CD8+ T-cells count in acute myocardial infarction in HIV disease in a predominantly male cohort

Higher cardiovascular disease risks in people living with HIV: A systematic review and meta-analysis

Background

The prognosis of AIDS after active antiretroviral therapy (ART) and the quality of life of people living with HIV (PLWH) are both affected by non-AIDS-related diseases such as cardiovascular disease (CVD). However, the specific risk ratios between PLWH and individuals negative for HIV are poorly understood. We aimed to systematically review and investigate the CVD risk factors associated with HIV.

Methods

We searched PubMed, Embase, Web of Science, and Cochrane Library databases between 1 January 2015, and 12 May 2023 for articles reported the prevalence and risk factors of CVD such as hypertension, dyslipidaemia, coronary artery disease (CAD), and myocardial infarction (MI). Due to the high heterogeneity, we used a random-effects model to analyse the data. All statistical analyses were performed using Stata/MP 17.0 with 95% confidence intervals (CIs).

Results

We analysed 31 eligible studies including 312 913 PLWH. People living with HIV had higher risks of dyslipidaemia (hazard ratio (HR) = 1.53; 95% CI = 1.29, 1.82), CAD (HR = 1.37; 95% CI = 1.24, 1.51), and MI (HR = 1.47; 95% CI = 1.28, 1.68) compared to individuals without HIV. However, there were no significant differences in the prevalence of hypertension between groups (HR = 1.17; 95% CI = 0.97, 1.41). Subgroup analysis revealed that men with HIV, PLWH who smoked and the elderly PLWH had a high prevalence of CVD. Moreover, the disease prevalence patterns varied among regions. In the USA and Europe, for instance, some HRs for CVD were higher than in other regions. Active ART initiation after 2015 appears to have a lower risk of CVD (hypertension, hyperlipidaemia, CAD). All outcomes under analysis showed significant heterogeneity (I2>70%, P < 0.001), which the available study-level variables could only partially account for.

Conclusions

People living with HIV had a higher CVD risk than the general population; thus, CVD prevention in PLWH requires further attention. Rapid initiation of ART may reduce the incidence of CVD in PLWH. For timely screening of CVD high-risk individuals and thorough disease management to prevent CVD, further studies are required to evaluate the risk factors for CVD among PLWH, such as age, region, etc.

Registration

PROSPERO (CRD42021255508).

CD4/CD8 ratio and CD8+ T-cell count as prognostic markers for non-AIDS mortality in people living with HIV. A systematic review and meta-analysis

Background

In people living with HIV (PLHIV), the CD4/CD8 ratio has been proposed as a useful marker for non-AIDS events. However, its predictive ability on mortality over CD4 counts, and the role of CD8+ T-cell counts remain controversial.

Methods

We conducted a systematic review and meta-analysis of published studies from 1996 to 2023, including PLHIV on antiretroviral treatment, and reporting CD4/CD8 ratio or CD8+ counts. The primary outcome was non-AIDS mortality or all-cause mortality. We performed a standard random-effects pairwise meta-analysis comparing low versus high CD4/CD8 ratio with a predefined cut-off point of 0.5. (CRD42020170931).

Findings

We identified 2,479 studies for screening. 20 studies were included in the systematic review. Seven studies found an association between low CD4/CD8 ratio categories and increased mortality risk, with variable cut-off points between 0.4-1. Four studies were selected for meta-analysis, including 12,893 participants and 618 reported deaths. Patients with values of CD4/CD8 ratio below 0.5 showed a higher mortality risk (OR 3.65; 95% CI 3.04 - 4.35; I2 = 0.00%) compared to those with higher values. While the meta-analysis of CD8+ T-cell counts was not feasible due to methodological differences between studies, the systematic review suggests a negative prognostic impact of higher values (>1,138 to 1,500 cells/uL) in the long term.

Conclusions

Our results support the use of the CD4/CD8 ratio as a prognostic marker in clinical practice, especially in patients with values below 0.5, but consensus criteria on ratio timing measurement, cut-off values, and time to event are needed in future studies to get more robust conclusions.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020170931, identifier CRD42020170931.

The association between the CD4/CD8 ratio and surgical site infection risk among HIV-positive adults: insights from a China hospital

Purpose

It is well known that the CD4/CD8 ratio is a special immune-inflammation marker. We aimed to explore the relationship between the CD4/CD8 ratio and the risk of surgical site infections (SSI) among human immunodeficiency virus (HIV)-positive adults undergoing orthopedic surgery.

Methods

We collected and analyzed data from 216 HIV-positive patients diagnosed with fractures at the department of orthopedics, Beijing Ditan Hospital between 2011 and 2019. The demographic, surgical, and hematological data for all patients were collected in this retrospective cohort study. We explored the risk factors for SSI using univariate and multivariate logistic regression analysis. Then, the clinical correlation between the CD4 count, CD4/CD8 ratio, and SSI was studied using multivariate logistic regression models after adjusting for potential confounders. Furthermore, the association between the CD4/CD8 ratio and SSI was evaluated on a continuous scale with restricted cubic spline (RCS) curves based on logistic regression models.

Results

A total of 23 (10.65%) patients developed SSI during the perioperative period. Patients with hepatopathy (OR=6.10, 95%CI=1.46-28.9), HIV viral load (OR=8.68, 95%CI=1.42-70.2; OR=19.4, 95%CI=3.09-179), operation time (OR=7.84, 95%CI=1.35-77.9), and CD4 count (OR=0.05, 95%CI=0.01-0.23) were risk factors for SSI (P-value < 0.05). Our study demonstrated that a linear relationship between CD4 count and surgical site infection risk. In other words, patients with lower CD4 counts had a higher risk of developing SSI. Furthermore, the relationship between CD4/CD8 ratio and SSI risk was non-linear, inverse 'S' shaped. The risk of SSI increased substantially when the ratio was below 0.913; above 0.913, the risk of SSI was almost unchanged. And there is a 'threshold-saturation' effect between them.

Conclusion

Our research shows the CD4/CD8 ratio could be a useful predictor and immune-inflammation marker of the risk of SSI in HIV-positive fracture patients. These results, from a Chinese hospital, support the beneficial role of immune reconstitution in HIV-positive patients prior to orthopedic surgery.

Circulating T Cells and Cardiovascular Risk in People With and Without HIV Infection

BACKGROUND

Lower CD4+ cell count in people with HIV infection (PWH) is associated with increased cardiovascular disease (CVD) risk. Whether subsets of CD4+ T helper cells are linked with CVD is unclear.

OBJECTIVES

The aim of this study was to explore the association between peripherally circulating CD4+ T cell subsets and incident CVD.

METHODS

Data from 1,860 participants (1,270 PWH) without prevalent CVD from the VACS (Veterans Aging Cohort Study), a prospective, observational cohort of veterans with and without HIV infection, were analyzed. T cell subsets were quantified in baseline samples using flow cytometry. Incident CVD events were identified using International Classification of Diseases-9th Revision and International Classification of Diseases-10th Revision diagnosis and procedure codes. Participants were followed from baseline date (2005-2006) to the first of CVD incidence, death, or September 30, 2016. Cox proportional hazards regression was used to model associations between these T cell subsets and the risk for incident CVD while adjusting for demographics and other CVD risk factors.

RESULTS

The median participant age at baseline was 51.6 years. Most were male (94%) and of Black race (69.1%). There were 344 incident CVD events (219 in PWH) during follow-up (median 9.8 years). In PWH, higher proportions (per SD increment) of T helper type 17 cells (adjusted HR: 1.19; 95% CI: 1.08-1.31), T effector memory cells re-expressing CD45RA (adjusted HR: 1.19; 95% CI: 1.07-1.34), and CD28null cells (adjusted HR: 1.18; 95% CI: 1.03-1.34) were significantly associated with an increased risk for incident CVD. Among those without HIV infection, no T cell subsets were significantly associated with CVD.

CONCLUSIONS

Among PWH, T helper type 17 cells, senescent cells, and CD4+ T effector memory cells re-expressing CD45RA were significantly associated with incident CVD that was not explained by CVD risk factors.

Predictive value of CD8+ T cell and CD4/CD8 ratio at two years of successful ART in the risk of AIDS and non-AIDS events

BACKGROUND

While increased CD8 counts and low CD4/CD8 ratio during treated HIV correlate with immunosenescence, their additional predictive values to identify individuals with HIV at higher risk of clinical events remain controversial.

METHODS

We selected treatment-naive individuals initiating ART from ACTG studies 384, 388, A5095, A5142, A5202, and A5257 who had achieved viral suppression at year 2. We examined the effect of CD8+ T cell counts and CD4/CD8 at year 2 on the probability of AIDS and serious non-AIDS events in years 3-7. We used inverse probability weighting methods to address informative censoring, combined with multivariable logistic regression models.

FINDINGS

We analyzed 5133 participants with a median age of 38 years; 959 (19%) were female, pre-ART median CD4 counts were 249 (Q1-Q3 91-372) cell/µL. Compared to participants with CD8 counts between 500/µL and 1499/µL, those with >1500/µL had a higher risk of clinical events during years 3-7 (aOR 1.75; 95%CI 1.33-2.32). CD4/CD8 ratio was not predictive of greater risk of events through year 7. Additional analyses revealed consistent CD8 count effect sizes for the risk of AIDS events and noninfectious non-AIDS events, but opposite effects for the risk of severe infections, which were more frequent among individuals with CD8 counts <500/µL (aOR 1.70; 95%CI 1.09-2.65).

INTERPRETATION

The results of this analysis with pooled data from clinical trials support the value of the CD8 count as a predictor of clinical progression. People with very high CD8 counts during suppressive ART might benefit from closer monitoring and may be a target population for novel interventions.

FUNDING

This research was supported by NIH/NIAID awards UM1 AI068634, UM1 AI068636, and UM1 AI106701 and Carlos III Health Institute and FEDER funds (BA21/00017 and BA21/00022).

Residual immune dysfunction under antiretroviral therapy

The usage of combination antiretroviral therapy in people with HIV (PWH) has incited profound improvement in morbidity and mortality. Yet, PWH may not experience full restoration of immune function which can manifest with non-AIDS comorbidities that frequently associate with residual inflammation and can imperil quality of life or longevity. In this review, we discuss the pathogenesis underlying chronic inflammation and residual immune dysfunction in PWH, as well as potential therapeutic interventions to ameliorate them and prevent incidence or progression of non-AIDS comorbidities. Current evidence advocates that early diagnosis and prompt initiation of therapy at high CD4 counts may represent the best available approach for an improved immune recovery in PWH.

[Cardiovascular risk calculators for people living with human immunodeficiency virus]

The increasing access and efficacy of antiretroviral therapy has allowed people living with human immunodeficiency virus to achieve a life expectancy similar to that of the general population. However, this goal may be affected by the increased risk of cardiovascular disease in this group. This risk is multifactorial, involving the high prevalence of traditional risk factors, the development of a pro-inflammatory state related to chronic infection, and the use of antiretroviral drugs with an adverse metabolic profile. In daily practice, in order to estimate this risk and guide medical decision-making, different calculators are available. These are based on data from population cohorts, many of them from human immunodeficiency virusnegative subjects. The main aim of this review is to describe the epidemiology of cardiovascular disease in people living with human immunodeficiency virus, the available risk calculators and their use.

Causative factors of liver fibrosis in HIV-infected patients. A single center study

BACKGROUND

Liver disease is a leading cause of morbidity and mortality among Human Immunodeficiency virus (HIV) infected patients; however no consensus exists on HIV-related risk factors for it. The aim of this study was to identify risk factors for liver fibrosis/cirrhosis in a cohort of Greek HIV-infected patients.

METHODS

Patients attending the HIV outpatient clinic of Pathophysiology Department at «Laiko» General Hospital in Athens, Greece, between December 2014 and December 2017 were eligible for inclusion. Inclusion criteria were confirmed HIV infection and age > 18 years. Exclusion criteria were Body-Mass index (BMI) > 40, liver metastases of malignant diseases and concurrent or previous chemotherapy. Liver stiffness (LS) was measured using Vibration Controlled Transient Elastography (TE) and laboratory tests were acquired in all patients. Patients were classified in 2 groups: those with mild or no fibrosis (equivalent to Metavir score F0-F2) and those with significant fibrosis (equivalent to Metavir score F3-F4).

RESULTS

A total of 187 consecutive patients were included in this study. Median TE value was 5.1 kilopascals (KPa) (range 2.8-26.3), with 92.5% (173/187) of the patients having no/mild fibrosis and 7.4% (14/187) significant fibrosis. On multivariate logistic regression analysis older patient's age, abnormal serum aspartate aminotransferase (AST) value, Hepatitis C virus (HCV) infection, alcohol abuse, CD4/CD8 ratio and an increased number of liver related events (LREs) were significantly correlated with liver fibrosis/cirrhosis.

CONCLUSIONS

In our cohort of HIV-infected individuals HCV/HIV co-infection, older age, alcohol abuse and CD4/CD8 ratio seem to correlate with fibrogenesis in the liver.

Trends in the risk of myocardial infarction among HIV-1-infected individuals relative to the general population in France: Impact of gender and immune status

We examined trends in the MI incidence and age at MI diagnosis among adults living with HIV-1 between 2000 and 2009, by comparison with the French MI registries, by gender. Age standardized incidence rates and standardized incidence-ratios (SIRs) were estimated for individuals included in the French hospital database on HIV (n = 71 204, MI = 663) during three periods: 2000-2002, 2003-2005 and 2006-2009. Median ages at MI diagnosis were compared using the Brown-Mood test. Over the study periods, the absolute rate difference and relative risks were higher in women than in men in 2000-2002 and 2006-2009, with respective SIRs 1.99 (1.39-2.75) and 1.12 (0.99-1.27) in 2006-2009. The trends were different for men and women with a decreasing trend in SIRs in men and no change in women. In both sexes, among individuals with CD4 ≥500/μL and controlled viral-load on cART, the risk was no longer elevated. Age at MI diagnosis was significantly younger than in the general population, especially among women (-6.2 years, p<0.001; men: -2.1 years, p = 0.02). In HIV-1-positive adults, absolute rate difference and relative risks and trends of MI were different between men and women and there was no additional risk among individuals on effective cART.

Inflammatory cells and their non-coding RNAs as targets for treating myocardial infarction

Myocardial infarction triggers infiltration of several types of immune cells that coordinate both innate and adaptive immune responses. These play a dual role in post-infarction cardiac remodeling by initiating and resolving inflammatory processes, which needs to occur in a timely and well-orchestrated way to ensure a reestablishment of normalized cardiac functions. Thus, therapeutic modulation of immune responses might have benefits for infarct patients. While such strategies have shown great potential in treating cancer, applications in the post-infarction context have been disappointing. One challenge has been the complexity and plasticity of immune cells and their functions in cardiac regulation and healing. The types appear in patterns that are temporally and spatially distinct, while influencing each other and the surrounding tissue. A comprehensive understanding of the immune cell repertoire and their regulatory functions following infarction is sorely needed. Processes of cardiac remodeling trigger additional genetic changes that may also play critical roles in the aftermath of cardiovascular disease. Some of these changes involve non-coding RNAs that play crucial roles in the regulation of immune cells and may, therefore, be of therapeutic interest. This review summarizes what is currently known about the functions of immune cells and non-coding RNAs during post-infarction wound healing. We address some of the challenges that remain and describe novel therapeutic approaches under development that are based on regulating immune responses through non-coding RNAs in the aftermath of the disease.

Posttransplant Immune Activation: Innocent Bystander or Insidious Culprit of Posttransplant Accelerated Atherosclerosis

Cardiovascular disease is a major cause of morbidity, disability, and mortality in kidney transplant patients. Cumulative reports indicate that the excessive risk of cardiovascular events is not entirely explained by the increased prevalence of traditional cardiovascular risk factors. Atherosclerosis is a chronic inflammatory disease, and it has been postulated that posttransplant immune disturbances may explain the gap between the predicted and observed risks of cardiovascular events. Although concordant data suggest that innate immunity contributes to the posttransplant accelerated atherosclerosis, only few arguments plead for a role of adaptive immunity. We report and discuss here consistent data demonstrating that CD8⁺ T cell activation is a frequent posttransplant immune feature that may have pro-atherogenic effects. Expansion of exhausted/activated CD8⁺ T cells in kidney transplant recipients is stimulated by several factors including cytomegalovirus infections, lymphodepletive therapy (e.g., antithymocyte globulins), chronic allogeneic stimulation, and a past history of renal insufficiency. This is observed in the setting of decreased thymic activity, a process also found in elderly individuals and reflecting accelerated immune senescence.

Combining CD4 recovery and CD4: CD8 ratio restoration as an indicator for evaluating the outcome of continued antiretroviral therapy: an observational cohort study

OBJECTIVES

Immune recovery following highly active antiretroviral therapy (HAART) is commonly assessed by the degree of CD4 reconstitution alone. In this study, we aimed to assess immune recovery by incorporating both CD4 count and CD4:CD8 ratio.

DESIGN

Observational cohort study SETTING AND PARTICIPANTS: Clinical data from Chinese HIV-positive patients attending the largest HIV service in Hong Kong and who had been on HAART for ≥4 years were accessed.

MAIN OUTCOME MEASURES

Optimal immune outcome was defined as a combination of a CD4 count ≥500/μL and a CD4:CD8 ratio ≥0.8.

RESULTS

A total of 718 patients were included for analysis (6353 person-years). At the end of year 4, 318 out of 715 patients achieved CD4 ≥500/μL, of which only 33% (105 out of 318) concurrently achieved CD4:CD8 ratio ≥0.8. Patients with a pre-HAART CD8 ≤800/μL (428 out of 704) were more likely to be optimal immune outcome achievers with CD4 ≥500/μL and CD4:CD8 ratio ≥0.8, the association of which was stronger after adjusting for pre-HAART CD4 counts. In a multivariable logistic model, optimal immune outcome was positively associated with male gender, younger pre-HAART age and higher pre-HAART CD4 count, longer duration of HAART and pre-HAART CD8 ≤800/μL. Treatment regimen and cumulative viral loads played no significant role in the pattern of immune recovery.

CONCLUSIONS

A combination of CD4 count and CD4:CD8 ratio could be a useful approach for the characterisation of treatment outcome over time, on top of monitoring CD4 count alone.

CCR5+ CD8 T-cell levels and monocyte activation precede the onset of acute coronary syndrome in HIV-infected patients on antiretroviral therapy

Acute coronary syndrome (ACS) is nowadays one of the leading causes of morbid-mortality in HIV-infected population, but innate and adaptive immune mechanisms preceding this event are unknown. In this work we comprehensively and longitudinally observed, by multiparametric flow cytometry and following a case-control design, increased CCR5⁺CD8⁺ T-cells levels and monocytes expressing activation and adhesion markers in HIV-infected patients who are going to suffer ACS. In addition, we found direct associations between activated CD8⁺ T-cells and myeloid cells that were only statistically significant in the group of patients with ACS and in the follow up time point just before the ACS. Our data highlight the important role of CCR5 in the onset of ACS and suggest this receptor as a marker of cardiovascular risk and potential therapeutic target to prevent the development of such non-AIDS-related event in HIV-infected patients.

Role of T-Cell Dysfunction, Inflammation, and Coagulation in Microvascular Disease in HIV

BACKGROUND

Compared to uninfected adults, HIV-infected adults on antiretroviral therapy are at increased risk of cardiovascular disease. Given the increase in T-cell dysfunction, inflammation, and coagulation in HIV infection, microvascular dysfunction is thought to contribute to this excess cardiovascular risk. However, the relationships between these variables remain undefined.

METHODS AND RESULTS

This was a cross-sectional study of 358 HIV-infected adults from the SCOPE cohort. Macrovascular endothelial function was assessed using flow-mediated dilation of the brachial artery and microvascular function by reactive hyperemia. T-cell phenotype was determined by flow cytometry. Plasma markers of inflammation (tumor necrosis factor-α, interleukin-6, high-sensitivity C-reactive protein, sCD14) and coagulation (fibrinogen, D-dimer) were also measured. In all HIV+ subjects, markers of inflammation (tumor necrosis factor-α, high-sensitivity C-reactive protein), coagulation (D-dimer) and T-cell activation (CD8+PD1+, CD4+interferon+cytomegalovirus-specific) were associated with worse reactive hyperemia after adjusting for traditional cardiovascular risk factors and co-infections. In treated and suppressed subjects, tumor necrosis factor-α and CD8+PD1+ cells remained associated with worse reactive hyperemia after adjustment. Compared to the untreated subjects, CD8+PD1+ cells were increased in the virally suppressed group. Reactive hyperemia was predictive of flow-mediated dilation.

CONCLUSIONS

CD8+PD1+ cells and tumor necrosis factor-α were associated with microvascular dysfunction in all HIV+ subjects and the treated and suppressed group. Additionally, D-dimer, high-sensitivity C-reactive protein, sCD-14, and interleukin-6 were associated with microvascular dysfunction in all HIV+ subjects. Although T-cell dysfunction, inflammation, and microvascular dysfunction are thought to play a role in cardiovascular disease in HIV, this study is the first to look at which T-cell and inflammatory markers are associated with microvascular dysfunction in HIV-infected individuals.

CD4+/CD8+ ratio, age, and risk of serious noncommunicable diseases in HIV-infected adults on antiretroviral therapy

OBJECTIVE

In virologically suppressed HIV-infected adults, noncommunicable diseases (NCDs) have been associated with immune senescence and low CD4/CD8 lymphocyte ratio. Age differences in the relationship between CD4/CD8 ratio and NCDs have not been described.

DESIGN

Observational cohort study.

METHODS

We assessed CD4/CD8 ratio and incident NCDs (cardiovascular, cancer, liver, and renal diseases) in HIV-infected adults started on antiretroviral therapy between 1998 and 2012. Study inclusion began once patients maintained virologic suppression for 12 months (defined as baseline). We examined age and baseline CD4/CD8 ratio and used Cox proportional hazard models to assess baseline CD4/CD8 ratio and NCDs.

RESULTS

This study included 2006 patients. Low baseline CD4/CD8 ratio was associated with older age, male sex, and low CD4 lymphocyte counts. In models adjusting for CD4 lymphocyte count, CD4/CD8 ratio was inversely associated with age (P < 0.01). Among all patients, 182 had incident NCDs, including 46 with coronary artery disease (CAD) events. CD4/CD8 ratio was inversely associated with risk of CAD events [adjusted HR per 0.1 increase in CD4/CD8 ratio = 0.87, 95% confidence interval (CI): 0.76-0.99, P = 0.03]. This association was driven by those under age 50 years (adjusted HR 0.83 [0.70-0.97], P = 0.02) vs. those over age 50 years (adjusted HR = 0.96 [0.79-1.18], P = 0.71). CD4/CD8 ratio was not significantly associated with incident noncardiac NCDs.

CONCLUSIONS

Higher CD4/CD8 ratio after 1 year of HIV virologic suppression was independently predictive of decreased CAD risk, particularly among younger adults. Advanced immune senescence may contribute to CAD events in younger HIV patients on antiretroviral therapy.