The CD4/CD8 Ratio is Inversely Associated with Carotid Intima-Media Thickness Progression in Human Immunodeficiency Virus-Infected Patients on Antiretroviral Treatment

Lipid and immunophenotypic profiles in hemodialysis patients with citrate vs. acetate dialysates

Background

Chronic kidney disease (CKD) is a significant cardiovascular (CV) risk factor, with dialysis-dependent CKD (DD-CKD) patients facing high mortality rates. Hypercholesterolemia is another crucial CV risk factor, typically managed with lipid-lowering therapy, though its efficacy in DD-CKD remains uncertain. Evidence shows mixed results regarding the benefits of statins in these patients. Citrate-based dialysates are known to reduce inflammatory biomarkers compared to acetate-based ones, potentially impacting lipid profiles and immune responses. This study aimed to determine the effects of citrate vs. acetate dialysate on lipid profiles and immunophenotypes in DD-CKD patients.

Methods

This unicentric, cross-over, prospective study included 21 hemodialysis patients (10 males, 11 females, average age 62.25 years). Each patient underwent 24 dialysis sessions (12 with each dialysate) and acted as their own control. Lipid profiles, immunological parameters, and nutritional and inflammatory markers were measured before the last session with each dialysate.

Results

After twelve dialysis sessions with citrate dialysate (CD), compared to acetate dialysate (AD), there was a statistically significant decline in TG and remnant cholesterol, with a decrease in HDL and an increase in LDL. Regarding immunology, C3 complement levels were higher, while CD3+ CD8+ and CD16+ 56+ lymphocytes were lower. Finally, total lymphocytes were lower with AD than with CD. We found no difference in predialysis nutritional nor inflammatory parameters except for ESR, which was higher when subjects used CD than AD.

Conclusion

There are significant differences in lipid and immunophenotypic profiles with CD in comparison to AD. Interestingly, there could be an advantageous profile given the reduced amount of remnant cholesterol and TG. However, further studies are needed to understand if the observed changes lead to beneficial hard clinical outcomes in DD-CKD patients.

Dynamics of peripheral T cell exhaustion and monocyte subpopulations in neurocognitive impairment and brain atrophy in chronic HIV infection

BACKGROUND

HIV-associated neurocognitive disorders (HAND) is hypothesized to be a result of myeloid cell-induced neuro-inflammation in the central nervous system that may be initiated in the periphery, but the contribution of peripheral T cells in HAND pathogenesis remains poorly understood.

METHODS

We assessed markers of T cell activation (HLA-DR + CD38+), immunosenescence (CD57 + CD28-), and immune-exhaustion (TIM-3, PD-1 and TIGIT) as well as monocyte subsets (classical, intermediate, and non-classical) by flow cytometry in peripheral blood derived from individuals with HIV on long-term stable anti-retroviral therapy (ART). Additionally, normalized neuropsychological (NP) composite test z-scores were obtained and regional brain volumes were assessed by magnetic resonance imaging (MRI). Relationships between proportions of immune phenotypes (of T-cells and monocytes), NP z-scores, and brain volumes were analyzed using Pearson correlations and multiple linear regression models.

RESULTS

Of N = 51 participants, 84.3% were male, 86.3% had undetectable HIV RNA < 50 copies/ml, median age was 52 [47, 57] years and median CD4 T cell count was 479 [376, 717] cells/uL. Higher CD4 T cells expressing PD-1 + and/or TIM-3 + were associated with lower executive function and working memory and higher CD8 T cells expressing PD-1+ and/or TIM-3+ were associated with reduced brain volumes in multiple regions (putamen, nucleus accumbens, cerebellar cortex, and subcortical gray matter). Furthermore, higher single or dual frequencies of PD-1 + and TIM-3 + expressing CD4 and CD8 T-cells correlated with higher CD16 + monocyte numbers.

CONCLUSIONS

This study reinforces evidence that T cells, particularly those with immune exhaustion phenotypes, are associated with neurocognitive impairment and brain atrophy in people living with HIV on ART. Relationships revealed between T-cell immune exhaustion and inflammatory in CD16+ monocytes uncover interrelated cellular processes likely involved in the immunopathogenesis of HAND.

Exercise to Prevent Accelerated Vascular Aging in People Living With HIV

Given advances in antiretroviral therapy, the mortality rate for HIV infection has dropped considerably over recent decades. However, people living with HIV (PLWH) experience longer life spans coupled with persistent immune activation despite viral suppression and potential toxicity from long-term antiretroviral therapy use. Consequently, PLWH face a cardiovascular disease (CVD) risk more than twice that of the general population, making it the leading cause of death among this group. Here, we briefly review the epidemiology of CVD in PLWH highlighting disparities at the intersections of sex and gender, age, race/ethnicity, and the contributions of social determinants of health and psychosocial stress to increased CVD risk among individuals with marginalized identities. We then overview the pathophysiology of HIV and discuss the primary factors implicated as contributors to CVD risk among PLWH on antiretroviral therapy. Subsequently, we highlight the functional evidence of premature vascular dysfunction as an early pathophysiological determinant of CVD risk among PLWH, discuss several mechanisms underlying premature vascular dysfunction in PLWH, and synthesize current research on the pathophysiological mechanisms underlying accelerated vascular aging in PLWH, focusing on immune activation, chronic inflammation, and oxidative stress. We consider understudied aspects such as HIV-related changes to the gut microbiome and psychosocial stress, which may serve as mechanisms through which exercise can abrogate accelerated vascular aging. Emphasizing the significance of exercise, we review various modalities and their impacts on vascular health, proposing a holistic approach to managing CVD risks in PLWH. The discussion extends to critical future study areas related to vascular aging, CVD, and the efficacy of exercise interventions, with a call for more inclusive research that considers the diversity of the PLWH population.

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.

The first taxonomic and functional characterization of human CAVD-associated microbiota

INTRODUCTION

Calcific aortic valve disease (CAVD) is the most common heart valve disorder, defined by a remodeling multistep process: namely, valve fibrosis with its area narrowing, impaired blood flow, and final calcification phase. Nowadays, the only treatment is the surgical valve replacement. As for other cardiovascular diseases, growing evidence suggest an active role of the immune system in the calcification process that could be modulated by the microbiota. To address this point, we aimed to investigate and characterize, for the first time, the presence of a valve microbiota and associated immune response in human CAVD.

METHOD

Calcified aortic valve (CAV) samples from twenty patients (11 from Germany and 9 from Italy) with diagnosis of severe symptomatic CAVD were used to assess the presence of infiltrating T cells, by cloning approach, and to characterize the valve microbiota, by 16S rRNA gene sequencing (NGS).

RESULTS

We documented the presence of infiltrating T lymphocytes, especially the T helper subset, in CAV samples. Moreover, we found a tissue-associated microbiota in freshly collected CAV samples, which was significantly different in Italian and German patients, suggesting potential correlation with other cardiovascular risk factors.

CONCLUSION

The presence of microbiota in inflamed CAV samples represents the right trigger point to explain the valve calcification process, encouraging further studies to explore the potential link between bacteria and adaptive immune response and to define the critical role of local microbiota-immunity axis on CAVD development.

Predictors of subclinical atherosclerosis in HIV

BACKGROUND

Cardiovascular disease is a major cause of morbidity and mortality in people with HIV. The detection of subclinical atherosclerosis through vascular ultrasound allows us to identify patients at an increased risk of cardiovascular disease as a primary prevention strategy; this test is not routine. Our objective is to identify predictors of subclinical atherosclerosis in a population with HIV.

METHODS

People with HIV infection were selected for primary prevention and underwent carotid and femoral ultrasound to detect atheromatous plaques. Logistic regression analysis including vascular risk factors was performed to predict the presence of atherosclerosis.

RESULTS

One hundred eighty-three patients were included, 54% of whom were smokers; the mean duration of HIV infection was 9.52 years, and all patients were undergoing antiretroviral treatment. Subclinical atherosclerosis was present in 62.29% of the patients; 83.32% had plaque in the carotid territory, 57.93% in the femoral territory and 25.6% in both vascular territories. Compared to those without atherosclerosis, patients with atherosclerosis were on average 5.35 years older (53.86 vs. 48.51, p < 0.001) and had a higher prevalence of smoking (63.23% vs. 39.12%, p = 0.020) and a CD4/CD8 ratio below 0.7 (44.23% vs. 29.02%, p = 0.043). A CD4/CD8 ratio lower than 0.3 was always associated with subclinical atherosclerosis (95% confidence interval (CI): 83.9-100%). The inclusion of smoking, the CD4/CD8 ratio and age in the logistic regression analysis led to a diagnostic yield of 72% measured by the area under the receiving operator characteristic (ROC) curve (95% CI: 64-80%).

CONCLUSIONS

Tobacco use, age and a CD4/CD8 ratio below 0.7 allow prediction of the presence of subclinical atherosclerosis in primary prevention. A CD4/CD8 ratio below 0.3 was a diagnostic indicator of atherosclerosis in HIV patients undergoing primary prevention in our sample.

CD4:CD8 Ratio and CD8 Cell Count and Their Prognostic Relevance for Coronary Heart Disease Events and Stroke in Antiretroviral Treated Individuals: The Swiss HIV Cohort Study

INTRODUCTION

HIV infection leads to a persistent expansion of terminally CD8 T cells and CD8 T suppressor cells, a marker of chronic immune activation leading to a low CD4:CD8 ratio that may persist in the presence of potent antiretroviral therapy and regained CD4 helper cells. It remains unclear whether a low CD4:CD8 ratio is associated with cardiovascular diseases.

METHODS

We conducted an observational cohort study to investigate the association of immune depression and activation as characterized by the proxy of the CD4:CD8 ratio on the hazard of coronary heart disease (CHD) and stroke among treated individuals living with HIV, while accounting for viral load and known risk factors for cardiovascular diseases and exposure to abacavir or protease inhibitors. We used Cox proportional hazard models with time-dependent cumulative and lagged exposures to account for time-evolving risk factors and avoid reverse causality.

RESULTS

CD4, CD8, and CD4:CD8 immunological markers were not associated with an increased hazard for CHD. CD8 cell count lagged at 12 months above 1000 cells per μL increased the hazard of stroke, after adjusting for sociodemographics, cardiovascular risk factors, and exposure to specific types of antiretroviral drugs.

CONCLUSIONS

This analysis of treated HIV-positive individuals within a large cohort with long-term follow-up does not provide evidence for a prognostic role of immune dysregulation regarding CHD. However, increased CD8 cell count may be a moderate risk factor for stroke. Early detection and treatment of HIV-positive individuals are crucial for an optimal immune restoration and a limited CD8 cells expansion.

A Lower CD4+/CD8+ Ratio Predicts Activities of Daily Living Decline Among Older Adults with HIV

Aging of people with human immunodeficiency virus (HIV) is a worldwide reality, and age-related conditions, including disability, have also increased. Efforts are being made to search for more specific markers of immune system malfunction, which serve as good predictors of adverse health-related outcomes. Therefore, this study aimed to determine the relationship between the CD4⁺/CD8⁺ ratio and functional decline in activities of daily living (ADL). Participants in this longitudinal study underwent a standardized comprehensive geriatric assessment by trained staff, using validated tools. Functional decline in ADL was established by the delta resulting from the subtraction of the score on the Barthel index at T₁ minus the score at T₀ (baseline). Multivariate linear regression analyses were used to determine the independent relationship between the CD4⁺/CD8⁺ ratio and ADL decline. Mean age was 57.9 (standard deviation 6.6; range 50-84 years), and 82.7% were men. Eleven of the 209 participants had disability for ADL at baseline. Multivariate linear regression analysis showed an inverse relationship between the log of CD4⁺/CD8⁺ ratio at baseline and the delta of Barthel index even after adjustment for multiple confounders (β = -1.68, 95% confidence interval -3.02 to -0.33; p = .01). A CD4⁺/CD8⁺ ratio of <1 predicts the development of functional decline in ADL. This ratio can be a useful marker to identify people at risk of disability and should be considered for the tailored management of older adults with HIV.

Low CD4/CD8 ratio is associated with increased morbidity and mortality in late and non-late presenters: results from a multicentre cohort study, 2004–2018

Background

To study whether the association between the CD4/CD8 ratio variation over time and the development of clinical outcomes vary in late presenters (CD4 count < 350/µL or AIDS event at enrolment) or advanced presenters (CD4 count < 200/µL or AIDS event at enrolment).

Methods

We included ART-naïve adults from the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) enrolled between January 2004 up to November 2018 and with at least 6 months of follow-up. We used extended Cox proportional hazard models to estimate the hazard ratios (HRs) for the association between CD4/CD8 ratio over time and a composite endpoint of the occurrence of the first AIDS event, first serious non-AIDS event or overall mortality occurring from 6 months after enrolment. HRs in non-late, late and advanced presenters were obtained by including an interaction term between late presentation status and CD4/CD8 ratio over time.

Results

Of 10,018 participants, 55.6% were late presenters and 26.5% were advanced presenters. Compared with CD4/CD8 ratio > 0.4, CD4/CD8 ratio ≤ 0.4 over time was associated with an increased risk of experiencing the composite endpoint in non-late (HR 1.90; 95%CI 1.48, 2.43), late (HR 1.94; 1.46, 2.57) and advanced presenters (HR 1.72; 1.26, 2.34). Similarly, CD4/CD8 ratio ≤ 0.4 over time was associated with a higher risk of developing an AIDS event (HR 3.31; 2.23, 4.93 in non-late; HR 2.75; 1.78, 4.27 in late and HR 2.25; 1.34, 3.76 in advanced presenters) or serious non-AIDS event (HR 1.39; 0.96, 2.02 in non-late, HR 1.62; 1.10, 2.40 in late and HR 1.49; 0.97, 2.29 in advanced presenters) as well as with a higher risk of overall mortality (HR 1.49; 0.92, 2.41 in non-late, HR 1.80; 1.04, 3.11 in late and HR 1.61; 0.92, 2.83 in advanced presenters) compared to CD4/CD8 > 0.4, regardless of the late presentation status.

Conclusions

A low CD4/CD8 measured over time is associated with increased risk of morbidity and mortality in people living with HIV independently of their late presentation status. These data support the prognostic role of CD4/CD8 over time and can help defining a subgroup of patients who need closer monitoring to avoid comorbidities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07352-z.

Exceptional T CD4+ Recovery Post-antiretroviral Is Linked to a Lower HIV Reservoir with a Specific Immune Differentiation Pattern

We present a cohort of individuals who reached CD4⁺ T cell counts of greater than 1,000 cells/mm³ (Hypers) after starting antiretroviral treatment (ART) and compared them with those who reached between 350 and 999 CD4⁺ T cells/mm³ (Concordants). Demographic data, immune recovery kinetics, T CD4⁺ subset phenotypes, and integrated HIV DNA were analyzed. Data from individuals living with HIV on their first ART regimen and after 48 months of follow-up were obtained. Immune phenotype by Flow Cytometry analysis on whole blood was performed, cytokines were measured, and integrated HIV-1 DNA was measured by polymerase chain reaction. From a total of 424 individuals, 26 Hypers (6.1%), 314 Concordants (74.1%), and 84 (19.8%) discordants were identified. Hypers had a higher proportion of CD4⁺-naive (Nv) T cells (37.6 vs. 24.8, p < .05), and a low proportion of CD4⁺ effector memory T cells (27.9 vs. 39.4, p < .05), with similar results found in CD8⁺ T cells. Hypers demonstrated a higher percentage of CD4⁺CD45RA⁺CD31^neg cells with a lower response to interleukin-2 stimulation and a lower integrated HIV-1 DNA/CD4 ratio (1.2 vs. 2.89, p < .05). In Hypers, T cell recovery occurs very early after initiation of ART. Following this initial recovery state, their CD4⁺ T cell level homeostasis seems to be driven by nonthymic-central-Nv cells. This exceptional recovery is associated with a lower HIV reservoir, which may be related to an increase in noninfected CD4⁺ T cells. These patients could then be eligible candidates for cure trials.

Moderate to intense physical activity is associated with improved clinical, CD4/CD8 ratio and immune activation status in HIV infected patients on ART

Background

Physical activity has anti-inflammatory effects and reduces morbidity and mortality in the general population, but its role in the clinical, CD4/CD8 ratio, and immune activation status of HIV-infected patients has been poorly studied.

Methods

A cross-sectional study was carried out in a cohort of 155 HIV-infected patients on stable antiretroviral therapy (ART) to compare clinical, biochemical, CD4/CD8 ratio, and immune activation status according to their physical activity in the last 2 years (sedentary/low vs moderate/intense) assessed by the iPAQ. A binary logistic regression and mixed analysis of variance were performed to evaluate the impact of levels of physical activity on CD4/CD8 ratio.

Results

In our series, 77 (49.7%) out of 155 patients were sedentary, and 78 (50.3%) practiced moderate/intense physical activity. Moderate/intense physical activity was associated with better metabolic control (lower body mass index, P = .024; glucose, P = .024; and triglyceride, P = .002) and CDC HIV stage (P = .046), lower CD8⁺ (P =  .018), CD4⁺CD8⁺ (P = .026), CD4⁺CD86⁺ (P = .045), CD4⁺HLA-DR⁺ (P = .011), CD8⁺HLA-DR⁺ (P = .048) T lymphocytes and CD16⁺HLA-DR⁺ natural killer cells (P = .026), and higher CD3⁺CD4⁺ T lymphocytes (P = .016) and CD4/CD8 ratio (P = .001). Sedentary lifestyle (odds ratio [OR], 2.12; P = .042), CD4 nadir (OR, 1.005; P < .001), and CD8⁺CD38⁺ T cells (OR, 1.27; P = .006) were independently associated with low CD4/CD8 ratio (<0.8). Earlier and more intense CD4/CD8 ratio recovery was observed in patients with higher physical activity in the 2-year follow-up with a significant interaction between these variables: F(2, 124) = 3.31; P = .049; partial η2 = 0.042.

Conclusions

Moderate to high physical activity is associated with beneficial health effects, improvement in metabolic profile, and reduction of chronic inflammation in patients with HIV. Although more studies and clinical trials are needed to confirm these findings, a healthy lifestyle including at least moderate physical activity should be recommended to HIV patients on stable ART.

Subclinical atherosclerosis and immune activation in young HIV-infected patients with telomere shortening

Background: To date, available data on premature aging in young HIV-infected adults are scarce and no reports offer comprehensive assessment of telomere shortening (TS) in relation to subclinical atherosclerosis (SCA). In this study, we investigate if telomere shortening and immune activation markers are associated with SCA, which is one of the main degenerative diseases in young HIV-infected adults.

Methods: A descriptive cross-sectional study was carried out in 149 HIV-infected patients on stable antiretroviral regimen (ART). Carotid intima-media thickness (cIMT) was estimated by carotid ultrasound. Quantitative singleplex PCR was performed to evaluate TS. The expression of activation/senescence markers was evaluated by multiparametric flow cytometry.

Results: TS was observed in 73 patients (49%). Higher cIMT was observed in patients with TS than those without it (0.86 vs. 0.80 mm; p=0.041). Patients under the age of 50 (defined as young adults) with TS showed higher absolute numbers of activated lymphocyte T cells CD8+CD38+ (3.94 vs. 2.34 cell/μl; p=0.07) and lymphocyte B cells CD19+CD38+ (3.07 vs. 2.10 cell/μl; p=0.004) compared to those without TS. In the multivariate analysis, the only factor independently associated with TS was the absolute number of lymphocyte T cells CD8+CD38+ T cells (OR = 1.18; 95%-CI = 1.00-1.39; p = 0.05).

Conclusion: Young HIV-infected adults show premature biological aging with accentuated immune activation. Chronic inflammation with excessive T-cells activation could be associated to TS, premature aging, and SCA in young HIV-infected adults.

Prevalence of Silent Atherosclerosis and Other Comorbidities in an Outpatient Cohort of Adults Living with HIV: Associations with HIV Parameters and Biomarkers

People living with HIV (PLWH) are at risk of noninfectious comorbidities. It is important to individualize those at higher risk. In a single-center cohort of PLWH, we performed a cross-sectional analysis of comorbidities, diagnosed according to standard procedures. The primary endpoint was the prevalence of subclinical carotid/coronary atherosclerosis. Secondary endpoints were its association with selected inflammatory/immune activation biomarkers and with other comorbidities. Associations were examined by using Chi-square or Fisher's exact test for categorical variables and Student or Wilcoxon tests for quantitative variables, and a stepwise multivariate logistical model was performed for further exploration. Among 790 participants [median age: 49.8 years (interquartile range, IQR: 44.5-55.6), 77.1% males, median CD4: 536/mm³ (IQR: 390-754), 83.6% with undetectable viral load], asymptomatic atherosclerosis was found in 26% and was associated in multivariate analysis with older age, longer known duration of infection, higher sCD14, and lower adiponectin levels. Hypertension was found in 33.5% of participants, diabetes in 19.4%, renal impairment in 14.6%, elevated low-density lipoprotein-cholesterol in 13.3%, elevated triglyceride/high-density lipoprotein (HDL)-cholesterol ratio in 6.6%, and osteoporosis in 7.9%. The presence of two or more comorbidities was found in 42.1% of participants and was associated in multivariate analysis with older age and longer exposure to antiretrovirals. Comorbidities were diversely associated with biomarkers: osteoporosis with higher IL-6, renal impairment with higher sCD14, hypertension with higher D-dimer, diabetes and elevated triglyceride/HDL-cholesterol ratio both with lower adiponectin and lower 25-hydroxyvitamin D. Asymptomatic atherosclerosis and multimorbidity were frequent in a cohort of middle-aged, well-controlled, PLWH and were associated with traditional and HIV-specific factors. Associations between morbidities and inflammatory/immune activation biomarkers were diverse.

The effect of T helper (Th)/T cytotoxic (Tc) ratio on disease severity in type A hemophilia patients

BACKGROUND AND OBJECTIVES

The aim of this study was to investigate the T helper (Th) to T cytotoxic (Tc) ratio in children suffering from type A hemophilia disease and to evaluate the correlation of this ratio with disease severity.

MATERIAL AND METHOD

Two mls of EDTA anti coagulated whole blood was collected. Immunophenotyping of lymphocytes count was carried out by FACS analysis using a double CD4 and CD8 kit. The mean ± SD of absolute numbers of CD4 and CD8 lymphocytes/ml was calculated and the ratio of CD4/CD8 was evaluated by statistical method.

RESULTS

Among 80 type A hemophilia patients, 66 (82.5%) were male. The mean age was 15 ± 3.51 years. 12 (15%) of them were suffering from mild disease and 68 (85%) had sever disease. The CD4 /CD8 ratio was obtained between 0.45 and 1.44 with mean1.79 ± 0.78. The correlation between this ration and disease severity was 0.019.

CONCLUSION

The results showed that CD4/CD8 ratio has correlation with disease severity in type A hemophilia patients, however there was no association between this ratio and gender.

Cardiovascular disease in HIV patients: recent advances in predicting and managing risk

INTRODUCTION

Cardiovascular disease (CVD) is one of the leading causes of mortality in virally suppressed people living with HIV (PLWH) and with an aging population, is likely to become one of the leading challenges in maintaining good health outcomes in HIV infection. However, factors driving the risk of CVD in PLWH are multiple and may be different from those of the general population, raising challenges to predicting and managing CVD risk in this population.

AREAS COVERED

In this review, we examine the relevant data regarding CVD in HIV infection including CVD prevalence, pathogenesis, and other contributing factors. We review the data regarding CVD risk prediction in PLWH and summarize factors, both general and HIV specific, that may influence CVD risk in this population. And finally, we discuss appropriate management of CVD risk in PLWH and explore potential therapeutic pathways which may mitigate CVD risk in the future in this population.

EXPERT OPINION

Following a comprehensive review of CVD risk in PLWH, we give our opinion on the primary issues in risk prediction and management of CVD in HIV infected individuals and discuss the future direction of CVD management in this population.

Plasma tissue factor and immune activation are associated with carotid intima-media thickness progression in treated HIV infection

OBJECTIVES

We evaluated the roles of biomarkers of immune activation with carotid intima-media thickness (CIMT) progression in treated HIV infection.

DESIGN

Longitudinal observational study of 118 treated and virologically suppressed individuals.

METHODS

We measured biomarkers of immune activation at baseline using cryopreserved samples. CIMT was measured at baseline and longitudinally using high-resolution ultrasound. Linear regression was used to estimate biomarker associations with CIMT progression, and logistic regression was used to model plaque progression.

RESULTS

The median duration of follow-up was 2.0 years. The median annual rate of change in mean CIMT was 6.0%. Rates of progression were more rapid in the bifurcation (5.6%/year, P = 0.006) and internal (6.5%/year, P = 0.0008) than common CIMT (4.3%/year). Incident plaque occurred in 13 of the 52 individuals without baseline plaque. In multivariable adjusted analysis, plasma tissue factor and monocyte chemoattractant protein-1 were associated with more rapid common CIMT progression (0.058 mm/year, P = 0.0004 and 0.067 mm/year, P = 0.017; all estimates per doubling). CD8 T-cell count and percentage of HLA-DRCD38CD8 T cells were associated with more rapid internal CIMT progression (0.10 mm/year, P = 0.008 and 0.054 mm/year, P = 0.045). CD8 T-cell count was also associated with 0.068 mm/year more rapid mean CIMT progression (P = 0.011). Each 10% increase in CD4 T-cell count at baseline was associated with a 34% reduced odds of plaque progression (P = 0.018).

CONCLUSION

Residual immune activation and plasma tissue factor are independently associated with CIMT progression in treated HIV infection. Interventions targeting coagulation and inflammatory pathways to reduce cardiovascular disease risk in HIV merit additional investigations.

Immune recovery markers in a double blind clinical trial comparing dolutegravir and raltegravir based regimens as initial therapy (SPRING-2)

Background

Multiple T-cell marker recovery (MTMR: CD4+ T-cells >500 cel/mm³ plus CD4+% >29% plus CD4+/CD8+ ratio >1) has been proposed as the most complete level of immune reconstitution. In this study we quantified differences in the CD4+/CD8+ ratio, CD4+% recovery and MTMR after starting HIV-1 treatment with dolutegravir (DTG) vs. raltegravir (RAL) plus a NRTI backbone.

Methods

Exploratory post-hoc analysis of the SPRING-2 study, a randomized double-blind clinical trial comparing DTG and RAL as third agents in naive HIV-infected patients at 100 sites in Canada, USA, Australia, and Europe. Percentage differences and corresponding precision based on 95% confidence intervals (CI) and p-values were calculated for i) CD4+/CD8+ ratio normalization, ii) CD4+% normalization, and iii) the achievement of MTMR.

Results

A total of 822 participants were analyzed (411 in each group). No statistically significant differences in the proportion of patients who reached a CD4+/CD8+ ratio ≥0.5 & ≥1 at w48 & w96 were observed. At w96, the proportion of patients with a CD4+/CD8+ ratio ≥1 was similar (30.43% DTG vs. 29.57% RAL). No differences were observed in the mean increase in CD4+/CD8+ ratio from baseline at both w48 & w96. Similarly, no significant differences in the CD4+/CD8+>29% were observed at w96 (72.95% DTG vs 69.28% RAL). The proportion of patients attaining MTMR criteria was also similar in the DTG group and the RAL group at w48 (20.33% vs. 18.26%; difference 2.07 (95%CI (-3.67;7.81) P = 0.481 and w96 (28.70% vs. 27.13; difference 1.56 (95%CI -5.22;8.34) P = 0.652).

Conclusion

After comparing DTG and RAL, no differences on immune recovery markers were observed.

Association Between Erectile Dysfunction and Carotid Subclinical Atherosclerosis in HIV-Infected Patients

BACKGROUND

Erectile dysfunction (ED) is frequent in HIV-infected patients, and it can be associated with atherosclerosis and cardiovascular events. So, the objective was to evaluate whether the presence of moderate-severe ED was a marker of subclinical atherosclerosis (SCA) in HIV-infected patients.

METHODS

A cross-sectional study was conducted in a cohort of HIV-infected patients. The presence of ED was assessed using the International Index of Erectile Function (IIEF-5) questionnaire. The presence of SCA was determined by calculating the mean carotid intima-media thickness with Doppler ultrasound. A logistic regression analysis was performed to check the variables associated with SCA.

RESULTS

One hundred thirty-nine men of 45 (10) years of age were included, of which 130 (94.9%) received antiretroviral therapy. In 30 (22%) patients, the Framingham score was higher than 10%. In 36 (25.9%) patients, ED was detected in a moderate-severe degree and in 53 (38.1%), SCA was detected. In the multivariate analysis, variables independently associated with the presence of SCA were as follows: older age [odds ratio (OR) = 1.22, confidence interval (CI) 95%: 1.1 to 1.35, P < 0.001] and moderate-severe ED (OR = 4.68, CI 95%: 1.18 to 18.5; P = 0.028). Variables associated with moderate-severe ED were as follows: age (OR = 1.107, CI 95%: 1.041 to 1.17, P < 0.001) and having antibodies for hepatitis C virus (OR = 5.12, CI 95%: 1.54 to 17.03, P < 0.001).

CONCLUSIONS

HIV-Infected patients often have moderate-severe ED, especially the elderly and coinfected patients with hepatitis C virus. ED can be an early clinical manifestation of incipient atherosclerosis, so its presence should involve a deep control of cardiovascular risk factors and using a regimen with a better atherogenic profile.

CD4/CD8 Ratio and CD4 Nadir Predict Mortality Following Noncommunicable Disease Diagnosis in Adults Living with HIV

Incidence of noncommunicable diseases (NCDs), including cardiovascular disease (CVD), cirrhosis, and non-AIDS-defining cancers (NADCs), have been associated with HIV viremia, CD4 cell counts, and CD4/CD8 ratio in persons living with HIV (PLWH). This study examined the importance of these markers to mortality risk following NCD diagnosis. We examined factors associated with mortality following incident CVD, cirrhosis, or NADCs in a clinical cohort of PLWH between 1998 and 2015. We calculated Kaplan-Meier estimates and used multivariable Cox proportional hazard models. We included 341 patients with NCDs (CVD = 169, cancer = 103, and cirrhosis = 67), of whom 129 died. Median age at NCD diagnosis was 49 years and median proportion of time before NCD with virologic suppression was 64%. Median survival after CVD was longer than for cancer or cirrhosis (11.6 years vs. 4.8 and 3.4 years, respectively; log rank test p < .001). In multivariable Cox proportional hazard models, higher CD4/CD8 ratio preceding NCD (adjusted hazard ratio [aHR] per 0.1 increase = 0.92 [95% confidence interval 0.85-0.99]) and higher CD4 nadir (aHR per 100 cells/μL = 0.84 [0.72-0.97]) were associated with decreased mortality risk. Neither CD4 cell count before NCD nor HIV viremia was statistically associated with mortality in adjusted models. When restricted to 116 patients with virologic suppression for ≥80% of time before NCD, only CD4 nadir was associated with mortality risk. Low CD4/CD8 ratio and CD4 nadir were associated with increased mortality risk after NCD, suggesting that prior immunosuppression or ongoing immune imbalance remain important for outcomes following serious NCDs.

Correlation of CD4/CD8 Ratio with Carotid Intima-Media Layer Thickness in HIV/AIDS Patients at Sanglah General Hospital, Bali, Indonesia

BACKGROUND:

The discovery of antiretroviral (ARV) drugs in 1996 led to a shift in the causes of mortality and morbidity of patients with HIV/AIDS. Initially, the cause of mortality and morbidity was associated with opportunistic infection HIV/AIDS-related complication, but now are more associated with non-AIDS complication such as cardiovascular disease. Atherosclerosis is a major cause of cardiovascular disease. The atherosclerosis was assessed by measuring carotid intima-media thickness (CIMT) using B mode ultrasound (USG), which is one of the diagnostic tools in indicating the presence of atherosclerotic plaque.

AIM:

This study aims to evaluate the ratio of CD4 / CD8 towards carotid intima-media thickness.

METHODS:

Design of study was analytic cross-sectional. This study was conducted in May – July 2017 in HIV patients who taken consecutively came to the VCT polyclinic of Sanglah hospital. Statistical analysis used Spearman correlation test to evaluate the correlation between the CD4/CD8 ratio and carotid intima-media thickness and multiple linear regression to predict carotid intima-media thickness through CD4/CD8 ratio.

RESULTS:

Total from 50 samples, data characteristic were 33 males (66%) and 17 females (34%), mean of age 30.60 ± 5.58 years, median of CD4/CD8 ratio 0.275 (0.02-1.39) and median of CIMT 0.75 (0.4-1.5) mm. There is a strong negative correlation (r = -0.85; p = 0.001) CD4/CD8 ratio with CIMT. The calculation of the prediction of carotid intima media thickness can be calculated through the equation Y = 0.727 -0.791 (X1) + 0.012 (X2), where X1 is CD4/CD8 ratio and X2 is the age of the patient.

CONCLUSION:

there is a significantly strong negative correlation between the CD4/CD8 ratio and CIMT in HIV patient who comes to VCT polyclinic of Sanglah Hospital. The smaller CD4/CD8 ratio, the value of CIMT will be thicker, and vice versa.

CD4/CD8 ratio improvement in HIV-1-infected patients receiving dual antiretroviral treatment

The CD4/CD8 ratio is an indirect marker of immune activation, immune senescence, and inflammation in HIV infection. We performed a prospective study of the CD4/CD8 ratio evolution in 245 virally-suppressed (median, 55 months) HIV-infected patients (29% females) who had switched to four dual antiretroviral regimens. At baseline, the median CD4/CD8 ratio was 0.71 (interquartile range, IQR, 0.46-0.97), associated with duration of HIV infection, nadir CD4+ cell count, and AIDS diagnosis. It was lower in the case of hepatitis C virus coinfection and cardiovascular disease (p = 0.09), but the ratio was higher in patients with chronic kidney disease, proteinuria, or osteoporosis. At 48 weeks, the median CD4/CD8 ratio increased by 3% (+0.02; IQR, -0.07, +0.09; p = 0.07); greater improvement was observed in patients with lower baseline ratios and previous AIDS diagnosis. The slope of increase was slower in patients with the highest baseline values. Also, there were no differences in the CD4/CD8 ratio increase according to type of dual regimen, after adjusting for baseline and HIV-related values. In conclusion, CD4/CD8 ratio increase is observed during suppressive dual regimens, and its extent is related to baseline values and previous HIV-related factors. Longer duration on antiretroviral therapy and drug toxicity could affect the evolution of this marker in the presence of comorbidities.

T cell senescence predicts subclinical atherosclerosis in HIV-infected patients similarly to traditional cardiovascular risk factors

The main objective of this study is to evaluate the predictive capacity of T cell activation/senescence in subclinical atherosclerosis (SCA) in a group of HIV-infected patients. So, a cross-sectional analysis was performed on 91 long-term triple-ART therapy HIV-infected patients from an observational and prospective cohort. Carotid Intima Media Thickness (cIMT) was measured. Binary logistic regression was used to evaluate independent variables associated with SCA. Compared to patients without SCA, patients with SCA (60.4%) were older (41.33 ± 9.04 vs. 51.73 ± 8.44 years old, p < 0.001) and showed Framingham risk score (2.63 ± 3.127 vs. 7.66 ± 5.84, p = 0.008), as well as higher numbers of CD4⁺CD8⁺ double positive T cells (0.50 ± 0.42% vs. 0.81 ± 0.79%, p = 0.037), CD8⁺CD28^- T cells (41.70 ± 16.96% vs. 50.22 ± 16.15%, p = 0.018), higher expression of CD28 on CD8⁺CD28⁺ T cells (1865 ± 789 vs. 2243 ± 917 MFI, P = 0.046). In contrast, they showed lower expression of CD38 on CD19⁺ B cells (65.38 ± 27.47% vs. 42.67 ± 30.26%, P < 0.001). Logistic multivariable analysis showed that Framingham risk score >10% (OR = 14.84, CI95% 1.63-125; p = 0.016) and numbers of CD8⁺CD28^- T cells (OR = 1.032, CI 95% 1-1.065; p = 0.045) were independent factors associated with SCA. Patients with CD8⁺CD28^- T cells ≥59% compared to those <59% had higher risk of SCA (OR = 4, CI95% 1.19-13.3, p = 0.024). Interestingly, 27.4% of patients with low Framingham risk score had elevated levels of CD8⁺CD28^- T cells. In conclusion, immune senescence represented by accumulation of CD8⁺CD28^- T cells may contribute to improve the predictive capacity of the Framingham risk score, especially when the scores are low and can explain, at least in part, the higher prevalence of SCA observed in long-term ART-treated stable HIV infected patients.

Impact of dolutegravir and efavirenz on immune recovery markers: results from a randomized clinical trial

OBJECTIVES

CD4/CD8 ratio and CD4+ T-cell percentage (CD4%) predicts the risk of AIDS and non-AIDS events. Multiple T-cell marker recovery (MTMR) has been proposed as the most complete level of immune reconstitution. We quantified differences in the CD4/CD8 ratio, CD4% recovery and MTMR after starting HIV-1 treatment with dolutegravir/abacavir/lamivudine vs. efavirenz (EFV)/tenofovir (TDF)/emtricitabine (FTC).

METHODS

Exploratory post hoc analysis of the SINGLE study, a randomized double-blind, clinical trial. Percentage differences and corresponding precision based on 95% confidence intervals, and p values were calculated for CD4/CD8 ratio normalization, CD4% normalization and the achievement of MTMR. Cox models taking into account competing risks were used to estimate sub-hazard ratios when comparing the times to normalization of the CD4/CD8 ratio and the CD4% by treatment arm.

RESULTS

Data from 833 participants were analysed (414 in the dolutegravir/abacavir/lamivudine arm). There were no statistically significant differences in the proportion of patients who reached a CD4/CD8 ratio ≥0.5 at weeks 48 and 96. However, at week 96, the proportion of patients with a CD4/CD8 ratio ≥1 was higher in the EFV-TDF-FTC group (difference, 11.70; 95% confidence interval, 4.49-18.91; p 0.002). The decrease from baseline in CD8+ cell count was consistently greater in the EFV-TDF-FTC arm. Analysis of CD4+ percentages showed no significant differences during the study. The proportion of patients attaining a MTMR was higher in the EFV-TDF-FTC group, although the difference was only statistically significant at week 96 (p 0.001).

CONCLUSIONS

EFV-TDF-FTC showed significantly greater increases in CD4/CD8 ratio ≥1.0 or MTMR beyond treatment week 96. Additional studies are necessary to better understand the impact of these findings.

Epidemiology of ischemic heart disease in HIV

PURPOSE OF REVIEW

The purpose of this review is to summarize and synthesize recent data on the risk of ischemic heart disease (IHD) in HIV-infected individuals.

RECENT FINDINGS

Recent studies in the field demonstrate an increasing impact of cardiovascular disease (CVD) on morbidity and mortality in HIV relative to AIDS-related diagnoses. Studies continue to support an approximately 1.5 to two-fold increased risk of IHD conferred by HIV, with specific risk varying by sex and virologic/immunologic status. Risk factors include both traditional CVD risk factors and novel, HIV-specific factors including inflammation and immune activation. Specific antiretroviral therapy (ART) drugs may increase CVD risk, yet the net effect of ART with viral suppression is beneficial with regard to CVD risk. Management of cardiovascular risk and prevention of CVD is complex, because current general population strategies target traditional CVD risk factors only. Extensive investigation is being directed at developing tailored CVD risk prediction algorithms and interventions to reduce CVD risk in HIV.

SUMMARY

Increased IHD risk is a significant clinical and public health challenge in HIV. The development and application of HIV-specific interventions to manage CVD risk factors and reduce CVD risk will improve the long-term health of this ageing population.

Revisiting a quarter of a century of simian immunodeficiency virus (SIV)-associated cardiovascular diseases at the German Primate Center

Human immunodeficiency virus (HIV) comorbidities have become clinically more important due to antiretroviral therapy. Although therapy increases life expectancy, it does not completely suppress immune activation and its associated complications. The simian immunodeficiency virus (SIV)-infected rhesus macaque (Macaca mulatta) represents a valuable model for the investigation of SIV-associated diseases. Although cardiovascular (CV) changes are common in HIV-infected patients, there are only a few reports on the incidence of CV findings in SIV-infected animals. In addition, potential associations between pathohistological findings and hematological parameters are still unclear.

We therefore conducted a retrospective analysis of 195 SIV-infected rhesus macaques that were euthanized with AIDS-related symptoms at the German Primate Center, Goettingen, over a 25-year period. Pathological findings were correlated with hematological data.

The main findings included myocarditis (12.8 %), endocarditis (9.7 %), and arteriopathy (10.3 %) in various organs. Thrombocytopenia occurred more frequently in macaques with endocarditis or arteriopathy than in macaques without CV disease (80 % in animals with endocarditis, 60 % in animals with arteriopathy, p<0.0001 and p=0.0016, respectively).

Further investigations of the interaction between coagulation markers, proinflammatory cytokines, and biomarkers associated with endothelial dysfunction (e.g., D-dimers) and histological data (vascular wall structure) may unravel the mechanisms underlying HIV/SIV-associated CV comorbidities.

Immunological and virological characterization of HIV-1 viremia controllers in the North Region of Brazil

Background

A rare phenotype of clinical non-progressors to AIDS is not well understood and the new protocol for universal treatment, may block the understanding of viral control thus it is crucial to define this controversial group.

Methods

A cohort of 30 persons followed a criteria for viremia control groups 1 (VC1; n = 2) and 2 (VC2; n = 7) and non-viral controllers (NC; n = 21) including number of years of diagnosis, LTCD4⁺, LTCD8⁺ counts, plasma viral load and the absence of ART; 241 uninfected control persons were matched to age and sex. Infected persons were regularly examined and submitted to two or three annual laboratory measurements. Polymorphisms and allele frequencies of CCR5Δ32 and SDF1–3’A were detected in the genomic DNA. Plasma levels of cytokines (IL-2, IL-4, IL-5, IL-9, IL-10, IL-13, IL-17 and IFN-y) were measured.

Results

The group investigated is originated from a miscigenetic population and demographic and social characteristics were not significantly relevant. LTCD4⁺ median values were higher among VC than NC, but significantly lower than uninfected controls. Evolution of LTCD4⁺ and LTCD8⁺ counts, showed a slight increase of LTCD4⁺ among VC, but a significant decrease in the NC. The percentage of annual change in LTCD4⁺ was also significantly different between the groups. LTCD4⁺/LTCD8⁺ ratio was inverted but not significant among the VC, thus the ratio may be a useful biomarker for the VC. A clear signature indicated a change from Th1 to Th2 cytokine profiles from VC to NC, respectively.

Conclusions

The knowledge of viral controllers characteristics in different population groups is important to define a strict universal definition for the sake of learning about the pathogenesis of HIV-1. Data on LTCD4⁺ seems to be stable and repetitive from published data, but the LTCD8⁺ response and the significance of LTCD4⁺/LTCD8⁺ ratio values are in need to further exploration as biomarkers. The change from Th1 to Th2 cytokine profile may help to design and adjust specific treatment protocols for the group.

The CD4/CD8 ratio is associated with coronary artery disease (CAD) in elderly Chinese patients

OBJECTIVE

The aim of this study was to investigate the relationship between number of circulating T cells and coronary artery disease (CAD) in an elderly Chinese population.

METHODS

A total of 295 elderly inpatients (age≥60) were included in this cross-sectional study. Their clinical and biochemical characteristics were recorded. Patients were divided to two groups: control patients and CAD patients. The risk factors of CAD were explored by binary logistic regression analysis.

RESULTS

Compared with control patients, the ratio of CD4 to CD8 T cells was significantly increased in CAD patients. There was no difference in the number of CD3, CD4, and CD8 T cells between the two groups. Multiple logistic regression analysis showed that CAD was independently associated with age, gender, body mass index (BMI), systolic blood pressure (SBP), chronic heart failure (CHF) and the CD4/CD8 ratio. In addition, after adjusting for different clinical parameters (including gender, age, CHF, hypertension, arrhythmia, SBP, and BMI), the risk of CAD was significantly increased in patients with a CD4/CD8 ratio>1.5.

CONCLUSIONS

There was a strong and independent association between the ratio of CD4/CD8 and CAD in elderly Chinese population.

Different impact of raltegravir versus efavirenz on CD4/CD8 ratio recovery in HIV-infected patients

OBJECTIVES

A low CD4/CD8 ratio during treated HIV identifies individuals with heightened immunoactivation and excess mortality. Whether ART regimens elicit distinct CD4/CD8 ratio recovery remains unknown. We aimed to compare the efficacy of an integrase inhibitor versus a non-nucleoside to normalize the CD4/CD8 ratio.

METHODS

We conducted a post hoc analysis of the STARTMRK study, a randomized, blinded, double-dummy Phase III trial of raltegravir versus efavirenz, and each in combination with tenofovir/emtricitabine, in treatment-naive HIV-infected adults. Blinding was maintained for the entire 5 year duration of the study. Kaplan-Meier methods for time-dependent variables were used to calculate the rates of CD4/CD8 normalization at different cut-offs and cumulative probabilities. Cox proportional hazard models were used to compare probabilities of CD4/CD8 normalization by treatment arm.

RESULTS

A total of 563 patients were analysed; 81% were males and the mean age (SD) was 37 (10) years. Raltegravir was associated with higher rates of CD4/CD8 ratio normalization at the >0.4 cut-off (median time to normalization = 56 versus 84 days; P = 0.048 by log-rank test). A Cox proportional hazard model stratified based on baseline CD4 counts showed an association between raltegravir and higher rates of CD4/CD8 ratio normalization (HR = 1.23; P = 0.02).

CONCLUSIONS

We herein show that normalization of the CD4/CD8 ratio above a clinically meaningful threshold may be dependent on the drug class used. Raltegravir showed faster CD4/CD8 ratio normalization compared with efavirenz, a finding with potential clinical implications. Whether other integrase inhibitors have a similar impact for this outcome remains to be explored.