Higher Veterans Aging Cohort Study (VACS) Index Scores in HIV-Positive Adults With CD4 counts <200 cells/mm3 Despite Viral Suppression

Strengths and Limitations of the Veterans Aging Cohort Study Index as a Measure of Physiologic Frailty

The Veterans Aging Cohort Study Index (VACS Index) is an index comprised of routine clinical laboratory tests that accurately and generalizably predicts all-cause mortality among those living with and without HIV infection. Increasing evidence supports its use as a measure of physiologic frailty among those aging with HIV because of its associations with frailty related outcomes including mortality, hospitalization, fragility fractures, serious falls, pneumonia, cognitive decline, delirium, and functional decline. In this review, we explore the evidence supporting the validity (construct, correlative, and predictive), responsiveness, and feasibility of the VACS Index as an early indicator of physiologic frailty. We also consider its limitations.

Albumin, white blood cell count, and body mass index improve discrimination of mortality in HIV-positive individuals

OBJECTIVE

Despite viral suppression and immune response on antiretroviral therapy, people with HIV infection experience excess mortality compared with uninfected individuals. The Veterans Aging Cohort Study (VACS) Index incorporates clinical biomarkers of general health with age, CD4 cell count, and HIV-1 RNA to discriminate mortality risk in a variety of HIV-positive populations. We asked whether additional biomarkers further enhance discrimination.

DESIGN AND METHODS

Using patients from VACS for development and from the Antiretroviral Therapy Cohort Collaboration (ART-CC) for validation, we obtained laboratory values from a randomly selected visit from 2000 to 2014, at least 1 year after antiretroviral therapy initiation. Patients were followed for 5-year, all-cause mortality through September 2016. We fitted Cox models with established predictors and added new predictors based on model fit and Harrell's c-statistic. We converted all variables to continuous functional forms and selected the best model (VACS Index 2.0) for validation in ART-CC patients. We compared discrimination using c-statistics and Kaplan-Meier plots.

RESULTS

Among 28 390 VACS patients and 12 109 ART-CC patients, 7293 and 722 died, respectively. Nadir CD4, CD8, and CD4 : CD8 ratio did not improve discrimination. Addition of albumin, white blood count, and BMI, improved c-statistics in VACS from 0.776 to 0.805 and in ART-CC from 0.800 to 0.831. Results were robust in all nine ART-CC cohorts, all lengths of follow-up and all subgroups.

CONCLUSION

VACS Index 2.0, adding albumin, white blood count, and BMI to version 1.0 and using continuous variables, provides improved discrimination and is highly transportable to external settings.

HIV-1 coreceptor tropism: A syllogistic connection with The Veterans Aging Cohort Study Index and the CD4/CD8 ratio

BACKGROUND

The association between X4 virus and an increased risk of non-AIDS-events has been reported. Morbidity/mortality due to non-AIDS events, which are properly predicted by the CD4/CD8 ratio and VACS index, have become particularly remarkable in HIV-infected patients receiving effective combined antiretroviral therapy (cART).

METHODS

We verified the validity of the syllogism: as HIV-tropism (CRT) contributes to the onset of non-AIDS events which are successfully predicted by the CD4/CD8 ratio and VACS index, then CRT correlates with these two variables. The CD4/CD8 ratio and VACS index at baseline and overtime were analyzed according to CRT tested before the first successful cART regimen in newly-diagnosed patients.

RESULTS

Patients with R5 variants had a significantly lower baseline VACS percentage risk [mean (95%CI):18.2%(16.1-20.3) vs 24.3%(18.2-22.5), p = 0.002] and higher baseline CD4/CD8 ratio [mean (95%CI):0.43 (0.38-0.47) vs 0.28 (0.19-0.36), p = 0.002] than non-R5 patients. After an initial drop, VACS increased again in R5 and non-R5 patients and the two trend curves almost overlapped. The CD4/CD8 ratio had an increasing trend in both R5 and non-R5 patients; however, even though non-R5 patients had a greater gain of CD4+, they maintained a lower CD4/CD8 ratio at any time point.

CONCLUSION

Our study confirms an association between pre-therapy CRT, CD4/CD8 ratio and VACS. A successful cART regimen positively affects the CD4/CD8 ratio; however, the disadvantage conferred by a non-R5 CRT is maintained overtime. The restoration of VACS in all patients could be directly due to variables included in the VACS calculation and to factors that adversely influence these variables.

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.

Frail and pre-frail phenotype is associated with pain in older HIV-infected patients

As HIV-infected patients grow older, some accumulate multiple health problems earlier than the noninfected ones in particular frailty phenotypes. Patients with frailty phenotype are at higher risk of adverse outcomes (worsening mobility, disability, hospitalization, and death within three years).Our study aimed to evaluate prevalence of frailty in elderly HIV-infected patients and to assess whether frailty is associated with HIV and geriatric factors, comorbidities, and precariousness in a French cohort of older HIV infected.This 18-month cross-sectional multicenter study carried in 2013 to 2014 had involved 502 HIV-infected patients aged 50 years and older, cared in 18 HIV-dedicated hospital medical units, located in South of France.Prevalence of frailty was 6.3% and of pre-frailty 57.2%. Low physical activity and weakness were the main frailty markers, respectively 49.4% and 19.9%. In univariate models, precariousness, duration of HIV antiretroviral treatment >15 years, 2 comorbidities or more, risk of depression, activities of daily living disability, and presence of pain were significantly associated with frail and pre-frail phenotype. Multivariate logistic regression analyses showed that only pain was significantly different between frail and pre frail phenotype versus non frail phenotype (odds ratio = 1.2; P = .002).Our study is the first showing a significant association between pain and frailty phenotype in older patients infected by HIV. As frailty phenotype could be potentially reversible, a better understanding of the underlying determinant is warranted. Further studies are needed to confirm these first findings.

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.

Short Communication: SCD14 and SCD163 Levels Are Correlated with VACS Index Scores: Initial Data from the Blunted Immune Recovery in CORE Patients with HIV (BIRCH) Cohort

The relationship between markers of monocyte/macrophage activation (sCD14 and sCD163) and components of the Veterans Aging Cohort Study (VACS) score, which predict mortality in patients with HIV, in immunologic nonresponders (INRs) is not defined. HIV(+) subjects with >12 months of continuous virologic suppression and persistent CD4 <250 cells/mm(3) were enrolled at the CORE Center, Chicago. Subjects had a single visit where history was taken and blood drawn. ELISA assays for sCD14 and sC163 were performed at Blood Systems, CA. Descriptive statistics were performed using SAS. We enrolled 43 subjects with persistent CD4 <250 after a median of 32 months of continuous viral suppression. We found elevated markers of monocyte/macrophage activation; sCD14 and sCD163 correlated with higher VACS scores as well as hepatitis C virus (HCV) coinfection and FIB-4 score, components of the VACS index. In this cohort of immunologic nonresponders, there was a significant correlation between markers of monocyte/macrophage activation and the VACS score. Among components of the VACS index, we did not find a significant association between HCV coinfection and sCD14; however, there was a significant association between HCV coinfection and sCD163.

Ageing with HIV: a multidisciplinary review

INTRODUCTION

After the introduction of highly active antiretroviral treatment, the course of HIV infection turned into a chronic disease and most of HIV-positive patients will soon be over 50 years old.

MATERIAL AND METHODS

This paper reviews the multiple aspects that physicians have to face while taking care of HIV-positive ageing patients including the definitions of frailty and the prevalence and risk factors of concomitant diseases. From a therapeutic point of view pharmacokinetic changes and antiretroviral-specific toxicities associated with ageing are discussed; finally therapeutic approaches to frailty are reviewed both in HIV-positive and negative patients.

CONCLUSION AND DISCUSSION

We conclude by suggesting that the combined use of drugs with the least toxicity potential and the promotion of healthy behaviours (including appropriate nutrition and exercise) might be the best practice for ageing HIV-positive subjects.

Biologic aging, frailty, and age-related disease in chronic HIV infection

PURPOSE OF REVIEW

Effective therapies have transformed HIV infection into a chronic disease, and new problems are arising related to aging. This article reviews the aging process, age-related deficit accumulation and frailty, and how these might be affected by chronic HIV infection.

RECENT FINDINGS

Aging is characterized by acceleration in the rate of unrepaired physiologic damage an organism accumulates. HIV infection is associated with many factors that might affect the aging process, including extrinsic behavioral risk factors and co-infections, and multiple intrinsic factors, including intercellular communication, inflammation, and coagulation pathways. Whether each factor affects the aging process, they likely result in an increase in the risk of adverse health outcomes, and so give rise to frailty, likely with several clinical manifestations.

SUMMARY

Age-related deficit accumulation is influenced by both the background or environmental rate of insults an organism sustains and the efficacy of intrinsic damage control and repair mechanisms. Both processes are likely affected in people living with HIV infection.

Frailty in people aging with human immunodeficiency virus (HIV) infection

The increasing life spans of people infected with human immunodeficiency virus (HIV) reflect enormous treatment successes and present new challenges related to aging. Even with suppression of viral loads and immune reconstitution, HIV-positive individuals exhibit excess vulnerability to multiple health problems that are not AIDS-defining. With the accumulation of multiple health problems, it is likely that many people aging with treated HIV infection may be identified as frail. Studies of frailty in people with HIV are currently limited but suggest that frailty might be feasible and useful as an integrative marker of multisystem vulnerability, for organizing care and for comprehensively measuring the impact of illness and treatment on overall health status. This review explains how frailty has been conceptualized and measured in the general population, critically reviews emerging data on frailty in people with HIV infection, and explores how the concept of frailty might inform HIV research and care.