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

Dynamic modulation of the non-canonical NF-κB signaling pathway for HIV shock and kill

HIV cure still remains an elusive target. The "Shock and Kill" strategy which aims to reactivate HIV from latently infected cells and subsequently kill them through virally induced apoptosis or immune mediated clearance, is the subject of widespread investigation. NF-κB is a ubiquitous transcription factor which serves as a point of confluence for a number of intracellular signaling pathways and is also a crucial regulator of HIV transcription. Due to its relatively lower side effect profile and proven role in HIV transcription, the non-canonical NF-κB pathway has emerged as an attractive target for HIV reactivation, as a first step towards eradication. A comprehensive review examining this pathway in the setting of HIV and its potential utility to cure efforts is currently lacking. This review aims to summarize non-canonical NF-κB signaling and the importance of this pathway in HIV shock-and-kill efforts.

Endothelial dysfunction, a predictor of cardiovascular disease in HIV patients on antiretroviral therapy: A systematic review and meta-analysis

Aim Although antiretroviral therapy (ART) is available, the rate of new HIV infections is alarming. With this trend, it is anticipated that the use of ART will continue to rise, potentially resulting in associated vascular disorders. Therefore, we aimed to examine the impact of ART on endothelial function in people living with HIV (PLHIV), a predictor of cardiovascular diseases.

METHOD

A comprehensive search for evidence was made on PubMed and Scopus on May 06, 2023, following the Preferred Reporting Items for Systematic Review and Meta-analysis. Cochrane and Newcastle-Ottawa quality assessment scales were used to evaluate quality, while the metaHun web tool and Review Manager version 5.4.1 were used for analysis. Subgroup, sensitivity, and publication bias were conducted for each outcome measure.

RESULTS

We identified 37 studies, including a sample size of 3700 with 2265 individuals on ART. The analyzed evidence showed a large significant effect of ART on vascular cell adhesion molecule-1, with a standardized mean difference (SMD) of -1.23 (95 % CI: -1.72, -0.74; p = 0.0013). Similarly, a significant medium effect of ART was observed on intercellular cell adhesion molecule-1 in PLHIV, with an SMD of -1.28 (95 % CI: -2.00, -0.56; p = 0.0231) compared to the control group. Furthermore, ART exhibited a significant but small effect on flow-mediated dilation (FMD) with an SMD of -0.40 (95 % CI: -0.62, -0.19, p = 0.0159).

CONCLUSION

Our findings show an improved endothelial function in PLHIV on ART, as demonstrated by reduced adhesion molecules; however, ART exhibited a small effect on FMD, thus suggesting PLHIV on ART may still be at risk of endothelial dysfunction and further cardiovascular diseases.

sCD163, sCD28, sCD80, and sCTLA-4 as soluble marker candidates for detecting immunosenescence

BACKGROUND

Inflammaging, the characteristics of immunosenescence, characterized by continuous chronic inflammation that could not be resolved. It is not only affect older people but can also occur in young individuals, especially those suffering from chronic inflammatory conditions such as autoimmune disease, malignancy, or chronic infection. This condition led to altered immune function and as consequent immune function is reduced. Detection of immunosenescence has been done by examining the immune risk profile (IRP), which uses flow cytometry. These tests are not always available in health facilities, especially in developing countries and require fresh whole blood samples. Therefore, it is necessary to find biomarkers that can be tested using stored serum to make it easier to refer to the examination. Here we proposed an insight for soluble biomarkers which represented immune cells activities and exhaustion, namely sCD163, sCD28, sCD80, and sCTLA-4. Those markers were reported to be elevated in chronic diseases that caused early aging and easily detected from serum samples using ELISA method, unlike IRP. Therefore, we conclude these soluble markers are beneficial to predict pathological condition of immunosenescence.

AIM

To identify soluble biomarkers that could replace IRP for detecting immunosenescence.

CONCLUSION

Soluble costimulatory molecule suchsCD163, sCD28, sCD80, and sCTLA-4 are potential biomarkers for detecting immunosenescence.

TWEAK and Fn14 are overexpressed in immune-mediated necrotizing myopathy: implications for muscle damage and repair

OBJECTIVES

TNF-like weak inducer of apoptosis (TWEAK) and its sole receptor fibroblast growth factor-inducible 14 (Fn14) are involved in various inflammatory conditions. This study was performed to investigate the potential role of TWEAK/Fn14 in immune-mediated necrotizing myopathy (IMNM).

METHODS

Muscle biopsies from patients with IMNM (n = 37) and controls (n = 11) were collected. Human muscle cells were treated with TWEAK in vitro. Muscle biopsies and cultured muscle cells were analysed by immunostaining and quantitative PCR. Serum levels of TWEAK and Fn14 were detected by ELISA.

RESULTS

TWEAK and Fn14 were overexpressed in IMNM muscle biopsies. The percentage of Fn14-positive myofibers correlated with disease severity, myonecrosis, regeneration and inflammation infiltrates. Fn14-positive myofibers tended to be surrounded or invaded by CD68+ macrophages. TWEAK treatment had a harmful effect on cultured muscle cells by inducing the production of multiple chemokines and pro-inflammatory cytokines. Serum Fn14 levels were increased in patients with IMNM and correlated with muscle weakness.

CONCLUSIONS

TWEAK/Fn14 signalling was activated in IMNM, most likely aggravating muscle damage via amplifying inflammatory response and macrophages chemotaxis. Fn14 seems to be a biomarker for assessing disease severity in IMNM. In addition, Fn14 may also contribute to muscle injury repair.

The performance of soluble CD163 as a non-invasive biomarker of liver damage in chronically HCV and HCV/HIV infected subjects

Macrophage activation plays a key role in liver disease progression. Soluble CD163 (sCD163) is a specific macrophage activation biomarker useful for clinical estimating damage severity and predicting outcome in different liver conditions. sCD163 performance as a non-invasive marker of liver damage was evaluated in plasma samples at time of biopsy in 120 patients with different hepatic conditions (56 HCV, 20 HCV/HIV, 10 HBV and 34 MAFLD). sCD163 values were compared with those of healthy donors and analyzed related to histological damage. sCD163 together with other clinical parameters were used to create a logistical regression model to predict significant fibrosis. Only patients with viral hepatitis showed higher sCD163 values compared to the control group (HCV p<0.0001; HCV/HIV p<0.0001; HBV p = 0.0003), but no significant differences regarding fibrosis stages were observed. The proposed model predicts fibrosis severity using the logarithm sCD163 concentration, platelet count and age, it demonstrated to be a good marker for the HCV monoinfected group (AUROC 0.834) and an excellent one for the HCV/HIV co-infected group (AUROC 0.997). Moreover, the model displayed a diagnostic performance similar to FIB-4 in HCV cases and FIB-4 and APRI in HCV/HIV coinfected cases, and it even managed to correctly classify some cases that had been misclassified. The proposed model is able to determine, in a non-invasive way, the liver fibrosis stage of HCV and HCV/HIV patients, so after validation, it could be used in a complementary way in the clinical practice whenever APRI and FIB-4 failed to determine damage severity in HCV and HCV/HIV cases.

Asymptomatic SARS-CoV-2 Infection Is Associated With Higher Levels of Serum IL-17C, Matrix Metalloproteinase 10 and Fibroblast Growth Factors Than Mild Symptomatic COVID-19

Young adults infected with SARS-CoV-2 are frequently asymptomatic or develop only mild disease. Because capturing representative mild and asymptomatic cases require active surveillance, they are less characterized than moderate or severe cases of COVID-19. However, a better understanding of SARS-CoV-2 asymptomatic infections might shed light into the immune mechanisms associated with the control of symptoms and protection. To this aim, we have determined the temporal dynamics of the humoral immune response, as well as the serum inflammatory profile, of mild and asymptomatic SARS-CoV-2 infections in a cohort of 172 initially seronegative prospectively studied United States Marine recruits, 149 of whom were subsequently found to be SARS-CoV-2 infected. The participants had blood samples taken, symptoms surveyed and PCR tests for SARS-CoV-2 performed periodically for up to 105 days. We found similar dynamics in the profiles of viral load and in the generation of specific antibody responses in asymptomatic and mild symptomatic participants. A proteomic analysis using an inflammatory panel including 92 analytes revealed a pattern of three temporal waves of inflammatory and immunoregulatory mediators, and a return to baseline for most of the inflammatory markers by 35 days post-infection. We found that 23 analytes were significantly higher in those participants that reported symptoms at the time of the first positive SARS-CoV-2 PCR compared with asymptomatic participants, including mostly chemokines and cytokines associated with inflammatory response or immune activation (i.e., TNF-α, TNF-β, CXCL10, IL-8). Notably, we detected 7 analytes (IL-17C, MMP-10, FGF-19, FGF-21, FGF-23, CXCL5 and CCL23) that were higher in asymptomatic participants than in participants with symptoms; these are known to be involved in tissue repair and may be related to the control of symptoms. Overall, we found a serum proteomic signature that differentiates asymptomatic and mild symptomatic infections in young adults, including potential targets for developing new therapies and prognostic tests.

Examining Depression as a Risk Factor for Cardiovascular Disease in People with HIV: A Systematic Review

BACKGROUND

People with human immunodeficiency virus (HIV) have an increased risk of cardiovascular disease (CVD) not fully accounted for by traditional or HIV-specific risk factors. Successful management of HIV does not eliminate this excess risk. Thus, there is a need to identify novel risk factors for CVD among people with HIV (PWH).

PURPOSE

Our objective was to systematically review the literature on one such candidate CVD risk factor in PWH-depression.

METHODS

A systematic literature search of PubMed, PsycINFO, EMBASE, Web of Science, and CINAHL was performed to identify published English-language studies examining associations of depression with clinical CVD, subclinical CVD, and biological mechanisms (immune activation, systemic inflammation, altered coagulation) among PWH between the earliest date and June 22, 2021.

RESULTS

Thirty-five articles were included. For clinical CVD (k = 8), findings suggests that depression is consistently associated with an increased risk of incident CVD. For subclinical CVD (k = 5), one longitudinal analysis reported a positive association, and four cross-sectional analyses reported null associations. For immune activation (k = 13), systemic inflammation (k = 17), and altered coagulation (k = 5), findings were mixed, and there was considerable heterogeneity in sample characteristics and methodological quality across studies.

CONCLUSIONS

Depression may be an independent risk factor for CVD among PWH. Additional research is needed to confirm depression's association with clinical CVD and to determine whether depression is consistently and meaningfully associated with subclinical CVD and biological mechanisms of CVD in HIV. We propose a research agenda for this emerging area.

Decreases in markers of monocyte/macrophage activation after hepatitis C eradication in HIV/hepatitis C virus coinfected women

OBJECTIVE

Eradication of hepatitis C virus (HCV) in HIV disease decreases liver and non-liver-related morbidity and mortality. Elevated markers of monocyte/macrophage activation (soluble CD163 and sCD14) are associated with excess non-AIDS morbidity and mortality in HIV. We examined the effect of HCV eradication on these markers in relation to change in hepatic fibrosis.

DESIGN

A nested substudy within a longitudinal observational cohort.

METHODS

We studied 126 HIV/HCV-coinfected women successfully treated for HCV, with undetectable HCV RNA at least 12 weeks after therapy completion. sCD163 and sCD14 were measured in serum collected before and after HCV eradication. Results were correlated with changes in markers of hepatic fibrosis.

RESULTS

Mean age of participants was 56.3 years, mean CD4+ cell count was 615, and 72% had suppressed HIV RNA. After treatment, sCD163 and sCD14 levels significantly decreased from pre-treatment levels in unadjusted analyses. After adjusting for age, race, hepatic fibrosis status, baseline HCV RNA, CD4 count and HIV RNA status, cigarette smoking, and alcohol use, the decreases in sCD163 and sCD14 remained significant. Decrease in pre-treatment to post-treatment sCD163 were significantly positively correlated with changes in FIB-4 (r = 0.250, P = 0.005) and APRI (r = 0.262, P = 0.003); similarly decrease in sCD14 was significantly positively correlated with changes in FIB-4 (r = 0.333, P = 0.0001) and APRI (r = 0.457, P < 0.0001).

CONCLUSION

HCV eradication is associated with significant reductions in monocyte/macrophage activation markers that correlate with reductions in markers of hepatic fibrosis. These findings support broad access to and early initiation of HCV treatment in order to decrease immune activation and improve health in HIV-infected persons.

Do COVID-19 Infections Result in a Different Form of Secondary Hemophagocytic Lymphohistiocytosis

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality across the world, with no current effective treatments available. Recent studies suggest the possibility of a cytokine storm associated with severe COVID-19, similar to the biochemical profile seen in hemophagocytic lymphohistiocytosis (HLH), raising the question of possible benefits that could be derived from targeted immunosuppression in severe COVID-19 patients. We reviewed the literature regarding the diagnosis and features of HLH, particularly secondary HLH, and aimed to identify gaps in the literature to truly clarify the existence of a COVID-19 associated HLH. Diagnostic criteria such as HScore or HLH-2004 may have suboptimal performance in identifying COVID-19 HLH-like presentations, and criteria such as soluble CD163, NK cell activity, or other novel biomarkers may be more useful in identifying this entity.

Plasma inflammatory biomarkers predict CD4+ T-cell recovery and viral rebound in HIV-1 infected Africans on suppressive antiretroviral therapy

This multi-country prospective study investigated whether persistent systemic inflammation, measured by eight plasma biomarkers, in HIV-1-infected Africans during suppressive antiretroviral therapy (ART) (viral load<50 copies/mL), was associated with CD4+ T-cell recovery and viral rebound (>1,000 copies/mL) during long-term treatment. On-ART sCD14 and CRP concentrations were inversely associated with subsequent CD4+ T-cell counts. Risk of viral rebound was increased for participants with higher on-ART CXCL10 concentrations, and reduced for those with a greater sCD163 decline during the first year of ART. Persistent systemic inflammation predicted CD4+ T-cell recovery and viral rebound, warranting further mechanistic research in relation to clinical outcomes.

Endothelial Dysfunction Is Related to Monocyte Activation in Antiretroviral-Treated People With HIV and HIV-Negative Adults in Kenya

BACKGROUND

Residual monocyte activation may contribute to increased risk for endothelial dysfunction and subsequent atherosclerotic cardiovascular diseases (CVDs) among people with HIV (PWH) on antiretroviral therapy (ART). We examined the relationship between monocyte activation and endothelial activation in PWH in Kenya.

METHODS

Serum levels of markers of endothelial activation (soluble/circulating intercellular [sICAM-1] and vascular [sVCAM-1] cell adhesion molecule-1), intestinal barrier dysfunction (intestinal fatty acid binding protein [I-FABP]), and monocyte activation (soluble CD14 [sCD14]) were measured in 275 PWH on ART and 266 HIV-negative persons. Linear regression was used to evaluate associations, adjusting for demographic and traditional CVD risk factors.

RESULTS

Among 541 participants, the median age was 43 years, 50% were female, and most PWH were virally suppressed (97%). sICAM-1 and sVCAM-1 levels were significantly higher in PWH than in HIV-negative participants (P < .001 for both). After further adjustment for traditional CVD risk factors, HIV infection remained associated with 49% (95% CI, 33% to 67%) greater sICAM-1 and 30% (95% CI, 14% to 48%) greater sVCAM-1 relative to uninfected controls. Adjustment for sCD14 substantially attenuated the difference between PWH and HIV-negative individuals. In a stratified analysis of PWH, both sICAM-1 and sVCAM-1 were positively associated with sCD14 (P < .001).

CONCLUSIONS

Despite viral suppression, African PWH have evidence of enhanced endothelial activation associated with sCD14, suggesting that monocyte activation plays a role in atherosclerotic plaque development. Future studies are needed to determine mechanistic pathways leading to monocyte activation in this population.

Novel Mechanism of Microvesicle Regulation by the Antiviral Protein Tetherin During HIV Infection

Background Microvesicles are cell membrane-derived vesicles that have been shown to augment inflammation. Specifically, monocyte-derived microvesicles (MDMVs), which can express the coagulation protein tissue factor, contribute to thrombus formation and cardiovascular disease. People living with HIV experience higher prevalence of cardiovascular disease and also exhibit increased levels of plasma microvesicles. The process of microvesicle release has striking similarity to budding of enveloped viruses. The surface protein tetherin inhibits viral budding by physically tethering budding virus particles to cells. Hence, we investigated the role of tetherin in regulating the release of MDMVs during HIV infection. Methods and Results The plasma of aviremic HIV-infected individuals had increased levels of tissue factor + MDMVs, as measured by flow cytometry, and correlated to reduced tetherin expression on monocytes. Superresolution confocal and electron microscopy showed that tetherin localized at the site of budding MDMVs. Mechanistic studies revealed that the exposure of monocytes to HIV-encoded Tat triggered tetherin loss and subsequent rise in MDMV production. Overexpression of tetherin in monocytes led to morphologic changes in the pseudopodia directly underneath the MDMVs. Further, tetherin knockout mice demonstrated a higher number of circulating MDMVs and less time to bleeding cessation. Conclusions Our studies define a novel regulatory mechanism of MDMV release through tetherin and explore its contribution to the procoagulatory state that is frequently observed in people with HIV. Such insights could lead to improved therapies for individuals infected with HIV and also for those with cardiovascular disease.

Targeting of CD163+ Macrophages in Inflammatory and Malignant Diseases

The macrophage is a key cell in the pro- and anti-inflammatory response including that of the inflammatory microenvironment of malignant tumors. Much current drug development in chronic inflammatory diseases and cancer therefore focuses on the macrophage as a target for immunotherapy. However, this strategy is complicated by the pleiotropic phenotype of the macrophage that is highly responsive to its microenvironment. The plasticity leads to numerous types of macrophages with rather different and, to some extent, opposing functionalities, as evident by the existence of macrophages with either stimulating or down-regulating effect on inflammation and tumor growth. The phenotypes are characterized by different surface markers and the present review describes recent progress in drug-targeting of the surface marker CD163 expressed in a subpopulation of macrophages. CD163 is an abundant endocytic receptor for multiple ligands, quantitatively important being the haptoglobin-hemoglobin complex. The microenvironment of inflammation and tumorigenesis is particular rich in CD163+ macrophages. The use of antibodies for directing anti-inflammatory (e.g., glucocorticoids) or tumoricidal (e.g., doxorubicin) drugs to CD163+ macrophages in animal models of inflammation and cancer has demonstrated a high efficacy of the conjugate drugs. This macrophage-targeting approach has a low toxicity profile that may highly improve the therapeutic window of many current drugs and drug candidates.

High soluble CD163 levels correlate with disease progression and inflammation in Kenyan children with perinatal HIV-infection

OBJECTIVES

CD163 is a hemoglobin scavenger receptor on monocytes and macrophages, cleaved to soluble CD163 (sCD163) in the plasma following activation. In HIV+ adults, sCD163 is linked to non-AIDS morbidity and predicts mortality, but there is limited data in children. We investigated sCD163 levels in HIV+ children and their correlations with disease progression, immune activation and gut mucosal damage.

DESIGN AND METHODS

We quantified sCD163 levels in Kenyan children aged 0-20 years with perinatal HIV infection, including 74 antiretroviral treatment (ART)-naïve (ART-) and 64 virally suppressed on ART (ART+), and 79 HIV unexposed-uninfected controls (HIV-). The cohort was divided into age groups 0-5 (younger) and 5-20 (older) years. Correlations between sCD163 and HIV viral load, %CD8, CD4 : CD8 ratio, markers of T-cell activation and proliferation, and gut mucosal damage were also assessed.

RESULTS

ART- children have higher sCD163 levels compared with HIV- and ART+ children (P ≤ 0.01); ART+ have equivalent sCD163 levels to HIV- children. In a prospective analysis, sCD163 levels decreased in older ART- children after 12 months of treatment (P < 0.0001). Regardless of age, sCD163 levels correlate with clinical disease progression measured by %CD4 T cells, CD4 : CD8 T-cell ratios and HIV viral load. sCD163 levels directly correlate with T-cell activation markers CD38, human leukocyte antigen-DR isotype, and Ki67 (P ≤ 0.01).

CONCLUSION

High plasma sCD163 levels in HIV+ children correlate with advancing disease and T-cell activation. ART initiation normalizes sCD163 levels and may alleviate HIV-related morbidities and improve long-term pediatric outcomes.

Insomnia as an Independent Predictor of Incident Cardiovascular Disease in HIV: Data From the Veterans Aging Cohort Study

BACKGROUND

Insomnia is associated with increased cardiovascular disease (CVD) risk in the general population and is highly prevalent in people with HIV. The CVD risk conferred by insomnia in the HIV population is unknown.

METHODS

Using the Veterans Aging Cohort Study Survey Cohort, insomnia symptoms were measured and dummy coded with the item, "Difficulty falling or staying asleep?" (5-point scale from no difficulty to bothers a lot). Incident CVD event ICD-9 codes (acute myocardial infarction, stroke, or coronary artery revascularization) were identified with the Department of Veterans Affairs (VA) and Medicare administrative data and VA fee-for-service data. Those with baseline CVD were excluded.

RESULTS

HIV-infected (N = 3108) veterans had a median follow-up time of 10.8 years, during which 267 CVD events occurred. Compared to HIV-infected veterans with no difficulty falling or staying asleep, HIV-infected veterans bothered a lot by insomnia symptoms had an increased risk of incident CVD after adjusting for demographics [hazard ratio (HR) = 1.64, 95% confidence interval (CI): 1.16 to 2.31, P = 0.005], CVD risk factors (HR = 1.62, 95% CI: 1.14 to 2.30, P = 0.007), additional potential confounders (hepatitis C infection, renal disease, anemia, alcohol use, and cocaine use; HR = 1.70, 95% CI: 1.19 to 2.43, P = 0.003), and HIV-specific factors (HIV-1 RNA, CD4 T-cell count, and antiretroviral therapy; HR = 1.66, 95% CI: 1.16 to 2.37, P = 0.005). Additional adjustment for nonbenzodiazepine sleep medication (HR = 1.62, 95% CI: 1.13 to 2.32, P = 0.009) did not attenuate the association; however, it fell short of significance at P < 0.01 after adjustment for depressive symptoms (HR = 1.51, 95% CI: 0.98 to 2.32, P = 0.060) or antidepressant medication (HR = 1.51, 95% CI: 1.04 to 2.19, P = 0.031).

CONCLUSIONS

Highly bothersome insomnia symptoms were significantly associated with incident CVD in HIV-infected veterans, suggesting that insomnia may be a novel, modifiable risk factor for CVD in HIV.

Inflammatory and cardiovascular diseases biomarkers in chronic hepatitis C virus infection: A review

Hepatitis C virus (HCV) infects 180 million people worldwide and over 4 million people in the United States. HCV infection is a major cause of chronic liver disease and is recognized as a risk factor for clinical cardiovascular disease (CVD). Many studies have shown increased prevalence of cardiac and inflammatory biomarkers in patients with chronic HCV infection (CHC), and though these markers may be used to risk stratify people for cardiac disease in the general population their role in the HCV population is unknown. Patients with CHC have elevated cardiac and inflammatory biomarkers compared to noninfected controls which may play a role in CVD risk stratification. We undertook a systematic review of inflammatory and cardiac biomarkers in people with HCV infection with a focus on the effect of CHC on serum levels of these markers and their utility as predictors of CVD in this population. Medline, EMBASE, and Cochrane databases were searched for relevant articles until June 2019. A total of 2430 results were reviewed with 115 studies included. Our review revealed that HCV infection significantly alters serum levels of markers of inflammation, endothelial function, and cardiac dysfunction prior to HCV treatment, and some of which may change in response to HCV therapy. Current risk stratification tools for development of CVD in the general population may not account for the increased inflammatory markers that appear to be elevated among HCV‐infected patients contributing to increased CVD risk.

Low CD4 Cell Counts Are Associated with Carotid Plaque and Intima-Media Thickness in Virologically Suppressed HIV-Infected Asians Older Than 50 Years

Information about the prevalence, and risk factors for subclinical atherosclerosis in an Asian HIV-infected population is limited. Carotid intima-media thickness (cIMT) is one predictor for the risk of cardiovascular disease (CVDs) and mortality. We evaluated the prevalence and risk factors related to carotid atherosclerosis among well-suppressed HIV-infected adults receiving long-term ART from Thailand. This was a cross-sectional study of HIV-infected adults >50 years of age and free from CVDs from Thailand during 1 March 2016 and 30 May 2017. Ultrasonography of the carotid was performed and read by cIMT experienced neurologists who were blinded from the patient care. Subclinical atherosclerosis was defined by carotid plaque or cIMT of the common carotid artery (CCA) >0.9 mm. Totally 316 HIV-infected adults (61% males) were included. Median age was 54.4 years and 15.8% were diabetic, 40.2% had hypertension, and 12.7% were current smokers. The median duration of ART was 16.3 years and 32% were currently on boosted protease inhibitor. The mean overall cIMT of the common carotid arteries were 0.63 (IQR 0.55-0.72) mm. Men had higher cIMT than women, 0.64 (IQR 0.56-0.76) vs. 0.60 (IQR 0.53-0.70), p = .03. Overall, 3.8% had cIMT >0.9 mm and 24.4% had carotid plaque. From the multivariate logistic regression analysis, age per 1 year increase [odds ratio (OR) 1.06; 95% confidence interval (CI) 1.003-1.12; p = .04] and nadir CD4 < 200 cells/mm³ (OR 1.8; 95%CI 1.02-3.18, p = .04) were significantly associated with subclinical atherosclerosis. High-sensitivity C-reactive protein was not associated with subclinical atherosclerosis. In this well-suppressed HIV-infected Aging Asian cohort with relatively low prevalence of current smokers, 26.9% of them had subclinical atherosclerosis. Advanced age and low nadir CD4 cell count were significantly associated with subclinical atherosclerosis. Given that approximately a quarter of the patients had carotid plaques, longitudinal studies to evaluate the development of future overt coronary artery disease and stroke are warranted.

Hepatitis C virus and cumulative infections are associated with atherogenic cardiovascular events in HIV-infected subjects

OBJECTIVES

to analyze the association between HCV coinfection and cumulative infections with the development of a cardiovascular disease in HIV-infected subjects.

METHODS

HIV-infected subjects attended at Virgen del Rocio University Hospital, between January 1982 and March 2018, were considered if fulfilled the following criteria: at least two visits to the HIV clinic, clinical records with data about VZV reactivation and bacterial infections, available data on HCV coinfection status. Atherogenic cardiovascular events were registered. To analyze factors associated with the development of cardiovascular event, a logistic regression analysis was performed.

RESULTS

823 subjects were included in the study. During the observational period, 58/823 (7.05%) developed a cardiovascular event. Advanced age at HIV-1 diagnosis, a low T-CD4 nadir, HCV coinfection and the burden of infections were independently associated with the risk of developing a cardiovascular event, apart from lipid levels and diabetes.

CONCLUSIONS

both HCV and the burden of infections are associated with an increased risk of cardivascular event in HIV-infected patients, together with other cardiovascular risk factors. Therapeutic strategies such as HCV erradication or VZV immunization could ameliorate cardiovascular risk in these subjects.

Inflammatory Mechanisms and Cascades Contributing to Neurocognitive Impairment in HIV/AIDS

Neurocognitive impairment caused by chronic human immunodeficiency virus (HIV) infection is a growing concern. In this chapter we discuss the inflammatory mechanisms underlying the pathology of asymptomatic and mild neurocognitive impairment in the context of antiretroviral therapy. We discuss the role of HIV, viral proteins, and virally infected cells on the development of neuroinflammation and the effect of viral proteins on the cells of the central nervous system.We examine how these collective factors result in an inflammatory context that triggers the development of neurocognitive impairment in HIV. We assess the contribution of antiretrovirals and drugs of abuse, including methamphetamine, cannabis, and opioids, to the neurotoxic and neuroinflammatory milieu that leads to the development of neurocognitive impairment in HIV-infected individuals. We also examined circulating biomarkers, NF-L, sCD163, and sCD14, pertinent to identifying changes in the CNS that could indicate real-time changes in patient physiology. Lastly, we discuss future studies, such as exosomes and the microbiome, which could play a role in the HIV-induced neuroinflammation that eventually manifests as cognitive impairment.

Asymmetrical Dimethylarginine Levels in Hepatitis B Virus-Positive Patients

BACKGROUND

High asymmetrical dimethylarginine (ADMA) levels have been associated with endothelial dysfunction and contribute to the development of several diseases. However, data on the relationship between hepatitis B virus (HBV) and ADMA are limited. The aim of our study was to explore the relationship between ADMA and HBV by comparing the ADMA levels in patients with chronic active hepatitis B (CHB), inactive HBV carriers (carriers), and healthy volunteers (controls).

METHODS

The participants were divided into three groups: 90 patients with CHB, 90 HBV carriers, and 90 controls. Serum ADMA levels were quantified using an ELISA kit (Cusabio, Wuhan, China). The data were analyzed using an ANOVA or the Kruskal-Wallis test as appropriate, with P<0.05 considered significant.

RESULTS

Serum ADMA levels were significantly higher in patients with CHB (228.35±91.10 ng/mL) than in HBV carriers (207.80±75.80 ng/mL) and controls (207.61±89.10 ng/mL) (P=0.049). The clinical scores of the patients were positively correlated with ADMA levels.

CONCLUSIONS

The elevated serum ADMA levels in patients with CHB confirm that HBV plays a role in vasculitis. Further investigation of the mechanisms contributing to the high levels of ADMA in CHB may contribute toward development of new treatment modalities.

Macrophage Activation Marker Soluble CD163 Is a Dynamic Marker of Liver Fibrogenesis in Human Immunodeficiency Virus/Hepatitis C Virus Coinfection

Background

Coinfection with human immunodeficiency virus (HIV) accelerates hepatitis C virus (HCV)-related liver fibrosis. Macrophages are triggered during both viral infections and are critical in liver inflammation/fibrogenesis. Liver fibrosis strongly associates with serum soluble CD163 (sCD163, a macrophage activation marker); comprehensive evaluation in HIV/HCV coinfection is lacking.

Methods

We retrospectively analyzed sCD163 (enzyme-linked immunosorbent assay) and hepatic CD163 (immunofluorescent CD163/CD68 costaining) in patients infected with HIV/HCV, HCV, or HIV, pre- and post-antiviral therapy.

Results

sCD163 was significantly higher in HIV/HCV compared to either monoinfection, and decreased following successful antiviral therapy, although did not fully normalize. In HIV/HCV, sCD163 was associated with necroinflammation, Ishak fibrosis scores, and noninvasive fibrosis scores. We observed a novel trend whereby sCD163 levels progressively increase with increasing Ishak fibrosis score, peaking at stage 4, above which levels plateaued. Periportal CD163+ macrophage frequency was also higher with increasing fibrosis score. When stratified by fibrosis stage, sCD163 levels were higher in HIV/HCV than HCV but only in individuals with mild to moderate fibrosis.

Conclusions

In HIV/HCV, increasing sCD163 levels accompanied periportal CD163+ macrophage enrichment in mild to moderate fibrosis, but not in established cirrhosis, suggesting that sCD163 is a dynamic biomarker of fibrogenesis rather than accumulated fibrosis. Our findings implicate HIV-related macrophage activation in accelerated fibrosis progression in HIV/HCV coinfection.

Zidovudine-Based Treatments Inhibit the Glycosylation of ADAM17 and Reduce CD163 Shedding From Monocytes

BACKGROUND

sCD163, a biomarker of monocyte-macrophage activation, has been identified as a predictor of all-cause mortality in treated HIV-infected individuals. Nevertheless, little is known about whether different antiretroviral drugs differentially regulate sCD163 levels and monocyte activation.

METHODS

A total of 123 patients receiving zidovudine (ZDV)-based (n = 55) or tenofovir disoproxil fumarate (TDF)-based (n = 68) antiretroviral regimens were enrolled, and their viral loads, CD4 counts, as well as plasma sCD163 and sCD14 levels were quantified. Twenty-eight (14 in each group) patients donated additional blood samples for flow cytometry and gene expression analyses using purified monocytes. THP-1 cultures were also used to investigate the effect of ZDV on ADAM17, which is responsible for CD163 shedding.

RESULTS

As compared to the TDF-treated group, the ZDV-treated group had lower plasma sCD163 levels and higher CD163 expression on CD14++CD16 monocytes. Five metabolic-inflammatory genes exhibited significantly different expression levels between purified monocytes of the ZDV and TDF groups (IL-6, 2.90-fold lower in ZDV group, P < 0.001; iNOS, 1.81-fold higher; CX3CR1, 1.72-fold lower; MIP-1β, 1.10-fold lower; and PPARγ-1, 1.36-fold higher, P < 0.05). Moreover, we show that ZDV treatment increases the surface expression of CD163 in cultured THP-1 cells, accompanied by the inhibition of glycosylation and surface expression of ADAM17.

CONCLUSIONS

Compared with TDF treatment, ZDV treatment causes lower plasma sCD163 levels, probably by inhibiting the glycosylation of ADAM17 and CD163 shedding. Our results show that ZDV functions as an ADAM17 inhibitor in vivo and extend our understanding of its immune-modulatory effects and adverse effects.

HIV disease is associated with increased biomarkers of endothelial dysfunction despite viral suppression on long-term antiretroviral therapy in Botswana

Background

Untreated HIV infection is associated with increased biomarkers of endothelial dysfunction. However, the predictors and degree of endothelial dysfunction among virally suppressed HIV–infected adults on long–term antiretroviral therapy (ART) have not been well studied in sub– Saharan Africa (SSA).

Methods

We enrolled 112 HIV–infected adults with virological suppression on long–term ART and 84 HIV–uninfected controls in Botswana. We measured plasma levels of markers of endothelial injury [soluble vascular adhesion molecule 1 (VCAM–1), intercellular adhesion molecule 1 (ICAM–1) and E–selectin] and plasma levels of biomarkers of inflammation [interleukin 6 (IL–6)] and monocyte activation (sCD163). Baseline traditional cardiovascular disease (CVD) risk factors and bilateral common carotid intima–media thickness (cIMT) were also available for all participants. We assessed whether HIV status (despite virological suppression on ART) was associated with biomarkers of endothelial dysfunction after controlling for traditional CVD risk factors in linear regression models. We additionally assessed the association between IL–6, sCD163 and cIMT with endothelial dysfunction in separate multivariate linear regression models, controlling for cIMT, among virally suppressed HIV–infected participants only.

Results

In multivariate analysis, HIV infection was significantly associated with increased VCAM–1 (p < 0.01) and ICAM–1 (p = 0.03) but not E–selectin (p = 0.74) levels. Within the HIV–positive group, higher sCD163 levels were associated with decreased ICAM–1 and E–selectin (p < 0.01 and p = 0.01, respectively) but not VCAM–1 (p = 0.13) levels. IL–6 was not associated with any of the biomarkers of endothelial dysfunction.

Conclusion

HIV disease was associated with biomarkers of endothelial dysfunction among virally suppressed adults in Botswana on long–term ART after controlling for traditional CVD risk factors. Future work should explore the clinical impact of persistent endothelial dysfunction following longterm HIV viral suppression on the risk of CVD clinical endpoints among HIV–infected patients in this setting.

Noncommunicable diseases in adolescents with perinatally acquired HIV-1 infection in high-income and low-income settings

PURPOSE OF REVIEW

Perinatally HIV-infected adolescents may be at increased risk of noninfectious comorbidities later in life. This review summarizes recent advances in the understanding of noncommunicable diseases (NCD) among HIV-infected adolescents in high-income and lower middle-income countries, and identifies key questions that remain unanswered. We review atherosclerotic vascular disease (AVD), chronic bone disease (CBD), chronic kidney disease (CKD), and chronic lung disease (CLD).

RECENT FINDINGS

Persistent immune activation and inflammation underlie the pathogenesis of AVD, highlighting the importance of treatment adherence and maintenance of viral suppression, and the need to evaluate interventions to decrease risk. Tenofovir disoproxil fumarate (TDF) and trials of vitamin D supplementation have been the focus of recent studies of CBD with limited studies to date evaluating tenofovir alafenamide as an alternative to TDF for decreasing risk for bone and renal adverse effects among HIV-infected adolescents. Recent studies of CKD have focused primarily on estimating prevalence in different settings whereas studies of CLD are limited.

SUMMARY

As perinatally HIV-infected children age into adolescence and adulthood with effective long-term ART, it is necessary to continue to evaluate their risks for noninfectious comorbidities and complications, understand mechanisms underlying their risks, and identify and evaluate interventions specifically in this population.

Transcriptomics and Targeted Proteomics Analysis to Gain Insights Into the Immune-control Mechanisms of HIV-1 Infected Elite Controllers

A small subset of HIV-1 infected individuals, the "Elite Controllers" (EC), can control viral replication and restrain progression to immunodeficiency without antiretroviral therapy (ART). In this study, a cross-sectional transcriptomics and targeted proteomics analysis were performed in a well-defined Swedish cohort of untreated EC (n=19), treatment naïve patients with viremia (VP, n=32) and HIV-1-negative healthy controls (HC, n=23). The blood transcriptome identified 151 protein-coding genes that were differentially expressed (DE) in VP compared to EC. Genes like CXCR6 and SIGLEC1 were downregulated in EC compared to VP. A definite distinction in gene expression between males and females among all patient-groups were observed. The gene expression profile between female EC and the healthy females was similar but did differ between male EC and healthy males. At targeted proteomics analysis, 90% (29/32) of VPs clustered together while EC and HC clustered separately from VP. Among the soluble factors, 33 were distinctive to be statistically significant (False discovery rate=0.02). Cell surface receptor signaling pathway, programmed cell death, response to cytokine and cytokine-mediated signaling seem to synergistically play an essential role in HIV-1 control in EC.

Active HCV infection is associated with increased circulating levels of interferon-gamma (IFN-γ)-inducible protein-10 (IP-10), soluble CD163 and inflammatory monocytes regardless of liver fibrosis and HIV coinfection

BACKGROUND AND OBJECTIVE

Interferon-gamma (IFN-γ)-inducible protein-10 (IP-10), soluble (s) CD163 and sCD14 play an important role in the pathogenesis of HCV and HIV infection and are involved in inflammation and liver fibrosis. The aim of the present study was to evaluate at a single time point, plasma soluble biomarkers and inflammatory monocytes subsets in different groups of subjects: (i) HIV monoinfected patients on suppressive ART; (ii) HIV/HCV coinfected patients on ART, with undetectable HIV viremia (including either subjects who had active HCV replication or those who cleared HCV); (iii) HCV monoinfected individual with active viral replication.

METHODS

Hundred and twenty-nine plasma samples were analyzed including HCV and HIV monoinfected patients, HIV/HCV coinfected patients, with active HCV infection (AHI) or with HCV viral clearance (VHC) and healthy donors (HD). Levels of IP-10, sCD163 and sCD14 were measured by ELISA. Absolute cell counts of monocyte subpopulations were enumerated in whole blood by using flow cytometric analyses.

RESULTS

IP-10 and sCD163 plasma levels were higher in HCV monoinfected and in AHI coinfected pts compared to HIV monoinfected and HD, whereas sCD14 levels were higher only in HIV monoinfected patients. Considering the degree of fibrosis, sCD163 and sCD14 levels positively correlated with kPa values (as assessed by fibroscan) and FIB-4 in HCV monoinfected group. On the other hand, IP-10 did not correlate with the fibrosis stage and it was found increased also in patients with low fibrosis. Moreover, we found an increase of the inflammatory NCM subset, in non-cirrhotic HCV subjects, while no alterations were observed in HIV, AHI and VHC.

CONCLUSIONS

Our study suggests a scenario in which active HCV infection is associated with a strong pro-inflammatory state, even in the initial stage of liver fibrosis, regardless the presence of HIV coinfection, thus underlying the need of an early anti-HCV treatment.

Brief Report: Macrophage Activation in HIV-2-Infected Patients Is Less Affected by Antiretroviral Treatment-sCD163 in HIV-1, HIV-2, and HIV-1/2 Dually Infected Patients

The course of disease among HIV-2, HIV-1, and HIV-1/2 dually infected patients is different. We investigated the macrophage activation marker soluble CD163 (sCD163) dynamics in 212 HIV-1, HIV-2, and HIV-1/2 dually infected patients. There were no differences in sCD163 levels at baseline or during follow-up without antiretroviral therapy (ART). At follow-up on ART, median sCD163 levels were decreased for HIV-1-infected patients (P < 0.001), but not among HIV-2 (P = 0.093) or HIV-1/2 dually infected patients (P = 0.145). The larger decrease in sCD163 levels among HIV-1-infected patients during ART may indicate an HIV type-dependent differential effect of ART on macrophage activation during HIV infection.

Soluble TWEAK may predict carotid atherosclerosis in treated HIV infection

BACKGROUND

Soluble Tumor Necrosis Factor Weak Inducer of Apoptosis (sTWEAK) has been proposed as a novel biomarker of cardiovascular disease risk. This study compares levels of sTWEAK, sCD163 and the sCD163/sTWEAK ratio in HIV-infected and uninfected patients and their associations with cardiovascular and inflammatory factors.

METHODS

The data for our analysis come from 274 HIV-infected adults and 59 controls. HIV participants were on stable antiretroviral therapy (ART). Wilcoxon-Mann-Whitney tests were used for comparing markers between HIV-infected participants with HIV viral load <50 copies/mL (aviremic group), HIV-infected participants with detectable viremia (HIV-1 RNA ≥50 copies/mL; viremic group) and HIV negative participants. Multivariable quantile regression analyses were used to assess associations of sTWEAK and sCD163 with other markers of inflammation and carotid intima-media thickness (cIMT).

RESULTS

Overall, 74% of participants were male; 59% were African-Americans; median age was 40 years and CD4 595 cells/mm3. Overall, HIV-infected participants had reduced sTWEAK and increased sCD163 levels compared to HIV-uninfected participants (p = 0.0001 for both markers). In addition, these biomarkers were significantly different between HIV-infected viremic and aviremic patients (p ≤ 0.01 for both markers). In multivariable models, sTWEAK and sCD163 in aviremic patients were significantly correlated with common carotid artery IMT (p ≤ 0.05). In HIV-infected aviremic participants, sTWEAK and sCD163 were both associated with IL-6, CD14 + CD16 + monocytes (p ≤ 0.02); additionally, sCD163 was associated with D-dimer- (β = -69.5, 0.05), VCAM (β = 72.4, p = 0.05), TNF RI (β = 91.1, p < 0.01), and TNF RII (β = 87.8, p < 0.01).

CONCLUSIONS

HIV-infected participants showed increased systemic inflammatory and monocyte activation markers. Soluble CD163 and sTWEAK levels were associated with carotid intima-media thickness.

HIV infection, antiretroviral therapy, and measures of endothelial function, inflammation, metabolism, and oxidative stress

Background

HIV-infected patients have an increased risk of cardiovascular disease (CVD). Impaired endothelial function is an early risk factor for CVD in the general population. It is presumed that HIV infection is associated with impaired endothelial function, but results have been inconsistent.

Objectives

Our objectives were to determine the relationships between HIV infection, virologic suppression with antiretroviral therapy (ART), in vivo measures of conduit artery and microvascular endothelial function, and circulating biomarkers of pathways associated with CVD.

Methods

We performed a cross-sectional analysis of three prospectively enrolled groups from a single center: 28 were HIV-infected and virologically-suppressed on a regimen of FTC/TDF/EFV (HIV+ART+), 44 were HIV-infected but not on ART (HIV+ART-), and 39 were HIV-uninfected healthy volunteers (HIV-) matched to the HIV+ART- group for age, sex, smoking status, and height. None had diabetes, uncontrolled hypertension, known CVD, or other pro-inflammatory condition. Flow mediated dilation (FMD), nitroglycerin-mediated dilation (NTGMD), reactive hyperemia velocity time integral (RHVTI), and FMD/RHVTI of the brachial artery were measured, as well as circulating biomarkers of systemic inflammation, metabolism, oxidative stress, and endothelial activation.

Results

No significant differences were found amongst the three groups in FMD (P = 0.46), NTGMD (P = 0.42), RHVTI (P = 0.17), and FMD/RHVTI (P = 0.22) in unadjusted comparisons. Adjusted ANOVA models which included brachial artery diameter, demographics, and conventional CVD risk factors did not appreciably change these findings. In pairwise comparisons, the HIV+ART- group had significantly higher soluble tumor necrosis factor receptor II, soluble CD163, β-2 microglobulin, interferon-γ- induced protein-10, tissue inhibitor of metalloproteinase-1, and vascular cell adhesion molecule-1 compared to the other two groups (all p<0.05). Correlates of endothelial function differed between study groups.

Conclusion

Although untreated HIV infection was associated with elevated levels of several biomarkers of inflammation and endothelial activation, we were unable to demonstrate differences in measures of conduit artery and microvascular endothelial function in this study population.

Pre-clinical carotid atherosclerosis and sCD163 among virally suppressed HIV patients in Botswana compared with uninfected controls

Objectives

Human immune deficiency virus (HIV) is associated with increased cardiovascular disease (CVD) risk, yet the relationship between HIV and carotid atherosclerosis / monocyte activation among virally suppressed HIV-infected patients in sub-Saharan Africa is not well understood.

Methods

We measured traditional CVD risk factors, bilateral distal common carotid intima media thickness (cIMT), presence of carotid plaque and plasma sCD163 levels among virally suppressed HIV-infected adults and HIV-uninfected controls, in a cross-sectional study in Gaborone, Botswana. The associations between HIV status, traditional CVD risk factors, sCD163 and outcome of cIMT were assessed in univariate and multivariate linear regression models.

Results

We enrolled 208 HIV-infected adults (55% Female, mean age 39 years) who had undetectable HIV-1 RNA on antiretroviral therapy and 224 HIV-uninfected controls (47% Female, mean age 37 years). There was no difference in cIMT between study groups, with mean cIMT 0.607mm and 0.599mm in HIV-infected and HIV-uninfected, respectively (p = 0.37). Plasma sCD163 was significantly higher in HIV-infected versus HIV-uninfected persons (1917ng/ml vs 1593ng/ml, p = 0.003), but was not associated with cIMT (p = 0.43 among all, p = 0.72 for HIV-infected only). In the final multivariate model, increased cIMT was associated with older age, being treated for hypertension, and higher non-HDL cholesterol among all (p<0.001, p = 0.03, p<0.001 respectively), and with older age and waist-hip ratio in HIV-infected participants (p = 0.02 & p = 0.02 respectively). Carotid plaque was present in a significantly higher proportion of HIV-infected adults (RR 2.15, 95% CI 1.22, 3.81).

Conclusions

HIV-infected participants aged 30–50 years who have achieved viral suppression did not have increased cIMT when compared to HIV-uninfected controls in Botswana. However, well-controlled HIV was associated with excess monocyte activation. Future work should explore the impact of subclinical atherosclerosis on CVD events among HIV-infected and -uninfected adults in Botswana.

The role of tumor necrosis factor-like weak inducer of apoptosis in atherosclerosis via its two different receptors

At present, it is commonly accepted that atherosclerosis is a chronic inflammatory disease characterized by disorder of the arterial wall. As one of the inflammatory cytokines of the tumor necrosis factor superfamily, tumor necrosis factor-like weak inducer of apoptosis (TWEAK) participates in the formation and progression of atherosclerosis. TWEAK, when binding to its initial receptor, fibroblast growth factor inducible molecule 14 (Fn14), exerts adverse biological functions in atherosclerosis, including dysfunction of endothelial cells, phenotypic change of smooth muscle cells and inflammatory responses of monocytes/macrophages. However, accumulating data supports that, besides Fn14, TWEAK also binds to cluster of differentiation (CD)163, an anti-inflammatory cytokine and a scavenger receptor exclusively expressed by monocytes and macrophages. Furthermore, it has been demonstrated that CD163 is able to internalize TWEAK and likely elicits protective effects in atherosclerosis by terminating inflammation induced by TWEAK. In the present study, the role of TWEAK in atherosclerosis was reviewed, with a predominant focus on CD163 and Fn14 receptors.

Marker of Endothelial Dysfunction Asymmetric Dimethylarginine Is Elevated in HIV Infection but Not Associated With Subclinical Atherosclerosis

BACKGROUND

Cardiovascular disease contributes to excess morbidity and mortality in HIV infection, and endothelial dysfunction may contribute to this pattern. We aimed to determine the endothelial function in treated and untreated HIV-infected individuals and investigate potential associations with viral replication, immune activation, coagulation, platelet function, and subclinical atherosclerosis.

METHODS

Asymmetric dimethylarginine (ADMA, marker of endothelial dysfunction) and soluble CD14 (sCD14, marker of monocyte activation) were measured in plasma from two previously established cross-sectional cohorts: cohort A including 50 untreated and 50 antiretroviral therapy (ART)-treated HIV-infected individuals with previously assessed coagulation and platelet function and cohort B including 105 HIV-infected individuals on ART and 105 uninfected controls with previously assessed coronary artery calcium score, myocardial perfusion defects, and carotid intima-media thickness.

RESULTS

Concentrations of ADMA were higher in HIV-infected individuals compared with uninfected controls, and higher ADMA was found in ART-treated compared with untreated HIV-infected individuals. ADMA was associated with viral load, sCD14, D-dimer, and low CD4 T-cell count in untreated HIV infection. Only viral load remained significant in multivariate analyses. In ART-treated HIV-infected individuals, ADMA was not associated with coronary artery calcium score, myocardial perfusion defects, or intima-media thickness.

CONCLUSIONS

Evidence of endothelial dysfunction was found in HIV infection and in untreated compared with treated HIV infection. In untreated HIV infection, the main driver of endothelial dysfunction was viral replication. Importantly, in treated HIV infection, ADMA was not associated with subclinical atherosclerosis. Thus, our data question the potential of ADMA as a useful biomarker of early atherosclerosis in treated HIV infection.

Telmisartan increases vascular reparative capacity in older HIV-infected adults: a pilot study

BACKGROUND

Endothelial progenitor cells (EPCs) are bone marrow-derived cells that contribute to vascular repair. EPCs may be reduced in HIV-infected (HIV+) persons, contributing to cardiovascular disease (CVD). Telmisartan is an angiotensin receptor blocker that increases EPCs in HIV-uninfected adults.

OBJECTIVE

To assess telmisartan's effects on EPC number and immunophenotype in older HIV + adults at risk for CVD.

METHODS

HIV + persons ≥50 years old with HIV-1 RNA < 50 copies/mL on suppressive antiretroviral therapy and ≥1 CVD risk factor participated in a prospective, open-label, pilot study of oral telmisartan 80 mg daily for 12 weeks. Using CD34 and CD133 as markers of early maturity and KDR as a marker of endothelial lineage commitment, EPCs were quantified via flow cytometry and defined as viable CD3^-/CD33^-/CD19^-/glycophorin^- cells of four immunophenotypes: CD133⁺/KDR⁺, CD34⁺/KDR⁺, CD34⁺/CD133⁺, or CD34⁺/KDR⁺/CD133⁺. The primary endpoint was a 12-week change in EPC subsets (NCT01578772).

RESULTS

Seventeen participants (88% men, median age 60 years and peripheral CD4⁺ T lymphocyte count 625 cells/mm³) enrolled and completed the study. After 6 and 12 weeks of telmisartan, frequencies of all EPC immunophenotypes were higher than baseline (all p < 0.10 except week 12 CD133⁺/KDR⁺ EPC, p = 0.13). Participants with lower baseline EPC levels had the largest gains. Additionally, the percentage of CD34⁺ cells with endothelial commitment (KDR⁺) increased.

CONCLUSIONS

Our data suggest that telmisartan use is associated with an increase in circulating EPCs in older HIV + individuals with CVD risk factors. Further controlled studies are needed to assess whether EPC increases translate to a reduction in CVD risk in this population.

Pathophysiology and management of cardiovascular disease in patients with HIV

Results from several studies have suggested that people with HIV have an increased risk of cardiovascular disease, especially coronary heart disease, compared with people not infected with HIV. People living with HIV have an increased prevalence of traditional cardiovascular disease risk factors, and HIV-specific mechanisms such as immune activation. Although older, more metabolically harmful antiretroviral regimens probably contributed to the risk of cardiovascular disease, new data suggest that early and continuous use of modern regimens, which might have fewer metabolic effects, minimises the risk of myocardial infarction by maintaining viral suppression and decreasing immune activation. Even with antiretroviral therapy, however, immune activation persists in people with HIV and could contribute to accelerated atherosclerosis, especially of coronary lesions that are susceptible to rupture. Therefore, treatments that safely reduce inflammation in people with HIV could provide additional cardiovascular protection alongside treatment of both traditional and non-traditional risk factors.

Plasma Soluble CD163 Level Independently Predicts All-Cause Mortality in HIV-1-Infected Individuals

BACKGROUND

CD163, a monocyte- and macrophage-specific scavenger receptor, is shed as soluble CD163 (sCD163) during the proinflammatory response. Here, we assessed the association between plasma sCD163 levels and progression to AIDS and all-cause mortality among individuals infected with human immunodeficiency virus type 1 (HIV).

METHODS

Plasma sCD163 levels were measured in 933 HIV-infected individuals. Hazard ratios (HRs) with 95% confidence intervals (CIs) associated with mortality were computed by Cox proportional hazards regression.

RESULTS

At baseline, 86% were receiving antiretroviral treatment, 73% had plasma a HIV RNA level of <50 copies/mL, and the median CD4(+) T-cell count was 503 cells/µL. During 10.5 years of follow-up, 167 (17.9%) died. Plasma sCD163 levels were higher in nonsurvivors than in survivors (4.92 mg/L [interquartile range {IQR}, 3.29-8.65 mg/L] vs 3.16 mg/L [IQR, 2.16-4.64 mg/L]; P = .0001). The cumulative incidence of death increased with increasing plasma sCD163 levels, corresponding to a 6% or 35% increased risk of death for each milligram per liter or quartile increase, respectively, in baseline plasma sCD163 level (adjusted HR, 1.06 [95% CI, 1.03-1.09] and 1.35 [95% CI, 1.13-1.63], respectively).

CONCLUSIONS

Plasma sCD163 was an independent marker of all-cause mortality in a cohort of HIV-infected individuals, suggesting that monocyte/macrophage activation may play a role in HIV pathogenesis and be a target of intervention.

Inflammation, immune activation, and cardiovascular disease in HIV

Cardiovascular disease is one of the leading causes of morbidity and mortality in people living with HIV. Several epidemiological studies have shown an increased risk of myocardial infarction and stroke compared to uninfected controls. Although traditional risk factors contribute to this increased risk of cardiovascular disease, HIV-specific mechanisms likely also play a role. Systemic inflammation has been linked to cardiovascular disease in several populations suffering from chronic inflammation, including people living with HIV. Although antiretroviral therapy reduces immune activation, levels of inflammatory markers remain elevated compared to uninfected controls. The causes of this sustained immune response are likely multifactorial and incompletely understood. In this review, we summarize the evidence describing the relationship between inflammation and cardiovascular disease and discuss potential anti-inflammatory treatment options for cardiometabolic disease in people living with HIV.

Systemic inflammation and liver damage in HIV/hepatitis C virus coinfection

OBJECTIVES

Chronic hepatitis C virus (HCV) and HIV viral infections are characterized by systemic inflammation. Yet the relative levels, drivers and correlates of inflammation in these settings are not well defined.

METHODS

Seventy-nine HIV-infected patients who had been receiving antiretroviral therapy (ART) for more than 2 years and who had suppressed plasma HIV levels (< 50 HIV-1 RNA copies/mL) were included in the study. Two patient groups, HCV-positive/HIV-positive and HCV-negative/HIV-positive, and a control group comprised of healthy volunteers (n = 20) were examined. Markers of systemic inflammation [interleukin (IL)-6, interferon gamma-induced protein (IP)-10, soluble tumour necrosis factor receptor-I (sTNF-RI) and sTNF-RII], monocyte/macrophage activation [soluble CD163 (sCD163), soluble CD14 and neopterin], intestinal epithelial barrier loss [intestinal fatty acid binding protein (I-FABP) and lipopolysaccharide (LPS)] and coagulation (d-dimers) were analysed. CD4 naïve T cells and CD4 recent thymic emigrants (RTEs) were enumerated.

RESULTS

Plasma levels of IP-10, neopterin and sCD163 were higher in HCV/HIV coinfection than in HIV monoinfection and were positively correlated with indices of hepatic damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the AST to platelet ratio index (APRI)]. Levels of I-FABP were comparably increased in HIV monoinfection and HIV/HCV coinfection but LPS concentrations were highest in HCV/HIV coinfection, suggesting impaired hepatic clearance of LPS. Plasma HCV levels were not related to any inflammatory indices except sCD163. In coinfected subjects, a previously recognized relationship of CD4 naïve T-cell and RTE counts to hepatocellular injury was defined more mechanistically by an inverse relationship to sCD163.

CONCLUSIONS

Hepatocellular injury in HCV/HIV coinfection is linked to elevated levels of certain inflammatory cytokines and an apparent failure to clear systemically translocated microbial products. A related decrease in CD4 naïve T cells and RTEs also merits further exploration.

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

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

HIV-1/HAART-Related Lipodystrophy Syndrome (HALS) Is Associated with Decreased Circulating sTWEAK Levels

BACKGROUND AND OBJECTIVES

Obesity and HIV-1/HAART-associated lipodystrophy syndrome (HALS) share clinical, pathological and mechanistic features. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is a multifunctional cytokine that plays an important role in obesity and related diseases. We sought to explore the relationship between HALS and circulating levels of soluble (s) TWEAK and its scavenger receptor sCD163.

METHODS

This was a cross-sectional multicenter study of 120 HIV-1-infected patients treated with a stable HAART regimen; 56 with overt HALS and 64 without HALS. Epidemiological and clinical variables were determined. Serum levels of sTWEAK and sCD163 levels were measured by ELISA. Results were analyzed with Student's t-test, Mann-Whitney U and χ2 test. Pearson and Spearman correlation were used to estimate the strength of association between variables.

RESULTS

Circulating sTWEAK was significantly decreased in HALS patients compared with non-HALS patients (2.81±0.2 vs. 2.94±0.28 pg/mL, p = 0.018). No changes were observed in sCD163 levels in the studied cohorts. On multivariate analysis, a lower log sTWEAK concentration was independently associated with the presence of HALS (OR 0.027, 95% CI 0.001-0.521, p = 0.027).

CONCLUSIONS

HALS is associated with decreased sTWEAK levels.

Late Antiretroviral Therapy (ART) Initiation Is Associated with Long-Term Persistence of Systemic Inflammation and Metabolic Abnormalities

Objectives

HIV-induced immunodeficiency is associated with metabolic abnormalities and systemic inflammation. We investigated the effect of antiretroviral therapy (ART) on restoration of insulin sensitivity, markers of immune activation and inflammation.

Methods

Immunological, metabolic and inflammatory status was assessed at antiretroviral therapy initiation and three years later in 208 patients from the ANRS-COPANA cohort. Patients were compared according to their pre-ART CD4⁺ cell count (group 1: ≤ 200/mm³, n = 66 vs. group 2: > 200/mm³, n = 142).

Results

Median CD4⁺ cell count increased in both groups after 3 years of successful ART but remained significantly lower in group 1 than in group 2 (404 vs 572 cells/mm³). Triglyceride and insulin levels were higher or tended to be higher in group 1 than in group 2 at ART initiation (median: 1.32 vs 0.97 mmol/l, p = 0.04 and 7.6 vs 6.8 IU, p = 0.09, respectively) and remained higher after three years of ART (1.42 vs 1.16 mmol/L, p = 0.0009 and 8.9 vs 7.2 IU, p = 0.01). After adjustment for individual characteristics and antiretroviral therapy regimens (protease inhibitor (PI), zidovudine), insulin levels remained significantly higher in patients with low baseline CD4⁺ cell count. Baseline IL-6, sCD14 and sTNFR2 levels were higher in group 1 than in group 2. Most biomarkers of immune activation/inflammation declined during ART, but IL-6 and hsCRP levels remained higher in patients with low baseline CD4⁺ cell count than in the other patients (median are respectively 1.4 vs 1.1 pg/ml, p = 0.03 and 2.1 vs 1.3 mg/ml, p = 0.07).

Conclusion

After three years of successful ART, low pretreatment CD4⁺ T cell count remained associated with elevated insulin, triglyceride, IL-6 and hsCRP levels. These persistent metabolic and inflammatory abnormalities could contribute to an increased risk of cardiovascular and metabolic disease.

Immune activation in the course of HIV-1 infection: Causes, phenotypes and persistence under therapy

Systemic immune activation is a striking consequence of HIV-1 infection. Even in virologically suppressed patients, some hyperactivity of the immune system and even of the endothelium and of the coagulation pathway may persist. Apart from immune deficiency, this chronic activation may contribute to various morbidities including atherothrombosis, neurocognitive disorders, liver steatosis and osteoporosis, which are currently main challenges. It is therefore of major importance to better understand the causes and the phenotypes of immune activation in the course of HIV-1 infection. In this review we will discuss the various causes of immune activation in HIV-1 infected organisms: the presence of the virus together with other microbes, eventually coming from the gut, CD4+ T cell lymphopenia, senescence and dysregulation of the immune system, and/or genetic factors. We will also describe the activation of the immune system: CD4+ and CD8+ T cells, B cells, NKT and NK cells, dendritic cells, monocytes and macrophages, and neutrophils of the inflammation cascade, as well as of the endothelium and the coagulation system. Finally, we will see that antiretroviral therapy reduces the hyperactivity of the immune and coagulation systems and the endothelial dysfunction, but often does not abolish it. A better knowledge of this phenomenon might help us to identify biomarkers predictive of non AIDS-linked comorbidities, and to define new strategies aiming at preventing their emergence.

Circulating Soluble CD163 is Associated with Steatohepatitis and Advanced Fibrosis in Nonalcoholic Fatty Liver Disease

OBJECTIVES:

Soluble CD163 (sCD163), a marker of Kupffer cell activation detectable in serum, correlates with inflammation and fibrosis in chronic viral hepatitis, but its role in nonalcoholic fatty liver disease is unknown. We hypothesized that sCD163 would correlate with nonalcoholic fatty liver disease activity and fibrosis.

METHODS:

Liver biopsies and serum were obtained from 145 obese subjects undergoing gastric bypass surgery. Subjects were divided into four groups based on fibrosis stage and nonalcoholic fatty liver disease activity score (NAS); Group 1: F0, NAS=0; Group 2: F<2, 0<NAS<5; Group 3: NAS≥5, F<3; or Group 4: F≥3, any NAS. Serum sCD163 and the monocyte/macrophage marker sCD14 were measured by enzyme-linked immunosorbent assay. Relationships between sCD163, sCD14, fibrosis stage, and NAS were examined. Area under the receiver operating charateristic for the diagnosis of nonalcoholic steatohepatitis based on the Clinical Research Network definition was calculated.

RESULTS:

sCD163 increased with progressive liver histology, with lowest values in normal histology and highest levels in those with nonalcoholic steatohepatitis and advanced fibrosis (Group 1: 552 ng/ml, Group 2: 721 ng/ml, Group 3: 803 ng/ml, and Group 4:1,031; P=0.001). sCD14 also differed significantly across groups (Group 1: 1,877 ng/ml, Group 2: 1632 ng/ml, Group 3: 1,706 ng/ml, and Group 4: 2111; P=0.008, respectively). sCD163 correlated with steatosis grade (P<0.001), lobular inflammation (P=0.033), and hepatocyte ballooning (P<0.001). In a multivariable ordered logistic regression model, there was a significant association between every 100 ng/ml increase in sCD163 and higher fibrosis stage, with an odds ratio of 1.16 (95% confidence interval 1.02–1.31), P=0.020. The odds ratios of the association between every 100 ng/ml increase in sCD163 and higher NAS was 1.17 (95% confidence interval 1.04–1.32), P=0.010. A sCD163-based predictive score demonstrated an area under the receiver operating charateristic of 0.70 (95% confidence interval: 0.58–0.82) for the diagnosis of nonalcoholic steatohepatitis. Soluble CD14 did not correlate with fibrosis stage or NAS.

CONCLUSIONS:

In obese subjects, serum sCD163, but not sCD14, correlated with fibrosis stage and NAS. These data support a role for activated Kupffer cells in the pathogenesis of nonalcoholic steatohepatitis and fibrosis, and suggest potential clinical utility for assessment of sCD163 levels.

Biomarkers of inflammation in HIV-infected Peruvian men and women before and during suppressive antiretroviral therapy

OBJECTIVE

Inflammatory biomarkers associated with cardiovascular disease are elevated in HIV-infected persons. These biomarkers improve with antiretroviral therapy (ART) but do not normalize to values observed in HIV-uninfected adults. Little is known regarding biomarkers of inflammation in HIV-infected Peruvians, in whom an increased burden of infectious diseases may exacerbate inflammation, and women, in whom sex difference may alter inflammation compared with men.

METHODS

Peruvians initiating first-line ART were enrolled in a prospective observational study. Individuals with suppression of HIV RNA plasma loads to less than 30 copies/ml when determined quarterly over 24 months of ART, had biomarkers of inflammation and cellular activation measured pre-ART and at 24-months of ART, and evaluated for associations with sex and clinical parameters.

RESULTS

Pre-ART high-sensitivity C-reactive protein (hsCRP) values of men were in the high-risk cardiovascular disease category (>3.0 mg/l) more frequently compared with women (P = 0.02); most women's values were in the low/average-risk categories. At 24 months of suppressive ART, hsCRP concentrations decreased in men (P = 0.03), but tended to increase in women, such that the proportion with high-risk hsCRP did not differ by sex. Pre-ART, soluble CD163 concentrations were higher in women compared with men (P = 0.02), and remained higher after 24 months of suppressive ART (P = 0.02). All other inflammatory biomarkers (P < 0.03) decreased across sexes. Biomarker concentrations were not associated with BMI or coinfections.

CONCLUSION

Elevated inflammatory biomarkers persisted despite 24 months of suppressive ART in a subset of Peruvians, and to a greater extent in women compared with men. These findings suggest that lifestyle or pharmacologic interventions may be required to optimize the health of HIV-infected Peruvians, particularly women.

Hemoglobin induces monocyte recruitment and CD163-macrophage polarization in abdominal aortic aneurysm

BACKGROUND

Increased hemoglobin (Hb) accumulation was reported in abdominal aortic aneurysms (AAAs). CD163 is a macrophage receptor involved in tissue Hb clearance, however its role in AAA has not been reported. We investigated the role of Hb on monocyte recruitment and differentiation towards CD163 expressing macrophages ex vivo, in vitro and in human AAA.

METHODS AND RESULTS

CD163 mRNA and protein expression was significantly higher in human AAA (n=7) vs. healthy wall (n=6). CD163 was predominantly found in adventitia of AAA, coinciding with areas rich in hemosiderin and adjacent to neoangiogenic microvessels. Dual CD14/CD163 expression was observed in recently infiltrated monocytes surrounding microvessels. A higher release of soluble CD163 was observed in the conditioned medium from AAA (AAA-CM, n=10), mainly in the adventitial layer. Similar to Hb, AAA-CM induced CD163-dependent monocyte chemotaxis, especially on circulating monocytes from AAA patients. Hb or AAA-CM promoted differentiation towards CD163(high)/HLA-DR(low)-expressing macrophages, with enhanced Hb uptake, increased anti-inflammatory IL-10 secretion and decreased pro-inflammatory IL-12p40 release. All these effects were partially suppressed when Hb was removed from AAA-CM. Separate analysis on circulating monocytes reported increased percentage of pre-infiltrating CD14(++)CD16(+) monocytes in patients with AAA (n=21), as compared to controls (n=14). A significant increase in CD163 expression in CD14(++)CD16(+) monocyte subpopulation was observed in AAA patients.

CONCLUSIONS

The presence of Hb in the adventitial AAA-wall promotes the migration and differentiation of activated circulating monocytes in AAA patients, explaining the existence of a protective CD163-macrophage phenotype that could take up the Hb present in the AAA-wall, avoiding its injurious effects.

Latent and Active Tuberculosis Infection Increase Immune Activation in Individuals Co-Infected with HIV

In recent years, chronic immune activation and systemic inflammation have emerged as hallmarks of HIV disease progression and mortality. Several studies indicate that soluble inflammatory biomarkers (sCD14, IL-6, IL-8, CRP and hyaluronic acid), as well as surface markers of T-cell activation (CD38, HLA-DR) independently predict progression to AIDS and mortality in HIV-infected individuals. While co-infections have been shown to contribute to immune activation, the impact of latent tuberculosis infection (LTBI), which is widely endemic in the areas most affected by the global AIDS epidemic, has not been evaluated. We hypothesized that both active and latent states of Mycobacterium tuberculosis co-infection contribute to elevated immune activation as measured by these markers. In HIV-infected individuals with active, but not latent TB, we found elevated levels of soluble markers associated with monocyte activation. Interestingly, T-cell activation was elevated individuals with both latent and active TB. These results suggest that in the highly TB- and HIV-endemic settings of southern Africa, latent TB-associated T-cell activation may contribute to HIV disease progression and exacerbate the HIV epidemic. In addition, our findings indicate that aggressive campaigns to treat LTBI in HIV-infected individuals in high-burden countries will not only impact TB rates, but may also slow HIV progression.

Significance

Latent tuberculosis, which affects an estimated 1/3 of the world's population, has long been thought to be a relatively benign, quiescent state of M. tuberculosis infection. While HIV co-infection is known to exacerbate M. tuberculosis infection and increase the risk of developing active TB, little is known about the potential effect of latent TB infection on HIV disease. This study shows that HIV-infected individuals with both active and latent TB have elevated levels of inflammation and immune activation, biomarkers of HIV disease progression and elevated risk of mortality. These results suggest that, in the context of HIV, latent TB infection may be associated with increased risk of progression to AIDS and mortality.

•

While HIV co-infection is known to exacerbate TB, little is known about the effect of latent TB infection on HIV disease.

•

In HIV-infected individuals, active and latent TB elevate immunological biomarkers of HIV morbidity and mortality.

•

In the context of HIV, latent TB infection may be associated with increased risk of progression to AIDS and mortality.

•

In addition to reducing TB transmission, aggressive treatment of latent TB infection may also reduce the progression of HIV.

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.

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.