Levels of sCD40 Ligand in Chronic and Acute Coronary Syndromes and its Relation to Angiographic Extent of Coronary Arterial Narrowing

Soluble CD40 Levels in Plasma Are Associated with Cardiovascular Disease and in Carotid Plaques with a Vulnerable Phenotype

BACKGROUND AND PURPOSE

CD40 and CD40 ligand (CD40L) are costimulatory molecules of the tumor necrosis factor receptor superfamily and well known for their involvement in inflammatory diseases: atherosclerotic mouse models with disrupted CD40 signalling develop lesions of reduced size with a more stable plaque profile. This study investigated the potential of plasma and intraplaque levels of CD40 and CD40L as markers for cardiovascular disease (CVD) in humans and their association with plaque stability.

METHODS

Soluble CD40 and CD40L (sCD40L) were measured in plasma in 1,437 subjects from The SUrrogate markers for Micro- and Macro-vascular hard endpoints for Innovative diabetes Tools (SUMMIT) cohort. Intra-plaque levels of sCD40 and sCD40L were measured in atherosclerotic plaque homogenates from 199 subjects of the Carotid Plaque Imaging Project (CPIP) cohort.

RESULTS

Both plasma sCD40 and sCD40L levels were elevated in individuals with prevalent stroke, while sCD40 levels also were higher in individuals with a prior acute myocardial infarction. Plasma levels of sCD40 correlated with carotid intima-media thickness and total carotid plaque area and were associated with risk of cardiovascular events over a 3-year follow-up period. Intra-plaque levels of sCD40 and sCD40L were associated with plaque components characteristic for plaque vulnerability and extracellular matrix remodelling.

CONCLUSIONS

Higher plasma sCD40 and sCD40L levels are associated with prevalent CVD. Plasma sCD40 levels also correlate with the severity of carotid atherosclerosis and predict future cardiovascular events, while intra-plaque levels correlate with a vulnerable plaque phenotype. Our findings thus demonstrate that elevated levels of sCD40 and sCD40L are markers of CVD.

Soluble CD40 ligand expression in stable atherosclerosis: A systematic review and meta-analysis

BACKGROUND AND AIMS

The role of inflammation in atherosclerosis development and expression in different arterial territories is unclear. Soluble CD40 ligand (sCD40L) mediates inflammation and atherogenesis. Through a systematic review and meta-analysis, we assessed whether sCD40L was dysregulated in stable atherosclerosis, irrespective of the diseased arterial territory, and whether this dysregulation differed according to the specific territory.

METHODS

Systematic literature searches were performed in MEDLINE, Cochrane Library, Web of Science, and Embase for studies reporting circulating sCD40L levels in individuals with and without stable atherosclerosis. sCD40L levels were compared using random-effects meta-analysis, weighted by the inverse variance method (study protocol: PROSPERO CRD42020181392).

RESULTS

Fifty-four studies (59 estimates) including 7705 patients and 7841 controls were analyzed. sCD40L levels were found to be increased in patients with atherosclerosis, irrespective of the territory (standardized mean difference [SMD] 0.43, 95% CI 0.29-0.57; 59 estimates; χ² heterogeneity p < 0.001; I² = 92%). SMD was greatest in carotid atherosclerosis (SMD 0.58, 95% CI 0.30-0.86; 17 estimates), followed by coronary (SMD 0.43, 95% CI 0.24-0.62; 33 estimates), lower extremity (SMD 0.26, 95% CI -0.02-0.54; 7 estimates), and renal atherosclerosis (SMD -0.07, 95% CI -2.77-2.64; 2 estimates) (χ² heterogeneity p < 0.001; I² ≥ 80% for all). Subgroup analysis revealed that sCD40L levels were increased in clinical, but not subclinical, atherosclerosis.

CONCLUSIONS

sCD40L levels were increased in stable atherosclerosis, particularly in the carotid and coronary territories. These novel data support sCD40L as a marker of systemic atherosclerosis, possibly with differential roles in specific territories.

Viewpoint: Reversible nature of platelet binding causing transfusion-related acute lung injury (TRALI) syndrome may explain dyspnea after ticagrelor and elinogrel

There may be a universal mechanism explaining dyspnea after ticagrelor and elinogrel, namely, transfusion-related acute lung injury (TRALI). Indeed, recent clinical trials with ticagrelor (DISPERSE, DISPERSE-II, and PLATO), and elinogrel (INNOVATE PCI) revealed double-digit rates of dyspnea after novel reversible antiplatelet agents. In contrast, dyspnea is not associated with conventional non-reversible agents such as aspirin, or thienopyridines (ticlopidine, clopidogrel, or prasugrel) suggesting distinct mechanism of shortness of breath after ticagrelor and elinogrel. The adenosine hypothesis has been offered to explain such adverse association. However, despite obvious similarity between ticagrelor and adenosine molecules, the chemical structure of elinogrel is entirely different. In fact, ticagrelor is a cyclopentyl-triazolo-pyrimidine, while elinogrel is a quinazolinedione. Since both agents cause dyspnea, the adenosine hypothesis is no longer valid. In contrast, the reversible nature of platelet inhibition attributable to both ticagrelor and elinogrel causing premature cell ageing, apoptosis, impaired turnover due to sequestration of overloaded, exhausted platelets in the pulmonary circulation are among potential autoimmune mechanism(s) resulting in the development of a TRALI-like reaction, and frequent dyspnea. Despite expected benefit for better bleeding control, further development of reversible antithrombins is severely limited due to the existence of a potentially universal serious adverse event, such as TRALI-syndrome with dyspnea as a predominant clinical manifestation. Since TRALI is an established number one contributor to mortality after blood transfusions, ticagrelor death “benefit”in PLATO is challenged further.

Levels of soluble TREM-like transcript 1 in patients presenting to the emergency department with chest pain

OBJECTIVE

Recent studies suggest that the soluble triggering receptor expressed on myeloid cells-like transcript 1 (sTLT-1) facilitate atherothrombosis. Therefore, we evaluated sTLT-1 as a functional measure of atherothrombosis in acute coronary syndrome (ACS).

METHODS

Levels of sTLT-1 were determined by enzyme-linked immunosorbent assay on plasma from patients with potential ACS and compared with an age-matched control group with similar risk factors for cardiovascular disease.

RESULTS

Of 53 patients enrolled, 19 patients were undergoing ACS (15 unstable angina, 2 non-ST-segment elevated myocardial infarction, and 2 ST-segment elevated myocardial infarction), 5 patients were found with noncardiac chest pain, and 29 were in the control group. The mean plasma sTLT-1 values in the ACS group were 4.644 ng/mL ± 1.277 standard error of the mean (SEM), in the noncardiac chest pain group were 0.708 ng/mL ± 0.427 SEM, and in the control group were 1.007 ng/mL ± 0.098 SEM.

CONCLUSION

A statistically significant difference exists between patients experiencing cardiogenic chest pain versus controls (P < .05), suggesting sTLT-1 as a potential tool for understanding atherothrombosis in ACS.

ETC-1002 regulates immune response, leukocyte homing, and adipose tissue inflammation via LKB1-dependent activation of macrophage AMPK

ETC-1002 is an investigational drug currently in Phase 2 development for treatment of dyslipidemia and other cardiometabolic risk factors. In dyslipidemic subjects, ETC-1002 not only reduces plasma LDL cholesterol but also significantly attenuates levels of hsCRP, a clinical biomarker of inflammation. Anti-inflammatory properties of ETC-1002 were further investigated in primary human monocyte-derived macrophages and in in vivo models of inflammation. In cells treated with ETC-1002, increased levels of AMP-activated protein kinase (AMPK) phosphorylation coincided with reduced activity of MAP kinases and decreased production of proinflammatory cytokines and chemokines. AMPK phosphorylation and inhibitory effects of ETC-1002 on soluble mediators of inflammation were significantly abrogated by siRNA-mediated silencing of macrophage liver kinase B1 (LKB1), indicating that ETC-1002 activates AMPK and exerts its anti-inflammatory effects via an LKB1-dependent mechanism. In vivo, ETC-1002 suppressed thioglycollate-induced homing of leukocytes into mouse peritoneal cavity. Similarly, in a mouse model of diet-induced obesity, ETC-1002 restored adipose AMPK activity, reduced JNK phosphorylation, and diminished expression of macrophage-specific marker 4F/80. These data were consistent with decreased epididymal fat-pad mass and interleukin (IL)-6 release by inflamed adipose tissue. Thus, ETC-1002 may provide further clinical benefits for patients with cardiometabolic risk factors by reducing systemic inflammation linked to insulin resistance and vascular complications of metabolic syndrome.

Pentoxifylline decreases soluble CD40 ligand concentration and CD40 gene expression in coronary artery disease patients

CONTEXT AND OBJECTIVE

Increased level of inflammatory mediators plays a central role in the features of coronary artery diseases (CAD). As pentoxifylline could suppress the inflammatory process and has shown some promising beneficial effects in inflammatory diseases, we evaluated the effect of 2 months pentoxifylline administration in patients with CAD.

MATERIALS AND METHODS

A randomized placebo-controlled double-blind study design was used. Forty CAD patients (32 males and 8 females) were randomized into either 2 months of pentoxifylline treatment (1200 mg/day) (n = 20) or placebo treatment (n = 20). Blood samples were obtained before and after treatment. Gene expression analysis for mRNA of CD40, p65 and IκBα in peripheral blood mononuclear cells (PBMCs) were performed using real-time reverse-transcription polymerase chain reaction (RT-PCR). Plasma concentration of soluble CD40 (sCD40) ligand as well as protein concentration of p50 were measured by ELISA method.

RESULTS

Pentoxifylline decreased CD40 mRNA by 45% (p < 0.05) in PBMCs and sCD40 ligand level in plasma of CAD patients by 34% (p < 0.01).

DISCUSSION AND CONCLUSION

Pentoxifylline treatment can suppress the CD40/CD40 ligand system activation in CAD patients. As this system has a role in plaque progression and plaque rupture, pentoxifylline could be a good choice for future studies in preventing cardiovascular events.

Tumor necrosis factor superfamily molecules in acute coronary syndromes

Accumulating evidence suggests that inflammatory pathways play an essential role in all stages of atherogenesis. Inflammatory processes are not only involved in plaque progression, but seem also to play a critical role in plaque rupture. Members of the tumor necrosis factor (TNF) superfamiliy are potent regulators of inflammation and cell survival and consist of 20 ligands that signal through 29 different receptors. Several lines of evidence suggest that TNF-related molecules are involved in the development of acute coronary syndromes (ACS). Most, convincing evidence exists for CD40 ligand-CD40 interaction, but several other members of the TNF superfamily seem also to be involved in this immune-mediated promotion of plaque instability, including LIGHT, receptor activator of nuclear factor κB ligand, and TNF-α. These plaque destabilization pathways involve the bidirectional interaction between platelets and endothelial cells/monocytes, activation of vascular smooth muscle cells, and co-stimulatory effects on T cells, promoting inflammation, thrombus formation, matrix degradation, and apoptosis. TNF-related pathways could contribute to the non-resolving inflammation that characterizes atherosclerosis, representing pathogenic loops that are operating during plaque rupture and the development of ACS. These TNF-related molecules could also represent attractive new targets for therapy in this disorder.

Elevated soluble CD40 ligand in diabetic patients with painless myocardial infarction

Because a useful biomarker for painless myocardial infarction (MI) has yet to be identified, the aim of this study was to identify a biomarker for diabetic patients with painless MI. A case-control design was used to compare inflammatory cytokine levels among 111 patients with diabetes mellitus, including 31 patients with stable coronary heart disease (CHD), 30 patients with painful MI, 20 patients with painless MI, and 30 age- and sex-matched patients without CHD (control group). In addition to baseline parameters, cytokine levels, including plasma high sensitivity C-reactive protein (HsCRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and soluble CD40 ligand (sCD40L) levels, were analyzed using enzyme-linked immunosorbent assays (ELISAs). No differences in baseline characteristics were observed for patients with painless MI as compared to the other patient groups. Significantly higher sCD40L, HsCRP, IL-6, and TNF-α levels were detected in patients with MI, and markedly elevated sCD40L and IL-6 levels were observed in patients with painless MI as compared to those with painful MI. sCD40L may be a useful biomarker for painless MI in diabetic patients, which could reduce misdiagnosis and expedite treatment. Further studies are required to validate the diagnostic utility of this putative biomarker as well as investigate the mechanism by which sCD40L is elevated in these patients.