Pre-cART Elevation of CRP and CD4+ T-Cell Immune Activation Associated With HIV Clinical Progression in a Multinational Case-Cohort Study

T-Cell Immune Dysregulation and Mortality in Women With Human Immunodeficiency Virus

SUMMARY

In women with HIV, higher activation and exhaustion of CD4+ T cells were associated with risk of non-HIV-related mortality during a median of 13.3 years of follow-up, independent of baseline demographic, behavioral, HIV-related, and cardiometabolic factors and longitudinal HIV disease progression.

BACKGROUND

Dysregulation of adaptive immunity is a hallmark of human immunodeficiency virus (HIV) infection that persists on antiretroviral therapy (ART). Few long-term prospective studies have related adaptive immunity impairments to mortality in HIV, particularly in women.

METHODS

Among 606 women with HIV in the Women's Interagency HIV Study, peripheral blood mononuclear cells collected from 2002 to 2005 underwent multiparameter flow cytometry. Underlying cause of death was ascertained from the National Death Index up to 2018. We examined associations of CD4+ and CD8+ T-cell activation (%CD38+HLA-DR+), senescence (%CD57+CD28-), exhaustion (%PD-1+), and nonactivation/normal function (%CD57-CD28+) with natural-cause, HIV-related, and non-HIV-related mortality.

RESULTS

At baseline, median participant age was 41, and 67% were on ART. Among 100 deaths during a median of 13.3 years follow-up, 90 were natural-cause (53 non-HIV-related, 37 HIV-related). Higher activation and exhaustion of CD4+ T cells were associated with risk of natural-cause and non-HIV-related mortality, adjusting for age, demographic, behavioral, HIV-related, and cardiometabolic factors at baseline. Additional adjustment for time-varying viral load and CD4+ T-cell count did not attenuate these associations. CD8+ T-cell markers were not associated with any outcomes adjusting for baseline factors.

CONCLUSIONS

Persistent CD4+ T-cell activation and exhaustion may contribute to excess long-term mortality risk in women with HIV, independent of HIV disease progression.

Inflammatory biomarkers and soft tissue changes among patients commencing second-line antiretroviral therapy after first-line virological failure

INTRODUCTION

We explored associations of inflammatory and immune activation biomarkers at baseline and percentage gain in peripheral and trunk fat and lean mass over 96 weeks in patients with confirmed virological failure initiating lopinavir-anchored second-line antiretroviral therapy (ART) regimens.

METHOD

We measured baseline plasma concentration of interleukin (IL)-6, tumour necrosis factor (TNF), neopterin, IL-6, high-sensitivity C-reactive protein (hs-CRP), D-dimer, soluble cluster of differentiation 14 (sCD14), and soluble CD163 in 123 participants of the SECOND-LINE body composition substudy. Linear regression assessed the association between biomarkers and percentage gain in limb/trunk fat and lean mass, adjusting for age, nucleoside or nucleotide reverse transcriptase inhibitor (N(t)RTI) use, body mass index, ethnicity, smoking, viral load, CD4+ T-cell counts, smoking, duration of ART use, and cholesterol.

RESULTS

Mean (standard deviation) age was 38 (7.3) years, CD4+ T-cell count was 252 (185.9) cells/μl, human immunodeficiency virus viral load was 4.2 (0.9) log10 copies/ml, 47% (58/123) were in the N(t)RTI arm (vs. raltegravir [RAL] arm in 53%); 56.1% (69/123) were females. In adjusted analyses, for every log10 increase in baseline levels of IL-6, neopterin, and D-dimer, the percentage gain in peripheral fat over 96 weeks was 11.8% (95% confidence interval [CI]: 0.9-22.6, P = 0.033); neopterin, 11.2% (95% CI: 3.2-19.2, P = 0.007); D-dimer 9.6% (95% CI: 3.1-15.9, P = 0.004), respectively. The associations remained significant when analysis was stratified by N(t)RTI vs. RAL and included only patients with viral suppression at week 48. A significant gradient in lean mass gain was seen across quartiles of IL-6, TNF, neopterin, hsCRP, D-dimer, and sCD14.

CONCLUSION

Inflammatory biomarkers provide important mechanistic insights into the pathogenesis of limb fat and lean mass changes independently of ART.

Decreased Activated CD4+ T Cell Repertoire Diversity After Antiretroviral Therapy in HIV-1/HCV Coinfection Correlates with CD4+ T Cell Recovery

Dysfunctional immune activation accumulates during chronic viral infection and contributes to disease pathogenesis. In HIV-1, immune activation is exacerbated by concurrent infection with hepatitis C virus (HCV), accelerating depletion of CD4+ T cells. HIV-1 suppression with antiretroviral therapy (ART) generally reconstitutes CD4+ T cell counts, while also reducing the proportion that is activated. Whether this immune reconstitution also reduces the complexity of the CD4+ T cell population is unknown. We sought to characterize the relationship between activated CD4+ T cell repertoire diversity and immune reconstitution following ART in HIV-1/HCV coinfection. We extracted T cell receptor (TCR) sequences from RNA sequencing data obtained from activated CD4+ T cells of HIV-1/HCV coinfected individuals before and after treatment with ART (clinical trial NCT01285050). There was notable heterogeneity in both the extent of CD4+ T cell reconstitution and in the change in activated CD4+ TCR repertoire diversity following ART. Decreases in activated CD4+ TCR repertoire diversity following ART were predictive of the degree of CD4+ T cell reconstitution. The association of decreased activated CD4+ TCR repertoire diversity and improved CD4+ T cell reconstitution may represent loss of nonspecifically activated TCR clonotypes, and possibly selective expansion of specifically activated CD4+ clones. These results provide insight into the dynamic relationship between activated CD4+ TCR diversity and CD4+ T cell recovery of HIV-1/HCV coinfected individuals after suppression of HIV-1 viremia.

Inflammation and microbial translocation measured prior to combination antiretroviral therapy (cART) and long-term probability of clinical progression in people living with HIV

BACKGROUND

Despite the effectiveness of cART, people living with HIV still experience an increased risk of serious non-AIDS events, as compared to the HIV negative population. Whether pre-cART microbial translocation (MT) and systemic inflammation might predict morbidity/mortality during suppressive cART, independently of other known risk factors, is still unclear. Thus, we aimed to investigate the role of pre-cART inflammation and MT as predictors of clinical progression in HIV+ patients enrolled in the Icona Foundation Study Cohort.

METHODS

We included Icona patients with ≥2 vials of plasma stored within 6 months before cART initiation and at least one CD4 count after therapy available. Circulating biomarker: LPS, sCD14, EndoCab, hs-CRP. Kaplan-Meier curves and Cox regression models were used. We defined the endpoint of clinical progression as the occurrence of a new AIDS-defining condition, severe non-AIDS condition (SNAEs) or death whichever occurred first. Follow-up accrued from the data of starting cART and was censored at the time of last available clinical visit. Biomarkers were evaluated as both binary (above/below median) and continuous variables (logescale).

RESULTS

We studied 486 patients with 125 clinical events: 39 (31%) AIDS, 66 (53%) SNAEs and 20 (16%) deaths. Among the analyzed MT and pro-inflammatory markers, hs-CRP seemed to be the only biomarker retaining some association with the endpoint of clinical progression (i.e. AIDS/SNAEs/death) after adjustment for confounders, both when the study population was stratified according to the median of the distribution (1.51 mg/L) and when the study population was stratified according to the 33% percentiles of the distribution (low 0.0-1.1 mg/L; intermediate 1.2-5.3 mg/L; high > 5.3 mg/L). In particular, the higher the hs-CRP values, the higher the risk of clinical progression (p = 0.056 for median-based model; p = 0.002 for 33% percentile-based model).

CONCLUSIONS

Our data carries evidence for an association between the risk of disease progression after cART initiation and circulating pre-cART hs-CRP levels but not with levels of MT. These results suggest that pre-therapy HIV-driven pro-inflammatory milieu might overweight MT and its downstream immune-activation.

Intrahepatic Viral Kinetics During Direct-Acting Antivirals for Hepatitis C in Human Immunodeficiency Virus Coinfection: The AIDS Clinical Trials Group A5335S Substudy

BACKGROUND

Direct-acting antivirals (DAAs) targeting hepatitis C virus (HCV) have revolutionized outcomes in human immunodeficiency virus (HIV) coinfection.

METHODS

We examined early events in liver and plasma through A5335S, a substudy of trial A5329 (paritaprevir/ritonavir, ombitasvir, dasabuvir, with ribavirin) that enrolled chronic genotype 1a HCV-infected persons coinfected with suppressed HIV: 5 of 6 treatment-naive enrollees completed A5335S.

RESULTS

Mean baseline plasma HCV ribonucleic acid (RNA) = 6.7 log10 IU/mL and changed by -4.1 log10 IU/mL by Day 7. In liver, laser capture microdissection was used to quantify HCV. At liver biopsy 1, mean %HCV-infected cells = 25.2% (95% confidence interval [CI], 7.4%-42.9%), correlating with plasma HCV RNA (Spearman rank correlation r = 0.9); at biopsy 2 (Day 7 in 4 of 5 participants), mean %HCV-infected cells = 1.0% (95% CI, 0.2%-1.7%) (P < .05 for change), and DAAs were detectable in liver. Plasma C-X-C motif chemokine 10 (CXCL10) concentrations changed by mean = -160 pg/mL per day at 24 hours, but no further after Day 4.

CONCLUSIONS

We conclude that HCV infection is rapidly cleared from liver with DAA leaving <2% HCV-infected hepatocytes at Day 7. We extrapolate that HCV eradication could occur in these participants by 63 days, although immune activation might persist. Single-cell longitudinal estimates of HCV clearance from liver have never been reported previously and could be applied to estimating the minimum treatment duration required for HCV infection.

Mapping the Lineage Relationship between CXCR5+ and CXCR5- CD4+ T Cells in HIV-Infected Human Lymph Nodes

CXCR5 is a key marker of follicular helper T (T_FH) cells. Using primary lymph nodes (LNs) from HIV-infected patients, we identified a population of CXCR5⁻ CD4⁺ T cells with T_FH-cell-like features. This CXCR5⁻ subset becomes expanded in severe HIV infection and is characterized by the upregulation of activation markers and high PD-1 and ICOS surface expression. Integrated analyses on the phenotypic heterogeneity, functional capacity, T cell receptor (TCR) repertoire, transcriptional profile, and epigenetic state of CXCR5⁻PD-1⁺ICOS⁺ T cells revealed a shared clonal relationship with T_FH cells. CXCR5⁻PD-1⁺ICOS⁺ T cells retained a poised state for CXCR5 expression and exhibited a migratory transcriptional program. TCR sequence overlap revealed a contribution of LN-derived CXCR5⁻PD-1⁺ICOS⁺ T cells to circulating CXCR5⁻ CD4⁺ T cells with B cell help function. These data link LN pathology to circulating T cells and expand the current understanding on the diversity of T cells that regulate B cell responses during chronic inflammation.

Follicular helper T (T_FH) cells are critical for antibody production. Del Alcazar et al. showed that T_FH cells can lose their characteristic chemokine receptor, giving rise to migratory populations of CXCR5⁻ T cells that retain B cell help function and are poised for CXCR5 expression.

Changes in Inflammation but Not in T-Cell Activation Precede Non-AIDS-Defining Events in a Case-Control Study of Patients on Long-term Antiretroviral Therapy

Background

We examined changes in soluble inflammatory cytokines and T-cell activation after antiretroviral therapy (ART) initiation in an AIDS Clinical Trials Group (ACTG) nested case-control study.

Methods

Cases were 143 human immunodeficiency virus (HIV)-infected adults who developed a non-AIDS event; 315 controls remained event-free. Specimens were tested pre-ART, year 1 post-ART, and at the visit preceding the event. Conditional logistic regression evaluated the associations of biomarker changes with non-AIDS events.

Results

Inflammatory and most activation biomarkers declined from pre-ART to year 1 for cases and controls. Subsequently, inflammatory biomarkers remained mostly stable in controls but not cases. Cellular activation markers generally declined for both cases and controls between year 1 and the pre-event sampling. Controls with greater pre-ART RNA levels or lower CD4+ levels had higher biomarker levels while also experiencing greater biomarker declines in the first year of ART. Changes in biomarkers to year 1 showed no significant associations with non-AIDS events. Cases, however, had significantly greater increases in all plasma biomarkers (but not cellular activation) from year 1 to the visit preceding the event.

Conclusions

Inflammation increases prior to non-AIDS events in treated HIV-infected adults. These biomarker changes may reflect subclinical disease processes or other alterations in the inflammatory environment that causally contribute to disease.

Clinical Trials Registration

NCT00001137.

Current and emerging therapies to combat persistent intracellular pathogens

Intracellular pathogens such as HIV, hepatitis B virus, and Mycobacterium tuberculosis are responsible for millions of deaths worldwide and represent major obstacles to global health. Current treatment options have improved patient outcomes and extended life-expectancy in many countries; however, challenges such as latency, drug-resistance, and inflammatory pathology have necessitated advancements in curative strategies which go beyond the traditional antimicrobial focus. This review highlights recent advances in host-directed therapies to eradicate intracellular pathogens or augment the endogenous immune response by targeting host cell pathways. The 'kick and kill' strategy for HIV latency, adjunct immunomodulatory compounds for tuberculosis, and pro-apoptotic small-molecule inhibitors in the case of chronic Hepatitis B are promising examples of host-directed therapies that signal a paradigm shift in treatment and management of chronic infectious disease.

Point-of-care C-reactive protein and risk of early mortality among adults initiating antiretroviral therapy

OBJECTIVES

In resource-limited settings, mortality in the initial months following antiretroviral therapy (ART) initiation remains unacceptably high. Novel tools to identify patients at highest risk of poor outcomes are needed. We evaluated whether elevated C-reactive protein (CRP) concentrations predict poor outcomes among people living with HIV (PLWH) initiating ART.

METHODS

We enrolled and followed for 3-months consecutive PLWH with pre-ART CD4 T-cell counts 350 cells/μl or less initiating ART from two HIV clinics in Uganda. Pre-ART CRP concentrations were measured from capillary blood using a point-of-care (POC) assay. After excluding patients with prevalent tuberculosis - the leading cause of HIV death - we measured 3-month mortality rates using Kaplan-Meier curves, used Cox regression to compare differences in survival, and used logistic regression to compare differences in the odds of opportunistic infections, between patients with and without elevated POC CRP (≥8 mg/l).

RESULTS

Of 1293 patients included [median CD4 T-cell count 181 (interquartile range 82-278)], 23 (1.8%) died within 3 months, including 19 of 355 (5.4%) with elevated POC CRP and four of 938 (0.4%) with nonelevated POC CRP. Eighty-six (6.7%) patients were diagnosed with opportunistic infections, including 39 of 355 (11.0%) with elevated POC CRP and 47 of 938 (5.0%) with nonelevated POC CRP. Elevated POC CRP was associated with mortality (adjusted hazard ratio 10.87, 95% confidence interval 3.64-32.47) and opportunistic infection (adjusted odds ratio 1.95, 95% confidence interval 1.23-3.07).

CONCLUSION

Among PLWH with advanced HIV, elevated pre-ART POC CRP concentrations are associated with early mortality and opportunistic infections. Pre-ART POC CRP testing may reduce mortality by identifying patients at high risk for poor outcomes.

Inflammation and micronutrient biomarkers predict clinical HIV treatment failure and incident active TB in HIV-infected adults: a case-control study

BACKGROUND

Various individual biomarkers of inflammation and micronutrient status, often correlated with each other, are associated with adverse treatment outcomes in human immunodeficiency virus (HIV)-infected adults. The objective of this study was to conduct exploratory factor analysis (EFA) on multiple inflammation and micronutrient biomarkers to identify biomarker groupings (factors) and determine their association with HIV clinical treatment failure (CTF) and incident active tuberculosis (TB).

METHODS

Within a multicountry randomized trial of antiretroviral therapy (ART) efficacy (PEARLS) among HIV-infected adults, we nested a case-control study (n = 290; 124 cases, 166 controls) to identify underlying factors, based on EFA of 23 baseline (pre-ART) biomarkers of inflammation and micronutrient status. The EFA biomarker groupings results were used in Cox proportional hazards models to study the association with CTF (primary analysis where cases were incident World Health Organization stage 3, 4 or death by 96 weeks of ART) or incident active TB (secondary analysis).

RESULTS

In the primary analysis, based on eigenvalues> 1 in the EFA, three factors were extracted: (1) carotenoids), (2) other nutrients, and (3) inflammation. In multivariable-adjusted models, there was an increased hazard of CTF (adjusted hazard ratio (aHR) 1.47, 95% confidence interval (CI)1.17-1.84) per unit increase of inflammation factor score. In the secondary incident active TB case-control analysis, higher scores of the high carotenoids and low interleukin-18 factor was protective against incident active TB (aHR 0.48, 95% CI 0.26-0.87).

CONCLUSION

Factors identified through EFA were associated with adverse outcomes in HIV-infected individuals. Strategies focused on reducing adverse HIV outcomes through therapeutic interventions that target the underlying factor (e.g., inflammation) rather than focusing on an individual observed biomarker might be more effective and warrant further investigation.

Effect of baseline micronutrient and inflammation status on CD4 recovery post-cART initiation in the multinational PEARLS trial

BACKGROUND & AIMS

Nutritional deficiency and inflammation may impact CD4+ T cell recovery during combination antiretroviral therapy (cART), particularly in resource-limited settings where malnutrition is prevalent. The aim of this study was to investigate the relationship of micronutrient and inflammation biomarkers to CD4 recovery after cART initiation.

METHODS

We conducted a secondary analysis of a random sub-cohort sample (n = 270) from a multinational randomized trial of cART regimen efficacy among 1571 cART-naïve adults. We measured pre-cART serum levels of micronutrients (Vitamin A, B₆, B₁₂, D, total carotenoids, selenium, and iron) and inflammation (C-reactive protein, soluble CD14 (sCD14), IFNγ, TNFα, Interleukin-6, and C-X-C motif chemokine 10 (CXCL10/IP10), EndoCab (IgM)) biomarkers. Biomarker status (i.e. micronutrient deficiency vs. sufficiency and elevated vs. low inflammation) was defined using established cutoffs or quartiles. Mixed-effects linear regression models were used to determine the association of baseline (pre-cART) concentrations of individual biomarkers with CD4 recovery through 96 weeks post-cART initiation.

RESULTS

In models adjusting for time-dependent viral load and baseline CD4 count, age, sex, body mass index, country, treatment regimen, anemia and hypoalbuminemia status, pre-cART vitamin D deficiency was associated with lower CD4 recovery (-14.9 cells/mm³, 95% CI: -27.9, -1.8) compared to sufficiency. In contrast, baseline selenium deficiency (20.8 cells/mm³, 95% CI: 3.3, 38.3), vitamin A deficiency (35.9 cells/mm³, 95% CI: 17.6, 54.3) and high sCD14 (23.4 cells/mm³, 95% CI: 8.9, 37.8) were associated with higher CD4 recovery compared to sufficient/low inflammation status.

CONCLUSIONS

In summary, baseline vitamin D deficiency was associated with diminished CD4 recovery after cART initiation; impaired CD4 recovery may contribute to the poor clinical outcomes recently observed in individuals with vitamin D deficiency. Vitamin A, selenium and sCD14 were associated with CD4 recovery but future studies are needed to further explore these relationships.

Management of Long-Term Complications of HIV Disease: Focus on Cardiovascular Disease

HIV-infected individuals on effective antiretroviral therapy experience a number of non-AIDS noncommunicable diseases, such as cardiovascular disease, more frequently than uninfected individuals. Common pathways for such diseases are chronic immune activation and inflammation, including the prolonged inflammation associated with lower nadir CD4+ cell count. Prevention and treatment of non-AIDS conditions include treatment of traditional risk factors, lifestyle interventions, earlier initiation of antiretroviral therapy, and potentially therapies specifically targeting inflammation and immune activation (eg, statins). This article summarizes a presentation by Judith S. Currier, MD, at the IAS-USA continuing education program, Improving the Management of HIV Disease, held in New York, New York, in February 2017.

Postvaccination C-Reactive Protein and C5/gp41732-744 Antibody Level Fold-Changes Over Baseline Are Independent Predictors of Therapeutic HIV Vaccine Effect in a Phase 2 Clinical Study of Vacc-4x

Therapeutic vaccination has the potential to contribute to functional HIV cure strategies. However, to show functional HIV cure, study participants must be taken off combination antiretroviral therapy (cART). The availability of suitable biomarkers that can predict viral load (VL) or CD4 count outcomes following therapeutic HIV vaccination would reduce the risks associated with cART interruption in such studies. This report sought to determine baseline and postvaccination biomarker predictors of vaccine effect (VE) on VL and CD4 counts following cART interruption in a double-blind, randomized phase 2 study of the peptide-based therapeutic HIV vaccine, Vacc-4x (n = 93), versus placebo (n = 43). Antibody responses to a novel envelope glycoprotein antigen, C5/gp41^732-744, and three safety marker measurements [C-reactive protein (CRP), white blood cell, and lactate dehydrogenase] were considered. Interaction tests in univariate and multivariate linear regression models were used to estimate the effect of biomarkers on VE, defined as the VL or CD4 count difference in Vacc-4x versus placebo groups. The reported q-values (considered significant for hypothesis-generating purposes if ≤0.2) accounted for multiple comparisons using the false discovery rate method. Data were analyzed from all available 58 Vacc-4x and 25 placebo recipients before cART resumption. Lower postvaccination fold-change over baseline of CRP concentration (interaction p- (q-) value = 0.005 (0.11) for VL) and higher fold-change of anti-C5/gp41^732-744 antibody levels (0.005 (0.11) for VL and 0.009 (0.20) for CD4) were associated with Vacc-4x benefit. These findings suggest potential roles for inflammation and immune activation markers in predicting therapeutic HIV VE.

Prevalence, Risk Factors, and Pathophysiology of Dysglycemia among People Living with HIV in Sub-Saharan Africa

OBJECTIVE

To review available literature on the prevalence, risk factors, pathophysiology, and clinical outcomes of dysglycemia among people living with HIV (PLHIV) in sub-Saharan Africa (SSA).

METHODS

Database search on PUBMED for eligible studies describing the prevalence, risk factors, pathophysiology, or clinical outcomes of dysglycemia in SSA PLHIV.

RESULTS

Prevalence of diabetes mellitus (DM) and pre-DM among SSA PLHIV ranged from 1% to 26% and 19% to 47%, respectively, in 15 identified studies. Older age and an elevated body mass index (BMI) were common risk factors for dysglycemia. Risk factors potentially more specific to PLHIV in SSA included exposure to older-generation thymidine analogues or protease inhibitors, malnutrition at ART initiation, a failure to gain fat mass on treatment, and elevated serum lipids. There is evidence of higher nephropathy and neuropathy rates among PLHIV in SSA with comorbid DM compared to HIV-negative individuals with DM.

CONCLUSION

There is a need for longitudinal studies to enhance understanding of the risk factors for dysglycemia among PLHIV in SSA, further research into optimal therapies to reduce pre-DM progression to DM among SSA PLHIV, and studies of the burden and phenotype of diabetic complications and other health outcomes among PLHIV with comorbid DM in SSA.

Intracellular HIV-1 RNA and CD4+ T-cell activation in patients starting antiretrovirals

OBJECTIVE

To assess if the reduction in HIV-1 RNA in CD4 T cells is correlated with the persistence of immune activation following early antiretroviral therapy (ART).

DESIGN

Clinical trial (NCT01285050).

METHODS

Next-generation sequencing was used to study total RNA from activated CD4 T cells (CD38 and human leukocyte antigen - antigen D related (HLA-DR) expressing) collected from 19 treatment-naïve HIV-1/hepatitis C virus-infected patients before and early after ART initiation (≥12 weeks after plasma HIV-1 RNA <50 copies/ml). To validate comparisons, pre and post-ART measures were adjusted for input RNA and overall read number.

RESULTS

As expected, ART use was associated with a median [interquartile range (IQR)] 4.3% (2.2-8.3) reduction in the proportion of activated CD4 T cells (P = 0.0008). Whereas in those activated CD4 T cells no consistent differences in overall gene expression were detected, interferon-stimulated gene expression declined (P < 2 × 10). Pre-ART, sorted activated CD4 T cells contained a median (IQR) of 959 (252-1614) HIV-1 reads/10 reads compared with 72 (55-152) HIV-1 reads/10 reads after at least 12 weeks of suppressive ART (P = 8 × 10). The decrease in HIV-1 reads in activated CD4 T cells was associated with the change in plasma HIV-1 RNA levels (r = 0.77, P = 2 × 10) and the change in the proportion of activated CD4 T cells (r = 0.70, P = 0.0016).

CONCLUSION

Months of ART led to a marked decrease in cell-associated HIV-1 RNA and interferon-stimulated genes expression in activated CD4 T cells that were strongly associated with the reduction in the proportion of activated CD4 T cells.

Immunologic Biomarkers, Morbidity, and Mortality in Treated HIV Infection

Despite marked improvements in the modern treatment era, human immunodeficiency virus (HIV)-infected individuals, particularly those who initiated antiretroviral therapy (ART) at advanced disease stages, continue to have increased age-related morbidity and mortality, compared with the general population. Immune activation and inflammation persist despite suppressive ART and predict many of these morbidities. The goal of this review is to examine the evidence suggesting a link between the persistent inflammatory state and morbidity and mortality in this setting, to describe the impact of early ART initiation on these factors, and to highlight important unanswered questions for the field. We also advance a hypothesis to explain why some morbidities-and their root inflammatory drivers-may be prevented more than others by early ART initiation.

Immunologic Pathways That Predict Mortality in HIV-Infected Ugandans Initiating Antiretroviral Therapy

The plasma kynurenine/tryptophan (KT) ratio, a marker of adaptive immune defects, strongly predicts mortality during treated human immunodeficiency virus (HIV) disease in Ugandans as compared to US-based populations. Here, the KT ratio and T-cell and plasma biomarkers of immune activation were measured among 535 HIV-infected Ugandans prior to ART initiation and at month 6 of viral suppression. The month 6 KT ratio (adjusted hazard ratio [aHR], 2.74), soluble CD14 level (aHR, 2.32), interleukin 6 level (aHR, 2.34), and D-dimer level (aHR, 1.95) were associated with mortality occurring ≥6 months after ART initiation. The KT ratio remained significantly predictive of mortality even after adjustment for the additional biomarkers, suggesting an independent contribution to clinical outcomes in resource-limited settings.

Continued Elevation of Interleukin-18 and Interferon-γ After Initiation of Antiretroviral Therapy and Clinical Failure in a Diverse Multicountry Human Immunodeficiency Virus Cohort

Background. We assessed immune activation after antiretroviral therapy (ART) initiation to understand clinical failure in diverse settings.

Methods. We performed a case-control study in ACTG Prospective Evaluation of Antiretrovirals in Resource-Limited Settings (PEARLS). Cases were defined as incident World Health Organization Stage 3 or 4 human immunodeficiency virus (HIV) disease or death, analyzed from ART weeks 24 (ART24) to 96. Controls were randomly selected. Interleukin (IL)-6, interferon (IFN)-γ-inducible protein-10, IL-18, tumor necrosis factor-α, IFN-γ, and soluble CD14 (sCD14) were measured pre-ART and at ART24 in plasma. Continued elevation was defined by thresholds set by highest pre-ART quartiles (>Q3). Incident risk ratios (IRRs) for clinical progression were estimated by Poisson regression, adjusting for age, sex, treatment, country, time-updated CD4⁺ T-cell count, HIV ribonucleic acid (RNA), and prevalent tuberculosis.

Results. Among 99 cases and 234 controls, median baseline CD4⁺ T-cell count was 181 cells/µL, and HIV RNA was 5.05 log₁₀ cp/mL. Clinical failure was independently associated with continued elevations of IL-18 (IRR, 3.03; 95% confidence interval [CI], 1.27–7.20), sCD14 (IRR, 2.17; 95% CI, 1.02–4.62), and IFN-γ (IRR, 0.08; 95% CI, 0.01–0.61). Among 276 of 333 (83%) who were virologically suppressed at ART24, IFN-γ was associated with protection from failure, but the association with sCD14 was attenuated.

Conclusions. Continued IL-18 and sCD14 elevations were associated with clinical ART failure. Interferon-γ levels may reflect preserved immune function.