations were proportionally increased in CD4 T-cells. Monocyte and granulocyte immunophenotypes were comparable. INR lymphocytes produced less IL-22, IFN-γ, IL-10 and IL-17 to stimuli. In contrast, monocyte cytokine production did not differ. The proportions of CD4+CD38+HLA-DR+ and CD4+PD1+ subpopulations showed an inversed correlation to lymphocyte cytokine production.

Conclusions

INR compared to IR have hyperactivated and exhausted CD4+ T-cells in combination with lymphocyte functional impairment, while innate immune responses were comparable. Our data provide a rationale to consider the use of anti-PD1 therapy in INR.

Pathological proliferation: a potential mechanism for poor CD4+ T cell recovery in people living with HIV

Background

People living with HIV (PLWH) fail to achieve normalization of CD4+ T cell counts and function, especially in immunological non-responders (INRs). The frequencies of Ki67+CD4+ T cells were inversely associated with CD4+ T cell counts in HIV infected patients. Early ART did not normalize CD4+ T cell proliferation. However, the features of the abnormal proliferation CD4+ T cell in INRs are far from known.

Method

PLWH were divided into INRs (n= 16) and immunological responders (IRs, n= 53) groups. Mass cytometry was applied to peripheral blood T cells to profile the immune cells and liquid chip technique was used to measure plasma levels of cytokines and chemokines. Correlation analyses were conducted to evaluate associations between the degree of CD4+ T cell proliferation and immune function.

Results

The percentage of Ki67+ CD4+ T cells were significant higher in INRs, and we defined these cells with significant higher level of Ki67, as over-proliferating cells. No significant difference of markers' expression (HLA-DR, CD38, CD57, PD-1, PD-L1, CD107a, perforin) was found between INRs and IRs. Compared with naïve CD4+ T cells in INRs, Ki67+ CD4+ T cells exhibited lower levels of CD57 and CD38. Whereas Ki67+ T cells exhibited higher levels of CD38 and CD57 and activation compared with differentiated mature central memory CD4+ T cells and effector memory CD4+ T cells. Ki67+ cells did not show higher levels of senescence and activation compared to certain Ki67- CD4+ central memory T cells in IRs. Furthermore, Ki67+ CD4+ Tcm cells exhibited positive correlations with pro-inflammatory cytokines.

Conclusion

We proposed and validated the hypothesis of "pathological proliferation" in INRs: excessive proliferation of CD4+ T cells in INRs may be accompanied by aberrant activation, senescence and loss of immune function. Eventually, such over-proliferating but poor-quality cells in INRs result in incomplete recovery of both CD4+ T cell counts and function. An intervention that enhancing the proliferative capacity or functional ability or both of CD4+ T cell in INRs might therefore be beneficial.

Factors associated with immunological non-response after ART initiation: a retrospective observational cohort study

BACKGROUND

Among people living with HIV (PLHIV) on antiretroviral therapy (ART), the mortality of immunological non-responders (INRs) is higher than that of immunological responders (IRs). However, factors associated with immunological non-response following ART are not well documented.

METHODS

We obtained data for HIV patients from the National Free Antiretroviral Treatment Program database in China. Patients were grouped into IRs (CD4 cell count ≥ 350 cells/μl after 24 months' treatment), immunological incomplete responders (ICRs) (200-350 cells/μl) and INRs (< 200 cells/μl). Multivariable logistic regression was used to assess factors associated with immunological non-response.

RESULTS

A total of 3900 PLHIV were included, among whom 2309 (59.2%) were IRs, 1206 (30.9%) ICRs and 385 (9.9%) INRs. In multivariable analysis, immunological non-response was associated with being male (2.07, 1.39-3.09), older age [40-49 years (vs. 18-29 years): 2.05, 1.29-3.25; 50-59 years: 4.04, 2.33-7.00; ≥ 60 years: 5.51, 2.84-10.67], HBV co-infection (1.63, 1.14-2.34), HCV co-infection (2.01, 1.01-4.02), lower CD4 + T cell count [50-200 cells/μl (vs. 200-350 cells/μl): 40.20, 16.83-96.01; < 50 cells/μl: 215.67, 85.62-543.26] and lower CD4/CD8 ratio (2.93, 1.98-4.34) at baseline. Compared with patients treated with non-nucleoside reverse transcriptase inhibitors (NNRTIs) based regimens, those receiving protease inhibitors (PIs) based regimens were less likely to be INRs (0.47, 0.26-0.82).

CONCLUSIONS

We found a sizable immunological non-response rate among HIV-infected patients. Being male, older age, coinfection with HBV and HCV, lower CD4 + T cell count and lower CD4/CD8 ratio are risk factors of immunological non-response, whereas PIs-based regimens is a protective factor.

Association of Alcohol Consumption With CD4 Recovery After Antiretroviral Therapy Initiation in St. Petersburg, Russia

BACKGROUND

Delayed CD4 recovery after initiating antiretroviral therapy (ART) is a novel potential mechanism by which alcohol consumption leads to increased morbidity and mortality in people with HIV. We hypothesized that alcohol consumption at ART initiation is associated with slower CD4 recovery.

METHODS

We retrospectively analyzed 2 pooled longitudinal alcohol/HIV cohorts (2014-2019) in St. Petersburg, Russia. Eligible participants initiated the first ART during parent studies; had alcohol consumption assessed by the blood biomarker, phosphatidylethanol (PEth), at the last research visit before ART initiation; and had ≥1 CD4 count measurement before and after initiating ART. Participants were stratified by low, moderate, and high PEth (<8, 8-80, and >80 ng/mL, respectively). We used random-effects piecewise linear regression models to estimate CD4 recovery, defined as CD4 count change per 30 days after ART initiation, by the alcohol group.

RESULTS

Of 60 eligible participants, median age was 34 years and 28% were female. The median pre-ART PEth in the low, moderate, and high PEth groups were <8, 23, and 232 ng/mL, respectively. After starting ART, the CD4 count increased by 13.60 cells/mm3/mo (95% CI: 0.33 to 26.87) with low PEth, 0.93 cells/mm3/mo (95% CI: -6.18 to 8.04) with moderate PEth, and 2.33 cells/mm3/mo (95% CI: -3.44 to 8.09) with high PEth.

CONCLUSIONS

Among Russians with HIV, we observed faster CD4 recovery after ART initiation in those with low alcohol consumption compared with those with moderate and high alcohol consumption, as assessed by PEth. This analysis provides further evidence for the possible value of alcohol reduction interventions for people with HIV who are initiating ART.

Prevalence of and prognosis for poor immunological recovery by virally suppressed and aged HIV-infected patients

Background

Antiretroviral therapy (ART) prolongs lifespan and decreases mortality of HIV infected patients. However, many patients do not achieve optimal immune reconstitution. The influence of non-optimal immune recovery on non-AIDS related diseases is not well defined in aged HIV-infected patients receiving ART.

Methods

A retrospective study was conducted at Tianjin Second People's Hospital, China to evaluate the association of an inadequate immunological response and non-AIDS diseases in HIV infected patients ≥60 years of age and virally suppressed for at least 2 years by ART.

Results

The study included patients (n = 666) who initiated ART between August 2009 and December 2020. The prevalence of patients with an inadequate immunological response was 29.6%. The percentage of non-AIDS diseases such as hypertension, cardiovascular disease (CVD), diabetes, tumor, and chronic kidney disease (CKD) was 32.9, 9.9, 31, 4.1, and 13%, respectively. In addition to baseline CD4+ T cell counts, CVD and tumor were associated with poor immune reconstitution in aged Chinese HIV-1 infected patients. The adjusted odds ratios (95% confidence interval) were AOR 2.45 (95% CI: 1.22-4.93) and 3.06 (95% CI: 1.09-8.56, p = 0.03). Inadequate immunological response was associated with greater mortality (AOR: 2.83, 95% CI: 1.42-5.67, p = 0.003) in this cohort.

Conclusion

These results tend to demonstrate appropriate drug selection at ART initiation and prevention of non-AIDS complications during ART decreased mortality of and an inadequate immunological response in aged HIV infected patients.

In HIV-Infected Immunological Non-Responders, Hepatitis C Virus Eradication Contributes to Incomplete Normalization of Systemic Inflammation Indexes, but Does Not Lead to Rapid CD4+ T-Cell Count Recovery

In HIV-positive individuals taking antiretroviral therapy, coinfection with hepatitis C virus (HCV) increases systemic inflammation, which interferes with the CD4+ T-cells regeneration. This study evaluated the effect of HCV eradication on systemic inflammation and CD4+ T-cell regeneration in patients who gave poor response to antiretroviral therapy, the so-called "immunological non-responders" (INRs). HIV-infected patients who received a course of direct-acting antivirals for treating hepatitis C were examined. The control groups included HIV/HCV-coinfected INRs and relatively healthy volunteers. It was established for the first time that HCV eradication is not accompanied by a complete suppression of systemic inflammation, but improves the T-cell pool composition: in INRs, the blood CD4+/CD8+ T-lymphocyte ratio increases and approaches those of healthy individuals. Apparently, in INRs treated for hepatitis C, the immune system recovery takes time and may be incomplete.

Cellular and molecular insights into incomplete immune recovery in HIV/AIDS patients

Highly active antiretroviral therapy (ART) can effectively inhibit virus replication and restore immune function in most people living with human immunodeficiency virus (HIV). However, an important proportion of patients fail to achieve a satisfactory increase in CD4⁺ T cell counts. This state is called incomplete immune reconstitution or immunological nonresponse (INR). Patients with INR have an increased risk of clinical progression and higher rates of mortality. Despite widespread attention to INR, the precise mechanisms remain unclear. In this review, we will discuss the alterations in the quantity and quality of CD4⁺ T as well as multiple immunocytes, changes in soluble molecules and cytokines, and their relationship with INR, aimed to provide cellular and molecular insights into incomplete immune reconstitution.

Elucidating the Gene Signatures and Immune Cell Types in HIV-Infected Immunological Non-Responders by Bioinformatics Analyses

Objective

Numerous studies have reported on the pathogenesis of poor immune reconstitution (PIR) after antiretroviral treatment in human immunodeficiency virus (HIV) patients. However, fewer studies focused on both immune-related genes (IRGs) and immune cells, and the correlation between IRGs and immune cells was evaluated via bioinformatics analyses.

Methods

Gene expression profiling of GSE143742 from the Gene Expression Omnibus (GEO) database was analyzed to get differentially expressed immune-related genes (DEIRGs). The enrichment analysis and protein-protein interaction (PPI) networks of DEIRGs were established. The relative fractions of 22 immune cell types were detected using the "CIBERSORT". The correlation analysis between DEIRGs and immune cells was constructed to discover the potential IRGs associated with immune cells. A logistic regression diagnostic model was built, and a receiver operating characteristic (ROC) curve was performed to evaluate the model's diagnostic efficacy. The CMap database was used to find molecules with therapeutic potential. RT-qPCR was used to verify the expression of the hub DEIRGs.

Results

We identified eight types of significantly changed immune cells and five hub IRGs in INRs. The DEIRGs were mainly enriched in lymphocyte activation, receptor-ligand activity, and T cell receptor signaling pathway. The correlation analysis showed that the expression of TNF, CXCR4 and TFRC correlate with CD8 cells, resting mast cells, activated NK cells, and naïve CD4 cells in INRs. Meanwhile, TFRC and IL7R relate to activated NK cells and resting memory CD4 cells respectively in IRs. A diagnostic model was constructed using multiple logistic regression and nine small molecules were identified as possible drugs.

Conclusion

In this study, we suggested that the process of PIR might be related to TNF, CXCR4, TFRC, CD48, and IL7R. And these IRGs play roles in regulating immune-competent cells. And our constructed diagnostic model has excellent effectiveness. Moreover, some small-molecule drugs are screened to alleviate PIR.

Low Dehydroepiandrosterone (DHEA) Level Is Associated with Poor Immunologic Response among People Living with HIV/AIDS

Dehydroepiandrosterone (DHEA) is an adrenal steroid converted to potent androgens. This study aimed to discover the association between serum DHEA levels and immunologic response in people with HIV/AIDS (PLWHA). We enrolled patients aged ≥ 18 years who were treated with combination antiretroviral therapy (cART). We measured CD4+ and CD8+ T-cell counts, HIV-RNA titres, and serum DHEA levels. We assigned each patient to a good- or poor-responder group depending on their CD4+ T-cell counts at study enrolment. Participants with CD4+ T-cell counts > 200/µL were assigned to the good-responder group, whilst those with CD4+ T-cell counts < 200/µL were assigned to the poor-responder group. The participants were followed up for 2 years. The poor-responder group showed lower CD4+ T-cell counts and higher HIV PCR titres at their initial HIV diagnosis and in their 2-year follow-up data. Serum DHEA level was lower in the poor-responder group. Multivariable logistic analysis showed that BMI, initial CD4+ T-cell counts, and serum DHEA level were clinical factors associated with poor immunologic responsiveness to cART in PLWHA. Therefore, DHEA may be used as an indicator of the immunological recovery of PLWHA.

Anti-SARS-COV-2 specific immunity in HIV immunological non-responders after mRNA-based COVID-19 vaccination

Individuals infected with the human immunodeficiency virus type 1 (HIV-1) belong to the group of people most vulnerable to SARS-CoV-2 infections and the associated disease COVID-19. Here we describe SARS-CoV-2-specific antibody and cellular immune responses in a small cohort of immunological non-responder HIV-1 patients (HIV-INRs) after receiving the COVID-19 mRNA-based BioNTech/Pfizer vaccine. Compared to the control group of vaccinated healthy individuals that all developed a virus-specific immune response, 5 of 10 vaccinated HIV-1 patients showed insufficient immune responses. The lack of response was not directly correlated with patients CD4 cell counts. Three of the five non-responders that agreed to receive a booster vaccination subsequently generated a virus-specific response. Thus, even HIV-INRs can be efficiently vaccinated against COVID-19 but may require a follow-up by virus-specific immune monitoring to guarantee clinical vaccine benefits.

Analysis of the Influencing Factors of Immunological Nonresponders in Wuhan, China

Objective

CD4⁺ cell recovery is hampered in some human immunodeficiency virus (HIV)-infected patients, despite a successful highly active antiretroviral therapy (HAART) with suppressed viral replication. We investigated the factors that might have hindered the CD4⁺ cell recovery in these patients.

Methods

In this retrospective study, we collected the data of all immune nonresponders (INRs) in Wuhan, China, until the end of 2020. A linear model was constructed based on the data from 220 patients with baseline and follow-up records. The response variables in this study were the CD4⁺ cell count increase. The predictor variables considered in this study were those factors likely to affect the CD4⁺ cell recovery.

Results

Our findings revealed that the plasma HIV-1 viral load of all patients was suppressed and 87.3% patients' CD4⁺ cells was increased after more than one year of the HAART treatment. In addition, their last follow-up showed a significant reduction in complications. In our results, the body mass index (BMI), number of months since HIV diagnosis to HAART start, and nonuse of co-trimoxazole were negatively correlated with the increase in CD4⁺ cells (P < 0.05). However, there were positive associations between serum creatinine levels and CD4⁺ cell recovery (P < 0.05). Further stratified analyses indicated that the associations between HAART replacement or creatinine usage and CD4⁺ cell growth were only observed in those participants with a BMI <18.5 (P < 0.05).

Conclusions

An early initiation of HAART and co-trimoxazole preventive therapy (CPT) can promote immune reconstitution. BMI and serum creatinine can serve as monitoring indicators of immune reconstitution prognosis after the HAART.

High incidence of subclinical peripheral artery disease in people with HIV

OBJECTIVE

Atherosclerosis is common in people with HIV (PWH). Peripheral artery disease (PAD) is the peripheral manifestation of atherosclerosis, but little is known about the incidence of PAD in PWH. Our objective was to determine the PAD incidence in PWH and to investigate potential risk factors.

DESIGN

Prospective longitudinal study on PWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) study cohort.

METHODS

We performed ankle-brachial index (ABI) measurements at study entry and at 2-year follow-up and included participants with normal ABI at study entry. We defined de novo PAD as ABI ≤0.9 at follow-up. Using Poisson regression adjusted for age, sex, and smoking, we investigated the role of traditional and HIV-related risk factors, including inflammatory markers.

RESULTS

Of 844 PWH followed for a median duration of 2.3 years, 30 (3.6%) developed de novo PAD. All cases were subclinical. Diabetes (relative risk [RR] = 4.90 [95% confidence interval [CI]: 1.99-12.1]), current CD4 count <350 cells/μl (2.66 [1.06-6.71]), longer duration of antiretroviral therapy (antiretroviral therapy [ART], 1.88 [1.06-3.33] per decade), and concentrations of high-sensitivity C-reactive protein (1.33 [1.08-1.63] per doubling) and interleukin-6 (1.38 [1.06-1.80] per doubling), were associated with de novo PAD.

CONCLUSIONS

PWH had a high incidence of de novo subclinical PAD. Diabetes, low current CD4 count, duration of ART, and inflammatory markers were associated with de novo PAD, indicating a possible role in PAD pathogenesis in PWH.

Mucosal-associated invariant T cells: a cryptic coordinator in HIV-infected immune reconstitution

Human immunodeficiency virus type 1 (HIV-1) infection causes considerable morbidity and mortality worldwide. Although antiretroviral therapy (ART) has largely transformed HIV infection from a fatal disease to a chronic condition, approximately 10%~40% of HIV-infected individuals who receive effective ART and sustain long-term viral suppression still cannot achieve optimal immune reconstitution. These patients are called immunological non-responders, a state associated with poor clinical prognosis. Mucosal-associated invariant T (MAIT) cells are an evolutionarily conserved unconventional T cell subset defined by expression of semi-invariant αβ T cell receptor (TCR), which recognizes metabolites derived from the riboflavin biosynthetic pathway presented on major histocompatibility complex (MHC)-related protein-1 (MR1). MAIT cells, which are considered to act as a bridge between innate and adaptive immunity, produce a wide range of cytokines and cytotoxic molecules upon activation through TCR-dependent and TCR-independent mechanisms, which is of major importance in defense against a variety of pathogens. In addition, MAIT cells are involved in autoimmune and immune-mediated diseases. The number of MAIT cells is dramatically and irreversibly decreased in the early stage of HIV infection and is not fully restored even after long-term suppressive ART. In light of the important role of MAIT cells in mucosal immunity and because microbial translocation is inversely associated with CD4⁺ T cell counts, we propose that MAIT cells participate in the maintenance of intestinal barrier integrity and microbial homeostasis, thus further affecting immune reconstitution in HIV-infected individuals. This article is protected by copyright. All rights reserved.

Adipokines as New Biomarkers of Immune Recovery: Apelin Receptor, RBP4 and ZAG Are Related to CD4+ T-Cell Reconstitution in PLHIV on Suppressive Antiretroviral Therapy

A significant proportion of people living with HIV (PLHIV) who successfully achieve virological suppression fail to recover CD4⁺ T-cell counts. Since adipose tissue has been discovered as a key immune organ, this study aimed to assess the role of adipokines in the HIV immunodiscordant response. This is a multicenter prospective study including 221 PLHIV starting the first antiretroviral therapy (ART) and classified according to baseline CD4⁺ T-cell counts/µL (controls > 200 cells/µL and cases ≤ 200 cells/µL). Immune failure recovery was considered when cases did not reach more than 250 CD4⁺ T cells/µL at 144 weeks (immunological nonresponders, INR). Circulating adipokine concentrations were longitudinally measured using enzyme-linked immunosorbent assays. At baseline, apelin receptor (APLNR) and zinc-alpha-2-glycoprotein (ZAG) concentrations were significantly lower in INRs than in immunological responders (p = 0.043 and p = 0.034), and they remained lower during all ART follow-up visits (p = 0.044 and p = 0.028 for APLNR, p = 0.038 and p = 0.010 for ZAG, at 48 and 144 weeks, respectively). ZAG levels positively correlated with retinol-binding protein 4 (RBP4) levels (p < 0.01), and low circulating RBP4 concentrations were related to a low CD4⁺ T-cell gain (p = 0.018 and p = 0.039 at 48 and 144 weeks, respectively). Multiple regression adjusted for clinical variables and adipokine concentrations confirmed both low APLNR and RBP4 as independent predictors for CD4⁺ T cells at 144 weeks (p < 0.001). In conclusion, low APLNR and RBP4 concentrations were associated with poor immune recovery in treated PLHIV and could be considered predictive biomarkers of a discordant immunological response.

A randomized, blinded, placebo-controlled trial of De Simone formulation probiotic during HIV-associated suboptimal CD4+ T cell recovery

OBJECTIVE

To assess whether probiotic supplementation may reduce disease-linked systemic immune activation in people living with HIV with the immunologic non-responder (INR) phenotype.

DESIGN

Phase 2b, randomized, double-blind, placebo-controlled pilot trial.

METHODS

HIV-positive individuals with blood CD4+ T cell counts <350/mm3 despite viral suppression were randomized 2:1 to receive De Simone Formulation Probiotic (DSFP; "Visbiome" commercially) or placebo for 48 weeks; target enrolment was 36 patients. The primary endpoint was change in blood CD8+ T cell co-expression of HLA-DR and CD38 ("CD8 activation"). Secondary endpoints included biomarkers of inflammation, immune reconstitution, bacterial translocation, and gut permeability. Adjusted linear regression and linear mixed methods regression evaluated the differences between study arms from baseline to week 48. Study monitoring was done by the CIHR Canadian HIV Trials Network Data Safety Monitoring Committee.

RESULTS

Nineteen patients received DSFP, while 10 received placebo. One probiotic-arm patient withdrew early. Blood CD8 activation increased 0.82 percentage points (pp) in the probiotic arm (95% confidence interval [CI];-1.23,2.87;) and decreased by 2.06pp in the placebo arm (-4.81,0.70; between arms p=0.097). CD4+ T cell activation (%HLA-DR+) decreased in the placebo arm (-3.79pp [-7.32,-0.26]) but increased in the probiotic arm (1.64 [-0.98,4.26]; between arms p=0.018). No differences were observed in plasma or urine biomarkers of inflammation or microbial translocation.

CONCLUSIONS

Blood immune activation markers in INR individuals on effective ART were not reduced by supplementation with DSFP; CD4+ T cell activation may have been increased.

Association between CD4+ T cell counts and gut microbiota and serum cytokines levels in HIV-infected immunological non-responders

Background

CD4⁺ T cell counts in certain human immunodeficiency virus (HIV)-infected patients called immunological non-responders (INRs) could not return to a normal level even with sustained antiretroviral therapy (ART) because of persistent immune activation, which is associated with pro-inflammatory cytokines production and an altered intestinal microbiome profile. Changes in gut bacterial composition have been linked to low CD4⁺ T cell counts in HIV-infected individuals. However, the association between CD4⁺ T cell counts and gut microbiota community composition and cytokines levels in INRs (CD4⁺ T cell counts < 500 cells/μL) from Yunnan Province, China, has not been previously investigated.

Methods

To address this issue, we carried out a cross-sectional study of 34 HIV-infected INRs. The patients were divided into CD4 count > 200 cells/μL group and CD4 count < 200 cells/μL group. The gut microbiota composition of each subject was analyzed by 16S rRNA gene sequencing. We also compared CD8⁺ T cell counts, pro-inflammatory cytokines levels, and nutritional status between the two groups.

Results

Compared to INRs with CD4 count > 200 cells/μL, those with CD4 count < 200 cells/μL had a lower CD4/CD8 ratio, lower nutritional status and higher serum levels of tumor necrosis factor (TNF)-α, interferon-γ-inducible protein (IP)-10 and interleukin (IL)-1α. Ruminococcaceae was less abundant in the CD4 count < 200 cells/μL group than in the CD4 count > 200 cells/μL group, and difference in alpha diversity was observed between the two groups. Moreover, CD4⁺ T cell counts were negatively associated with TNF-α and IL-1α levels and positively associated with the relative abundance of Ruminococcaceae.

Conclusions

Our study demonstrated that lower CD4⁺ T cell counts in INRs are associated with a reduced abundance of Ruminococcaceae in the gut and elevated serum pro-inflammatory cytokines levels. Thus, interventions targeting gut microbiota to increase CD4⁺ T cell counts are a potential strategy for promoting immune reconstitution in HIV-infected INRs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06491-z.

Human umbilical cord mesenchymal stem cell transfusion in immune non-responders with AIDS: a multicenter randomized controlled trial

We examined the safety and efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) infusion for immune non-responder (INR) patients with chronic HIV-1 infection, who represent an unmet medical need even in the era of efficient antiretroviral therapy (ART). Seventy-two INR patients with HIV were enrolled in this phase II randomized, double-blinded, multicenter, placebo-controlled, dose-determination trial (NCT01213186) from May 2013 to March 2016. They were assigned to receive high-dose (1.5 × 106/kg body weight) or low-dose (0.5 × 106/kg body weight) hUC-MSC, or placebo. Their clinical and immunological parameters were monitored during the 96-week follow-up study. We found that hUC-MSC treatment was safe and well-tolerated. Compared with baseline, there was a statistical increase in CD4+ T counts in the high-dose (P < 0.001) and low-dose (P < 0.001) groups after 48-week treatment, but no change was observed in the control group. Kaplan-Meier analysis revealed a higher cumulative probability of achieving an immunological response in the low-dose group compared with the control group (95.8% vs. 70.8%, P = 0.004). However, no significant changes in CD4/CD8+ T counts and CD4/CD8 ratios were observed among the three groups. In summary, hUC-MSC treatment is safe. However, the therapeutic efficacy of hUC-MSC treatment to improve the immune reconstitution in INR patients still needs to be further investigated in a large cohort study.

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.