Elevated soluble CD40 ligand is related to the endothelial adhesion molecules in patients with acute coronary syndrome

Elevated circulating inflammatory biomarker levels in the SIRT1-NF-κB-sCD40L pathway in patients with acute myocardial infarction: a case-control study

BACKGROUND

Inflammation plays a key role in atherosclerosis development and progression. However, the role of novel inflammatory biomarker pathways, namely the SIRT1-NF-κB-sCD40L, in the etiopathogenesis of human atherosclerosis remains undefined. This study was designed to evaluate the changes and clinical implications of these inflammatory mediators in the plasma of patients with acute myocardial infarction (AMI).

METHODS

The peripheral arterial blood of 88 participants (68 patients with AMI and 20 age-matched controls), was drawn prior to performing coronary angiography (CAG). The SIRT1, NF-κB, and sCD40L plasma levels were quantified using ELISA. Spearman's analysis was used to evaluate the correlation between the three inflammatory markers, while Pearson's test assessed their potential correlation with cardiac troponin T (TNT) levels. Sensitivity, specificity, and area under the ROC curve (AUC) were calculated as measures of diagnostic accuracy.

RESULTS

Patients with AMI showed higher levels of circulating SIRT1, NF-κB, and sCD40L compared to the age-matched controls (p < 0.05). However, the plasma concentrations of these three inflammatory mediators did not differ between the ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) patients. Additionally, in patients with AMI, the SIRT1 level was positively correlated with NF-κB and sCD40L levels (p < 0.001). Likewise, the levels of SIRT1, NF-κB and sCD40L were positively correlated with TNT levels (p < 0.001). More importantly, the ROC analysis showed that the diagnostic accuracy of AMI was significantly higher when NF-κB or sCD40L level was used in combination with TNT levels (p < 0.05).

CONCLUSIONS

The levels of the circulating inflammatory biomarkers, including SIRT1, NF-κB, and sCD40L, were significantly elevated in patients with AMI. These novel biomarkers can improve the diagnostic accuracy of AMI when combined with TNT.KEY MESSAGESAMI is a potentially lethal CAD and is the leading cause of mortality and morbidity worldwide. Inflammation plays a key role in atherosclerosis development and progression. The levels of the circulating novel inflammatory biomarkers, including SIRT1, NF-κB, and sCD40L, were significantly elevated in patients with AMI.The SIRT1 level was positively correlated with NF-κB and sCD40L levels in patients with AMI.The levels of SIRT1, NF-κB and sCD40L were positively correlated with TNT levels.The ROC analysis showed that the diagnostic accuracy of AMI was significantly higher when NF-κB or sCD40L level was used in combination with TNT levels.SIRT1/NF-κB/sCD40L axis inhibition is a potential new target for AMI treatment.

Effect of Low High-Density Lipoprotein Level on Endothelial Activation and Prothrombotic Processes in Coronary Artery Disease-A Pilot Study

High-density lipoproteins (HDL) play an important role in the prevention of atherosclerosis. The aim of the study was to assess the relationship between serum HDL-C concentration and proinflammatory/prothrombic activation in coronary artery disease (CAD) patients. The study group included 27 acute myocardial infarction (AMI) patients and 30 stable angina pectoris (SA) patients. The control group consisted of 23 people without cardiac symptoms. In the AMI and SA groups, a lower HDL-C and a higher LDL-C/HDL-C index were observed. The SA patients had lower total cholesterol, LDL-C, sE-selectin ligand, as well as higher triglycerides and CD40 concentration in comparison with both the control and AMI groups. A higher von Willebrand Factor and intercellular adhesion molecule-1 were found in both study groups. Low HDL-C concentration in the CAD patients may intensify pro-inflammatory endothelial activation and prothrombotic processes. A low concentration of HDL-C and a high value of the LDL-C/HDL-C index seem to be better indices of atherogenic processes than the LDL-C concentration alone.

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.

Evaluation of serum sCD40L and homocysteine levels with subclinical atherosclerosis indicators in patients with psoriasis: a pilot study

Psoriasis is a chronic inflammatory process associated with an increased risk of cardiovascular risk factors. sCD40L has been suggested to have a possible role in the pathogenesis, of psoriasis and is known to be associated with inflammation, atherogenesis and cardiovascular events. This study investigated cardiovascular risk factors (sCD40L and homocysteine) as well as subclinical atherosclerosis indicators in psoriatic patients and control subjects. The study included 56 consecutive patients with chronic plaque-type psoriasis and 53 age and gender matched healthy controls admitted to a university hospital. Serum sCD40L and homocysteine levels were measured by ELISA. Carotid artery intima-media thickness and brachial artery flow mediated dilatation (FMD) measurements were determined ultrasonographically. Subjects who had a history of cardiovascular diseases and cardiovascular risk factors and receiving any systemic treatment were excluded from the study. Plasma sCD40L levels were significantly higher in psoriasis patients compared with healthy controls (1.33±0.72 vs. 0.98±0.70 ng/ml P=0.012), whereas plasma homocysteine levels did not differ significantly between the two groups. FMD was significantly reduced in the psoriasis group compared to the controls (3.83±5.03 vs. 8.45±7.27% P=0.0001). Multiple linear regression analyses indicated a significant association between psoriasis, sCD40L, and FMD. Psoriatic patients had higher sCD40L levels than healthy controls, which may lead to an increase in cardiovascular diseases. sCD40L may be a more reliable and early predictive marker of cardiovascular events in psoriatic patients. New treatmentoptions that will be developed over sCD40L will benefit in prevention of psoriasis and its cardiovascular comorbidities.

Pathophysiological roles and clinical importance of biomarkers in acute coronary syndrome

Early diagnosis of acute coronary syndrome (ACS) is important to guide appropriate therapy at a time when it is most likely to be of value. Accurate prognostic and risk stratification will facilitate high-risk patients to have early advanced diagnostic investigations and early appropriate interventions in a cost-effective and efficient manner, while those patients at low risk of ACS complications do not need such costly diagnostic tests and unnecessary hospital admission. Recent investigations have demonstrated that elevation of biomarkers upstream from acute-phase biomarkers, biomarkers of plaque destabilization and rupture, biomarkers of myocardial ischemia, necrosis, and dysfunction may provide an earlier assessment of patient risk and identify patients with higher risk of having an adverse event. This review provides an overview of the pathophysiology and clinical characteristics of several well-established biomarkers as well as emerging biomarkers that may have potential clinical utility in patients with ACS. Such emerging biomarkers hold promise and need to be more thoroughly evaluated before utilization in routine clinical practice.

The tumor necrosis factor superfamily in heart failure

Numerous clinical studies have established that tumor necrosis factor (TNF)-alpha may play a pathogenic role in the development and progression of heart failure (HF). Recent reports suggest that other ligands in the TNF superfamily could also play a pathogenic role in chronic HF. TNF superfamily ligands are expressed predominantly by cells in the immune system, while the TNF receptor superfamily are expressed by a wide variety of cells, including myocardial cells. Several pathways are activated by ligand-receptor interactions, but of particular importance is the nuclear factor (NF)-kappaB pathway which is activated in the failing human heart. All ligands in the TNF superfamily have the potential to activate NF-kappaB, leading to transcription of genes involved in apoptosis, cell survival, proliferation, inflammation and hypertrophic signaling in cardiomyocytes. Among several TNF superfamily members that are activated in HF, the authors' have recentlyshown that CD40L-CD40 and OPG-RANK-RANKL interactions may be implicated in the pathogenesis of HF through different mechanisms, possibly representing new targets for therapy in this disorder.

Biomarkers of platelet activation in acute coronary syndromes

The most convincing evidence for the participation of platelets in arterial thrombosis in humans comes from studies of platelet activation in patients with acute coronary syndromes (ACS) and from trials of antiplatelet drugs. Both strongly support the concept that repeated episodes of platelet activation over the thrombogenic surface of a vulnerable plaque may contribute to the risk of death from coronary causes. However, the relation of in vivo platelet activation and adverse clinical events to results of platelet function tests remains largely unknown. A valuable marker of in vivo platelet activation should be specific, unaltered by pre-analytical artefacts and reproducibly measured by easily performed methods. This article describes current biomarkers of platelet activation in ACS, reviews their advantages and disadvantages, discusses their potential pitfalls, and demonstrates emerging data supporting the positive clinical implications of monitoring in vivo platelet activation in the setting of ACS.

P-selectin, E-selectin, and CD40L over time in chronic hemodialysis patients

The aim of this study was to measure P-selectin, E-selectin, and CD-4L levels over time in chronic hemodialysis (HD) patients. Thirty stable patients with end-stage renal failure undergoing chronic HD were included in the study. Blood samples were obtained before HD for measurement of P-selectin, E-selectin, and CD-40L. Measurements were performed at month 0 (T0), 3 (T2), 8 (T3), and 13 (T4). The levels of P-selectin, E-selectin, and CD40L were also analyzed according to the occurrence of cardiovascular disease (CVD) and to CVD-related mortality. The levels of CD40L and P-selectin changed significantly over time, decreasing at month 3 and 6 and returning at the T0 levels at month 13. Conversely, E-selectin levels did not. The levels of CD40L, P-selectin and E-selectin over time did not differ significantly between patients with age ≤ 65 or > 65 years, between patients with or without CVD, or between patients who died or who survived during the follow-up. In end-stage renal failure patients undergoing chronic HD, CD40L and P-selectin, but not E-selectin, showed a transient decrease over time, and the serum levels of these molecules were not associated with CVD or with CVD-related mortality.

Activation of platelets and cellular coagulation in cerebral small-vessel disease

Platelets and monocytes play a pivotal role in the initiation and progression of large-vessel atherosclerosis. An up-regulation of various platelet and coagulation activation markers has been described in cardiovascular diseases and in patients with acute cerebral ischemia. In the present study the role of platelets and cellular coagulation activation in cerebral small-vessel disease (cSVD) was assessed. In 24 patients with cSVD but without established large-vessel disease, whole blood samples were obtained. Patients were divided into three subgroups (Fazekas 1, 2 and 3) according to extent of cSVD based on morphological magnetic resonance imaging criteria. Surface expression of CD40L and CD62P on platelets, tissue-factor exposition on monocytes and platelet-monocyte aggregates were measured with flow cytometry. Plasma levels of soluble CD40L, interleukin (IL)-6 and IL-7 were assessed by ELISA. Patients with cSVD show a significantly elevated expression of platelet CD40L (P < 0.001) and CD62P (P < 0.023), significantly elevated amounts of platelet-monocyte aggregates (P < 0.004), a significantly enhanced tissue-factor exposition on monocytes (P < 0.019) and significantly lower plasma levels of IL-7 compared to 10 healthy controls. However, this platelet and monocyte activation did not correlate with the severity of cSVD. Patients with cSVD show an up-regulation of the platelet CD40L and CD62P system and an activation of cellular coagulation which might contribute to the initiation and progression of cSVD.

The levels of soluble CD40 ligand and C-reactive protein in normal weight, overweight and obese people

OBJECTIVE

Obesity has been suggested as an independent risk factor for cardiovascular disease. Increasing evidence shows that engagement of soluble CD40 ligand (sCD40L) with its receptor plays a crucial role in the pathogenesis of atherosclerosis. The aim of the present study was to test whether obesity is associated with low-grade systemic inflammation as measured by serum high-sensitive C-reactive protein (hsCRP) and sCD40L concentration.

METHODS

Serum hsCRP and sCD40L concentrations were measured in 148 nondiabetic people. The participants were divided into three groups depending upon their body mass index (BMI) levels: Group 1 (normal weight), BMI<25 kg/m(2); Group 2 (overweight), BMI 25 kg/m(2) to 29.9 kg/m(2); and Group 3 (obese), BMI>or=30 kg/m(2).

RESULTS

Obese people had more elevated hsCRP levels than both their normal weight and overweight counterparts (P=0.000 and P=0.000, respectively). Similarly, serum concentrations of sCD40L were significantly higher, statistically, in obese subjects compared with normal weight subjects (P=0.003). In addition, obese subjects had higher values of sCD40L than overweight subjects, but the difference did not reach statistical significance (P=0.063). The levels of high-density lipoprotein cholesterol were significantly lower in obese subjects compared to normal weight subjects (P=0.048). The analysis of platelet count disclosed a statistically significant difference between obese subjects and normal weight subjects (P=0.028). The levels of BMI were positively correlated with the serum levels of hsCRP and sCD40L in all subjects (r=0.514, P=0.000 and r=0.283, P=0.000, respectively). Levels of hsCRP were positively correlated with waist circumference, fasting glucose, total cholesterol, triglyceride, low-density lipoprotein cholesterol, leukocytes, platelets, systolic and diastolic blood pressure. Similarly, soluble CD40L levels were positively correlated with waist circumference, fasting glucose and leukocytes.

CONCLUSION

Obese patients showed a significant increase of hsCRP and sCD40L levels compared with normal weight subjects, which might contribute to the known proinflammatory milieu found in these patients.

Modified serum profiles of inflammatory and vasoconstrictive factors in patients with emotional stress-induced acute coronary syndrome during World Cup Soccer 2006

OBJECTIVES

We sought to assess whether emotional stress-induced acute coronary syndrome (ACS) is mediated by increased inflammatory and vasoconstrictive mediators.

BACKGROUND

The World Cup soccer 2006 has been shown to provoke levels of stress sufficient to increase the incidence of ACS. However, the mechanisms by which stress translates into vascular injury up to plaque rupture still remain elusive.

METHODS

Serum levels of soluble CD40L (sCD40L), soluble vascular cell adhesion molecule (sVCAM)-1, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor (TNF)-alpha, high-sensitivity C-reactive protein (hsCRP), regulated on activation, normal T-cell expressed and secreted (RANTES), and endothelin (ET)-1 were determined in patients who experienced an ACS during World Cup matches, in ACS reference patients (not associated with emotional stress), and in healthy volunteers. Correlations and receiver-operating characteristic curves were calculated to develop multivariable analysis and to investigate the diagnostic value of each parameter.

RESULTS

The sCD40L, sVCAM-1, MCP-1, TNF-alpha, and ET-1 were significantly higher in study patients compared with the reference group. The hsCRP was similar in both groups, whereas RANTES was decreased in study patients. A positive correlation was found between ET-1 and soccer-induced enhanced levels of sCD40L, sVCAM-1, MCP-1, and TNF-alpha. Receiver-operating characteristic analysis displayed high performance of both MCP-1 and ET-1 as a measure to discriminate between stress-induced ACS and ACS controls.

CONCLUSIONS

Stress-induced ACS is associated with a profound increase of inflammatory and vasoconstrictive mediators. The evaluation of a targeted drug delivery, such as anti-inflammatory agents, ET-1 receptor antagonists, or inhibition of endothelin-converting enzyme is warranted to reduce stress-mediated cardiovascular morbidity.

Enhanced levels of soluble CD40 ligand and C-reactive protein in a total of 312 patients with metabolic syndrome

The metabolic syndrome (MS) is associated with a systemic inflammatory response that plays an important pathogenetic role in atherothrombotic disease. Increasing evidence indicates that CD40-CD40 ligand interactions constitute an important mediator for vascular inflammation. The purpose of this study was to assess whether high-sensitivity C-reactive protein (hs-CRP) and soluble CD40 ligand (sCD40L) levels were increased in patients with MS. During the study period from January 2004 to August 2004, 312 patients with MS and 98 control subjects were included. Anthropometric measurements, blood pressure assessment, electrocardiography, and blood measurements including fasting blood glucose, postprandial blood glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, glycated hemoglobin, white blood cell (WBC), platelets, hs-CRP, and sCD40L were performed. Patients with MS were divided into 3 groups based upon their glucose tolerance (group 1, normal glucose tolerance; group 2, prediabetic group; and group 3, diabetes mellitus). Patients with MS showed a significant increase of WBC, hs-CRP, and sCD40L levels compared with control subjects. The levels of both hs-CRP and sCD40L were positively correlated with body mass index (BMI). High-sensitivity CRP levels were also positively correlated with waist circumferences, fasting blood glucose, postprandial blood glucose, and glycated hemoglobin, and negatively correlated with high-density lipoprotein cholesterol. In patients with MS, both hs-CRP and sCD40L levels were positively correlated with WBC count. We found a positive correlation between sCD40L and platelets. Among the subgroups of patients with MS, the mean levels of WBC, hs-CRP, and sCD40L did not show any significant differences. In conclusion, elevated levels of WBC, hs-CRP, and sCD40L in MS patients provide further insight into the relationship between MS and inflammation. In our study, positive correlations between BMI and both hs-CRP and sCD40L levels suggest that BMI is an important determinant of a chronic inflammatory state in patients with MS. Moreover, this study reports significantly increased levels of WBC, hs-CRP, and sCD40L not only in diabetic subjects with MS but also in prediabetic subjects and nondiabetic subjects with MS compared with control subjects. Our data suggest that MS patients have proinflammatory state independent of their glucose tolerance status. In our study, the positive correlation between the levels of sCD40L and platelets in patients with MS supports previous reports indicating that sCD40L are derived predominantly from platelets.

The CD40/CD40 ligand system: linking inflammation with atherothrombosis

The role of CD40/CD40 ligand (CD40L) in atherothrombosis is now widely accepted. However, the exact mechanisms linking the CD40/CD40L system and the soluble form of CD40 ligand (sCD40L) with atherothrombosis are currently a topic of intensive research. CD40L and sCD40L belong to the tumor necrosis factor superfamily, and they are molecules with a dual prothrombotic and proinflammatory role. They are expressed in a variety of tissues such as the immune system (in both B and T cells), the vascular wall, and activated platelets. Soluble CD40L has multiple autocrine, paracrine, and endocrine actions, and it may trigger key mechanisms participating in atherothrombosis. CD40/CD40L may participate in the development of coronary atherosclerosis and the triggering of acute coronary syndromes, while sCD40L seems to have a prognostic role not only in subjects with advanced atherosclerosis but also in the general population. Although conventional cardiovascular medication such as antiplatelet therapy, statins, angiotensin-converting enzyme inhibitors, and many others have been shown to reduce both sCD40L and cardiovascular risk, it is still unclear whether specific treatments targeting the CD40/CD40L system will prove to be beneficial against atherothrombosis in the near future.

CD40-CD40 ligand interactions in oxidative stress, inflammation and vascular disease

CD40 ligand (CD40L) and its receptor CD40 participate in numerous inflammatory pathways that contribute to multiple pathophysiological processes. A role for CD40-CD40L interactions has been identified in atherosclerosis, and such interactions are known to destabilize atherosclerotic plaques by inducing the expression of cytokines, chemokines, growth factors, matrix metalloproteinases and pro-coagulant factors. The CD40-CD40L interaction has also been implicated in immune system disorders. Recent studies have suggested that CD40-CD40L interactions regulate oxidative stress and affect various signaling pathways in both the immunological and cardiovascular systems. Here, we discuss the emerging role of CD40-CD40L-mediated processes in oxidative stress, inflammatory pathways and vascular diseases. Understanding the roles and regulation of CD40-CD40L-mediated oxidative signaling in immune and non-immune cells could facilitate the development of therapeutics targeting diverse inflammatory diseases.

Pioglitazone decreased CD40/CD40L expression on human umbilical vein endothelial cells induced by oxidized low-density lipoprotein

BACKGROUND

The CD40/CD40 ligand pathway mediated inflammatory processes are important in atherogenesis and the formation of the intraplaque lipid pool. We tested the hypothesis that pioglitazone could decrease lectin-like oxLDL receptor-1 (LOX-1) and CD40/CD40L expression on human umbilical vein endothelial cells (HUVECs) induced by oxidized low-density lipoprotein (oxLDL).

METHODS

HUVECs were incubated with oxLDL for 24h with or without pretreated by pioglitazone. Expression of CD40/CD40L on the cell surface was detected by flow cytometry. CD40/CD40L and LOX-1 mRNA expression were evaluated by RT-PCR. The expression of LOX-1 on HUVECs was determined by cell immunohistochemistry.

RESULTS

OxLDL increased the expression of CD40 and CD40L in a dose- and time-dependent manner. Pretreatment of HUVECs with pioglitazone (1 and 10 micromol/l) for 60 min decreased the expression of CD40 mRNA induced by oxLDL by 16% and 52%, respectively (both P<0.05). Pretreatment of HUVECs with pioglitazone (1 and 10 micromol/l) for 60 min decreased the expression of CD40L mRNA induced by oxLDL by 16% and 43% (both P<0.05). Also, pretreatment of HUVECs with pioglitazone (1 and 10 micromol/l) for 60 min also significantly decreased CD40 and CD40L expression on HUVECs induced by oxLDL in a concentration-dependent manner. Pretreatment of HUVECs with pioglitazone (1 and 10 micromol/l) decreased oxLDL induced upregulation mRNA of LOX-1 by 11% and 28%, respectively. Furthermore, through immunohistochemistry, we found that pioglitazone could decrease the LOX-1 expression on HUVECs induced by oxLDL.

CONCLUSION

Pioglitazone inhibited the upregulation of LOX-1 on HUVECs elicited by oxLDL and subsequently decreased HUVECs CD40/CD40L expression induced by oxLDL. These observations provided novel insight into a potential novel anti-inflammatory pathway of thiazolidinediones.

Soluble CD40 ligand in acute and chronic heart failure

AIMS

Inflammatory cytokines may play a pathogenic role in heart failure (HF). CD40-CD40 ligand (CD40L) interactions are important in atherogenesis and based on its role in inflammation we sought to evaluate the role of CD40L in human HF.

METHODS AND RESULTS

Serum levels of soluble (s) CD40L were measured in 236 patients with acute HF following myocardial infarction, treated with either angiotensin-converting enzyme (ACE)-inhibition or angiotensin II blockade and followed for 2 years, and in 116 patients with chronic HF. Our main findings were: (i) patients with acute HF had increased sCD40L levels, particularly those with severe HF, diabetes, or hypertension; (ii) when these patients were followed longitudinally, persistently raised sCD40L levels were found throughout the observation period with no effect of captopril or losartan; (iii) the increase in sCD40L during follow-up was not seen in patients receiving warfarin therapy; (iv) patients with chronic HF also had raised sCD40L, significantly correlated with clinical severity, neurohormonal dysregulation, and left ventricular dysfunction; (v) studies from different blood compartments suggest that the vasculature of lower extremities and the failing myocardium itself may produce and secrete sCD40L in chronic HF.

CONCLUSION

Our findings may suggest a pathogenic role for enhanced CD40-CD40L interactions in human HF.

Platelets and anti-platelet therapy

Platelets play a central role in the hemostatic process and consequently are similarly involved in the pathological counterpart, thrombosis. They adhere to various subendothelial proteins, exposed either by injury or disease, and subsequently become activated by the thrombogenic surface or locally produced agonists. These activated platelets aggregate to form a platelet plug, release agonists which recruit more platelets to the growing thrombus, and provide a catalytic surface for thrombin generation and fibrin formation. These platelet-rich thrombi are responsible for the acute occlusion of stenotic vessels and ischemic injury to heart and brain. A range of anti-platelet drugs are currently used, both prophylactically and therapeutically, in regimens to manage thrombo-embolic disorders. These include inhibitors of the generation, or effects, of locally produced agonists; several large clinical trials have supported roles for cyclooxygenase inhibitors, which prevent thromboxane generation, and thienopyridine derivatives, which antagonize ADP receptors. Similarly intravenous alpha IIb beta 3 antagonists have been shown to be effective anti-thrombotics, albeit in highly selective situations; in contrast, to date studies with their oral counterparts have been disappointing. Recent advances in understanding of platelet physiology have suggested several novel, if yet untested, targets for anti-platelet therapy. These include the thrombin receptor, the serotonin handling system, and the leptin receptor.

Mutations of CD40 ligand in two patients with hyper-IgM syndrome

Two patients with the X-linked form of the hyper-IgM syndrome have been studied. Both patients present: 1. Mutations in the CD40L gene (a nonsense point mutation that introduces a termination codon at the extracellular domain of the protein, and a deletion that eliminates exon 4 as consequence of an abnormal splicing). 2. Lack of CD40L expression on the lymphocyte surface after stimulation with ionomycin and PMA. 3. Altered lymphocytic proliferation in response to anti-CD3. 4. Hyper IgM, low IgG and IgA levels and neutropenia. One of the patients shows, in addition, low Natural Killer cell numbers and severe herpetic infections, which distinguishes this case from the common hyper-IgM syndrome phenotype. Finally, a hyper-IgM stable phenotype has been immortalized by Herpes virus Saimiri for the first time.

Cellular adhesion molecules and cardiovascular disease. Part II. Their association with conventional and emerging risk factors, acute coronary events and cardiovascular risk prediction

The role of cellular adhesion molecules in the patho-genesis of atherosclerosis has now been clearly demonstrated. Plasma levels of adhesion molecules, which have been shed from the cell surface, have also been associated with the presence of clinical atherosclerotic disease, cardiovascular risk factors and acute coronary syndromes. However, there is little consensus in the literature, including between the large well-designed population studies. This may be explained either by unrecognized confounding factors or, alternatively, by the unpredictable relationship between cell surface expression and activity of cellular adhesion molecules and their shedding into the plasma under different circumstances. Probably for the latter reasons, there is at present little evidence that the measurement of circulating adhesion molecules is likely to offer any additional benefit for individual patients above the assessment of conventional cardiovascular risk factors in the assessment of either the extent of, or future risk from, cardiovascular disease.

Prothrombotic determinants of coronary atherothrombosis

An acute coronary syndrome (ACS) is the clinical manifestation of a thrombotic event occurring within a coronary artery narrowed by atherosclerosis. This atherothrombotic event is thought to occur following destabilizing changes within the atherosclerotic plaque, rendering it a surface on which thrombus can develop. The development and progression of this thrombus are determined by deleterious perturbations in the hemostatic equilibrium within the local environment of the plaque that favor thrombosis. Major risk factors for the development of atherosclerotic disease have been clearly established and are targets of aggressive modification in an effort to impede the development or slow the progression of disease. While conferring an increased risk for plaque development, these and other risk factors also establish a prothrombotic milieu within the microenvironment of the atherosclerotic plaque that favors thrombosis. This review seeks to address these traditional and emerging risk factors from the context of their pathologic effects on local hemostatic balance. Aggressive risk factor modification not only reduces atherosclerotic disease development and progression, but also ameliorates the prothrombotic state, and ultimately serves to reduce atherothrombotic events.

Raised serum levels of soluble CD40 ligand in patients with familial hypercholesterolemia: downregulatory effect of statin therapy

OBJECTIVES

In the present study, we investigated the effects of statins on serum levels of soluble CD40 ligand (sCD40L) in patients with familial hypercholesterolemia (FH).

BACKGROUND

Atherosclerotic disease seems to involve inflammatory and immunologic mechanisms, and sCD40L has recently been identified as one of the key players in the atherosclerotic process. HMG-Co A reductase inhibitors, statins, have been recognized as immunomodulators and reduce cardiovascular events and mortality, but the effects of statins on sCD40L has not been clarified.

METHODS

In a randomized, double-blind, clinical trial, as part of the Atorvastatin versus Simvastatin on Atherosclerosis Progression (ASAP) trial, 110 patients with FH were given atorvastatin 80 mg/daily (n = 57) or simvastatin 40 mg/daily (n = 53) for two years.

RESULTS

Our main findings were: 1) at baseline patients with FH had significantly higher (approximately 27-fold) serum levels of sCD40L than healthy controls; 2) statin therapy markedly decreased serum levels of sCD40L (approximately 40% reduction); 3) this decrease in sCD40L was found during both "aggressive" (i.e., atorvastatin) and "conventional" (i.e., simvastatin) statin therapy and was not correlated with the degree of reduction in cholesterol levels.

CONCLUSIONS

Our findings may suggest enhanced CD40L-CD40 interaction in FH and that this inflammatory response may be downregulated by statins.