Arterial inflammation in patients with HIV

HIV infection and arterial inflammation assessed by (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET): a prospective cross-sectional study

BACKGROUND

HIV-infected patients are at increased risk of myocardial infarction and arterial inflammation has been suggested as a pathophysiological explanation. We compared the uptake of (18)F-fluorodeoxyglucose (FDG) by PET in four arterial regions, and factors associated with FDG uptake in well-treated HIV-infected patients without cardiovascular disease (CVD) and healthy controls.

METHODS AND RESULTS

We prospectively scanned 26 HIV-infected patients on stable antiretroviral therapy and 25 healthy volunteers with FDG PET/CT, measuring standardized uptake values (SUV) in the carotid arteries, the ascending, descending, and abdominal aorta. We performed correlation analyses between FDG uptake and intima-media thickness (IMT), and soluble biomarkers of inflammation. We found no difference in arterial FDG uptake between the HIV-infected patients and healthy controls quantified either as mean SUVmax or target-to background ratio in the carotid region, the ascending aorta, the descending aorta, or the abdominal aorta. Correlations between SUV, IMT, and soluble biomarkers were scarce in both groups.

CONCLUSION

In a group of optimally treated HIV-infected patients with full viral suppression, low Framingham risk score and no known CVD, we found no evidence of increased arterial inflammation as assessed by FDG PET/CT compared to healthy volunteers.

High Soluble CD14 Levels at Primary HIV-1 Infection Predict More Rapid Disease Progression

The soluble CD14 (sCD14) level was found associated with mortality during the chronic phase of human immunodeficiency virus (HIV) infection. Here we assessed its prognostic value in 138 patients with primary HIV infection. Higher sCD14 levels were associated with death, from myocardial infarction, but this was based on 3 deaths only. Among 68 untreated patients, those with higher sCD14 levels had more rapid spontaneous CD4 cell decline during the first 18 months following primary infection. This association persisted after adjustment for age, the CD4 cell count, and HIV viral load at diagnosis.

Increased mortality after a first myocardial infarction in human immunodeficiency virus-infected patients; a nested cohort study

AIMS

HIV infection may be associated with an increased recurrence rate of myocardial infarction. Our aim was to determine whether HIV infection is a risk factor for worse outcomes in patients with coronaray artery disease.

METHODS

We compared data aggregated from two ongoing cohorts: (i) the Acute Myocardial Infarction in Switzerland (AMIS) registry, which includes patients with acute myocardial infarction (AMI), and (ii) the Swiss HIV Cohort Study (SHCS), a prospective registry of HIV-positive (HIV+) patients. We included all patients who survived an incident AMI occurring on or after 1st January 2005. Our primary outcome measure was all-cause mortality at one year; secondary outcomes included AMI recurrence and cardiovascular-related hospitalisations. Comparisons used Cox and logistic regression analyses, respectively.

RESULTS

There were 133 HIV+, (SHCS) and 5,328 HIV-negative [HIV-] (AMIS) individuals with incident AMI. In the SHCS and AMIS registries, patients were predominantly male (72% and 85% male, respectively), with a median age of 51 years (interquartile range [IQR] 46-57) and 64 years (IQR 55-74), respectively. Nearly all (90%) of HIV+ individuals were on successful antiretroviral therapy. During the first year of follow-up, 5 (3.6%) HIV+ and 135 (2.5%) HIV- individuals died. At one year, HIV+ status after adjustment for age, sex, calendar year of AMI, smoking status, hypertension and diabetes was associated with a higher risk of death (HR 4.42, 95% CI 1.73-11.27). There were no significant differences in recurrent AMIs (4 [3.0%] HIV+ and 146 [3.0%] HIV- individuals, OR 1.16, 95% CI 0.41-3.27) or in hospitalization rates (OR 0.68 [95% CI 0.42-1.11]).

CONCLUSIONS

HIV infection was associated with a significantly increased risk of all-cause mortality one year after incident AMI.

Plaque burden in HIV-infected patients is associated with serum intestinal microbiota-generated trimethylamine

OBJECTIVE

Some intestinal microbiota-generated metabolites of phosphatidylcholine are recognized to be proatherogenic. As the HIV population is vulnerable to cardiovascular disease and can develop intestinal dysbiosis associated with systemic inflammation, we investigated the novel relationship between microbiota-derived metabolites of phosphatidylcholine and coronary atherosclerosis in HIV.

DESIGN/METHODS

One hundred and fifty-five HIV-infected and 67 non-HIV-infected individuals without known history of cardiovascular disease were previously recruited to assess coronary plaque by computed tomography angiography. In the current study, we evaluate whether serum choline, trimethylamine (TMA), or trimethylamine-N-oxide (TMAO) levels are associated with plaque features.

RESULTS

Young, asymptomatic HIV-infected patients (age 47 ± 7 years) demonstrated significantly higher prevalence of plaque (53 vs. 35%, P = 0.01) and number of total plaque segments (1.8 ± 2.5 vs. 1.2 ± 2.2, P = 0.03) when compared with well matched noninfected individuals with similar comorbidities. TMA was significantly associated with calcium score (r = 0.22, P = 0.006), number of total (r = 0.20, P = 0.02) and calcified (r = 0.18, P = 0.03) plaque segments, and calcium plaque volume (r = 0.19, P = 0.02) and mass (r = 0.22, P = 0.009) in the HIV cohort only. In multivariate modeling among HIV-infected patients, TMA remained significantly associated with calcium score (P = 0.008), number of total (P = 0.005) and calcified (P = 0.02) plaque segments, and calcium plaque volume (P = 0.01) and mass (P = 0.007), independent of Framingham risk score. In contrast, there was no association of TMAO to coronary plaque features in either cohort.

CONCLUSION

A link between TMA and atherosclerosis has not previously been established. The current study suggests that TMA may be a nontraditional risk factor related to the number of plaque segments and severity of calcified plaque burden in HIV.

Anaemia is associated with monocyte activation in HIV-infected adults on antiretroviral therapy

BACKGROUND

Anaemia has been linked with mortality in HIV infection. The mechanism of anaemia in the era of contemporary antiretroviral therapy is not understood. The aim of this study was to describe the association between anaemia and markers of immune activation and inflammation in a cohort of HIV-infected adults on stable antiretroviral therapy.

METHODS

We performed a cross-sectional study of HIV-infected adults on antiretroviral therapy with HIV-1 RNA<1,000 copies/ml. Soluble and cellular markers of inflammation and immune activation were measured. Relationships between haemoglobin levels, anaemia (haemoglobin <13 g/dl for men and <12 g/dl for women) and mild anaemia (haemoglobin <14 g/dl for men and <13 g/dl for women) and these markers were explored using multivariable linear regression.

RESULTS

Among the 147 participants, median age was 46 years, 78% were men, 68% were African American and 29% were Caucasian. Median body mass index (BMI) was 26.7 kg/m(2), nadir and current CD4(+) T-cell counts were 179 and 613 cells/mm(3), respectively, and 78% had HIV-1 RNA<50 copies/ml (range 20-600 copies/ml). Median (IQR) haemoglobin was 14.3 (13.1-15.1) g/dl; 14% were anaemic and 33% had at least mild anaemia. In multivariable analyses, mild anaemia was independently associated with female sex, older age, shorter duration of antiretroviral therapy, lower white blood cell count, higher platelet count, higher sCD14 and a greater number of CD14(dim)CD16(+) cells or 'patrolling' monocytes, which remained significant after further adjusting for race and BMI.

CONCLUSIONS

Having haemoglobin <14 g/dl for men and <13 g/dl for women was independently associated with monocyte activation (sCD14 and CD14(dim)CD16(+) cells) in HIV-infected adults on stable antiretroviral therapy.

The CD14 C-260T single nucleotide polymorphism (SNP) modulates monocyte/macrophage activation in treated HIV-infected individuals

Background

HIV-infected individuals have an increased risk of cardiovascular disease (CVD). T-allele carriers of the CD14 C-260T single-nucleotide polymorphism (SNP) have reported increased expression of the LPS-binding receptor, CD14 and inflammation in the general population. Our aim was to explore the relationship of this SNP with monocyte/macrophage activation and inflammation and its association with sub-clinical atherosclerosis in HIV-infected individuals.

Methods

Patients with no pre-existing CVD risk factors on suppressive antiretroviral therapy were recruited from University Malaya Medical Centre, Malaysia (n = 84). The CD14 C-260T and TLR4 SNPs, Asp299Gly and Thr399Ile were genotyped and soluble(s) CD14 and sCD163 and high-sensitivity C-reactive protein, hsCRP were measured in plasma. Subclinical atherosclerosis was assessed by measuring carotid intima media thickness (cIMT). The association between CD14 C-260T SNP carriage and cIMT was assessed in a multivariable quantile regression model where a p-value of <0.05 was considered significant.

Results

We found the CD14 C-260T T-allele in 56% of the cohort and evidence of subclinical atherosclerosis in 27%. TT genotype was associated with higher sCD163 (p = 0.009) but only marginally higher sCD14 (p = 0.209) and no difference in hsCRP (p = 0.296) compared to CC/CT. In multivariable analysis, only Framingham risk score was independently associated with higher cIMT while lower sCD163 was trending towards significance. No association was found in TT-genotype carriers and cIMT measurements.

Conclusion

The CD14 C-260T SNP was associated with increased monocyte activation but not systemic inflammation or cIMT in this HIV-infected cohort with low CVD risk profile.

Soluble CD163 is associated with shortened telomere length in HIV-infected patients

Telomere length (TL) and immune activation markers were measured in a cohort of HIV-infected (n = 102) and age-matched non-HIV-infected (n = 41) men. TL was significantly shorter in HIV-infected compared with non-HIV-infected subjects (P = 0.04). Univariate analysis revealed a strong inverse relationship of TL to sCD163, and thus, monocyte/macrophage activation, among the HIV group (ρ = -0.30, P = 0.003). In multivariate modeling among the whole group, HIV-positive serostatus (P = 0.06) and sCD163 (P = 0.05) remained predictors of TL controlling for age and smoking status. Our data demonstrate that increased immune activation relates to shorter TL in HIV.

Cardiovascular disease risk in an aging HIV population: not just a question of biology

PURPOSE OF REVIEW

The objective of this review is to appraise recently published literature that describes the relationship between HIV, biologic and environmental risk factors, and cardiovascular disease (CVD) risk with particular emphasis on the aging HIV population and to demonstrate that these biologic and environmental factors may interact to increase the risk of CVD in the HIV population.

RECENT FINDINGS

The mechanisms linking HIV and CVD are multifactorial and encompass biological and 'environmental' modalities including multimorbid conditions that co-occur with HIV, immunologic alterations associated with HIV, polypharmacy (which affects adherence and increases likelihood of adverse drug-drug interactions) and healthcare disparities in CVD risk reduction by HIV status.

SUMMARY

Data regarding optimal treatment strategies that balance immunological restoration and CVD risk reduction are needed.

Differential levels of soluble inflammatory markers by human immunodeficiency virus controller status and demographics

Background. Human immunodeficiency virus (HIV)-1 elite controllers (ECs) represent an ideal population to study the effects of HIV persistence on chronic inflammation in the absence of antiretroviral therapy (ART).

Methods. Twenty inflammatory markers measured in cohorts of ECs, HIV suppressed noncontrollers, and HIV-uninfected controls were compared using rank-based tests and partial least squares discriminant analysis (PLSDA). Spearman correlations were determined among the inflammatory markers, residual viremia by the single-copy assay, and CD4⁺ T cell slope.

Results. Significant differences were seen between cohorts in 15 of the soluble inflammatory markers. Human immunodeficiency virus-1 ECs were found to have the highest levels for all of the markers with the exception of RANTES. In particular, median levels of 7 inflammatory markers (soluble CD14 [sCD14], interferon [IFN]-γ, IFN-γ-inducible protein [IP]-10, interleukin [IL]-4, IL-10, sCD40L, and granulocyte-macrophage colony-stimulating factor) were twice as high in the HIV-1 ECs compared with either of the HIV-suppressed or uninfected groups. Multivariate PLSDA analysis of inflammatory markers improved differentiation between the patient cohorts, discerning gender differences in inflammatory profile amongst individuals on suppressive ART. Soluble markers of inflammation in ECs were not associated with either levels of residual HIV-1 viremia or CD4⁺ T cell decline.

Conclusions. Despite maintaining relatively low levels of viremia, HIV-1 ECs had elevated levels of a set of key inflammatory markers. Additional studies are needed to determine whether ECs may benefit from ART and to further evaluate the observed gender differences.

Effects of statin therapy on coronary artery plaque volume and high-risk plaque morphology in HIV-infected patients with subclinical atherosclerosis: a randomised, double-blind, placebo-controlled trial

BACKGROUND

HIV-infected patients have a high risk of myocardial infarction. We aimed to assess the ability of statin treatment to reduce arterial inflammation and achieve regression of coronary atherosclerosis in this population.

METHODS

In a randomised, double-blind, placebo-controlled trial, 40 HIV-infected participants with subclinical coronary atherosclerosis, evidence of arterial inflammation in the aorta by fluorodeoxyglucose (FDG)-PET, and LDL-cholesterol concentration of less than 3.37 mmol/L (130 mg/dL) were randomly assigned (1:1) to 1 year of treatment with atorvastatin or placebo. Randomisation was by the Massachusetts General Hospital (MGH) Clinical Research Pharmacy with a permuted-block algorithm, stratified by sex with a fixed block size of four. Study codes were available only to the MGH Research Pharmacy and not to study investigators or participants. The prespecified primary endpoint was arterial inflammation as assessed by FDG-PET of the aorta. Additional prespecified endpoints were non-calcified and calcified plaque measures and high risk plaque features assessed with coronary CT angiography and biochemical measures. Analysis was done by intention to treat with all available data and without imputation for missing data. The trial is registered with ClinicalTrials.gov, number NCT00965185.

FINDINGS

The study was done from Nov 13, 2009, to Jan 13, 2014. 19 patients were assigned to atorvastatin and 21 to placebo. 37 (93%) of 40 participants completed the study, with equivalent discontinuation rates in both groups. Baseline characteristics were similar between groups. After 12 months, change in FDG-PET uptake of the most diseased segment of the aorta was not different between atorvastatin and placebo, but technically adequate results comparing longitudinal changes in identical regions could be assessed in only 21 patients (atorvastatin Δ -0.03, 95% CI -0.17 to 0.12, vs placebo Δ -0.06, -0.25 to 0.13; p=0.77). Change in plaque could be assessed in all 37 people completing the study. Atorvastatin reduced non-calcified coronary plaque volume relative to placebo: median change -19.4% (IQR -39.2 to 9.3) versus 20.4% (-7.1 to 94.4; p=0.009, n=37). The number of high-risk plaques was significantly reduced in the atorvastatin group compared with the placebo group: change in number of low attenuation plaques -0.2 (95% CI -0.6 to 0.2) versus 0.4 (0.0, 0.7; p=0.03; n=37); and change in number of positively remodelled plaques -0.2 (-0.4 to 0.1) versus 0.4 (-0.1 to 0.8; p=0.04; n=37). Direct LDL-cholesterol (-1.00 mmol/L, 95% CI -1.38 to 0.61 vs 0.30 mmol/L, 0.04 to 0.55, p<0.0001) and lipoprotein-associated phospholipase A2 (-52.2 ng/mL, 95% CI -70.4 to -34.0, vs -13.3 ng/mL, -32.8 to 6.2; p=0.005; n=37) decreased significantly with atorvastatin relative to placebo. Statin therapy was well tolerated, with a low incidence of clinical adverse events.

INTERPRETATION

No significant effects of statin therapy on arterial inflammation of the aorta were seen as measured by FDG-PET. However, statin therapy reduced non-calcified plaque volume and high-risk coronary plaque features in HIV-infected patients. Further studies should assess whether reduction in high-risk coronary artery disease translates into effective prevention of cardiovascular events in this at-risk population.

FUNDING

National Institutes of Health, Harvard Clinical and Translational Science Center, National Center for Research Resources.

Splenic metabolic activity predicts risk of future cardiovascular events: demonstration of a cardiosplenic axis in humans

OBJECTIVES

This study sought to determine whether splenic activation after acute coronary syndrome (ACS) is linked to leukocyte proinflammatory remodeling and whether splenic activity independently predicts the risk of cardiovascular disease (CVD) events.

BACKGROUND

Pre-clinical data suggest the existence of a cardiosplenic axis, wherein activation of hematopoietic tissues (notably in the spleen) results in liberation of proinflammatory leukocytes and accelerated atherosclerotic inflammation. However, it is presently unknown whether a cardiosplenic axis exists in humans and whether splenic activation relates to CVD risk.

METHODS

(18)F-fluorodeoxyglucose ((18)FDG)-positron emission tomography (PET) imaging was performed in 508 individuals across 2 studies. In the first study, we performed FDG-PET imaging in 22 patients with recent ACS and 22 control subjects. FDG uptake was measured in spleen and arterial wall, whereas proinflammatory gene expression of circulating leukocytes was assessed by quantitative real-time polymerase chain reaction. In a second study, we examined the relationship between splenic tissue FDG uptake with subsequent CVD events during follow-up (median 4 years) in 464 patients who previously had undergone FDG-PET imaging.

RESULTS

Splenic activity increased after ACS and was significantly associated with multiple indices of inflammation: 1) up-regulated gene expression of proinflammatory leukocytes; 2) increased C-reactive protein; and 3) increased arterial wall inflammation (FDG uptake). Moreover, in the second study, splenic activity (greater than or equal to the median) was associated with an increased risk of CVD events (hazard ratio [HR]: 3.3; 95% confidence interval [CI]: 1.5 to 7.3; p = 0.003), which remained significant after adjustment for CVD risk factors (HR: 2.26; 95% CI: 1.01 to 5.06; p = 0.04) and for arterial FDG uptake (HR: 2.68; 95% CI: 1.5 to 7.4; p = 0.02).

CONCLUSIONS

Our findings demonstrate increased splenic metabolic activity after ACS and its association with proinflammatory remodeling of circulating leukocytes. Moreover, we observed that metabolic activity of the spleen independently predicted risk of subsequent CVD events. Collectively, these findings provide evidence of a cardiosplenic axis in humans similar to that shown in pre-clinical studies.

Influence of immune activation and inflammatory response on cardiovascular risk associated with the human immunodeficiency virus

Patients infected with the human immunodeficiency virus (HIV) have an increased cardiovascular risk. Although initially this increased risk was attributed to metabolic alterations associated with antiretroviral treatment, in recent years, the attention has been focused on the HIV disease itself. Inflammation, immune system activation, and endothelial dysfunction facilitated by HIV infection have been identified as key factors in the development and progression of atherosclerosis. In this review, we describe the epidemiology and pathogenesis of cardiovascular disease in patients with HIV infection and summarize the latest knowledge on the relationship between traditional and novel inflammatory, immune activation, and endothelial dysfunction biomarkers on the cardiovascular risk associated with HIV infection.

Increased systemic inflammation is associated with cardiac and vascular dysfunction over the first 12 weeks of antiretroviral therapy among undernourished, HIV-infected adults in Southern Africa

INTRODUCTION

Persistent systemic inflammation is associated with mortality among undernourished, HIV-infected adults starting antiretroviral therapy (ART) in sub-Saharan Africa, but the etiology of these deaths is not well understood. We hypothesized that greater systemic inflammation is accompanied by cardiovascular dysfunction over the first 12 weeks of ART.

METHODS

In a prospective cohort of 33 undernourished (body mass index <18.5 kg/m²) Zambian adults starting ART, we measured C-reactive protein (CRP), tumor necrosis factor-α receptor 1 (TNF-α R1), and soluble CD163 and CD14 at baseline and 12 weeks. An EndoPAT device measured the reactive hyperemia index (LnRHI; a measure of endothelial responsiveness), peripheral augmentation index (AI; a measure of arterial stiffness), and heart rate variability (HRV; a general marker of autonomic tone and cardiovascular health) at the same time points. We assessed paired changes in inflammation and cardiovascular parameters, and relationships independent of time point (adjusted for age, sex, and CD4+ T-cell count) using linear mixed models.

RESULTS

Serum CRP decreased (median change -3.5 mg/l, p=0.02), as did TNF-α R1 (-0.31 ng/ml, p<0.01), over the first 12 weeks of ART. A reduction in TNF-α R1 over 12 weeks was associated with an increase in LnRHI (p=0.03), and a similar inverse relationship was observed for CRP and LnRHI (p=0.07). AI increased in the cohort as a whole over 12 weeks, and a reduction in sCD163 was associated with a rise in the AI score (p=0.04). In the pooled analysis of baseline and 12 week data, high CRP was associated with lower HRV parameters (RMSSD, p=0.01; triangular index, p<0.01), and higher TNF- α R1 accompanied lower HRV (RMSSD, p=0.07; triangular index, p=0.06).

CONCLUSIONS

Persistent inflammation was associated with impaired cardiovascular health over the first 12 weeks of HIV treatment among undernourished adults in Africa, suggesting cardiac events may contribute to high mortality in this population.

Elevated plasma soluble CD14 and skewed CD16+ monocyte distribution persist despite normalisation of soluble CD163 and CXCL10 by effective HIV therapy: a changing paradigm for routine HIV laboratory monitoring?

Objective

We investigated plasma and flow cytometric biomarkers of monocyte status that have been associated with prognostic utility in HIV infection and other chronic inflammatory diseases, comparing 81 HIV⁺ individuals with a range of treatment outcomes to a group of 21 healthy control blood donors. Our aim is to develop and optimise monocyte assays that combine biological relevance, clinical utility, and ease of adoption into routine HIV laboratory practice.

Design

Cross-sectional evaluation of concurrent plasma and whole blood samples.

Methods

A flow cytometry protocol was developed comprising single-tube CD45, CD14, CD16, CD64, CD163, CD143 analysis with appropriately matched isotype controls. Plasma levels of soluble CD14 (sCD14), soluble CD163 (sCD163) and CXCL10 were measured by ELISA.

Results

HIV status was associated with significantly increased expression of CD64, CD143 and CD163 on CD16⁺ monocytes, irrespective of the virological response to HIV therapy. Plasma levels of sCD14, sCD163 and CXCL10 were also significantly elevated in association with viremic HIV infection. Plasma sCD163 and CXCL10 levels were restored to healthy control levels by effective antiretroviral therapy while sCD14 levels remained elevated despite virological suppression (p<0.001).

Conclusions

Flow cytometric and plasma biomarkers of monocyte activation indicate an ongoing systemic inflammatory response to HIV infection, characterised by persistent alterations of CD16⁺ monocyte expression profiles and elevated sCD14 levels, that are not corrected by antiretroviral therapy and likely to be prognostically significant. In contrast, sCD163 and CXCL10 levels declined on antiretroviral therapy, suggesting multiple activation pathways revealed by these biomarkers. Incorporation of these assays into routine clinical care is feasible and warrants further consideration, particularly in light of emerging therapeutic strategies that specifically target innate immune activation in HIV infection.

The effect of hepatitis C virologic clearance on cardiovascular disease biomarkers in human immunodeficiency virus/hepatitis C virus coinfection

Background

 Successful hepatitis C virus (HCV) treatment may reduce cardiovascular disease (CVD) risk and improve levels of CVD biomarkers produced outside the liver (nonhepatic biomarkers).

Methods

 Stored serum or plasma from before and 24 weeks after end of HCV treatment (EOT) from human immunodeficiency virus (HIV)/HCV-coinfected subjects who received up to 72 weeks of peginterferon/ribavirin, 27 with and 27 without sustained virologic response (SVR) matched by race, ethnicity and sex, were tested for nonhepatic (soluble intercellular adhesion molecule-1 [sICAM-1], soluble P-selectin [sP-selectin], interleukin [IL]-6, d-dimer, and lipoprotein-associated phospholipase A₂ [Lp-PLA₂]) and hepatic (cholesterol and high-sensitivity C-reactive protein) CVD and macrophage activation markers (soluble CD163 [sCD163] and soluble CD14). Changes in biomarkers and their association with SVR were examined by t tests or Wilcoxon tests and regression models.

Results

 Of the 54 subjects, 30 were white, 24 were black, and 44 were male. Pretreatment levels of nonhepatic biomarkers were high: sICAM-1 overall median, 439.2 ng/mL (interquartile range [IQR], 365.6–592.8]; sP-selectin, 146.7 ng/mL (IQR, 94.1–209.9), and IL-6, 2.32 pg/mL (IQR, 1.61–3.49). Thirty-seven of 52 (71%) subjects had Lp-PLA₂ >235 ng/mL. Sustained virologic response was associated with decrease in sICAM-1 (P = .033) and sCD163 (P = .042); this result was attenuated after controlling for changes in the alanine aminotransferase level. At 24 weeks after EOT, 17 (63%) SVRs had Lp-PLA₂ >235 ng/mL vs 25 (93%) non-SVRs (P = .021).

Conclusions

 Hepatitis C virus clearance may reduce hepatic and, subsequently, systemic inflammation and CVD risk in HIV/HCV coinfection.

Noninvasive imaging of arterial inflammation using FDG-PET/CT

PURPOSE OF REVIEW

Noninvasive imaging of atherosclerotic plaques has substantially advanced over the past decade such that currently available imaging techniques allow for characterization of high-risk morphological features of the plaques and quantification of the biological activity within the atherosclerotic milieu. Vascular PET/CT imaging provides insights into the biological activity of atherosclerotic plaques and, in particular, plaque inflammation. Fluoro-deoxyglucose-PET/CT imaging is currently used to improve the understanding of atherosclerotic pathophysiology, facilitate the discovery of new treatments and improve clinical prognostication in humans.

RECENT FINDINGS

Several studies have evaluated the feasibility, validity and reproducibility of fluoro-deoxyglucose-PET/CT for imaging of atherosclerotic plaque inflammation. Fluoro-deoxyglucose-PET/CT imaging is demonstrated to have the potential to predict the efficacy of novel antiatherosclerotic therapeutics by using a relatively small sample size and within a relatively short time period in several multicenter trials.

SUMMARY

The currently feasible assessment of inflammation within the atherosclerotic plaques has been demonstrated to enhance assessment of clinical risk, provide a better understanding of therapeutic efficacy of novel drugs, and it may provide a window into inflammation within the coronary tree. Further technological advances in PET technology have the potential to catalyze further progress in imaging of atherosclerotic plaque biology.

T-cell activation, both pre- and post-HAART levels, correlates with carotid artery stiffness over 6.5 years among HIV-infected women in the WIHS

OBJECTIVE

T-cell activation is a major pathway driving HIV disease progression. Little is known regarding the impact of T-cell activation on HIV-associated atherosclerosis and cardiovascular disease, a common comorbidity in HIV infection. We hypothesized that T-cell activation will predict vascular stiffness, a measure of subclinical atherosclerosis.

DESIGN

Linear regression models evaluated the covariate-adjusted association of T-cell activation with vascular stiffness.

METHODS

CD38 and HLA-DR expression on CD4⁺ and CD8⁺ T cells was assessed by flow cytometry among 59 HIV-negative and 376 HIV-infected (185 hepatitis C coinfected) women in the Women's Interagency HIV Study. T-cell activation was defined by CD8⁺CD38⁺DR+ and CD4⁺CD3⁺8DR+. Multiple activation assessments over 6.5 years were averaged. In 140 women, T-cell activation was measured before and after highly active antiretroviral therapy (HAART) initiation. Carotid artery ultrasounds were completed a median of 6.5 years after last measurement of T-cell activation and carotid artery stiffness including distensibility and elasticity were calculated.

RESULTS

Percentages of CD4⁺ and CD8⁺ T-cell activation were significantly higher in HIV- infected compared with HIV-negative women. Among HIV-negative women, T-cell activation was not associated with carotid artery stiffness. Among HIV-infected women, higher CD4⁺ T-cell activation levels significantly predicted increased arterial stiffness independent of CD4⁺ cell count and HIV RNA. The association was stronger among HIV/hepatitis C-coinfected women compared with HIV-monoinfected women; however, the difference was not statistically significant (P for interaction >0.05). Pre- and post-HAART levels of CD4⁺ T-cell activation significantly predicted carotid artery stiffness.

CONCLUSIONS

Persistent T-cell activation, even after HAART initiation, can contribute to structural and/or functional vascular damage accelerating atherogenesis in HIV infection. These results need to be confirmed in a longitudinal prospective study.

Inflammatory co-morbidities in HIV+ individuals: learning lessons from healthy ageing

Increased life expectancy due to improved efficacy of cART has uncovered an increased risk of age-related morbidities in HIV+ individuals and catalyzed significant research into mechanisms driving these diseases. HIV infection increases the risk of non-communicable diseases common in the aged, including cardiovascular disease, neurocognitive decline, non-AIDS malignancies, osteoporosis, and frailty. These observations suggest that HIV accelerates immunological ageing, and there are many immunological similarities with the aged, including shortened telomeres, accumulation of senescent T cells and altered monocyte phenotype/function. However, the most critical similarity between HIV+ individuals and the elderly, which most likely underpins the heightened risk of non-communicable diseases, is chronic inflammation and associated immune activation. Here, we review the similarities between HIV+ individuals and the aged regarding the pathogenesis of inflammatory diseases, the current evidence for mechanisms driving these processes and discuss current and potential therapeutic strategies for addressing inflammatory co-morbidity in HIV+ infection.

Risk of coronary heart disease in patients with HIV infection

The lives of individuals infected with HIV who have access to combination antiretroviral therapy (cART) are substantially prolonged, which increases the risk of developing non-AIDS comorbidities, including coronary heart disease (CHD). In Europe and the USA, individuals with HIV infection have a ∼1.5-fold increased risk of myocardial infarction relative to uninfected individuals. In Africa, the relative risk of myocardial infarction is unknown, but broadened access to life-extending cART suggests that rates of CHD will rise in this and other resource-constrained regions. Atherogenesis in HIV is affected by complex interactions between traditional and immune risk factors. cART has varied, regimen-specific effects on metabolic risk factors. Overall, cART seems to lessen proatherogenic immune activation, but does not eliminate it even in patients in whom viraemia is suppressed. Current strategies to decrease the risk of CHD in individuals infected with HIV include early initiation of cART regimens with the fewest metabolic adverse effects, and careful management of traditional CHD risk factors throughout treatment. Future strategies to prevent CHD in patients with HIV infection might involve the use of HIV-tailored CHD risk-prediction paradigms and the administration of therapies alongside cART that will further decrease proatherogenic HIV-specific immune activation.

Elevated rates of intracerebral hemorrhage in individuals from a US clinical care HIV cohort

OBJECTIVE

To compare rates of intracerebral hemorrhage (ICH) in HIV-infected and uninfected individuals in a large clinical care cohort and to assess risk factors associated with ICH.

METHODS

We identified incident ICH in HIV-infected and uninfected control cohorts from the Partners Health Care system using ICD-9-CM codes. We constructed Cox proportional hazards models to estimate adjusted hazard ratios for HIV infection and other predictors of ICH.

RESULTS

The incidence rate of ICH was 2.29 per 1,000 person-years in HIV-infected individuals compared with 1.23 per 1,000 person-years in uninfected individuals, with an unadjusted incidence rate ratio of 1.85 (95% confidence interval 1.37-2.47, p < 0.001). In a multivariable model, HIV infection was independently associated with a higher hazard of ICH, although its effect diminished with increasing age. Female sex was associated with a lower hazard of ICH in the uninfected cohort but not in the HIV cohort. CD4 count <200 × 10(6) cells/L and anticoagulant use were predictive of ICH.

CONCLUSIONS

HIV infection conferred an increased adjusted hazard of ICH, which was more pronounced in young patients and in women.

The importance of monocytes and macrophages in HIV pathogenesis, treatment, and cure

Monocytes and macrophages play critical roles in HIV transmission, viral spread early in infection, and as a reservoir of virus throughout infection. There has been a recent resurgence of interest in the biology of monocyte subsets and macrophages and their role in HIV pathogenesis, partly fuelled by efforts to understand difficulties in achieving HIV eradication. This article examines the importance of monocyte subsets and tissue macrophages in HIV pathogenesis. Additionally, we will review the role of monocytes and macrophages in the development of serious non-AIDS events including cardiovascular disease and neurocognitive impairment, their significance in viral persistence, and how these cells represent an important obstacle to achieving HIV eradication.

A soluble form of the macrophage-related mannose receptor (MR/CD206) is present in human serum and elevated in critical illness

BACKGROUND

This study tests the hypothesis that the mannose receptor (MR/CD206), which is expressed primarily by macrophages and dendritic cells, can be found in a soluble form (sMR, sMR) in human serum. Furthermore, we wished to establish and validate an enzyme-linked immunosorbent assay (ELISA) for sMR and to perform initial studies exploring the potential of sMR as a biomarker.

METHODS

Western blotting identified a single band of approximately 170 kDa in human serum, and MALDI MS/MS of the purified protein confirmed it to be sMR. An ELISA was established and validated with a measurement range of 1-256 µg/L.

RESULTS

The 95% reference interval was 0.10-0.43 mg/L based on measurements of serum samples from healthy individuals (n=217). Samples from hospitalised patients (n=219) revealed that more than 50% of patients had concentrations above 0.43 mg/L. Very high concentrations (up to 6.2 mg/L) were observed in critically ill patients with sepsis and/or severe liver disease.

CONCLUSIONS

This study documents, for the first time, the presence of sMR in human serum and describes an optimised ELISA suitable for quantitative measurements. Levels of sMR are strongly elevated in several disease states, including sepsis and liver disease, and the protein therefore shows promise as a new biomarker.

Clinical and immunologic predictors of death after an acute opportunistic infection: results from ACTG A5164

BACKGROUND

In the pre-antiretroviral therapy (ART) era, markers of increased disease severity during an acute opportunistic infection (OI) were associated with mortality. Even with ART, mortality remains high during the first year after an OI in persons with advanced HIV infection, but it is unclear whether previous predictors of mortality remain valid in the current era.

OBJECTIVE

To determine clinical and immunological predictors of death after an OI.

METHODS

We used clinical data and stored plasma from ACTG A5164, a multicenter study evaluating the optimal timing of ART during a nontuberculous OI. We developed Cox models evaluating associations between clinical parameters and plasma marker levels at entry and time to death over the first 48 weeks after the diagnosis of OI. We developed multivariable models incorporating only clinical parameters, only plasma marker levels, or both.

RESULTS

The median CD4+ T-cell count in study participants at baseline was 29 cells/µL. Sixty-four percent of subjects had Pneumocystis jirovecii pneumonia (PCP). Twenty-three of 282 (8.2%) subjects died. In univariate analyses, entry mycobacterial infection, OI number, hospitalization, low albumin, low hemoglobin, lower CD4, and higher IL-8 and sTNFrII levels and lower IL-17 levels were associated with mortality. In the combined model using both clinical and immunologic parameters, the presence of an entry mycobacterial infection and higher sTNFrII levels were significantly associated with death.

CONCLUSIONS

In the ART era, clinical risk factors for death previously identified in the pre-ART era remain predictive. Additionally, activation of the innate immune system is associated with an increased risk of death following an acute OI.

Cardiovascular disease associated with the human immunodeficiency virus: an update

OPINION STATEMENT

With the advent of increasingly available antiretroviral therapy (ART), the life expectancy of HIV-infected persons is increasing. As they age, HIV-infected persons have increased propensity to typical diseases of aging including cardiovascular disease and accelerated atherosclerosis. The pathogenesis of HIV-associated atherosclerosis is complex and involves a state of chronic inflammation, exposure to traditional risk factors, and metabolic side effects of ART. Treatment of HIV-associated atherosclerosis should include special attention to drug-drug interactions and is best accomplished by a multidisciplinary team experienced in the care of HIV-infected persons.

HCV, but not HIV, is a risk factor for cerebral small vessel disease

OBJECTIVES

With the aging of HIV populations, vascular contributions to neuropathogenesis are increasingly important. Indirect analyses of cerebral small vessel disease have been performed, but there have been no direct studies of human brain to elucidate risk factors for arteriolar sclerosis.

METHODS

Mean arteriolar wall thickness (sclerotic index, SI) was measured in the deep cerebral white matter of 126 brains (96 HIV+, 30 HIV-). Correlations with SI were performed for age, sex, race, hypertension, hyperlipidemia, diabetes, obesity, cirrhosis, hepatitis C virus (HCV) infection, herpes infection, HIV infection, HIV risk, cocaine use, CD4 count, plasma HIV load, and combination antiretroviral therapy (cART) at the time of death.

RESULTS

Age, hypertension, race, HCV, and cirrhosis were associated with SI; of the HIV variables, only cART at death was associated with SI. To address colinearity, partial correlations were run with HCV and cirrhosis, hypertension and race, and hypertension and age. With HCV controlled, cirrhosis lost significance; with hypertension controlled, age lost significance. For the entire sample, HCV, African American race, and hypertension accounted for 15% of SI variance in multivariate analysis. Each was independently associated with SI, and HCV had the largest effect. For the HIV sample, inclusion of cART in the model increased R (2) to 0.205, with only HCV, hypertension, and cART remaining significant or trend level.

CONCLUSIONS

This tissue-based analysis of cerebral arteriolar disease demonstrates that HCV constitutes an independent risk, in addition to African American race, hypertension, and cART. Further study is needed to understand what aspects of HCV and cART contribute to cerebrovascular neuropathogenesis.

Prognostic indicators for recurrent thrombotic events in HIV-infected patients with acute coronary syndromes: use of registry data from 12 sites in Europe, South Africa and the United States

AIMS

Limited data are available on prognostic indicators for HIV patients presenting with ACS.

METHODS AND RESULTS

Data on consecutive patients with HIV infection receiving standard highly active antiretroviral therapy (HAART) presenting with ACS between January 2001 and September 2012 were collected. Cardiac death and myocardial infarction (MI) were the primary end-points. 10,050 patients with ACS were screened, and among them a total of 201 patients (179 [89%] males and a median age of 53 [47-62] years) were included, 48% of them admitted for ST-elevation myocardial infarction and 14% having left ventricular systolic dysfunction (LVSD) at discharge. CD4+ counts less than 200 cells/mm(3) were reported in 18 patients (9%), and 136 patients (67%) were treated with nucleoside-reverse transcriptase inhibitors (NRTI). After a median of 24 months (10-41), 30 patients (15%) died, 12 (6%) for cardiac reasons, 20 (10%) suffered a MI, 29 (15%) a subsequent revascularization, and 7 (3%) a stent thrombosis. Other than LVSD (hazard ratio=6.4 [95% confidence interval [CI]: 1.6-26: p=0.009]), the only other independent predictor of cardiac death was not being treated with NRTI (hazard ratio=9.9 [95% CI: 2.1-46: p=0.03); a CD4 cell count <200 cells/mm(3) was the only predictor of MI (hazard ratio=5.9 [95% CI: 1.4-25: p=0.016]).

CONCLUSIONS

HIV patients presenting with ACS are at significantly increased risk for cardiac death if not treated with NRTI, and at significantly increased risk of MI if their CD4 cell count is <200 cells/mm(3), suggesting that the stage of HIV disease (and lack of NRTI treatment) may contribute to cardiovascular instability.

From wasting to obesity, changes in nutritional concerns in HIV/AIDS

Optimal nutrition is an important part of human immunodeficiency virus (HIV) care; to support the immune system, limit HIV-associated complications as well as maintain better quality of life and survival. The presentation and nature of malnutrition in patients with HIV has changed dramatically over the past 30 years from predominantly a wasting syndrome to lipodystrophy and, now, frailty. Nevertheless, we continue to see all 3 presentations in patient care today. The pathogenesis of poor nutrition in HIV-infected patients depends on caloric intake, intestinal nutrient absorption/translocation, and resting energy expenditure, which are features seen in all chronic diseases.

Cardiovascular disease in HIV: traditional and nontraditional risk factors

A new paradigm for atherogenesis in HIV infection is emerging, in which viral replication and microbial translocation result in ongoing T-cell and monocyte activation, with persistent inflammation leading to the development of atypical, high-risk morphology plaques. These plaques, characterized by low attenuation and positive remodeling, can be found even among HIV-infected patients who are at low risk for cardiovascular disease based on traditional risk factors. Prevention of cardiovascular events in HIV infection requires modulation of traditional risk factors and is also likely to require effective antiinflammatory treatment strategies. Statins, which are traditionally used to treat dyslipidemia, have also been shown to exert antiinflammatory effects associated with clinical benefit and may be useful to treat and prevent cardiovascular disease in HIV-infected patients. However, large-scale studies of statins in the context of HIV infection must be conducted. This article summarizes a presentation by Steven K. Grinspoon, MD, at the IAS-USA continuing education program held in Chicago, Illinois, in May 2014.

Dyslipidemia and cardiovascular risk in human immunodeficiency virus infection

The pathogenesis of atherosclerosis in human immunodeficiency virus (HIV)-infected individuals is incompletely understood and appears to be multifactorial. Proatherogenic changes in blood and tissue lipids are associated with an increased risk of cardiovascular disease among HIV-infected subjects, and these changes may be both quantitative (dyslipidemia) and qualitative. In view of the pivotal role of dyslipidemia in the process of atherosclerosis, the increased incidence of dyslipidemia in HIV-infected individuals, and the emerging role of lipid abnormalities in systemic pathophysiologic processes such as immune activation, we review the contributions of dyslipidemia to cardiovascular risk in HIV infection.

Increased coronary vessel wall thickness in HIV-infected young adults

BACKGROUND

Individuals with long-term human immunodeficiency virus (HIV) infection are at risk for premature vasculopathy and cardiovascular disease (CVD). We evaluated coronary vessel wall thickening, coronary plaque, and epicardial fat in patients infected with HIV early in life compared with healthy controls.

METHODS

This is a prospective cross-sectional study of 35 young adults who acquired HIV in early life and 11 healthy controls, free of CVD. Time resolved phase-sensitive dual inversion recovery black-blood vessel wall magnetic resonance imaging (TRAPD) was used to measure proximal right coronary artery (RCA) wall thickness, and multidetector computed tomography (CT) angiography was used to quantify coronary plaque and epicardial fat.

RESULTS

RCA vessel wall thickness was significantly increased in HIV-infected patients compared with sex- and race-matched controls (1.32 ± 0.21 mm vs 1.09 ± 0.14 mm, P = .002). No subject had discrete plaque on CT sufficient to cause luminal narrowing, and plaque was not related to RCA wall thickness. In multivariate regression analyses, smoking pack-years (P = .004) and HIV infection (P = .007) were independently associated with thicker RCA vessel walls. Epicardial fat did not differ between groups. Among the HIV-infected group, duration of antiretroviral therapy (ART) (P = .02), duration of stavudine exposure (P < .01), low-density lipoprotein cholesterol (P = .04), and smoking pack-years (P < .01) were positively correlated with RCA wall thickness.

CONCLUSIONS

This investigation provides evidence of subclinical coronary vascular disease among individuals infected with HIV in early life. Increased duration of ART, hyperlipidemia, and smoking contributed to proximal RCA thickening, independent of atherosclerotic plaque quantified by CT. These modifiable risk factors appear to influence early atherogenesis as measured by coronary wall thickness and may be important targets for CVD risk reduction.

HIV is an independent predictor of aortic stiffness

BACKGROUND

Patients with treated Human Immunodeficiency Virus-1 (HIV) infection are at increased risk of cardiovascular events. Traditionally much of this risk has been attributed to metabolic and anthropometric abnormalities associated with HIV, which are similar to the metabolic syndrome (MS), an established risk factor for cardiovascular mortality. It remains unclear whether treated HIV infection is itself associated with increased risk, via increase vascular stiffness.

METHODS

226 subjects (90 with HIV) were divided into 4 groups based on HIV and MS status: 1) HIV-ve/MS-ve, 2) HIV-ve/MS + ve, 3) HIV + ve/MS-ve and 4)HIV + ve/MS + ve. CMR was used to determine aortic pulse wave velocity (PWV) and regional aortic distensibility (AD).

RESULTS

PWV was 11% higher and regional AD up to 14% lower in the HIV + ve/MS-ve group when compared to HIV-ve/MS-ve (p < 0.01 all analyses). PWV and AD in the HIV + ve/MS-ve group was similar to that observed in the HIV-ve/MS + ve group (p > 0.99 all analyses). The HIV + ve/MS + ve group had 32% higher PWV and 30-34% lower AD than the HIV-ve/MS-ve group (all p < 0.001), and 19% higher PWV and up to 31% lower AD than HIV + ve/MS-ve subjects (all p < 0.05). On multivariable regression, age, systolic blood pressure and treated HIV infection were all independent predictors of both PWV and regional AD.

CONCLUSION

Across multiple measures, treated HIV infection is associated with increased aortic stiffness and is also an independent predictor of both PWV and regional AD. The magnitude of the effect of treated HIV and MS are similar, with additive detrimental effects on central vascular elasticity.

18F-fluorodeoxyglucose positron emission tomography/computed tomography enables the detection of recurrent same-site deep vein thrombosis by illuminating recently formed, neutrophil-rich thrombus

BACKGROUND

Accurate detection of recurrent same-site deep vein thrombosis (DVT) is a challenging clinical problem. Because DVT formation and resolution are associated with a preponderance of inflammatory cells, we investigated whether noninvasive (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging could identify inflamed, recently formed thrombi and thereby improve the diagnosis of recurrent DVT.

METHODS AND RESULTS

We established a stasis-induced DVT model in murine jugular veins and also a novel model of recurrent stasis DVT in mice. C57BL/6 mice (n=35) underwent ligation of the jugular vein to induce stasis DVT. FDG-PET/computed tomography (CT) was performed at DVT time points of day 2, 4, 7, 14, or 2+16 (same-site recurrent DVT at day 2 overlying a primary DVT at day 16). Antibody-based neutrophil depletion was performed in a subset of mice before DVT formation and FDG-PET/CT. In a clinical study, 38 patients with lower extremity DVT or controls undergoing FDG-PET were analyzed. Stasis DVT demonstrated that the highest FDG signal occurred at day 2, followed by a time-dependent decrease (P<0.05). Histological analyses demonstrated that thrombus neutrophils (P<0.01), but not macrophages, correlated with thrombus PET signal intensity. Neutrophil depletion decreased FDG signals in day 2 DVT in comparison with controls (P=0.03). Recurrent DVT demonstrated significantly higher FDG uptake than organized day 14 DVT (P=0.03). The FDG DVT signal in patients also exhibited a time-dependent decrease (P<0.01).

CONCLUSIONS

Noninvasive FDG-PET/CT identifies neutrophil-dependent thrombus inflammation in murine DVT, and demonstrates a time-dependent signal decrease in both murine and clinical DVT. FDG-PET/CT may offer a molecular imaging strategy to accurately diagnose recurrent DVT.

Increased arterial inflammation relates to high-risk coronary plaque morphology in HIV-infected patients

BACKGROUND

Mechanisms predisposing HIV-infected patients to increased cardiovascular disease (CVD) risk remain unclear.

OBJECTIVE

To determine the interrelationship between arterial inflammation and high-risk coronary plaque morphology in HIV-infected patients with subclinical coronary atherosclerosis.

METHODS

Forty-one HIV-infected patients on stable antiretroviral therapy without known CVD but with atherosclerotic plaque on coronary CT angiography were evaluated with F-FDG-PET. Patients were stratified into 2 groups based on relative degree of arterial inflammation [aortic target-to-background ratio (TBR)]. High-risk coronary atherosclerotic plaque morphology features were compared between groups.

RESULTS

HIV-infected patients with higher and lower TBRs were similar with respect to traditional CVD risk parameters. Among HIV-infected patients with higher TBR, an increased percentage of patients demonstrated at least 1 low-attenuation coronary atherosclerotic plaque (40% vs. 10%, P = 0.02) and at least 1 coronary atherosclerotic plaque with both low attenuation and positive remodeling (35% vs. 10%, P = 0.04). Moreover, in the higher TBR group, both the number of low-attenuation plaques per patient (P = 0.02) and the number of vulnerability features in the most vulnerable plaque (P = 0.02) were increased. TBR grouping remained significantly related to the number of low-attenuation plaques/subject (β = 0.35, P = 0.004), controlling for age, gender, low-density lipoprotein, duration of HIV, and CD4.

CONCLUSIONS

These data demonstrate a relationship between arterial inflammation on F-FDG-PET and high-risk coronary atherosclerotic plaque features among HIV-infected patients with subclinical coronary atherosclerosis. Further studies are needed to determine whether arterial inflammation and related high-risk coronary morphology increase the risk of clinical CVD events in the HIV population.

Elevated numbers of CD163+ macrophages in hearts of simian immunodeficiency virus-infected monkeys correlate with cardiac pathology and fibrosis

The role of macrophage activation, traffic, and accumulation on cardiac pathology was examined in 23 animals. Seventeen animals were simian immunodeficiency virus (SIV) infected, 12 were CD8 lymphocyte depleted, and the remaining six were uninfected controls (two CD8 lymphocyte depleted, four nondepleted). None of the uninfected controls had cardiac pathology. One of five (20%) SIV-infected, non-CD8 lymphocyte-depleted animals had minor cardiac pathology with increased numbers of macrophages in ventricular tissue compared to controls. Seven of the 12 (58%) SIV-infected, CD8 lymphocyte-depleted animals had cardiac pathology in ventricular tissues, including macrophage infiltration and myocardial degeneration. The extent of fibrosis (measured as the percentage of collagen per tissue area) was increased 41% in SIV-infected, CD8 lymphocyte-depleted animals with cardiac pathology compared to animals without pathological abnormalities. The number of CD163+ macrophages increased significantly in SIV-infected, CD8 lymphocyte-depleted animals with cardiac pathology compared to ones without pathology (1.66-fold) and controls (5.42-fold). The percent of collagen (percentage of collagen per total tissue area) positively correlated with macrophage numbers in ventricular tissue in SIV-infected animals. There was an increase of BrdU+ monocytes in the heart during late SIV infection, regardless of pathology. These data implicate monocyte/macrophage activation and accumulation in the development of cardiac pathology with SIV infection.

Preventing Heart Failure in Inflammatory and Immune Disorders

Patients with chronic inflammatory diseases are at increased risk for heart failure due to ischemic heart disease and other causes including heart failure with preserved ejection fraction. Using rheumatoid arthritis and treated HIV infection as two prototypical examples, we review the epidemiology and potential therapies to prevent heart failure in these populations. Particular focus is given to anti-inflammatory therapies including statins and biologic disease modifying drugs. There is also limited evidence for lifestyle changes and blockade of the renin-angiotensin-aldosterone system. We conclude by proposing how a strategy for heart failure prevention, such as the model tested in the Screening To Prevent Heart Failure (STOP-HF) trial, may be adapted to chronic inflammatory disease.

Monocytes as regulators of inflammation and HIV-related comorbidities during cART

Combined antiretroviral therapy (cART) extends the lifespan and the quality of life for HIV-infected persons but does not completely eliminate chronic immune activation and inflammation. The low level of chronic immune activation persisting during cART-treated HIV infection is associated with the development of diseases which usually occur in the elderly. Although T-cell activation has been extensively examined in the context of cART-treated HIV infection, monocyte activation is only beginning to be recognized as an important source of inflammation in this context. Here we examine markers and sources of monocyte activation during cART-treated HIV infection and discuss the role of monocytes during cardiovascular disease, HIV-associated neurocognitive disorder, and innate immune aging.

Association between latent proviral characteristics and immune activation in antiretrovirus-treated human immunodeficiency virus type 1-infected adults

Generalized immune activation during HIV infection is associated with an increased risk of cardiovascular disease, neurocognitive disease, osteoporosis, metabolic disorders, and physical frailty. The mechanisms driving this immune activation are poorly understood, particularly for individuals effectively treated with antiretroviral medications. We hypothesized that viral characteristics such as sequence diversity may play a role in driving HIV-associated immune activation. We therefore sequenced proviral DNA isolated from peripheral blood mononuclear cells from HIV-infected individuals on fully suppressive antiretroviral therapy. We performed phylogenetic analyses, calculated viral diversity and divergence in the env and pol genes, and determined coreceptor tropism and the frequency of drug resistance mutations. Comprehensive immune profiling included quantification of immune cell subsets, plasma cytokine levels, and intracellular signaling responses in T cells, B cells, and monocytes. These antiretroviral therapy-treated HIV-infected individuals exhibited a wide range of diversity and divergence in both env and pol genes. However, proviral diversity and divergence in env and pol, coreceptor tropism, and the level of drug resistance did not significantly correlate with markers of immune activation. A clinical history of virologic failure was also not significantly associated with levels of immune activation, indicating that a history of virologic failure does not inexorably lead to increased immune activation as long as suppressive antiretroviral medications are provided. Overall, this study demonstrates that latent viral diversity is unlikely to be a major driver of persistent HIV-associated immune activation.

IMPORTANCE

Chronic immune activation, which is associated with cardiovascular disease, neurologic disease, and early aging, is likely to be a major driver of morbidity and mortality in HIV-infected individuals. Although treatment of HIV with antiretroviral medications decreases the level of immune activation, levels do not return to normal. The factors driving this persistent immune activation, particularly during effective treatment, are poorly understood. In this study, we investigated whether characteristics of the latent, integrated HIV provirus that persists during treatment are associated with immune activation. We found no relationship between latent viral characteristics and immune activation in treated individuals, indicating that qualities of the provirus are unlikely to be a major driver of persistent inflammation. We also found that individuals who had previously failed treatment but were currently effectively treated did not have significantly increased levels of immune activation, providing hope that past treatment failures do not have a lifelong "legacy" impact.

HIV-infected individuals with low CD4/CD8 ratio despite effective antiretroviral therapy exhibit altered T cell subsets, heightened CD8+ T cell activation, and increased risk of non-AIDS morbidity and mortality

A low CD4/CD8 ratio in elderly HIV-uninfected adults is associated with increased morbidity and mortality. A subset of HIV-infected adults receiving effective antiretroviral therapy (ART) fails to normalize this ratio, even after they achieve normal CD4+ T cell counts. The immunologic and clinical characteristics of this clinical phenotype remain undefined. Using data from four distinct clinical cohorts and three clinical trials, we show that a low CD4/CD8 ratio in HIV-infected adults during otherwise effective ART (after CD4 count recovery above 500 cells/mm3) is associated with a number of immunological abnormalities, including a skewed T cell phenotype from naïve toward terminally differentiated CD8+ T cells, higher levels of CD8+ T cell activation (HLADR+CD38+) and senescence (CD28- and CD57+CD28-), and higher kynurenine/tryptophan ratio. Changes in the peripheral CD4/CD8 ratio are also reflective of changes in gut mucosa, but not in lymph nodes. In a longitudinal study, individuals who initiated ART within six months of infection had greater CD4/CD8 ratio increase compared to later initiators (>2 years). After controlling for age, gender, ART duration, nadir and CD4 count, the CD4/CD8 ratio predicted increased risk of morbidity and mortality. Hence, a persistently low CD4/CD8 ratio during otherwise effective ART is associated with increased innate and adaptive immune activation, an immunosenescent phenotype, and higher risk of morbidity/mortality. This ratio may prove useful in monitoring response to ART and could identify a unique subset of individuals needed of novel therapeutic interventions.

CROI 2014: Viral hepatitis and complications of HIV disease and antiretroviral therapy

The remarkable advances in interferon-sparing, all-oral hepatitis C virus (HCV) treatment were a highlight of the 2014 Conference on Retroviruses and Opportunistic Infections (CROI). The backbone of the nucleotide inhibitor sofosbuvir and the nonstructural protein 5A (NS5A) inhibitor ledipasvir with an additional third agent (HCV protease inhibitor or HCV nonnucleoside reverse transcriptase inhibitor) led to a sustained virologic response (SVR) rate 12 weeks after cessation of treatment of 95% to 100% after only 6 weeks of treatment. These results demonstrate the potential of combination directacting antiviral (DAA) therapy for abbreviated, well-tolerated, and highly effective HCV treatment. Two triple-drug regimens that comprised 12 weeks of an NS5A inhibitor, an HCV protease inhibitor, and a nonnucleoside inhibitor also resulted in SVRs of more than 90% in patients with HCV genotype 1. HIV coinfection does not appear to negatively impact response to DAA-based HCV therapy, as evidenced by similar response rates in HIV/HCV-coinfected patients compared with HCV-monoinfected patients receiving interferonsparing or -containing regimens. There was continued emphasis at CROI 2014 on non-AIDS complications of HIV infection, specifically cardiovascular disease, renal insufficiency, and bone and endocrine disorders that persist among patients with treated HIV disease and contribute to morbidity and mortality. Finally, new data on novel drugs and combinations for treatment of tuberculosis (TB), patient outcomes using new rapid TB diagnostics, and a short-course TB prevention strategy were presented.

Arterial disease in patients with human immunodeficiency virus infection: what has imaging taught us?

With advances in antiretroviral therapy (ART), individuals with human immunodeficiency virus (HIV) infection are living longer and increasingly die of non-HIV-related diseases, such as cardiovascular disease (CVD). Several observational studies suggest that HIV-infected patients on ART are at increased risk of CVD; however, the precise mechanisms underlying the association between HIV infection and CVD risk are uncertain. Atherosclerosis and arterial disease in HIV-infected individuals is a multifactorial process with several potential targets for research and therapeutic intervention. This paper critically reviews the contributions of imaging to our understanding of arterial disease, atherosclerosis, and CVD risk in HIV-infected individuals. In general, the findings of studies using carotid ultrasound, coronary computed tomographic angiography, and aortic positron emission tomography agree with those from observational studies of CVD events and suggest that HIV infection is associated with an increased risk of CVD. Observational studies of CVD outcomes and studies using carotid intima-media thickness suggest that there is a moderate increase in CVD risk related to HIV serostatus. Less can be said about the role of ART and specific ART therapies in CVD risk, mainly because imaging studies have had serious methodological limitations that diminish their generalizability. Brachial artery reactivity testing has been especially useful for elucidating the arterial pathophysiology of HIV infection and its treatments, as well as the arterial effects of interventions for treating HIV and dyslipidemia. Aortic positron emission tomography has been especially useful for evaluating arterial inflammation. Coronary artery calcium has not proven to be a useful marker of subclinical atherosclerosis in HIV-infected individuals. Imaging studies support the intriguing hypothesis that persistent inflammation and immune dysregulation contribute to increased CVD risk among treated and suppressed patients with HIV infection.

Soluble CD14 is independently associated with coronary calcification and extent of subclinical vascular disease in treated HIV infection

OBJECTIVE

To use multimodality imaging to explore the relationship of biomarkers of inflammation, T-cell activation and monocyte activation with coronary calcification and subclinical vascular disease in a population of HIV-infected patients on antiretroviral therapy (ART).

DESIGN

Cross-sectional.

METHODS

A panel of soluble and cellular biomarkers of inflammation and immune activation was measured in 147 HIV-infected adults on ART with HIV RNA less than 1000 copies/ml and low-density lipoprotein cholesterol (LDL-C) 130  mg/dl or less. We examined the relationship of biomarkers to coronary calcium (CAC) score and multiple ultrasound measures of subclinical vascular disease.

RESULTS

Overall, median (interquartile range, IQR) age was 46 (40-53) years; three-quarters of participants were male and two-thirds African-American. Median 10-year Framingham risk score was 6%. Participants with CAC more than 0 were older, less likely to be African-American and had higher current and lower nadir CD4 T-cell counts. Most biomarkers were similar between those with and without CAC; however, soluble CD14 was independently associated with CAC after adjustment for traditional risk factors. Among those with a CAC score of zero, T-cell activation and systemic inflammation correlated with carotid intima-media thickness and brachial hyperemic velocity, respectively. Compared with normal participants and those with CAC only, participants with increasing degrees of subclinical vascular disease had higher levels of sCD14, hs-CRP and fibrinogen (all P<0.05).

CONCLUSION

Soluble CD14 is independently associated with coronary artery calcification, and, among those with detectable calcium, predicts the extent of subclinical disease in other vascular beds. Future studies should investigate the utility of multimodality imaging to characterize vascular disease phenotypes in this population.

Impact of inflammation on vascular disease in hypertension

Low grade inflammation exerts a crucial pathogenic role in hypertension and cardiovascular disease. A large body of evidence indicates that innate and adaptive immune systems, and in particular T cells, are involved. A balance between T-effector lymphocytes and Treg lymphocytes represents a crucial regulatory mechanism that, when altered, favours blood pressure elevation and organ damage development. Of note, Treg lymphocytes exert important anti-inflammatory properties, whose activities guarantees vascular homeostasis and protects the vessel wall from the development of atherosclerosis. In humans, most of evidence ascertaining essential hypertension as a condition of chronic low-grade inflammatory status revealed a strict and independent association between CRP, TNF-α, IL-6 or adhesion molecules and vascular changes in essential hypertensive patients. Evidence of involvement of the immune system in vasculature from patients with hypertension or cardiovascular disease starts to appear in literature. Further investigation on immunity, including the role of T-lymphocytes, will help develop of new therapeutic targets that may improve outcomes in hypertension and cardiovascular disease and discover novel approaches in the treatment of hypertension and vascular disease.

Macrophage inflammatory markers are associated with subclinical carotid artery disease in women with human immunodeficiency virus or hepatitis C virus infection

OBJECTIVE

Infection with hepatitis C virus (HCV) or human immunodeficiency virus (HIV) may be associated with atherosclerosis and vascular disease. Macrophages are a major component of atherosclerotic plaque, and classically activated (M1) macrophages contribute to plaque instability. Our goal was to identify plasma biomarkers that reflect macrophage inflammation and are associated with subclinical atherosclerosis.

APPROACH AND RESULTS

We tested whether M1 macrophages produce galectin-3-binding protein in vitro. Then, we measured galectin-3-binding protein and the soluble macrophage biomarkers soluble cluster of differentiation (CD) 163 and soluble CD14 in 264 participants in the Women's Interagency HIV Study. Women were positive for HIV, HCV, both, or neither (66 in each group, matched for age, race/ethnicity, and smoking status). Carotid artery disease was assessed by ultrasound measurement of right distal common carotid artery intima-media thickness, distensibility, and presence of atherosclerotic lesions (intima-media thickness >1.5 mm). Plasma galectin-3-binding protein was higher in HCV+ than HCV- women (P<0.01) but did not differ by HIV status. The 3 inflammatory macrophage markers were significantly correlated with each other and negatively correlated with CD4+ counts in HIV-infected women. We defined a macrophage score as 1, 2, or 3 biomarkers elevated above the median. In models adjusted for traditional risk factors, higher macrophage scores were significantly associated with increased atherosclerotic lesions and lower carotid distensibility. Receiver-operator curve analysis of lesions revealed that the markers added predictive value beyond traditional risk factors and C-reactive protein.

CONCLUSIONS

The macrophage inflammatory markers galectin-3-binding protein, soluble CD163, and soluble CD14 are significantly associated with carotid artery disease in the setting of HIV and HCV infection.

Association of esophageal inflammation, obesity and gastroesophageal reflux disease: from FDG PET/CT perspective

OBJECTIVE

Gastroesophageal reflux disease (GERD) is associated with bothersome symptoms and neoplastic progression into Barrett's esophagus and esophageal adenocarcinoma. We aim to determine the correlation between GERD, esophageal inflammation and obesity with 18F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT).

METHODS

We studied 458 subjects who underwent a comprehensive health check-up, which included an upper gastrointestinal endoscopy, FDG PET/CT and complete anthropometric measures. GERD symptoms were evaluated with Reflux Disease Questionnaire. Endoscopically erosive esophagitis was scored using the Los Angeles classification system. Inflammatory activity, represented by standardized uptake values (SUVmax) of FDG at pre-determined locations of esophagus, stomach and duodenum, were compared. Association between erosive esophagitis, FDG activity and anthropometric evaluation, including body mass index (BMI), waist circumference, visceral and subcutaneous adipose tissue volumes were analyzed.

RESULTS

Subjects with erosive esophagitis (n = 178, 38.9%) had significantly higher SUVmax at middle esophagus (2.69±0.74 vs. 2.41±0.57, P<.001) and esophagogastric junction (3.10±0.89 vs. 2.38±0.57, P<.001), marginally higher at upper esophageal sphincter (2.29±0.42 vs. 2.21±0.48, P = .062), but not in stomach or duodenum. The severity of erosive esophagitis correlated with SUVmax and subjects with Barrett's esophagus had the highest SUVmax at middle esophagus and esophagogastric junction. Heartburn positively correlated with higher SUVmax at middle oesophagus (r = .262, P = .003). Using multivariate regression analyses, age (P = .027), total cholesterol level (P = .003), alcohol drinking (P = .03), subcutaneous adipose tissue (P<.001), BMI (P<.001) and waist circumference (P<.001) were independently associated with higher SUVmax at respective esophageal locations.

CONCLUSIONS

Esophageal inflammation demonstrated by FDG PET/CT correlates with endoscopic findings and symptomatology of GERD. Obesity markers, both visceral and general, are independent determinants of esophageal inflammation.

Transfer of intracellular HIV Nef to endothelium causes endothelial dysfunction

With effective antiretroviral therapy (ART), cardiovascular diseases (CVD) are emerging as a major cause of morbidity and death in the aging HIV-infected population. To address whether HIV-Nef, a viral protein produced in infected cells even when virus production is halted by ART, can lead to endothelial activation and dysfunction, we tested Nef protein transfer to and activity in endothelial cells. We demonstrated that Nef is essential for major endothelial cell activating effects of HIV-infected Jurkat cells when in direct contact with the endothelium. In addition, we found that Nef protein in endothelial cells is sufficient to cause apoptosis, ROS generation and release of monocyte attractant protein-1 (MCP-1). The Nef protein-dependent endothelial activating effects can be best explained by our observation that Nef protein rapidly transfers from either HIV-infected or Nef-transfected Jurkat cells to endothelial cells between these two cell types. These results are of in vivo relevance as we demonstrated that Nef protein induces GFP transfer from T cells to endothelium in CD4.Nef.GFP transgenic mice and Nef is present in chimeric SIV-infected macaques. Analyzing the signal transduction effects of Nef in endothelial cells, we found that Nef-induced apoptosis is mediated through ROS-dependent mechanisms, while MCP-1 production is NF-kB dependent. Together, these data indicate that inhibition of Nef-associated pathways may be promising new therapeutic targets for reducing the risk for cardiovascular disease in the HIV-infected population.

Reduced sTWEAK and increased sCD163 levels in HIV-infected patients: modulation by antiretroviral treatment, HIV replication and HCV co-infection

Background

Patients infected with the human immunodeficiency virus (HIV) have an increased risk of cardiovascular disease due to increased inflammation and persistent immune activation. CD163 is a macrophage scavenger receptor that is involved in monocyte-macrophage activation in HIV-infected patients. CD163 interacts with TWEAK, a member of the TNF superfamily. Circulating levels of sTWEAK and sCD163 have been previously associated with cardiovascular disease, but no previous studies have fully analyzed their association with HIV.

Objective

The aim of this study was to analyze circulating levels of sTWEAK and sCD163 as well as other known markers of inflammation (hsCRP, IL-6 and sTNFRII) and endothelial dysfunction (sVCAM-1 and ADMA) in 26 patients with HIV before and after 48 weeks of antiretroviral treatment (ART) and 23 healthy subjects.

Results

Patients with HIV had reduced sTWEAK levels and increased sCD163, sVCAM-1, ADMA, hsCRP, IL-6 and sTNFRII plasma concentrations, as well as increased sCD163/sTWEAK ratio, compared with healthy subjects. Antiretroviral treatment significantly reduced the concentrations of sCD163, sVCAM-1, hsCRP and sTNFRII, although they remained elevated when compared with healthy subjects. Antiretroviral treatment had no effect on the concentrations of ADMA and sTWEAK, biomarkers associated with endothelial function. The use of protease inhibitors as part of antiretroviral therapy and the presence of HCV-HIV co-infection and/or active HIV replication attenuated the ART-mediated decrease in sCD163 plasma concentrations.

Conclusion

HIV-infected patients showed a proatherogenic profile characterized by increased inflammatory, immune-activation and endothelial-dysfunction biomarkers that partially improved after ART. HCV-HIV co-infection and/or active HIV replication enhanced immune activation despite ART.