Assessing immunophenotyping performance: proficiency-validation for adopting improved flow cytometry methods

Decreased but persistent epigenetic age acceleration is associated with changes in T-cell subsets after initiation of highly active antiretroviral therapy in persons living with HIV

Introduction

Persons living with HIV (PLWH) experience the early onset of age-related illnesses, even in the setting of successful human immunodeficiency virus (HIV) suppression with highly active antiretroviral therapy (HAART). HIV infection is associated with accelerated epigenetic aging as measured using DNA methylation (DNAm)-based estimates of biological age and of telomere length (TL).

Methods

DNAm levels (Infinium MethylationEPIC BeadChip) from peripheral blood mononuclear cells from 200 PLWH and 199 HIV-seronegative (SN) participants matched on chronologic age, hepatitis C virus, and time intervals were used to calculate epigenetic age acceleration, expressed as age-adjusted acceleration residuals from 4 epigenetic clocks [Horvath's pan-tissue age acceleration residual (AAR), extrinsic epigenetic age acceleration (EEAA), phenotypic epigenetic age acceleration (PEAA), and grim epigenetic age acceleration (GEAA)] plus age-adjusted DNAm-based TL (aaDNAmTL). Epigenetic age acceleration was compared for PLWH and SN participants at two visits: up to 1.5 years prior and 2-3 years after HAART (or equivalent visits). Flow cytometry was performed in PLWH and SN participants at both visits to evaluate T-cell subsets.

Results

Epigenetic age acceleration in PLWH decreased after the initiation of HAART but remained greater post-HAART than that in age-matched SN participants, with differences in medians of 6.6, 9.1, and 7.7 years for AAR, EEAA, and PEAA, respectively, and 0.39 units of aaDNAmTL shortening (all p < 0.001). Cumulative HIV viral load after HAART initiation was associated with some epigenetic acceleration (EEAA, PEAA, and aaDNAmTL), but even PLWH with undetectable HIV post-HAART showed persistent epigenetic age acceleration compared to SN participants (p < 0.001). AAR, EEAA, and aaDNAmTL showed significant associations with total, naïve, and senescent CD8 T-cell counts; the total CD4 T-cell counts were associated with AAR, EEAA, and PEAA (p = 0.04 to <0.001). In an epigenome-wide analysis using weighted gene co-methylation network analyses, 11 modules demonstrated significant DNAm differences pre- to post-HAART initiation. Of these, nine were previously identified as significantly different from pre- to post-HIV infection but in the opposite direction.

Discussion

In this large longitudinal study, we demonstrated that, although the magnitude of the difference decreases with HAART is associated with the cumulative viral load, PLWH are persistently epigenetically older than age-matched SN participants even after the successful initiation of HAART, and these changes are associated with changes in T-cell subsets.

Vision Problems As a Contributor to Lower Engagement in Care Among Aging Men Living with HIV

PURPOSE

To investigate vision impairment as a barrier to engagement in medical care among aging persons living with HIV (PLWH) who experience multimorbidity and complex care needs.

SETTING

Multicenter AIDS Cohort Study (MACS), a prospective observational cohort of aging PLWH men.

METHODS

We examined relationships of self-reported vision difficulty with indicators of care engagement: 1) adherence to HIV antiretroviral therapy (ART; defined as taking ≥95% of medications); 2) self-reported avoidance of medical care; 3) self-reported tendency to ask a doctor questions about care (>2 questions at a medical visit), as well as with quality of life. A modified version of the National Eye Institute Vision Function Questionnaire was administered at three semi-annual visits (from October 2017 to March 2019) to assess difficulty performing vision-dependent tasks.

RESULTS

We included 1063 PLWH (median age 57 years, 31% Black). Data on care engagement outcomes were analyzed using repeated measures logistic regression with generalized estimating equations adjusted for race, and at visit values for age, education level, depressive symptoms, alcohol use, and smoking status. Compared to no vision difficulty, those reporting moderate to extreme vision difficulty on at least one task had 2.2 times higher odds (95% CI: 1.4, 3.4) of having less than optimal ART adherence, 1.9 times higher odds (95% CI: 1.1, 3.4) of avoiding necessary medical care and median quality of life scores 8 points lower.

CONCLUSION

These findings suggest vision impairment decreases medical care engagement including HIV care and quality of life among aging PLWH.

Shorter total sleep time is associated with lower CD4+/CD8+ T cell ratios in virally suppressed men with HIV

Study Objectives

Although poor sleep quality is associated with lower CD4+ T cell counts among people living with HIV (PLWH), the association between objective sleep metrics and T lymphocyte subset counts is unknown. We evaluated the association between polysomnography (PSG) derived sleep metrics and T lymphocyte subpopulations in a cohort of men living with HIV.

Methods

Virally suppressed men living with HIV participating in the Multicenter AIDS Cohort Study underwent home overnight PSG. We assessed the association of PSG parameters with CD4+ and CD8+ T cell counts and the CD4+/CD8+ T cell ratio.

Results

Overall, 289 men with mean (±SD) age 55.3 ± 11.3 years and mean CD4+ T cell count 730 ± 308 cells/mm3 were evaluated. Total sleep time (TST) was significantly associated with CD8+ but not CD4+ T cell counts. After adjusting for age, race, depressive symptoms, antidepressant use, and non-nucleoside reverse transcriptase inhibitors use, every hour of shorter TST was associated with an additional 33 circulating CD8+ T cells/mm3 (p = 0.05) and a 5.6% (p = 0.0007) decline in CD4+/CD8+ T cell ratio. In adjusted models, every hour of shorter rapid eye movement (REM) sleep was associated with an additional 113 CD8+ T cells/mm3 (p = 0.02) and a 15.1% lower CD4+/CD8+ T cell ratio (p = 0.006). In contrast, measures of sleep efficiency and sleep-disordered breathing were not associated with differences in T lymphocyte subpopulations.

Conclusions

Our findings suggest that shorter TST and REM sleep durations are associated with differences in T lymphocyte subpopulations among men living with HIV. Addressing sleep may reflect a novel opportunity to improve immune function in PLWH.

Accelerated aging with HIV begins at the time of initial HIV infection

Living with HIV infection is associated with early onset of aging-related chronic conditions, sometimes described as accelerated aging. Epigenetic DNA methylation patterns can evaluate acceleration of biological age relative to chronological age. The impact of initial HIV infection on five epigenetic measures of aging was examined before and approximately 3 years after HIV infection in the same individuals (n=102). Significant epigenetic age acceleration (median 1.9-4.8 years) and estimated telomere length shortening (all p≤ 0.001) were observed from pre-to post-HIV infection, and remained significant in three epigenetic measures after controlling for T cell changes. No acceleration was seen in age- and time interval-matched HIV-uninfected controls. Changes in genome-wide co-methylation clusters were also significantly associated with initial HIV infection (p≤ 2.0 × 10^-4). These longitudinal observations clearly demonstrate an early and substantial impact of HIV infection on the epigenetic aging process, and suggest a role for HIV itself in the earlier onset of clinical aging.

Prevalence and Consequences of Perceived Vision Difficulty in Aging Adults with HIV Infection

PURPOSE

Despite well-known ocular complications of HIV-related immune suppression, few studies have examined the prevalence and consequences of visual impairment among aging long-term survivors of HIV.

DESIGN

Retrospective cohort study.

METHODS

Aging HIV-infected (HIV+) men who have sex with men (MSM) and HIV-uninfected (HIV-) MSM controls reported their difficulty performing 6 vision-dependent tasks (difficulty defined as: no, a little, moderate, and extreme difficulty). Relationships were examined using logistic regression, regressing each outcome separately on categorical visual function responses, with missing data multiply imputed.

RESULTS

There were 634 age-matched pairs for a total sample of 1,268 MSM of 1,700 MSM with available data. The median age was 60 years old (interquartile range [IQR], 54, 66), and 23% were African American. Among HIV+ men, 95% were virally suppressed (viral load <400 copies/mL). HIV+ men were more likely to report moderate or extreme difficulty performing at least 1 task (21% for HIV+ compared to 13% for HIV-; P < .01). Participants reporting extreme vision-related difficulty performing at least 1 task had 11.2 times the odds of frailty (95% confidence interval [CI], 5.2-23.9), 2.6 times the odds of a slow gait speed (95% CI, 1.4-4.8), and 3.2 times the odds of impaired instrumental activities of daily living (95% CI: 1.6-6.3) compared to those reporting no vision-related difficulty on any task.

CONCLUSIONS

Perceived vision difficulty was more common among older HIV+ MSM than age-matched HIV- MSM controls and was associated with higher risk of depression and physical function loss among MSM.

Marijuana use and pneumonia risk in a cohort of HIV-infected and HIV-uninfected men

BACKGROUND

The prevalence of marijuana use is increasing in the United States. Marijuana smoking has been shown to impair the microbicidal activity of alveolar macrophages and decrease the number of ciliated epithelial cells in the bronchi with a parallel increase in the number of mucus-secreting surface epithelial cells, which may increase the risk of pneumonia. However, it remains unclear whether there is an association between smoking marijuana and pneumonia.

METHODS

Using data from the Multicenter AIDS Cohort Study (MACS), a long-term observational cohort study of men who have sex with men in the United States, we used Cox proportional hazards models to estimate the risk of pneumonia among HIV-infected (n = 2784) and HIV-uninfected (n = 2665) men from 1984 to 2013, adjusted for time-varying and fixed baseline covariates.

RESULTS

Weekly or daily marijuana use was not significantly associated with increased risk of pneumonia among HIV-uninfected men (adjusted hazard ratio; 95% confidence limits: 0.83, 0.56-1.23). In the disaggregated dose-response analysis, daily use (0.68, 0.34-1.35) was associated with a lower point estimate than weekly use [0.99, 0.79-1.25].

CONCLUSION

Marijuana smoking was not associated with a significant increase in risk of pneumonia among HIV-infected or HIV-uninfected men.

Multicentre Harmonisation of a Six-Colour Flow Cytometry Panel for Naïve/Memory T Cell Immunomonitoring

Background

Personalised medicine in oncology needs standardised immunological assays. Flow cytometry (FCM) methods represent an essential tool for immunomonitoring, and their harmonisation is crucial to obtain comparable data in multicentre clinical trials. The objective of this study was to design a harmonisation workflow able to address the most effective issues contributing to intra- and interoperator variabilities in a multicentre project.

Methods

The Italian National Institute of Health (Istituto Superiore di Sanità, ISS) managed a multiparametric flow cytometric panel harmonisation among thirteen operators belonging to five clinical and research centres of Lazio region (Italy). The panel was based on a backbone mixture of dried antibodies (anti-CD3, anti-CD4, anti-CD8, anti-CD45RA, and anti-CCR7) to detect naïve/memory T cells, recognised as potential prognostic/predictive immunological biomarkers in cancer immunotherapies. The coordinating centre distributed frozen peripheral blood mononuclear cells (PBMCs) and fresh whole blood (WB) samples from healthy donors, reagents, and Standard Operating Procedures (SOPs) to participants who performed experiments by their own equipment, in order to mimic a real-life scenario. Operators returned raw and locally analysed data to ISS for central analysis and statistical elaboration.

Results

Harmonised and reproducible results were obtained by sharing experimental set-up and procedures along with centralising data analysis, leading to a reduction of cross-centre variability for naïve/memory subset frequencies particularly in the whole blood setting.

Conclusion

Our experimental and analytical working process proved to be suitable for the harmonisation of FCM assays in a multicentre setting, where high-quality data are required to evaluate potential immunological markers, which may contribute to select better therapeutic options.

Relationship Between T-Cell Responses to CMV, Markers of Inflammation, and Frailty in HIV-uninfected and HIV-infected Men in the Multicenter AIDS Cohort Study

Background

Both aging and treated human immunodeficiency virus (HIV)-infected populations exhibit low-level chronic immune activation of unknown etiology, which correlates with morbidity and mortality. Cytomegalovirus (CMV) infection is common in both populations, but its relation to immune activation is unknown.

Methods

T cells from men who have sex with men (22 virologically suppressed HIV+, 20 HIV-) were stimulated with peptides spanning 19 CMV open reading frames, and intracellular cytokine responses were assessed. Soluble and cellular inflammatory markers were assessed by multiplex electrochemiluminescence and flow cytometry, respectively. Frailty was assessed by the Fried criteria.

Results

All men had responses to CMV. Proportions of CMV-responsive T cells correlated strongly (r ≥ 0.6 or ≤ -0.6; P < .05) with immunologic markers, depending on donor HIV and frailty status. Markers significantly correlated in some groups after adjustment for multiple comparisons included interferon-γ, tumor necrosis factor-α, interleukin-6, and several chemokines in serum, and the proportion of activated T cells. The magnitude of the CD4 IL-2 response significantly predicted onset of frailty in HIV- nonfrail men, but not in HIV+ nonfrail men.

Conclusions

T-cell responses to CMV may strongly influence chronic immune activation in HIV-uninfected and virologically suppressed HIV-infected men, and may predict frailty in HIV-uninfected men.

Vitamin D Metabolites in Aging HIV-Infected Men: Does Inflammation Play a Role?

The inflammatory context of HIV infection has been posited to contribute to the higher comorbidity risk noted in HIV-infected populations. One possible pathway may involve 1,25-dihydroxyvitamin D [1,25(OH)2D], which plays a wide biologic role in many tissues. We sought to investigate whether inflammation was associated with vitamin D metabolites in a cohort of HIV-infected (HIV+) men receiving treatment and HIV-uninfected (HIV-) men. Vitamin D metabolites, including 25-hydroxyvitamin D [25(OH)D] and 1,25(OH)2D, were measured along with 24 inflammatory markers among Multicenter AIDS Cohort Study participants. Exploratory factor analysis reduced inflammatory marker data to a smaller set of inflammatory processes (IPs). Multivariate linear regression was used to evaluate associations between vitamin D metabolites and IPs. There were 466 HIV+ and 100 HIV- men, who contributed 658 stored samples from 1998 to 2008. We found three IPs with IP 1 characterized by sTNF-R2, sIL-2Rα, sCD27, BAFF, sgp130, sCD14, CXCL10 (IP-10), and sIL-6R. While none of the three IPs was associated with 25(OH)D levels in either HIV+ or HIV-, higher levels of IP 1 were significantly associated with the reduced levels of 1,25(OH)2D in HIV+, and a similar although nonsignificant trend was seen in HIV-. The association between 1,25(OH)2D and inflammation found among HIV-infected men suggests a possible mechanism whereby inflammation leads to the increased comorbidity risk noted among HIV-infected individuals.

Metabolic health across the BMI spectrum in HIV-infected and HIV-uninfected men

OBJECTIVES

In the general population, metabolic health often declines as BMI increases. However, some obese individuals maintain metabolic health. HIV and antiretroviral therapy have been associated with metabolic disturbances. We hypothesized that HIV-infected (HIV) men on suppressive antiretroviral therapy experience less metabolic health than HIV-uninfected (HIV) men across all BMI categories.

DESIGN/METHODS

In a cross-sectional analysis of 1018 HIV and 1092 HIV men enrolled in the multicenter AIDS cohort study, Poisson regression with robust variance determined associations between HIV serostatus and metabolic health prevalence (defined as meeting ≤2 of 5 National Cholesterol Education Program Adult Treatment Panel III metabolic syndrome criteria), adjusting for age, race, BMI category, smoking, and hepatitis C virus infection status.

RESULTS

HIV men were younger (54 vs. 59 years) and had lower median BMI (25 vs. 27 kg/m). Nonobese HIV men had lower metabolic health prevalence than HIV men (BMI ≤25 kg/m: 80 vs. 94%, P < 0.001; BMI 25-29 kg/m: 64 vs. 71%, P = 0.05), but metabolic health prevalence among obese men did not differ by HIV serostatus (BMI 30-34 kg/m: 35 vs. 39%, P = 0.48; BMI ≥35 kg/m: 27 vs. 25%, P = 0.79). In the adjusted model, nonobese HIV men were less likely to demonstrate metabolic health than nonobese HIV men. Among HIV men, per year darunavir, zidovudine, and stavudine use were associated with lower metabolic health likelihood.

CONCLUSION

Metabolically healthy obesity prevalence does not differ by HIV serostatus. However, among nonobese men, HIV infection is associated with lower metabolic health prevalence, with associations between lack of metabolic health and darunavir and thymidine analog nucleoside reverse transcriptase inhibitor exposure observed.

Vitamin D Deficiency and Metabolism in HIV-Infected and HIV-Uninfected Men in the Multicenter AIDS Cohort Study

We evaluated associations of serum 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) levels in a cohort of HIV-infected and HIV-uninfected men at risk for infection in the United States. Stored samples collected between 1999 and 2008 were tested for vitamin D metabolites between 2014 and 2015. Vitamin D deficiency was defined as a serum concentration of 25[OH]D <20 ng/ml. Multivariate models were used to assess associations of various demographic and clinical factors with vitamin D status. HIV-infected men on effective antiretroviral therapy (n = 640) and HIV-uninfected men (n = 99) had comparable levels of 25[OH]D and 1,25[OH]2D, and prevalences of vitamin D deficiency were 41% in HIV-infected and 44% in HIV-uninfected men, respectively. Self-reported black or other non-white race, obesity, and normal kidney function were significant predictors of vitamin D deficiency regardless of HIV serostatus. Lower CD4+ T cell count was associated with vitamin D deficiency in HIV-infected men, while current ritonavir use was protective. Self-reported black race was the only factor significantly associated with higher levels of 1,25[OH]2D (vs. whites; β = 4.85 pg/ml, p = .003). Levels of 1,25[OH]2D and 25[OH]D were positively correlated in HIV-infected men (β = 0.32 pg/ml, p < .001), but not in uninfected men (β = -0.09 pg/ml, p = .623; p < .05 for interaction). Vitamin D deficiency was prevalent regardless of HIV serostatus in this cohort, suggesting that HIV infection did not confer additional risk of deficiency in this cohort of well-treated HIV-infected men. However, HIV infection and race may have implications for vitamin D metabolism and 1,25[OH]2D levels.

Inflammation, Immune Activation, Immunosenescence, and Hormonal Biomarkers in the Frailty-Related Phenotype of Men With or at Risk for HIV Infection

Background

The extent to which inflammation, immune activation/immunosenescence, and hormonal abnormalities are driven by human immunodeficiency virus (HIV) or frailty is not clear.

Methods

HIV-infected frail men (n = 155) were matched to nonfrail, HIV-infected (n = 141) and HIV-uninfected (n = 150) men by age, calendar year, and antiretroviral therapy use (HIV-infected men only). Frailty was defined by ≥3 frailty-related phenotype criteria (weight loss, exhaustion, low activity, slowness) at ≥2 visits, or at 1 visit with ≥1 criteria at ≥2 visits. The following measurements were obtained: interleukin 6, high-sensitivity C-reactive protein, soluble receptors for tumor necrosis factor α 1 and 2, the percentages of CD4+CD28-, CD8+CD28-, CD4+CD38+HLA-DR+, and CD8+CD38+HLA-DR+ T cells, dehydroepiandrosterone sulfate, free testosterone, homeostatic model assessment of insulin resistance, and insulin-like growth factor 1. Log-linear regressions were adjusted for a priori selected covariates to determine differences by frailty and HIV status.

Results

In multivariate analyses adjusted for covariates, frailty was associated among HIV-infected men with higher interleukin 6 and high-sensitivity C-reactive protein and lower free testosterone and dehydroepiandrosterone levels. In contrast, HIV infection but not frailty was associated with significantly greater immune senescence (percentage of CD4+CD28- or CD8+CD28- T cells) and immune activation (percentages of CD4+CD38+HLA-DR+ and CD8+CD38+HLA-DR+ T cells).

Conclusions

Frailty among HIV-infected men was associated with increased inflammation and lower hormone levels, independent of comorbid conditions. Interventions targeting these pathways should be evaluated to determine the impact on prevention or reversal of frailty among HIV-infected men.

Glomerular filtration rate and proteinuria associations with coronary artery calcium among HIV-infected and HIV-uninfected men in the Multicenter AIDS Cohort Study

BACKGROUND

Decreased kidney function and greater albuminuria are associated with increased incidence and extent of coronary artery calcium (CAC). We investigated whether the associations between kidney function and urine protein-to-creatinine ratio (UPCR) with CAC differ by HIV serostatus.

METHODS

Using data from the Multicenter AIDS Cohort Study, a prospective multicenter US study of men who have sex with men, we carried out a cross-sectional study comprised of 592 HIV-infected (HIV+) and 378 uninfected (HIV-) men who underwent noncontrast computed tomography to measure CAC. Logistic and linear regression models were used to determine whether HIV infection modified associations of estimated glomerular filtration rate and UPCR with the presence and extent of CAC, adjusting for age, race, and cardiovascular risk factors.

RESULTS

Every 10 U decrease in estimated glomerular filtration rate below 90 ml/min/1.73 m was significantly associated with 1.3-fold [95% confidence interval (CI): 1.06-1.51] higher odds of CAC presence and was similar by HIV serostatus (Pinteraction=0.37). Greater UPCR was associated with more extensive CAC, with a change in log CAC score of 0.32 (95% CI: 0.10-0.55) per 1% increase in UPCR. There was a strong trend for effect modification by HIV serostatus for this association [HIV-: 0.75 (95% CI: 0.26-1.25); HIV+: 0.22 (95% CI: -0.03 to 0.47), Pinteraction=0.06].

CONCLUSION

Greater CAC burden is apparent among individuals with early kidney disease, irrespective of HIV serostatus. Increased UPCR is associated with a greater extent of CAC with a trend for differences by HIV serostatus; a clearer proteinuria/CAC extent relationship was apparent among HIV- patients.

Visceral fat is associated with brain structure independent of human immunodeficiency virus infection status

The combined effects of human immunodeficiency virus (HIV), obesity, and elevated visceral adipose tissue (VAT) on brain structure are unknown. In a cross-sectional analysis of Multicenter AIDS Cohort Study (MACS) participants, we determined associations between HIV serostatus, adiposity, and brain structure. Men (133 HIV+, 84 HIV-) in the MACS Cardiovascular 2 and magnetic resonance imaging (MRI) sub-studies with CT-quantified VAT and whole brain MRI measured within 1 year were assessed. Voxel-based morphometry analyzed brain volumes. Men were stratified by elevated (eVAT, ≥100cm²) or "normal" (nVAT, <100cm²) VAT. Forward stepwise modeling determined associations between clinical and demographic variables and regional brain volumes. eVAT was present in 67% of men. Groups were similar in age and education, but eVAT men were more likely to be HIV+ and have hypertension, diabetes mellitus, body mass index >25 kg/m², smaller gray and white matter volumes, and larger cerebrospinal fluid volume than nVAT men. In multivariate analysis, hypertension, higher adiponectin, higher interleukin-6, age, diabetes mellitus, higher body mass index, and eVAT were associated with brain atrophy (p < 0.05, ordered by increasing strength of association), but HIV serostatus and related factors were generally not. No interactions were observed. Greater VAT was associated with smaller bilateral posterior hippocampus and left mesial temporal lobe and temporal stem white matter volume. Traditional risk factors are more strongly associated with brain atrophy than HIV serostatus, with VAT having the strongest association. However, HIV+ MACS men had disproportionately greater VAT, suggesting the risk for central nervous system effects may be amplified in this population.

Effect of HIV-infection and cumulative viral load on age-related decline in grip strength

OBJECTIVE

Grip strength predicts functional decline and death, and is regarded as a biomarker of biological aging. The primary objective of this manuscript was to assess differences in the rate of decline in grip strength in persons aging with and without HIV.

DESIGN

Grip strength was assessed in 1552 (716 HIV+ and 836 HIV-) men aged at least 50 years participating in the Multicenter AIDS Cohort Study between 2007 and 2014.

METHODS

Grip strength decline was modeled longitudinally, adjusting for serostatus, demographics, comorbidities, and conditions. In HIV-specific models, coefficients were included for cumulative viral load and history of AIDS.

RESULTS

Grip strength at the age of 50 years averaged 37.9 and 38.2 kg for HIV+ and HIV- men, respectively (P = 0.70). In fully adjusted models, grip strength declined 0.33 kg/year in HIV- men (P < 0.001) and 0.42 kg/year in HIV+ men (P = 0.01). In HIV-stratified models, higher cumulative viral load indicated greater strength decline (-0.884 kg for 3.1-4.0 log10 copies-years/ml and -1.077 kg for ≥4.1 log10 copies-years/ml) relative to men with consistently low viral load (≤3.0 log10 copies-years/ml). Adjusted Cox proportional hazard models revealed a 70% greater risk of clinically weak grip strength in HIV+ men (adjusted hazard ratio 1.70; 95% confidence interval, 1.22-2.40).

CONCLUSION

Grip strength decline is accelerated in HIV-infected men, which may contribute to decreased life expectancy and lower quality of life with aging. Greater cumulative viral load exposure appears to be an important driver of this decline and underscores the importance of early initiation of therapy.

Speech audiometry findings from HIV+ and HIV- adults in the MACS and WIHS longitudinal cohort studies

The purpose of this study was to compare various speech audiometry measures between HIV+ and HIV- adults and to further evaluate the association between speech audiometry and HIV disease variables in HIV+ adults only. Three hundred ninety-six adults from the Multicenter AIDS Cohort Study (MACS) and Women's Interagency HIV Study (WIHS) completed speech audiometry testing. There were 262 men, of whom 117 (44.7%) were HIV+, and 134 women, of whom 105 (78.4%) were HIV+. Speech audiometry was conducted as part of the standard clinical audiological evaluation that included otoscopy, tympanometry, and pure-tone air- and bone-conduction thresholds. Specific speech audiometry measures included speech recognition thresholds (SRT) and word recognition scores in quiet presented at 40dB sensation level (SL) in reference to the SRT. SRT data were categorized in 5-dB steps from 0 to 25dB hearing level (HL) with one category as ≥30dB HL while word recognition scores were categorized as <90%, 90-99%, and 100%. A generalized estimating equations model was used to evaluate the association between HIV status and both ordinal outcomes. The SRT distributions across HIV+ and HIV- adults were similar. HIV+ and HIV- adults had a similar percentages of word recognition scores <90%, a lower percentage of HIV- adults had 90-99%, but HIV- adults had a higher percentage of 100%. After adjusting for covariables, HIV+ adults were borderline significantly more likely to have a higher SRT than HIV- adults (odds ratio [OR]=1.45, p=0.06). Among HIV+ adults, HIV-related variables (i.e., CD4+ T-cell counts, HIV viral load, and ever history of clinical AIDS) were not significantly associated with either SRT or word recognition score data. There was, however, a ceiling effect for word recognition scores, probably the result of obtaining this measure in quiet with a relatively high presentation level. A more complex listening task, such as speech-in-noise testing, may be a more clinically informative test to evaluate the effects of HIV on speech communication.

Inflammatory Biomarkers and Mortality Risk Among HIV-Suppressed Men: A Multisite Prospective Cohort Study

BACKGROUND

Human immunodeficiency virus (HIV)-induced inflammation and immune activation persist after initiation of combination antiretroviral therapy (cART) and HIV suppression and may contribute to mortality risks that exceed those in HIV-uninfected populations, though associations are unclear.

METHODS

In the prospective Multicenter AIDS Cohort Study, comprising men who have sex with men from Baltimore, Chicago, Los Angeles, and Pittsburgh, concentrations of 24 biomarkers of inflammation and immune activation were measured in stored serum from HIV-positive men obtained after cART-induced HIV suppression between 1996 and 2009. The outcome was nonaccidental death, with follow-up until 2014. We used Cox proportional hazards models to test whether biomarker concentrations predict time from HIV suppression to death and adjusted for multiple tests. Exploratory factor analysis (EFA) was employed to identify groupings of biomarkers that predict mortality risk.

RESULTS

Of 670 men followed up from HIV suppression, 54 died by the end of 2013. After adjustment for age, CD4(+) cell count, hepatitis B or C virus infection, and smoking, concentrations in the highest quartile of 4 biomarkers were significantly associated with mortality risk after controlling the false discovery rate at 5%: interleukin (IL) 6 (hazard ratio, 3.54; 95% confidence interval, 2.06-6.10), soluble IL 2Rα (3.29, 1.85-5.85), soluble CD14 (2.67, 1.55-4.61), and chemokine (CXC motif) ligand 13 (CXCL13; 2.26; 1.29-3.95). EFA yielded 2 biomarker groupings that were independent predictors of mortality risk.

CONCLUSIONS

Despite having undetectable HIV RNA levels during cART, men with higher concentrations of several biomarkers (particularly IL 6, soluble IL 2Rα, soluble CD14, and CXCL13) had higher hazards of long-term mortality. Correlations observed among biomarker concentrations may represent underlying inflammatory processes that contribute to mortality risk.

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.

Long-term impact of HIV wasting on physical function

BACKGROUND

The long-term consequences of wasting among HIV-infected persons are not known.

DESIGN

HIV-infected men surviving ≥2 years based on Kaplan-Meier analysis after a clinical diagnosis or weight trajectory consistent with wasting and with available physical function assessment data [grip strength, gait speed, and quality of life (QoL)] were matched to HIV-infected and uninfected men without wasting.

METHODS

Matching criteria at the functional assessment included age, calendar year, and CD4 T-cell count and plasma HIV-1 RNA (HIV-infected only). Multivariable linear regression analyses adjusted for age, cohort, race, hepatitis C status, and number of comorbid illnesses were used to assess the impact of wasting on subsequent physical function.

RESULTS

Among 85 HIV-infected men surviving ≥2 years after wasting, we evaluated physical function outcomes compared with 249 HIV-infected and 338 HIV-uninfected men with no historical wasting. In multivariable regression models, HIV-infected men with prior wasting had lower grip strength and poorer physical QoL than HIV-infected men with no wasting (P ≤ 0.03), and poorer physical QoL, but higher mental QoL than HIV-uninfected men (P ≤ 0.05). When controlling for measures of immune suppression (nadir CD4 T-cell count/AIDS, the association between wasting and physical QoL was markedly attenuated, whereas there was minimal impact on the association between wasting and grip strength.

CONCLUSIONS

HIV-infected wasting survivors had weaker grip strength compared with HIV-infected persons without wasting; immune suppression was associated only with physical QoL. HIV-infected survivors of wasting may represent a population of adults at increased risk for physical function decline.

Associations between Tobacco, Alcohol, and Drug Use with Coronary Artery Plaque among HIV-Infected and Uninfected Men in the Multicenter AIDS Cohort Study

BACKGROUND

We characterized associations between smoking, alcohol, and recreational drug use and coronary plaque by HIV serostatus within the Multicenter AIDS Cohort Study (MACS).

METHODS

MACS participants (N = 1005, 621 HIV+ and 384 HIV-) underwent non-contrast CT scanning to measure coronary artery calcium; 764 underwent coronary CT angiograms to evaluate plaque type and extent. Self-reported use of alcohol, tobacco, smoked/inhaled cocaine, methamphetamine, ecstasy, marijuana, inhaled nitrites, and erectile dysfunction drugs was obtained at semi-annual visits beginning 10 years prior to CT scanning. Multivariable logistic and linear regression models were performed, stratified by HIV serostatus.

RESULTS

Among HIV+ men, current smoking, former smoking, and cumulative pack years of smoking were positively associated with multiple coronary plaque measures (coronary artery calcium presence and extent, total plaque presence and extent, calcified plaque presence, and stenosis >50%). Smoking was significantly associated with fewer plaque measures of comparable effect size among HIV- men; current smoking and calcified plaque extent was the only such association. Heavy alcohol use (>14 drinks/week) was associated with stenosis >50% among HIV+ men. Among HIV- men, low/moderate (1-14 drinks/week) and heavy alcohol use were inversely associated with coronary artery calcium and calcified plaque extent. Few significant associations between other recreational drug use and plaque measures were observed.

CONCLUSION

Smoking is strongly associated with coronary plaque among HIV+ men, underscoring the value of smoking cessation for HIV+ persons. Alcohol use may protect against coronary artery calcium and calcified plaque progression in HIV- (but not HIV+) men. Few positive associations were observed between recreational drug use and coronary plaque measures.

Accelerated Longitudinal Gait Speed Decline in HIV-Infected Older Men

BACKGROUND

Gait speed predicts functional decline, disability, and death and is considered a biomarker of biological aging. Changes in gait speed in persons aging with HIV may provide an important method of gauging health and longevity in an under assessed population. The objective of this study was to evaluate and quantify the rate of gait speed decline in HIV-infected (HIV⁺) men compared with HIV-uninfected (HIV⁻) men.

METHODS

The study was nested in the Multicenter AIDS Cohort Study. The primary outcome was usual gait speed in meters per second measured between 2007 and 2013. Differences in the rate of gait speed decline and the incidence of clinically slow gait (<1.0 m/s) were assessed using multivariate linear regression models and Cox proportional hazards models, respectively.

RESULTS

A total of 2025 men (973 HIV⁺ and 1052 HIV⁻) aged 40 years and older contributed 21,187 person-visits (9955 HIV⁺ and 11,232 HIV⁻) to the analysis. Average gait speeds at the age 50 years were 1.24 and 1.19 m/s in HIV⁻ and HIV⁺ men, respectively (P < 0.001). In fully adjusted models, gait speed decline averaged 0.009 m/s per year after age 50 years (P < 0.001); this decline was 0.025 m/s per year greater in HIV⁺ men (P < 0.001). Moreover, HIV⁺ men had a 57% greater risk of developing clinically slow gait (adjusted hazard ratio = 1.57, 95% confidence interval: 1.27 to 1.91).

CONCLUSIONS

These findings indicate a faster rate of functional decline in HIV-infected men, suggesting greater risks of disability and death with advancing age.

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

BACKGROUND

Both HIV infection and frailty have been associated with chronic immune activation. One possible explanation for this chronic immune activation could be low levels of CD4(+) T regulatory cells (Tregs), which suppress immune responses.

METHODS

HIV-uninfected (HIV-) and HIV-infected (HIV+) men in the Multicenter AIDS Cohort Study (MACS) were classified as frail (or nonfrail) if they expressed (or did not express) the Fried frailty phenotype at two consecutive study visits. Percentages and absolute numbers of total Tregs, and percentages of different subsets of Tregs and of activated T cells were measured by flow cytometry. The function of Tregs was measured by suppression of T-cell proliferation.

RESULTS

Percentages of Tregs were higher, rather than lower, in frail men than in nonfrail men, and this difference was significant for HIV- men. Percentages of subsets of Tregs did not differ significantly by frailty status. Among HIV+ men, the suppressive function of Tregs was similar between frail and nonfrail men. Percentages of Tregs and activated T cells were negatively correlated in nonfrail men (HIV- and HIV+) and in frail HIV- men, but this correlation was strongly positive in frail HIV+ men.

CONCLUSION

These data suggest that: (a) Tregs were not deficient in frail men; and (b) the immunological pathophysiology of frailty may differ by HIV status.

Adiponectin and interleukin-6, but not adipose tissue, are associated with worse neurocognitive function in HIV-infected men

BACKGROUND

Generalized obesity has been associated with cognitive decline, a process potentially mediated by adipocytokines. The effects of regional adipose tissue (AT) on cognition, however, are not well understood. We explored cross-sectional relationships between regional AT, adipocytokines, inflammatory markers and neuropsychological (NP) test scores among HIV+ and HIV- men enrolled in the Multicenter AIDS Cohort Study.

METHODS

Visceral, subcutaneous abdominal and subcutaneous thigh AT areas were quantified by computed tomography (CT). NP tests (Trail Making Test parts A and B, and Symbol-Digit Modalities) obtained within 2 years of CT screened for psychomotor speed and executive function. Adiponectin, leptin, interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) were measured.

RESULTS

Of 509 HIV+ and 271 HIV- participants, HIV+ men (98% on antiretroviral therapy, 81% HIV-1 RNA<50 copies/ml) had lower median subcutaneous AT and adiponectin levels and higher hs-CRP levels, but visceral AT, body mass index, IL-6 and NP scores did not vary by HIV serostatus. In multivariable analysis, older age, ≤ high school education and African American race, but not AT area or site, were associated with worse NP test scores among all participants. In HIV+ only, higher adiponectin and IL-6 were associated with worse cognitive function independent of AT area. No HIV-specific factors were associated with NP test scores.

CONCLUSIONS

Demographic factors were associated with NP test performance, but regional adiposity was not. In HIV+ only, higher adiponectin and IL-6 were associated with worse NP test scores, supporting a role for chronic inflammation and adipocytokine imbalance in neurocognitive decline in HIV+ persons.

Kidney Dysfunction and Markers of Inflammation in the Multicenter AIDS Cohort Study

BACKGROUND

Human immunodeficiency virus (HIV)-infected individuals are at higher risk for chronic kidney disease than HIV-uninfected individuals. We investigated whether the inflammation present in treated HIV infection contributes to kidney dysfunction among HIV-infected men receiving highly active antiretroviral therapy.

METHODS

The glomerular filtration rate (GFR) was directly measured (using iohexol) along with 12 markers of inflammation in Multicenter AIDS Cohort Study participants. Exploratory factor analysis was used to identify inflammatory processes related to kidney dysfunction. The estimated levels of these inflammatory processes were used in adjusted logistic regression analyses evaluating cross-sectional associations with kidney function outcomes.

RESULTS

There were 434 HIV-infected men receiving highly active antiretroviral therapy and 200 HIV-uninfected men. HIV-infected men were younger (median age, 51 vs 53 years) and had higher urine protein-creatinine ratios (median, 98 vs 66 mg/g) but comparable GFRs (median, 109 vs 106 mL/min|1.73 m(2)). We found an inflammatory process dominated by markers: soluble tumor necrosis factor receptor 2, soluble interleukin 2 receptor α, soluble gp130, soluble CD27, and soluble CD14. An increase of 1 standard deviation in that inflammatory process was associated with significantly greater odds of GFR ≤90 mL/min/1.73 m(2) (odds ratio, 2.0) and urine protein >200 mg/g (odds ratio, 2.3).

CONCLUSIONS

Higher circulating levels of immune activation markers among treated HIV-infected men may partially explain their higher burden of kidney dysfunction compared with uninfected men.

Hearing loss among HIV-seropositive and HIV-seronegative men and women

IMPORTANCE

Age-related hearing loss affects quality of life. Data on hearing loss among aging human immunodeficiency virus-seropositive (HIV+) adults are limited.

OBJECTIVE

To evaluate pure-tone hearing thresholds among HIV+ and HIV-seronegative (HIV-) adults and to determine whether HIV disease variables and antiretroviral therapy are associated with pure-tone threshold levels.

DESIGN, SETTING, AND PARTICIPANTS

A total of 262 men (117 HIV+) from the Baltimore, Maryland/Washington, DC, site of the Multicenter AIDS Cohort Study and 134 women (105 HIV+) from the Washington, DC, site of the Women's Interagency HIV Study participated. Pure-tone air conduction thresholds were collected in a sound-treated room for each ear at frequencies from 250 through 8000 Hz. Linear mixed regression models tested the effect of HIV on hearing after adjustment for age, sex, race, and noise exposure history.

MAIN OUTCOMES AND MEASURES

Low-frequency pure-tone average (LPTA) at 250, 500, 1000, and 2000 Hz and high-frequency PTA (HPTA) at 3000, 4000, 6000, and 8000 Hz. Differential HIV effects for LPTA and HPTA and better/worse ear were also examined. CD4⁺ and CD8⁺ T-cell counts, log10 plasma HIV RNA concentrations, receipt of AIDS diagnosis, and cumulative duration of antiretroviral therapy were included in the models for HIV+ participants only.

RESULTS

HPTA and LPTA were significantly higher (18%: estimated ratio, 1.18 [95% CI, 1.02-1.36]; P = .02; and 12%: estimated ratio, 1.12 [95% CI, 1.00-1.26]; P = .05, respectively) for HIV+ participants compared with HIV- participants for the better ear. The direction of the effect was consistent across both the better and worse ears. There were no significant associations between HIV disease variables or treatment variables and LPTA or HPTA.

CONCLUSIONS AND RELEVANCE

The HIV+ adults had significantly poorer lower-frequency and higher-frequency hearing than HIV- adults. High-frequency hearing loss is consistent with an accelerated aging (presbycusis); low-frequency hearing loss in middle age is unexpected. Because some vowels and consonants have predominantly low-frequency acoustic energy, poor low-frequency hearing may impair communication in HIV+ individuals.

The effect of HAART-induced HIV suppression on circulating markers of inflammation and immune activation

OBJECTIVES

To investigate the impact of HAART-induced HIV suppression on levels of 24 serological biomarkers of inflammation and immune activation.

DESIGN

A prospective cohort study.

METHODS

Biomarkers were measured with multiplex assays in centralized laboratories using stored serum samples contributed by 1697 men during 8903 person-visits in the Multicenter AIDS Cohort Study (MACS) from 1984 to 2009. Using generalized gamma models, we compared biomarker values across three groups, adjusting for possible confounders: HIV-uninfected (NEG); HIV-positive, HAART-naive (NAI); and HAART-exposed with HIV RNA suppressed to less than 50 copies/ml plasma (SUP). We also estimated changes in biomarker levels associated with duration of HIV suppression, using splined generalized gamma regression with a knot at 1 year.

RESULTS

Most biomarkers were relatively normalized in the SUP group relative to the NAI group; however, 12 biomarkers in the SUP group were distinct (P < 0.002) from NEG values: CXCL10, C-reactive protein (CRP), sCD14, sTNFR2, tumour necrosis factor-alpha (TNF-α), sCD27, sGP130, interleukin (IL)-8, CCL13, BAFF, GM-CSF and IL-12p70. Thirteen biomarkers exhibited significant changes in the first year after viral suppression, but none changed significantly after that time.

CONCLUSION

Biomarkers of inflammation and immune activation moved towards HIV-negative levels within the first year after HAART-induced HIV suppression. Although several markers of T-cell activation returned to levels present in HIV-negative men, residual immune activation, particularly monocyte/macrophage activation, was present. This residual immune activation may represent a therapeutic target to improve the prognosis of HIV-infected individuals receiving HAART.

A Brief Chronicle of CD4 as a Biomarker for HIV/AIDS: A Tribute to the Memory of John L. Fahey

Foundational cellular immunology research of the 1960s and 1970s, together with the advent of monoclonal antibodies and flow cytometry, provided the knowledge base and the technological capability that enabled the elucidation of the role of CD4 T cells in HIV infection. Research identifying the sources and magnitude of variation in CD4 measurements, standardized reagents and protocols, and the development of clinical flow cytometers all contributed to the feasibility of widespread CD4 testing. Cohort studies and clinical trials provided the context for establishing the utility of CD4 for prognosis in HIV-infected persons, initial assessment of in vivo antiretroviral drug activity, and as a surrogate marker for clinical outcome in antiretroviral therapeutic trials. Even with sensitive HIV viral load measurement, CD4 cell counting is still utilized in determining antiretroviral therapy eligibility and time to initiate therapy. New point of care technologies are helping both to lower the cost of CD4 testing and enable its use in HIV test and treat programs around the world.

Sleep disordered breathing, fatigue, and sleepiness in HIV-infected and -uninfected men

Study Objectives

We investigated the association of HIV infection and highly active antiretroviral therapy (HAART) with sleep disordered breathing (SDB), fatigue, and sleepiness.

Methods

HIV-uninfected men (HIV−; n = 60), HIV-infected men using HAART (HIV+/HAART+; n = 58), and HIV-infected men not using HAART (HIV+/HAART−; n = 41) recruited from two sites of the Multicenter AIDS cohort study (MACS) underwent a nocturnal sleep study, anthropometric assessment, and questionnaires for fatigue and the Epworth Sleepiness Scale. The prevalence of SDB in HIV- men was compared to that in men matched from the Sleep Heart Health Study (SHHS).

Results

The prevalence of SDB was unexpectedly high in all groups: 86.7% for HIV−, 70.7% for HIV+/HAART+, and 73.2% for HIV+/HAART−, despite lower body-mass indices (BMI) in HIV+ groups. The higher prevalence in the HIV− men was significant in univariate analyses but not after adjustment for BMI and other variables. SDB was significantly more common in HIV− men in this study than those in SHHS, and was common in participants with BMIs <25 kg/m². HIV+ men reported fatigue more frequently than HIV− men (25.5% vs. 6.7%; p = 0.003), but self-reported sleepiness did not differ among the three groups. Sleepiness, but not fatigue, was significantly associated with SDB.

Conclusions

SDB was highly prevalent in HIV− and HIV+ men, despite a normal or slightly elevated BMI. The high rate of SDB in men who have sex with men deserves further investigation. Sleepiness, but not fatigue, was related to the presence of SDB. Clinicians caring for HIV-infected patients should distinguish between fatigue and sleepiness when considering those at risk for SDB, especially in non-obese men.

Association between systemic inflammation and obstructive sleep apnea in men with or at risk for HIV infection

BACKGROUND

We sought to determine whether markers of systemic inflammation are associated with the presence of moderate/severe obstructive sleep apnea (OSA) and whether this association differs based on HIV and HIV treatment status.

METHODS

HIV-uninfected men (HIV-; n=60), HIV-infected men receiving HAART (HIV+/HAART; n=58) and HIV-infected men not receiving HAART (HIV+/no HAART; n=41) underwent polysomnograpy and measurement of plasma levels of tumour necrosis factor (TNF)-α, soluble TNF-α receptors I and II (sTNFRI and sTNFRII) and interleukin (IL)-6. The relationship between moderate/severe OSA (respiratory disturbance index ≥15 apnea/hypopnea events/h) and inflammatory markers was assessed with multivariable regression models.

RESULTS

Compared with the HIV- men, HIV+/HAART men and HIV+/no HAART men had higher levels of TNF-α, sTNFRI and sTNFRII, independent of age, race, smoking status, obstructive lung disease (OLD) and body mass index (BMI). Moderate/severe OSA was present in 48% of the sample (HIV- 57%; HIV+/HAART 41%; HIV+/no HAART 44%). Among the HIV+/no HAART men, but not in the other groups, TNF-α, sTNFRII and IL-6 levels were higher in those with moderate/severe OSA compared to men with no/mild OSA after adjustment for age, race, smoking status, OLD and BMI. Within this group, the association of high TNF-α concentrations with moderate/severe OSA was also independent of CD4(+) T-cell count and plasma HIV RNA concentration.

CONCLUSIONS

Compared with HIV+/HAART men and HIV- men, markers of systemic inflammation were higher in HIV+/no HAART men. In these men, TNF-α was significantly related to OSA, independent of HIV-related covariates.

Factors affecting glomerular filtration rate, as measured by iohexol disappearance, in men with or at risk for HIV infection

OBJECTIVE

Formulae used to estimate glomerular filtration rate (GFR) underestimate higher GFRs and have not been well-studied in HIV-infected (HIV(+)) people; we evaluated the relationships of HIV infection and known or potential risk factors for kidney disease with directly measured GFR and the presence of chronic kidney disease (CKD).

DESIGN

Cross-sectional measurement of iohexol-based GFR (iGFR) in HIV(+) men (n = 455) receiving antiretroviral therapy, and HIV-uninfected (HIV(-)) men (n = 258) in the Multicenter AIDS Cohort Study.

METHODS

iGFR was calculated from disappearance of infused iohexol from plasma. Determinants of GFR and the presence of CKD were compared using iGFR and GFR estimated by the CKD-Epi equation (eGFR).

RESULTS

Median iGFR was higher among HIV(+) than HIV(-) men (109 vs. 106 ml/min/1.73 m(2), respectively, p = .046), and was 7 ml/min higher than median eGFR. Mean iGFR was lower in men who were older, had chronic hepatitis C virus (HCV) infection, or had a history of AIDS. Low iGFR (≤90 ml/min/1.73 m(2)) was associated with these factors and with black race. Other than age, factors associated with low iGFR were not observed with low eGFR. CKD was more common in HIV(+) than HIV(-) men; predictors of CKD were similar using iGFR and eGFR.

CONCLUSIONS

iGFR was higher than eGFR in this population of HIV-infected and -uninfected men who have sex with men. Presence of CKD was predicted equally well by iGFR and eGFR, but associations of chronic HCV infection and history of clinically-defined AIDS with mildly decreased GFR were seen only with iGFR.

Age, comorbidities, and AIDS predict a frailty phenotype in men who have sex with men

BACKGROUND

Adults aging with HIV infection are at risk for age-related comorbidities and syndromes, such as frailty. The objective of this study was to evaluate the expression and predictors of the frailty phenotype (FP) among HIV-infected (HIV+) and HIV-uninfected (HIV-) men who have sex with men.

METHODS

A prospective, observational cohort study was nested in the Multicenter AIDS Cohort Study from October 2007-September 2011. FP conversion was defined as the onset of FP over two consecutive study visits. Adjusted odds ratios and 95% confidence intervals ([,]) for FP conversion were estimated using logistic regression models with generalized estimating equations.

RESULTS

Of 10,571 completed study visits from 1,946 men who have sex with men, 12% and 9% were FP+ among HIV+ and HIV- men, respectively (p = .002). The proportion of FP+ visits increased with age regardless of HIV status, but was significantly greater in HIV+ compared to HIV- men aged 50-64 years. Of the 10,276 consecutive visit pairs contributed by participants, 5% (537) were classified as FP conversion, and 45% of the men with FP conversion had only one FP+ study visit. FP conversion was significantly associated with a history of AIDS (adjusted odds ratios = 2.26 [1.50, 3.39], but not with HIV+ alone (adjusted odds ratios = 1.26 [0.98, 1.64]). Among men who had one or more FP+ visits, 34% of HIV+ and 38% of HIV- men had less than two comorbidities.

CONCLUSIONS

These findings suggest that expression of the FP can be measured in men who have sex with men with and without HIV infection and reflects multisystem dysfunction in this population; further investigations are needed to better understand clinical utility.

HIV therapy, metabolic and cardiovascular health are associated with glomerular hyperfiltration among men with and without HIV infection

OBJECTIVE

Diabetes and hypertension, common conditions in antiretroviral-treated HIV-infected individuals, are associated with glomerular hyperfiltration, which precedes the onset of proteinuria and accelerated kidney function decline. In the Multicenter AIDS Cohort Study, we examined the extent to which hyperfiltration is present and associated with metabolic, cardiovascular, HIV and treatment risk factors among HIV-infected men.

DESIGN

Cross-sectional cohort using direct measurement of glomerular filtration rate by iohexol plasma clearance for 367 HIV-infected men and 241 HIV-uninfected men who were free of chronic kidney disease.

METHODS

Hyperfiltration was defined as glomerular filtration rate above 140-1 ml/min per 1.73 m per year over age 40. Multivariate logistic regression was used to estimate the odds ratios (ORs) of prevalent hyperfiltration for metabolic, cardiovascular, HIV and cumulative antiretroviral exposure factors.

RESULTS

Among individuals without chronic kidney disease, the prevalence of hyperfiltration was higher for HIV-infected participants (25%) compared to uninfected participants (17%; P = 0.01). After adjustment, HIV infection remained associated with hyperfiltration [OR 1.70, 95% confidence interval (CI) 1.11-2.61] and modified the association between diabetes and hyperfiltration, such that the association among HIV-uninfected men (OR 2.56, 95% CI 1.33-5.54) was not observed among HIV-infected men (OR 1.19, 95% CI 0.69-2.05). These associations were independent of known risk factors for hyperfiltration. Indicators of hyperglycemia and hypertension were also associated with hyperfiltration as was cumulative zidovudine exposure.

CONCLUSION

Hyperfiltration, a potential modifiable predictor of kidney disease progression, is significantly higher among antiretroviral-treated HIV-infected men. Furthermore, HIV-infection nullifies the association of diabetes and hyperfiltration present in HIV-uninfected men.

Statistical methods for the assessment of EQAPOL proficiency testing: ELISpot, Luminex, and Flow Cytometry

In September 2011 Duke University was awarded a contract to develop the National Institutes of Health/National Institute of Allergy and Infectious Diseases (NIH/NIAID) External Quality Assurance Program Oversight Laboratory (EQAPOL). Through EQAPOL, proficiency testing programs are administered for Interferon-γ (IFN-γ) Enzyme-linked immunosorbent spot (ELISpot), Intracellular Cytokine Staining Flow Cytometry (ICS) and Luminex-based cytokine assays. One of the charges of the EQAPOL program was to apply statistical methods to determine overall site performance. We utilized various statistical methods for each program to find the most appropriate for assessing laboratory performance using the consensus average as the target value. Accuracy ranges were calculated based on Wald-type confidence intervals, exact Poisson confidence intervals, or via simulations. Given the nature of proficiency testing data, which has repeated measures within donor/sample made across several laboratories; the use of mixed effects models with alpha adjustments for multiple comparisons was also explored. Mixed effects models were found to be the most useful method to assess laboratory performance with respect to accuracy to the consensus. Model based approaches to the proficiency testing data in EQAPOL will continue to be utilized. Mixed effects models also provided a means of performing more complex analyses that would address secondary research questions regarding within and between laboratory variability as well as longitudinal analyses.

Cochlear function among HIV-seropositive and HIV-seronegative men and women

OBJECTIVES

There is limited research about cochlear function in adults who are human immunodeficiency virus (HIV) positive (+). The aim of the present study was to collect measures of cochlear function in a large sample of adults with, or at risk for, HIV infection, to evaluate associations between HIV status, HIV treatment, and cochlear function.

DESIGN

Distortion product otoacoustic emissions (DPOAEs) were used to evaluate cochlear function in 506 participants; 329 men, 150 of whom were HIV+, and 177 women, 136 of whom were HIV+. DPOAEs were measured at frequencies 1000, 2000, 3000, 4000, and 6000 Hz. A DPOAE nonresponse (NR) was defined as an absolute DPOAE level less than -15 dB SPL or a difference between the absolute DPOAE level and the background noise level less than 6 dB. The total number of NRs was calculated for each ear. The associations of demographic variables, HIV status, and HIV treatment with number of NRs were evaluated with univariate and multivariate ordinal regression models.

RESULTS

There was a statistically significant increase in the odds of higher numbers of NRs with age, being male, and being non-Black, but not with HIV status. Among HIV+ participants, there were no statistically significant associations of the HIV disease status or treatment variables with higher number of NRs.

CONCLUSION

The authors found no evidence of impaired cochlear function by HIV disease status or highly active antiretroviral therapy-treated HIV infection in this cross-sectional study.

Prevalence of abnormalities in vestibular function and balance among HIV-seropositive and HIV-seronegative women and men

Background

Most HIV-seropositive subjects in western countries receive highly active antiretroviral therapy (HAART). Although many aspects of their health have been studied, little is known about their vestibular and balance function. The goals of this study were to determine the prevalences of vestibular and balance impairments among HIV-seropositive and comparable seronegative men and women and to determine if those groups differed.

Methods

Standard screening tests of vestibular and balance function, including head thrusts, Dix-Hallpike maneuvers, and Romberg balance tests on compliant foam were performed during semiannual study visits of participants who were enrolled in the Baltimore and Washington, D. C. sites of the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study.

Results

No significant differences by HIV status were found on most tests, but HIV-seropositive subjects who were using HAART had a lower frequency of abnormal Dix-Hallpike nystagmus than HIV-seronegative subjects. A significant number of nonclassical Dix-Hallpike responses were found. Age was associated with Romberg scores on foam with eyes closed. Sex was not associated with any of the test scores.

Conclusion

These findings suggest that HAART-treated HIV infection has no harmful association with vestibular function in community-dwelling, ambulatory men and women. The association with age was expected, but the lack of association with sex was unexpected. The presence of nonclassical Dix-Hallpike responses might be consistent with central nervous system lesions.

Comparison of interlaboratory variation in absolute T-cell counts by single-platform and optimized dual-platform methods

BACKGROUND

Previous studies have reported that the adoption of a single-platform flow cytometry cell counting method resulted in lower interlaboratory variation in absolute T cell counts as compared to predicate dual-platform flow cytometry methods which incorporate independent automated lymphocyte counts (Schnizlein-Bick et al., Clin Diagn Lab Immunol 2000;7:336-343; Reimann et al., Clin Diagn Lab Immunol 2000;7:344-351). In the present study, we asked whether use of a single-platform method could reduce variation in absolute cell counts across the laboratories in the Multicenter AIDS Cohort Study (MACS) (n = 4), as suggested by the studies cited.

METHODS

Identical study samples were shipped overnight to the MACS laboratories either by the National Institute of Allergy and Infectious Diseases, Division of AIDS Immunology Quality Assessment (NIAID- IQA) proficiency-testing program (n = 14), or by the Los Angeles site of the MACS (n = 10). For each sample, two tubes of blood were received; one was used for an automated complete blood count and differential, and the other for flow cytometry. The latter was performed using both our current dual-platform method (three-color CD45 gating and automated hematology) and the single-platform method (with TruCOUNT beads to generate the absolute counts).

RESULTS

The median percent coefficients of variation (%CVs) for the dual-platform and single-platform methods were 6.6 and 9.9, respectively, for CD4 T cell counts, and 5.9 and 8.5, respectively, for CD8 T cell counts (n = 24). These differences were not statistically significant. The differences in absolute T-cell counts between the MACS sites and the median of all laboratories participating in the NIAID-IQA were smaller for the dual-platform than for single-platform absolute count method.

CONCLUSION

In contrast to previous reports, we did not observe lower interlaboratory variation across the MACS sites for single-platform absolute lymphocyte subset counting relative to dual-platform methods. This result may be at least partly explained by the lower interlaboratory variation with the optimized dual-platform method in this study relative to the previous reports.