CD40 ligand enhances monocyte tissue factor expression and thrombin generation via oxidative stress in patients with hypercholesterolemia

OBJECTIVES: We tested the hypothesis that CD40 ligand (CD40L) induces a prothrombotic state by enhancing oxidative stress. BACKGROUND: Patients with hypercholesterolemia show an ongoing prothrombotic state, but the underlying mechanism is still unclear. METHODS: Circulating levels of the soluble form of CD40L (sCD40L), prothrombin fragment (F1+2, a marker of thrombin generation), and 8-hydroxy-2'-deoxyguanosine (8-OHdG, a marker of oxidative stress) were measured in 40 patients with hypercholesterolemia and in 20 age- and gender-matched healthy subjects. RESULTS: Patients with hypercholesterolemia showed significantly higher levels of sCD40L (p <0.005), 8-OHdG (p <0.005), and prothrombin F1+2 (p <0.005), as compared with control subjects. Soluble CD40L significantly correlated with 8-OHdG (r=0.85, p <0.0001) and prothrombin F1+2 (r=0.83, p <0.0001); a significant correlation between 8-OHdG and prothrombin F1+2 was also observed (r=0.64, p <0.0001). An in vitro study demonstrated that CD40L-stimulated monocytes from patients with hypercholesterolemia expressed more tissue factor (TF) and prothrombin F1+2 than monocytes from controls; co-incubation of monocytes with either an inhibitor of NADPH oxidase or an inhibitor of phosphatidylinositol-3-kinase significantly reduced CD40L-mediated clotting activation. A marked inhibition of CD40L-mediated clotting activation was also observed in two male patients with hereditary deficiency of gp91 phox, the central core of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Finally, we demonstrated that CD40L-mediated clotting activation was significantly inhibited by vitamin C, a known antioxidant. CONCLUSIONS: This study indicates that in patients with hypercholesterolemia, CD40L over-expresses TF and increases the thrombin generation rate by an oxidative stress-mediated mechanism that requires the activation of NADPH oxidase.     

Usefulness of preprocedural soluble CD40 ligand for predicting restenosis after percutaneous coronary intervention in patients with stable coronary artery disease

CD40-CD40 ligand interaction is involved in the inflammatory pathogenesis of atherosclerosis but clinical data about its role in stent restenosis are still limited. We investigated the effect of preprocedural CD40 ligand (sCD40L) on stent restenosis. We enrolled 36 patients (mean age 61.4 +/- 8.5 years) with stable angina who underwent successful stent implantation. Control angiograms were performed in all patients after 6 months. Plasma sCD40L and high-sensitive C-reactive protein levels were measured before stent implantation and at 1 and 6 months after the procedure. Angiographically proven restenosis rate was 27.8%. Plasma sCD40L levels were significantly higher (preprocedural 0.74 +/- 0.79) and more prolonged in patients with stent restenosis compared with patients without stent restenosis (0.02 +/- 0.22 ng/ml, p < 0.001). According to receiver-operator characteristic analysis, sCD40L > 0.41 ng/ml was the best distinguished parameter between patients with and without restenosis. At the multivariate logistic regression analysis, preprocedural sCD40L was an independent predictor (RR 39.4, 95% confidence interval 4.05 to 383.8, p = 0.002) of stent restenosis after adjusting for confounding variables, including diabetes, reference vessel diameter, lesion length, stent diameter, stent length, and baseline high-sensitive C-reactive protein. Sensitivity, specificity, and positive and negative predictive values and likelihood ratio of preprocedural sCD40L levels in stent restenosis were 78%, 92%, 78%, 92%, and 9.37%, respectively. In conclusion, enhanced inflammation of plaque (increased sCD40L) before percutaneous coronary intervention may increase the rate of stent restenosis. Increased preprocedural sCD40L level is an independent predictor of stent restenosis. We can use this marker for the assessment of risk stratification before planning stent implantation.     

Probucol and atorvastatin decrease urinary 8-hydroxy-2'-deoxyguanosine in patients with diabetes and hypercholesterolemia

To clarify whether probucol and statins suppress oxidative stress in diabetic patients, we studied the effects of probucol and the statin atorvastatin on urinary 8-hydroxy-2'deoxyguanosine (8-OHdG) levels in diabetics with hypercholesterolemia. A randomized, open study was performed on a total of 36 patients with type 2 diabetes and hypercholesterolemia. The patients were randomly assigned to a probucol group (500 mg/day, n = 18) or an atorvastatin group (10 mg/day, n = 18). During three months, total- and LDL-cholesterol decreased significantly in both groups. LDL-cholesterol was significantly lower in the atorvastatin group than probucol group. HDL-C decreased significantly in the probucol group and did not change in the atorvastatin group. 8-OHdG decreased significantly in both groups after 3 months; 12.4 +/- 7.5 to 8.1 +/- 4.2 ng/mg/Cr in the atorvastatin group (p < 0.05) and 12.3 +/- 8.8 to 6.8 +/- 2.6 ng/mg/Cr in the probucol group (p < 0.05), and these changes did not differ significantly between the two groups. But, in patients with high 8-OHdG levels (more than 10 ng/mg/Cr) before administration, urinary 8-OHdG decreased significantly from 19.5 +/- 4.9 to 9.2 +/- 3.4 ng/mg Cr (p < 0.01) in the atorvastatin group, and from 19.7 +/- 8.2 to 6.67 +/- 2.2 ng/mg Cr (p < 0.01) in the probucol group. Urinary 8-OHdG was significantly lower in the probucol group than in the atorvastatin group after the second and third months of administration (p < 0.05). These results suggest that while probucol and atorvastatin both reduce systemic oxidative stress, probucol might be the more useful in patients with strong oxidative stress.     

Effect of continuous positive airway pressure on soluble CD40 ligand in patients with obstructive sleep apnea syndrome

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for atherosclerosis. CD40-CD40 ligand interaction promotes several proinflammatory mediators and plays a pivotal role in the various stages of atherosclerotic diseases. The present study examines whether CD40 ligation contributes to outcomes in patients with OSAS. METHODS: The study population comprised OSAS patients with an apnea hypopnea index (AHI) > or = 30 (n = 35) and control subjects (AHI < 5; n = 16). We measured serum levels of soluble CD40 ligand (sCD40L), tumor necrosis factor (TNF)-alpha, and hypersensitive C-reactive protein (hsCRP) before and after nasal continuous positive airway pressure (nCPAP) therapy for 3 months. RESULTS: Baseline levels of sCD40L were significantly higher in patients with OSAS (6.93 +/- 4.64 ng/mL) [mean +/- SD] than in control subjects (3.43 +/- 2.11 ng/mL, p < 0.01). Baseline levels of sCD40L positively correlated with TNF-alpha but not with hsCRP. The elevation of sCD40L was improved for 1 night after nCPAP therapy (3.83 +/- 2.78 ng/mL, p < 0.001). Even though patients with severe OSAS did not receive any other medication to control atherosclerotic risk factors for 3 months, nCPAP was continued to reduce the levels of sCD40L. CONCLUSION: The present study suggested that sCD40L is a key factor that links OSAS and atherosclerotic progression.     

The effects of simvastatin, losartan, and combined therapy on soluble CD40 ligand in hypercholesterolemic, hypertensive patients

The proinflammatory mediator CD40 ligand plays an important role in atherogenesis. Biological mechanisms underlying statin and angiotensin II type 1 receptor blocker therapies differ. Therefore, we compared the effects of these therapies either alone or in combination on plasma soluble CD40 ligand (sCD40L). This was a randomized, double-blind, placebo-controlled cross-over trial with three treatment arms (each 2 months) and two washout periods (each 2 months). Forty-seven hypertensive, hypercholesterolemic patients were given simvastatin 20mg and placebo, simvastatin 20mg and losartan 100mg, or losartan 100mg and placebo daily during each 2 month treatment period. Simvastatin alone did not significantly reduce sCD40L levels relative to baseline measurements when the entire cohort was analyzed. However, simvastatin significantly reduced sCD40L levels from 5.10+/-0.34 to 3.07+/-0.43ng/ml (P=0.002) in a subgroup of 18 patients with high baseline sCD40L levels >2.95ng/ml. Combined therapy or losartan alone significantly decreased plasma sCD40L levels relative to baseline measurements by 14+/-7% (P=0.001) and 13+/-10% (P=0.001), respectively. These decreases were significantly greater than those observed with simvastatin alone (P=0.023 by ANOVA). Significant inverse correlations between baseline sCD40L levels and percent changes in sCD40L levels were observed (r=-0.456, P=0.001 after simvastatin alone; r=-0.476, P<0.001 after combined therapy; r=-0.451, P=0.002 after losartan alone). Losartan alone or combined therapy significantly reduced plasma sCD40L levels more than simvastatin alone in our subjects. Simvastatin, losartan and combined therapy significantly reduced sCD40L to the greatest extent in patients with high baseline sCD40L levels.     

Plasma, serum, and platelet expression of CD40 ligand in adults with cardiovascular disease

The application of soluble CD40 ligand (sCD40L) as a biomarker has garnered great scientific and clinical interest. However, there are many uncertainties with regard to the biology of sCD40L. Although presumed to be a marker of platelet activation, relative levels in plasma, serum, and platelet expression are unknown, as is the optimal method for its measurement. We measured CD40L from serum, platelet-poor plasma, and platelet surface in adults who had stable cardiovascular disease (CVD) and those who had unstable CVD (n = 40). Plasma sCD40L did not differ significantly between groups. Serum sCD40L was significantly lower (1.4 +/- 1.3 vs 5.2 +/- 3.7 ng/ml, p <0.001) and platelet membrane CD40L expression was higher (1.4 +/- 0.7% vs 0.9 +/- 0.6%, p = 0.03) in unstable compared with stable CVD. When the 2 groups were considered together, there was a significant correlation between plasma and serum sCD40L levels (rho = 0.4, p = 0.02) and negative correlations between plasma (rho = -0.3, p = 0.04) and serum (rho = -0.4, p = 0.01) sCD40L levels with platelet membrane CD40L expression. In unstable CVD, the correlation between sCD40L measurements was poor. Consistent with enhanced platelet activation, there was a positive correlation between platelet aggregation and surface CD40L expression (rho = 0.5, p = 0.02) and between platelet expression of CD40L and P-selectin (rho = 0.4, p = 0.05) in unstable CVD. There was no correlation between CD40L and platelet count or C-reactive protein. Only surface expression of CD40L compared with platelet-derived (plasma) or total (serum) CD40L level proved a reliable marker of platelet function in patients who had stable CVD and those who had unstable CVD. In conclusion, our data demonstrate the complex nature of CD40L and highlight the distinct processes of expression, shedding, and clearance of this ligand in patient populations.     

氯吡格雷抑制急性冠状动脉综合征患者血小板释放可溶性CD40配体

目的探讨在非ST段抬高急性冠状动脉综合征（non—ST-segment elevation acute coronary syndromes，NSTEACS）患者短期应用氯吡格雷是否有抑制ADP诱导血小板释放可溶性CD40配体（sCD40L）的作用。方法NSTEACS42例，患者服用氯吡格雷6—8d，治疗前后采静脉血。提取富含血小板血浆（platelet rich plasma，PRP）并用二磷腺苷诱导血小板聚集和释放sCD40L，在不同时间点终止反应，用酶联免疫法测量sCD40L浓度，进行自身前后对照。结果治疗前后血浆sCD40L分别为（0．20±0．16）μg／L和（0．19±0．18）μg/L（P〉0．05）；治疗前后PRP受ADP诱导后20min释放的sCD40L浓度分别为（4．3±2．5）μg／L和（2.8±1．9）μg／L（P〈0．001），诱导后40min释放的sCD40L浓度分别为（5．3±3．1）μg／L和（2．9±1．6）μg／L（P〈0．001）。结论短期应用氯吡格雷可能对非sT段抬高急性冠状动脉综合征患者血小板炎症因子sCD40L释放具有抑制作用，提示氯吡格雷很可能具有抗炎效应．     

Oxidative-stress-mediated arterial dysfunction in patients with peripheral arterial disease.

AIMS: To investigate the existence of a relationship among flow-mediated dilation (FMD), nitric oxide (NO), and oxidative stress in patients with peripheral arterial disease (PAD), and to assess if the administration of an antioxidant was able to improve arterial dilatation. METHODS AND RESULTS: We performed a cross-sectional study comparing FMD, 8-Hydroxy-2-deoxy-2-deoxyguanosine (8-OHdG), a marker of oxidative stress, and nitrite/nitrate (NOx) serum levels in a population of 25 PAD patients and 40 controls. In the second part of the study, 21 PAD patients were randomly allocated to a treatment sequence of 7 days of i.v. infusion of placebo or 6 g/day propionyl-L-carnitine (PLC) in a cross-over design. Compared with controls, patients with PAD had enhanced 8-OHdG serum levels (2.4 +/- 1.2 vs. 4.24 +/- 3.11 ng/mL; P < 0.001), reduced NOx (17.02 +/- 6.11 vs. 11.28 +/- 6.02 microM; P < 0.001), and lowered FMD (10.34 +/- 2.14 vs. 6.69 +/- 2.95; P < 0.001). PLC infusion was associated with an increase of FMD [from 6.6 +/- 0.6 to 11.1 +/- 1.2% (mean +/- SE), P = 0.004] and NOx (from 14.5 +/- 1.4 to 17.1 +/- 1.2 microM; +18%, P = 0.012) and a decrease of 8-OHdG (from 3.62 +/- 0.37 to 2.64 +/- 0.32 ng/mL; -27%, P < 0.001). No changes were observed after placebo treatment. CONCLUSION: This study shows that in PAD patients, oxidative stress is implicated in determining reduced FMD.     

The proinflammatory mediator CD40 ligand is increased in the metabolic syndrome and modulated by adiponectin

OBJECTIVES: We hypothesized that the CD40/CD40 ligand (CD40L) system is up-regulated in the metabolic syndrome (MS) and modulated by adiponectin (AN). The objectives were: 1) to compare plasma and monocyte CD40L in patients with MS and controls and its association with clinical and biochemical parameters, 2) to investigate platelets as a source of soluble CD40L (sCD40L), and 3) to analyze the effects of AN on CD40/CD40L. METHODS: Plasma sCD40L and AN were measured in 246 controls and 128 patients with MS by ELISA. Monocyte CD40/CD40L expression and platelet CD40L content and release were compared in patients with MS and controls. Monocytes and endothelial cells were cultured with AN and CD40/CD40L expression determined by real-time RT-PCR and Western blotting. RESULTS: Patients with MS had higher sCD40L and lower AN levels than controls (0.89 +/- 0.1 vs. 0.76 +/- 0.07 ng/ml and 10.10 +/- 0.65 vs. 12.99 +/- 0.80 microg /ml, P < 0.05). Monocyte CD40/CD40L expression was higher (P < 0.05) in patients than controls (CD40: 1.31 +/- 0.31 vs. 0.80 +/- 0.14 arbitrary units; CD40L: 1.24 +/- 0.85 vs. 0.43 +/- 0.14 pg/microg protein). No differences were observed on CD40L content between resting platelets from patients with MS and controls (7.7 +/- 3.5 vs. 7.2 +/- 2.2 pg/microg protein). Stimulated platelets from patients with the MS released more (P < 0.05) sCD40L than controls (582 +/- 141 vs. 334 +/- 60% change vs. nonstimulated platelets). AN reduced CD40L mRNA and protein expression in monocytes from MS patients and endothelial cells. CONCLUSIONS: The enhanced sCD40L and cellular CD40L expression in the MS suggests that CD40L is of pathophysiological relevance in MS. Also, a new antiinflammatory effect of AN is described through the modulation of the CD40/CD40L system.     

Impact of nasal continuous positive airway pressure therapy on markers of platelet activation in patients with obstructive sleep apnea

BACKGROUND: Considerable evidence implicates CD40 signaling in the pathogenesis of atheromas. Exposure to CD40 ligand induces platelet-leukocyte conjugation, a heightened expression of inflammatory cytokines, matrix-degrading enzymes, and procoagulant factors. OBJECTIVES: To investigate the association between plasma soluble CD40 ligand (sCD40L) and platelet-monocyte aggregates in patients with obstructive sleep apnea (OSA) and to determine whether treatment of OSA with nasal continuous positive airway pressure (nCPAP) alters this relationship. METHODS: Twelve patients with OSA who were free of other diseases and 12 healthy controls matched for age, gender, and body mass index had blood drawn for sCD40L and platelet-monocyte aggregate measurements. A repeat assessment was obtained following 8 weeks of nCPAP therapy. RESULTS: Subjects with OSA had significantly higher plasma sCD40L levels and exhibited elevated platelet-monocyte aggregates compared to nonapneic subjects (7.6 +/- 4.3 versus 1.7 +/- 1.1, p = 0.004; and 41.3 +/- 23.7 versus 6.7 +/- 4.9, p = 0.001, respectively). Both parameters correlated positively with the percentage of time spent with SpO(2) <90% (r = 0.69, p = 0.01 and r = 0.6, p = 0.03, respectively). After 8 weeks of nCPAP treatment, sCD40 levels declined by 47% (p = 0.003) and platelet-monocyte aggregates by 42% (p = 0.002). None of the controls showed any changes in either sCD40L or platelet- monocyte aggregates after nCPAP therapy. CONCLUSIONS: OSA is associated with upregulation of circulating sCD40L levels and platelet-monocyte aggregation that may account for the increased incidence of cardiovascular events in this population. Treatment with nCPAP may alleviate this risk.     

Role of vitamin E-coated membrane in reducing advanced glycation end products in hemodialysis patients: a pilot study

INTRODUCTION: Advanced glycation end products (AGEs) are markers of oxidative stress. AIMS: To assess if a vitamin-E-coated dialyzer affects plasma AGE levels and endothelial function in hemodialysis patients. METHODS: 16 patients were dialyzed with a synthetic modified cellulose membrane (SMC, n = 8) or a vitamin E-coated dialyzer (n = 8), respectively. At week 32 endothelial function was determined as brachial artery flow-mediated dilatation (FMD). Total AGEs, free pentosidine (FP), protein-bound pentosidine (BP) and autoantibodies against oxidized LDL (ox-LDL-autoantibodies) were assessed at baseline (T0) and at 16, 32, 40 and 42 weeks (T16, T32, T40 and T42). RESULTS: At T16 and T32 FP and BP were lower in vitamin E than in SMC (T 16: 88.7 +/- 8.96 vs. 124.2 +/- 11.90 pmol/ml plasma; p = 0.04, and 22.9 +/- 2.99 vs. 32.8 +/- 2.98 pmol/mg proteins; p = 0.04. T32: 78.7 +/- 8.54 vs. 123.7 +/- 10.15 pmol/ml plasma; p = 0.007, and 19.9 +/- 2.0 vs. 33.67 +/- 2.41 pmol/mg proteins; p = 0.001). In vitamin E, AGEs were lower at T32, T40 and T42 (946.7 +/- 80.91 vs. 1,351.2 +/- 179.33 AU/ml, p = 0.05; 986.9 +/- 59.63 vs. 1,509.9 +/- 154.17 AU/ml, p = 0.013; 890.3 +/- 73.70 vs. 1,453.9 +/- 153.16 AU/ml, p = 0.009). At T32 AGEs, ox-LDL autoantibodies and FMD were inversely correlated (R = -0.70 p = 0.007 and R = -0.59, p = 0.04, respectively). CONCLUSIONS: Vit E-coated membrane reduces plasma AGEs levels and AGEs values are negatively correlated with FMD.     

Homocysteine modulates the CD40/CD40L system.

OBJECTIVES: This study evaluated the impact of hyperhomocysteinemia (HHcy) on the CD40/CD40 ligand (CD40L) dyad in vivo and in vitro. BACKGROUND: Hyperhomocysteinemia is associated with an increased incidence of atherothrombosis, although the molecular mechanisms of this association are incompletely defined. The CD40L pair triggers inflammatory signals in cells of the vascular wall, representing a major pathogenetic pathway of atherosclerosis. METHODS: We used a commercially available enzyme-linked immunosorbent assay kit to evaluate circulating levels of soluble (s) CD40L in 24 patients with HHcy and 24 healthy subjects. We also used real-time polymerase chain reaction and flow cytometry to determine expression levels of CD40 and vascular cell adhesion molecule (VCAM)-1 in human umbilical vein endothelial cells (HUVECs) and of CD40L in human platelets. RESULTS: The sCD40L levels were significantly increased in HHcy patients (median [interquartile range] 8.0 [0.7 to 10.5] ng/ml vs. 2.1 [1.9 to 2.3] ng/ml, p = 0.0001). Positive correlations were noted between log sCD40L and log homocysteine (Hcy) (R = 0.68, p < 0.0001) or log sVCAM-1 (R = 0.41, p < 0.005). Homocysteine significantly stimulated CD40 mRNA expression in HUVECs (p = 0.033). Consistently, 24-h exposure to Hcy increased the percentage of CD40-expressing cells (p = 0.00025). Homocysteine also significantly enhanced CD40L expression in platelets (p = 0.025) to a comparable extent as that of thrombin. Notably, Hcy increased VCAM-1 protein expression induced by CD40L in HUVECs (p = 0.0046). CONCLUSIONS: The present results uncover a potential molecular target of Hcy, namely the CD40/CD40L dyad. Collectively, they indicate that upregulation of CD40/CD40L signaling may represent a link between HHcy and an increased risk of cardiovascular disease.     

Thromboxane-dependent CD40 ligand release in type 2 diabetes mellitus.

OBJECTIVES: The goals of this study were to characterize the platelet contribution to soluble CD40 ligand (sCD40L), to correlate its formation with the extent of oxidative stress and platelet activation, and to investigate the effects of improved metabolic control and low-dose aspirin on these processes. BACKGROUND: Inflammation, oxidative stress, and platelet activation are involved in the pathogenesis of type 2 diabetes (T2DM) and its complications. The CD40-CD40L interactions result in inflammatory and pro-thrombotic responses. METHODS: Urinary 8-iso-prostaglandin (PG)F2alpha and 11-dehydro-thromboxane (TX)B2, in vivo markers of oxidative stress and platelet activation, respectively, plasma CD40L, and C-reactive protein (CRP) were measured in 114 T2DM patients and 114 control patients. A randomized, parallel group, 17-day study of aspirin (30, 100, or 325 mg/day) was performed in 18 T2DM patients. A similar study was performed in six healthy volunteers (aspirin, 100 mg/day). Twenty poorly controlled T2DM patients were studied before and after improved metabolic control. RESULTS: Compared with control patients, diabetic patients showed significantly higher levels of 8-iso-PGF2alpha, 11-dehydro-TXB2, sCD40L, and CRP. On multiple regression analysis, 11-dehydro-TXB2 and 8-iso-PGF2alpha excretion rates predicted sCD40L levels. Soluble CD40L linearly correlated with 11-dehydro-TXB2 (rho = 0.67, p < 0.0001), and both were reduced after one week of aspirin (p < 0.0026), with slow recovery over 10 days after aspirin withdrawal. Improved metabolic control was associated with a reduction in sCD40L, 8-iso-PGF2alpha, and 11-dehydro-TXB2. CONCLUSIONS: This study provides several lines of evidence for the dependence of sCD40L release on TXA(2)-dependent platelet activation in T2DM and provides novel mechanistic insight into the amplification loops of persistent platelet activation in this setting.     

Total and biologically active serum-soluble CD154 in patients with chronic idiopathic urticaria.

The pathogenesis of chronic idiopathic urticaria (CIU) is not understood completely; however, autoimmunity has been implicated. Because membrane and soluble forms of CD154 have been reported to be increased, in several autoimmune diseases, we have quantified the soluble CD154 (sCD154) molecule by a sandwich enzyme-linked immunosorbent assay in serum samples of 32 patients with CIU (aged 32 +/- 12 years) and compared them with 32 age- and sex-matched nonallergic controls. A marked increase was observed in patients with CIU as compared with controls (4.8 +/- 2.6 ng/mL versus 2.9 +/- 0.9 ng/mL; p < 0.0005). No significant differences were found between groups of patients with positive or negative autologous serum skin test. A biological assay to determine sCD154 showed that patients with positive autologous serum skin test have the highest levels (4.9 +/- 1.2 ng/mL) of biologically active sCD154 as compared with their negative counterparts (2.2 +/- 1.3 ng/mL; p < .001) and controls (0.6 +/- 0.3 ng/mL; p < 0.001). Active sCD154 can be derived from mast cell activation or other leukocytes. It is concluded that active sCD154 may be involved in the immune activation observed in patients with CIU.     

Levels of soluble CD8 antigen and circulating immune complexes in intravenous drug abusers: relationships to HIV antibody serology

A total of 36 intravenous drug abusers (IVDA) were studied for circulating immune complexes (CIC) and serum soluble CD8 antigen (sCD8). None had symptoms or signs of AIDS-related complex or AIDS. sCD8 levels were significantly higher in 18 patients who had HIV antibody (Ab) compared with 18 patients who were HIV Ab negative (1640 +/- 578 virus 804 +/- 264 U/ml, p less than 0.0001). In HIV Ab+ patients but not in HIV Ab- patients, sCD8 levels significantly correlated with percentages and absolute numbers of activated CD3+DR+ peripheral blood mononuclear cells (p = 0.0024 and 0.0183, respectively). Also in HIV Ab+ patients, CIC levels were significantly greater for both anti-C3 binding (13.1 +/- 11.1 versus 2.9 +/- 3.4 micrograms/ml, p = 0.002) and C1q binding (23.5 +/- 20.2 versus 6.3 +/- 4.3 micrograms/ml, p = 0.001) CIC. Serum C4 concentrations were lower in the HIV Ab+ patient group (33.9 +/- 10.1 versus 41.6 +/- 12.4 mg/dL, p = 0.043). In the seropositive group, IgG levels were higher (2206 +/- 859 versus 1615 +/- 645 mg/dl) and total CD4 cell counts were lower (757 +/- 344 versus 1172 +/- 402 cells per mm3), but at a less significant level (p = 0.024 and 0.005, respectively), than that seen for sCD8 and C1q CIC differences. These results suggest that elevations of both the lymphocyte activation marker sCD8 and antigen nonspecific CIC characterize earlier stages of HIV infection in IVDA.     

Different behaviour of soluble CD40L concentrations can be reflected by variations of preanalytical conditions.

INTRODUCTION: Biomarkers reflecting an inflammatory or immunological response are increasingly offered to improve the risk stratification of patients. For example, current evidence suggests that soluble CD40 ligand (sCD40L) is elevated in patients with acute coronary syndrome. But only a few data are available to evaluate the influence of preanalytic conditions on sCD40L values. METHODS: Blood samples of seven healthy blood donors were collected in tubes without additives and in EDTA- or citrate-filled tubes at various storage conditions. Platelet count was modified by serum dilution, and sCD40L was measured in platelet-rich-plasma and in whole blood. sCD40L levels were determined by an commercially available ELISA-Kit. RESULTS: Immediately after blood sample assessment, sCD40L levels in serum samples were elevated (1258+/-820 pg/ml) compared to EDTA (64+/-32 pg/ml) and citrate (60+/-8.5 pg/ml) values. Additionally, sCD40L levels were dependent on storage duration. After platelet activation, sCD40L levels were significantly increased to 8278+/-2453 pg/ml and were significantly correlated to platelet count (r=0.96). CONCLUSIONS: Soluble CD40L levels were clearly influenced by preanalytical conditions and were dependent on storage duration, sample technique and platelet count. These influences should be considered by the determination and evaluation of sCD40L concentrations.     

中国人群CD40L G基因单核苷酸多态性对急性冠状动脉综合征影响的相关性研究

目的新近的研究提示CD40/CD40L信号途径对急性冠状动脉综合征的发病及预后均具有一定影响。本研究旨在探讨CD40L G基因单核苷酸多态性与急性冠状动脉综合征患者冠状动脉病变程度间的关系。方法搜集2008年8月至2010年8月间在北京安贞医院抢救中心确诊为急性冠状动脉综合征的患者共482例,总结分析其临床特征、相关危险因素及血清单核细胞和血小板表达CD40水平以及CD40L G基因单核苷酸多态性对冠状动脉病变程度的影响。结果 (1)6.8%(n=33)的急性冠状动脉综合征患者未检测到血清sCD40L(<95 ng/L),449例患者平均血清sCD40L为296±25 ng/L,sCD40L平均水平男性为309 ng/L,女性为195 ng/L,男性高于女性(P<0.001),sCD40L水平随着冠状动脉病变程度加重而升高(P<0.001)。(2)不同基因型间血清sCD40L水平与冠状动脉评分存在显著性差异(P<0.001),趋势具有统计学意义。其中以GG基因型的sCD40L水平最高,为409ng/L,冠状动脉病变程度最严重(P<0.001)。(3)多因素分析显示,在矫正年龄、性别及高血脂、高血压、糖尿病等危险因素后,CD40L G基因多态性与冠状动脉病变程度密切相关,它们的OR值分别为1.00、1.32、3.41(P≤0.001)。结论急性冠状动脉综合征患者血清sCD40L水平及CD40L G基因多态性与冠状动脉病变程度密切相关,在急性冠状动脉综合征临床危险分层中,血清sCD40L水平及CD40L G基因多态性是一个不容忽视的方面。     

The monocytic lineage specific soluble CD163 is a plasma marker of coronary atherosclerosis

BACKGROUND: CD163 is a monocyte-macrophage lineage specific scavenger receptor that mediates the uptake and clearance of haptoglobin-haemoglobin complexes, and soluble CD163 (sCD163) is also present in plasma. As atherosclerosis involves infiltration by monocyte-derived macrophages, we investigated whether sCD163 may act as a marker of coronary atherosclerosis (CAD). METHODS AND RESULTS: Clinical features were identified and plasma was collected from 147 consecutive patients presenting for coronary angiography. Patients were classified as having CAD+, or being free of CAD- haemodynamically significant (>50% luminal diameter) coronary stenoses in one or more major coronary arteries (1, 2 or 3 vessel disease), and sCD163 concentration was measured by ELISA. Plasma sCD163 was non-parametrically distributed, being significantly higher in CAD+ patients (median 2.47 mg/L, 25th-75th percentile, 1.79-3.5mg/L) than in CAD- patients (2.09, 1.31-2.72 mg/L) (p=0.021, Mann-Whitney U-test). LogsCD163 increased significantly with increasing CAD extent (p=0.0036) and was significantly greater in patients with 3 vessel disease than in CAD- patients (p<0.001). Whereas logsCD163 correlated with CAD extent (Spearman r=0.22, p=0.008), logCRP did not, and sCD163 was only weakly correlated with CRP (r=0.19, p=0.039). Importantly, multivariate linear regression identified that sCD163 (p=0.0021) was a significant predictor of CAD extent and was independent of conventional risk factors age (p<0.0001), hypercholesterolemia (p=0.0023), hypertension (p=0.068), and current smoking (p=0.066). CONCLUSIONS: The monocyte-specific marker sCD163 is a novel potential plasma marker of coronary atherosclerotic burden.     

Prognostic value of plasma soluble CD40 ligand in patients with chronic non-valvular atrial fibrillation.

AIMS: We aimed to clarify whether determination of levels of soluble CD40 ligand (sCD40L) could predict subsequent thrombo-embolic events in patients with non-valvular atrial fibrillation (NVAF). METHODS AND RESULTS: Forty-four consecutive outpatients (mean age: 58 +/- 6 years, 20 male) with chronic NVAF who were not receiving aspirin and had no thrombus or spontaneous echo contrast (SEC) on left atrium (LA) or left atrial appendage (LAA) were included in the study. The patients had no history of an embolic event and were followed up 24 +/- 2 months for thrombo-embolic events. sCD40L was determined at the enrollment. All patients were evaluated by means of SEC and thrombus formation by transoesophageal echocardiography at the end of follow-up period. Twelve (27%) patients had SEC and 2 (5%) patients had thrombus on LAA. Ischaemic stroke occurred in 2 (4.5%) patients and transient ischaemic attack developed in 4 (9%) patients during follow-up. sCD40L was significantly higher in patients with LASEC (0.41 +/- 0.05 vs. 0.16 +/- 0.04 ng/mL, P = 0.02) and embolic events (0.74 +/- 0.05 vs. 0.19 +/- 0.03 ng/mL, P = 0.001) than in those without. sCD40L levels were significantly related to the LASEC grade (R = 0.377, P = 0.02). In multivariable analysis, while independent variables for SEC or thrombus formation were LA diameter, sCD40L levels, and the duration of AF, independent variables for cerebrovascular events were the existence of SEC or thrombus formation on LAA, and sCD40L level. CONCLUSION: Plasma sCD40L may prospectively predict stroke in AF. sCD40L may provide useful marker to identify patients at high thrombo-embolic risk with NVAF.     

Pancreatic B-cell function is altered by oxidative stress induced by acute hyperglycaemia.

AIMS: Type 2 diabetes is preceded by a symptom-free period of impaired glucose tolerance (IGT). Pancreatic B-cell function decreases as glucose intolerance develops. In many patients with IGT, fasting blood glucose is within normal limits and hyperglycaemia occurs only postprandially. We examined whether pancreatic B-cell function changes during acute hyperglycaemia induced by oral glucose loading. METHODS: We calculated the insulinogenic index (I.I.) as an indicator of pancreatic B-cell function and measured serum levels of thioredoxin, a marker of cellular redox state, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative stress, during a 75-g oral glucose tolerance test (OGTT) in 45 subjects [24 patients with normal glucose tolerance (NGT), 14 with IGT and seven with Type 2 diabetes]. RESULTS: Thioredoxin levels decreased after glucose loading [66.1 +/- 23.7, *59.3 +/- 22.4, *49.3 +/- 21.2 and *37.7 +/- 18.0 ng/ml, fasting (0 min) and at 30, 60 and 120 min, respectively; *P < 0.001 vs. fasting]. In contrast, concentrations of 8-OHdG peaked at 30 min and then gradually decreased (0.402 +/- 0.123, *0.440 +/- 0.120, 0.362 +/- 0.119 and 0.355 +/- 0.131 ng/ml, *P < 0.05 vs. fasting, P < 0.01 vs. 30 min). The insulinogenic index correlated with the change in thioredoxin levels (r = 0.34, P < 0.05). However, there was no relationship with the change in 8-OHdG levels from 0 to 30 min. CONCLUSIONS: Hyperglycaemia in response to oral glucose impairs pancreatic B-cell function with decreasing thioredoxin levels. The augmented oxidative stress induced by hyperglycaemia may affect the cellular redox state. These findings strongly suggest that repeated postprandial hyperglycaemia may play an important role in the development and progression of diabetes mellitus.