Regulatory T Cells, Frailty, and Immune Activation in Men Who Have Sex With Men in the Multicenter AIDS Cohort Study

Complete CD16A Deficiency and Defective NK Cell Function in a Man Living with HIV

A man living with HIV was found to lack expression of CD16A on his natural killer (NK) cells and monocytes. Genetic analysis revealed compound heterozygous deletion of FCGR3A, the gene encoding CD16A. The case's NK cells showed: (a) no antibody-dependent cell-mediated cytotoxicity and very low spontaneous cytotoxicity; (b) an immature phenotype marked by high expression of CD94, CD2, NKG2A, and NKG2D, and low expression of KIR2DL2 and CD57; (c) no expression of KIR3DL1 and very low expression of FcRγ; and (d) normal cytokine production. The case's monocytes and DCs were similar phenotypically and functionally to those from the donors matched for HIV status, age, and percentage of NK cells in the peripheral blood. In contrast to previously reported people with CD16A deficiency, this man did not have a history of severe infections with herpes viruses, suggesting that other immune cells and/or immunoregulatory function of NK cells may compensate for deficiency of cytolytic NK cells.

Characterization of data-driven geriatric syndrome clusters in older people with HIV: a Mexican multicenter cross-sectional study

Background

As living with HIV has been proposed as a condition that may accelerate aging, the main objective of this work was to estimate the prevalence of geriatric syndromes (GS) among older Mexicans with HIV dwelling in the community. Secondly, to evaluate whether the accumulation of GS could be associated with an adverse HIV-related clinical profile, independent of chronological age.

Methods

Multicenter, cross-sectional study including 501 community-dwelling people aged ≥50 years with HIV. The overall prevalence of nine selected GS and their cumulative number were estimated. An Age-Independent Cumulative Geriatric Syndromes scale (AICGSs) was constructed, and correlations between the AICGSs and HIV-related parameters assessed. Finally, k-mean clustering analyses were performed to test the secondary objective.

Findings

Median age 56 (IQR: 53-61) years, 81.6% of men. Polypharmacy (74.8%), sensorial deficit (71.2%), cognitive impairment (53.6%), physical disability (41.9%), pre-frailty (27.9%), and falls (29.7%), were the more prevalent GS. A significant negative correlation was found between the AICGSs and normalized values of CD4+ nadir cell counts (r = -0.126; 95%: CI: -0.223 to -0.026, p < 0.05). Similarly, a significant inverse adjusted association between the CD4+ nadir cells and the AICGSs was observed on linear regression analysis (β -0.058; 95%: CI: -0.109 to -0.007, p = 0.03). Cluster analysis identified three differentiated groups varying by age, metabolic comorbidities, AICGSs, and HIV-related parameters.

Interpretation

An elevated prevalence of GS was observed in the studied population. Moreover, the accumulation of GS was associated with adverse HIV-related profiles, independent of age. Thus, early detection and management of GS are crucial to promote healthier aging trajectories in people with HIV.

Funding

This work was funded in part by the National Center for the Prevention and Control of HIV/AIDS in Mexico (CENSIDA)-National Ministry of Health.

Pressing Questions and Challenges in the HIV-1 and SARS-CoV-2 Syndemic

Since emerging into the human population in late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has reached across the globe to infect >80 million people. The coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 can range in severity from mild and asymptomatic to severe and fatal. Identifying risk factors for adverse outcomes in COVID-19 is a major challenge. In the context of the existing HIV-1 pandemic, whether COVID-19 disproportionately burdens people living with HIV-1 infection (PLWH) is unclear. The following discussion highlights pressing questions and challenges in the HIV-1 and SARS-CoV-2 syndemic, including (i) age, sex, and race as drivers of COVID-19 severity; (ii) whether chronic inflammation common in PLWH influences immune response; (iii) whether disease severity and trajectory models for COVID-19 ought to be calibrated for PLWH; (iv) vaccine considerations, and finally, (v) long-term health outcomes in PLWH that are further burdened by coinfection with SARS-CoV-2.

Assessment, prevalence, and correlates of frailty among middle-aged adults with HIV in rural Uganda

We investigated the prevalence and risk factors for frailty among people with HIV (PWH) in rural Uganda (n = 55, 47% male, mean age 44 years). Frailty was defined according to the Fried criteria with self-reported physical activity level replacing the Minnesota Leisure Time Activity Questionnaire. Alternate classifications for physical activity utilized were the sub-Saharan Africa Activity Questionnaire and the International Physical Activity Questionnaire. Eleven participants (19%) were frail. Frail participants were older (p < 0.001), less likely to be on antiretroviral therapy (p = 0.03), and had higher rates of depression (p < .001) and HIV-associated neurocognitive disorder (p = 0.003). Agreement between physical activity measures was sub-optimal. Prevalence of frailty was high among PWH in rural Uganda, but larger sample sizes and local normative data are needed.

Frailty in People Living with HIV

PURPOSE OF REVIEW

Different factors contribute to the decreased overall long-term survival in treated people living with HIV (PLWH). This paper will review the state of physical frailty which limits successful aging in PLWH.

RECENT FINDINGS

Identifiable events on the continuum from clinical normality to heightened risk of adverse health outcomes contribute to frailty. These center on chronic inflammation leading to destabilization of autoregulated physiologic systems challenged by environmental and biologic challenges. Frailty assessment can inform the profile of aging PLWH at increased risk of common age-related disorders and geriatric syndromes. Biologic and psychosocial risk factors promoting progression to and reversion from a dynamic state of frailty are being investigated, allowing for preventative interventions to be considered. Insights gained from studying frail PLWH will help adapt an interdisciplinary geriatric model of health care for selected PLWH. This will improve the health and well-being of aging PLWH.

Tfh cell subset biomarkers and inflammatory markers are associated with frailty status and frailty subtypes in the community-dwelling older population: a cross-sectional study

We conducted a cross-sectional study investigating community-dwelling older population to determine association between immunoscenescence marker, inflammatory cytokines and frailty. Frailty status was classified with 33-item modified frailty index and latent class analysis was applied to explore the latent classes (subtypes) of frailty. In multivariable analysis, higher Tfh2 cells were associated with a higher risk of frailty [1.13(1.03–1.25)] in females, but a lower risk of cognitive and functional frail [0.92(0.86–0.99)] and physiological frail [0.92(0.87–0.98)]. Additionally, a greater risk of multi-frail and physiological frail correlated with low Tfh1 [0.77(0.60–0.99); 0.87(0.79–0.96)] and Tfh17 cells [0.79(0.65–0.96); 0.86(0.78–0.94)], respectively. Higher B cells were associated with decreased frailty/pre-frailty both in females [0.89(0.81–0.98)] and males [0.82(0.71–0.96)], but did not correlate with frailty subtypes. Regarding inflammatory markers, participants in the TGF-β 2^nd quartile showed a decreased risk of pre-frailty/frailty in females [0.39(0.17–0.89)] and psychological frail [0.37(0.16–0.88)], compared with those in the top tertile. Moreover, we found participants in the 2^nd tertile for IL-12 levels showed a decreased risk of physiological frail [0.40 (0.17–0.97)]. Our study highlights the importance of Tfh cell subsets and inflammatory markers in frailty in a sex-specific manner, particularly in terms of frailty subtype.

The dynamic association between Frailty, CD4 and CD4/CD8 ratio in people aging with HIV

Objective

To investigate the association between current CD4+ T-cell count and CD4/CD8+ ratio with severity of frailty among people aging with HIV.

Methods

Cross-sectional observational study analysing data from all study visits in the ongoing prospective Modena HIV Metabolic Clinic Cohort between 2006 and 2015. Frailty severity was assessed using a frailty index (FI). We visualized the relationships between frailty index score and current CD4 cell count and CD4/CD8 ratio on two different curves adjusted for age, sex, and duration of HIV infection.

Results

Frailty index scores exhibited an inverse relationship with current CD4 count, up to 900 cells/μL. The CD4/CD8 ratio was inversely correlated with frailty index both below and above the cut-off of 900 CD4 cells/μL.

Conclusions

Frailty in PLWH is inversely associated with both immune-activation, depicted by CD4/CD8 ratio and immune-deficit depicted by CD4 count. The first association shows a linear shape while the second shows a hook-shape with a turning point at 900 cells. Above this cut off level CD4 do not represent a significant risk factor for frailty.

Assessment of sarcopenia in virally suppressed HIV-infected Asians receiving treatment

OBJECTIVES

In a clinic-based, treated HIV-infected cohort, we identified individuals with sarcopenia and compared with age, sex and ethnically matched controls; and investigated associated risk factors and health outcomes.

DESIGN

Sarcopenia (age-related muscle loss) causes significant morbidity to the elderly, leading to frequent hospitalizations, disability and death. Few have characterized sarcopenia in the HIV-infected who experience accelerated aging.

METHODS

Sarcopenia was defined as low muscle mass with weak grip strength and/or slow gait speed using lower 20th percentiles of controls. Multivariate logistic and linear regression analyses were used to explore risk factors and health-related outcomes associated with sarcopenia among HIV-infected individuals.

RESULTS

We recruited 315 HIV-infected individuals aged at least 25 years with at least 1-year history of undetectable viral load on treatment (HIV RNA <50 copies/ml). Percentage of sarcopenia in 315 HIV-infected was 8%. Subsequently, 153 of the 315 were paired with age, sex and ethnically matched HIV-uninfected. The percentage of sarcopenia in the HIV-infected (n = 153) compared with uninfected (n = 153) were 10 vs. 6% (P = 0.193) respectively, whereas of those at least 50 years of age among them were 17% vs. 4% (P = 0.049), respectively. Associated risk factors among the HIV-infected include education level, employment status, BMI, baseline CD4 cell count, duration on NRTIs and GGT levels. Identified negative outcomes include mortality risk scores [5.42; 95% CI 1.46-9.37; P = 0.007) and functional disability (3.95; 95% CI 1.57-9.97; P = 0.004).

CONCLUSION

Sarcopenia is more prevalent in HIV-infected at least 50 years old compared with matched controls. Our findings highlight associations between sarcopenia with loss of independence and greater healthcare burden among treated HIV-infected individuals necessitating early recognition and intervention.

Can Biomarkers Advance HIV Research and Care in the Antiretroviral Therapy Era?

Despite achieving human immunodeficiency virus type 1 (HIV-1) RNA suppression below levels of detection and, for most, improved CD4+ T-cell counts, those aging with HIV experience excess low-level inflammation, hypercoagulability, and immune dysfunction (chronic inflammation), compared with demographically and behaviorally similar uninfected individuals. A host of biomarkers that are linked to chronic inflammation are also associated with HIV-associated non-AIDS-defining events, including cardiovascular disease, many forms of cancer, liver disease, renal disease, neurocognitive decline, and osteoporosis. Furthermore, chronic HIV infection may interact with long-term treatment toxicity and weight gain after ART initiation. These observations suggest that future biomarker-guided discovery and treatment may require attention to multiple biomarkers and, possibly, weighted indices. We are clinical trialists, epidemiologists, pragmatic trialists, and translational scientists. Together, we offer an operational definition of a biomarker and consider how biomarkers might facilitate progress along the translational pathway from therapeutic discovery to intervention trials and clinical management among people aging with or without HIV infection.

Predictors of transitions in frailty severity and mortality among people aging with HIV

BACKGROUND

People aging with HIV show variable health trajectories. Our objective was to identify longitudinal predictors of frailty severity and mortality among a group aging with HIV.

METHODS

Exploratory analyses employing a multistate transition model, with data from the prospective Modena HIV Metabolic Clinic Cohort Study, based in Northern Italy, begun in 2004. Participants were followed over four years from their first available visit. We included all 963 participants (mean age 46.8±7.1; 29% female; 89% undetectable HIV viral load; median current CD4 count 549, IQR 405-720; nadir CD4 count 180, 81-280) with four-year data. Frailty was quantified using a 31-item frailty index. Outcomes were frailty index score or mortality at four-year follow-up. Candidate predictor variables were baseline frailty index score, demographic (age, sex), HIV-disease related (undetectable HIV viral load, current CD4+ T-cell count, nadir CD4 count, duration of HIV infection, and duration of antiretroviral therapy [ARV] exposure), and behavioral factors (smoking, injection drug use (IDU), and hepatitis C virus co-infection).

RESULTS

Four-year mortality was 3.0% (n = 29). In multivariable analyses, independent predictors of frailty index at follow-up were baseline frailty index (RR 1.06, 95% CI 1.05-1.07), female sex (RR 0.93, 95% CI 0.87-0.98), nadir CD4 cell count (RR 0.96, 95% CI 0.93-0.99), duration of HIV infection (RR 1.06, 95% CI 1.01-1.12), duration of ARV exposure (RR 1.08, 95% CI 1.02-1.14), and smoking pack-years (1.03, 1.01-1.05). Independent predictors of mortality were baseline frailty index (OR 1.19, 1.02-1.38), current CD4 count (0.34, 0.20-0.60), and IDU (2.89, 1.30-6.42).

CONCLUSIONS

Demographic, HIV-disease related, and social and behavioral factors appear to confer risk for changes in frailty severity and mortality among people aging with HIV.

Correlates of frailty phenotype and frailty index and their associations with clinical outcomes

OBJECTIVES

Frailty is a predictor of adverse health outcomes and can be measured across the life course, including among people living with HIV. The purpose of this study was to examine two commonly used measures of frailty - the frailty index (FI) and frailty phenotype - to assess common characteristics and to describe associations with multimorbidity, falls, and disability in people aging with HIV.

METHODS

This was a cross-sectional observational study including 482 consecutive HIV-infected patients (mean age 53.9 ± SD 6.9 years; 75% male) attending the multidisciplinary metabolic clinic at the University of Modena, Italy. Frailty was measured with the frailty phenotype and a 37-item FI.

RESULTS

The mean FI score was 0.28±0.1 and frailty phenotype categories were: 3.1% frail, 51.9% pre-frail, and 45% robust. The duration of antiretroviral therapy was significantly different across levels of frailty as measured by both frailty tools (P < 0.01), but the nadir CD4 count was only significant for the FI (P = 0.01); current CD4 count was not significantly different across frailty levels using either tool. Both frailty measures were associated with multimorbidity; the FI was associated with Instrumental Activities of Daily Living impairment and falls history, whereas the frailty phenotype was not.

CONCLUSIONS

The frailty phenotype and the FI demonstrated similar characteristics in patients at a tertiary-level HIV clinic. The FI had a stronger association with age, nadir CD4 count, comorbidities, falls, and disability. Integrating frailty assessments in clinical practice will be crucial for the development of interventions in age-related conditions, including disability and falls, in older persons living with HIV.

Geriatric syndromes: new frontiers in HIV and sarcopenia

: HIV infection, in many circumstances, can now be managed as a chronic disease due to the marked increase in life expectancy since the introduction of combination antiretroviral therapy (ART). As the patients who first had access to combination ART age into their 50s and 60s, the effects of chronic HIV infection on health have become an important research focus in HIV infection. People living with HIV appear to exhibit an earlier occurrence of some aging-related conditions compared to people without HIV, in part due to higher rates of comorbidities, high-risk behaviors (e.g. smoking, substance use), chronic immune activation, inflammation, and ART-specific factors. Some studies have even suggested an earlier-than-expected appearance of the 'geriatric syndromes,' which are complex medical syndromes of older adults that are associated with morbidity and mortality. The geriatric syndromes include a wide variety of disease processes ranging from incontinence and dementia to impairments in physical function. This review will focus on one geriatric syndrome, sarcopenia, in older HIV-infected populations, and its relation to other aging syndromes, including frailty and falls. The contribution of HIV itself, ART exposure, and specific comorbidities, and the importance of early recognition and prevention of these aging syndromes will be highlighted.

Frailty and physical function in older HIV-infected adults

Background and Objectives

HIV patients have seen accelerated ageing. Our objective was to determine the prevalence of frailty, to evaluate factors associated with frailty and to evaluate physical function in older HIV-infected adults.

Design

this was a cross-sectional study.

Setting

outpatient clinics of two public university hospitals in Madrid (Spain).

Methods

frailty was defined according to the criteria of Fried: shrinking, weakness, poor endurance and energy, slowness and low physical activity level, being frail those who met at least three criteria, prefrail one or two criteria and robust when they met no criteria. Physical function was assessed using standardised methods.

Results

we evaluated 117 HIV-infected patients. Mean age was 61.3 ([standard deviation] 6.87) years. All patients were on antiretroviral therapy. Median current CD4+ T-cell count was 638 (144-1871) cells/μl, and median CD4/CD8 ratio was 0.79 (0.00-3.62). The prevalence of frailty was 15.4%, and that of prefrailty was 52.1%. In the multivariate analyses depressive symptoms (OR [95% CI], 9.20 [2.17-39.05]) and CD4/CD8 ratio (OR 0.11 [0.02-0.61]) were associated with frailty. Even though 100% of the patients were able to walk and perform basic activities of daily life independently, functional impairment was high (20% slow gait and 55% Short Physical Performance Battery ≤9).

Conclusions

HIV-infected patients aged ≥55 years have a high prevalence of frailty and a high burden of functional impairment. Optimal management of this population requires close collaboration between infectious diseases specialists and geriatricians.

Frailty and Circulating Markers of Inflammation in HIV+ and HIV- Men in the Multicenter AIDS Cohort Study

BACKGROUND

Frailty is associated with immune activation and inflammation in the elderly general population, but whether this is true in the younger HIV-infected (HIV+) population is not known.

METHODS

We analyzed 24 serologic biomarkers of monocyte, T-cell, or B-cell activation in HIV- (n = 207) and HIV+ (n = 714; 75% virologically suppressed) men who have sex with men in the Multicenter AIDS Cohort Study (MACS) and were classified as frail or nonfrail according to expression or nonexpression of the frailty phenotype at 2 consecutive study visits.

RESULTS

After correction for multiple comparisons and adjustment for age, race, study site, and education, frailty in HIV+ men was significantly (P < 0.002) associated with higher levels of sCD14, sIL2Rα, sTNF-R2, IL-6, and TNF-α; the association with higher levels of C-reactive protein (CRP) approached significance (P = 0.003). After further adjustment for body mass index (BMI), smoking, and comorbidities, only the association with C-reactive protein was significant at P < 0.002, with levels approximately 50% higher in frail compared with nonfrail men. These conclusions were not altered by restricting the analysis to HIV+ men who were virologically suppressed. Among HIV- men, none of these markers differed significantly by frailty.

CONCLUSIONS

These data suggest that frailty in virologically suppressed HIV+ men was associated with immune activation beyond that due to treated HIV infection. The inflammatory markers associated with frailty were primarily products of activated monocytes/macrophages. Much, but not all, activation was accounted for by harmful behaviors and comorbidities. However, C-reactive protein, which is regulated by IL-6, was elevated in HIV+ frail men independent of these factors.

The effect of cellular isolation and cryopreservation on the expression of markers identifying subsets of regulatory T cells

BACKGROUND

The role of CD4(+) regulatory T cells (Tregs) and their subsets during HIV infection is controversial. Cryopreserved peripheral blood mononuclear cells (PBMC) are an important source for assessing number and function of Tregs. However, it is unknown if PBMC isolation and cryopreservation affect the expression of CD120b and CD39, markers that identify specific subsets of Tregs.

METHODS

HIV-uninfected (HIV-) and -infected (HIV+) men were randomly selected from the Multicenter AIDS Cohort Study (MACS). Percentages of CD120b(+) and CD39(+) Tregs measured by flow cytometry in whole blood and in corresponding fresh and cryopreserved PBMC were compared.

RESULTS

Percentages of CD120b(+) Tregs were significantly lower in a) fresh PBMC relative to whole blood, and b) freshly thawed frozen PBMC relative to fresh PBMC when the recovery of viable cryopreserved cells was low. When present, low expression of CD120b in frozen PBMC was reversible by 4h of in vitro culture. In contrast, expression of CD39 on Tregs was not affected by isolation and/or cryopreservation of PBMC, or by relative recovery of cryopreserved PBMC. These findings were unaffected by the HIV status of the donor.

CONCLUSION

The data suggest that percentages of CD120b(+) Tregs and CD39(+) Tregs can be validly measured in either whole blood or PBMC (fresh and frozen) in HIV- and HIV+ men. However, for measurement of CD120b(+) Tregs one type of sample should be used consistently within a given study, and thawed frozen cells may require in vitro culture if recovery of viable cells is low.