Soluble CD40L, platelet surface CD40L and total platelet CD40L in congestive heart failure: relationship to platelet volume, mass and granularity

Background. Many complications associated with congestive heart failure (CHF) have a thrombosis-related aetiology, which may involve platelets. The immune modulator pair CD40-CD40L has been proposed to be an important link between inflammation and thrombosis and may be important in the pathophysiology of CHF. Objective. To study soluble CD40L (sCD40L), platelet surface CD40L (%GCD40L) and total platelet CD40L (pCD40L) levels in CHF patients, their relationships to other platelet indices (platelet volume, mass and component) and to assess their prognostic value. Methods. We measured sCD40L (by ELISA); pCD40L (by a platelet lysate assay); platelet surface CD40L (%GCD40L) expression by flow cytometry; mean platelet volume (MPV), mean platelet mass (MPM) and mean platelet component (MPC); in 108 patients with stable CHF. Levels were compared with 37 ‘healthy controls’ and 63 ‘disease controls’. After a median follow-up period of 490 days, clinical endpoints were determined. Results. pCD40L was significantly higher in CHF than disease controls, but not sCD40L or %GCD40L levels. CHF patients and disease controls had higher MPV (one-way anova , P < 0.0001), whilst MPC was significantly lower in CHF patients (P < 0.0001), compared to healthy controls. All indices related to CD40L (i.e. sCD40L, pCD40L and %GCD40L) were neither related to disease severity or left ventricular ejection function, nor to clinical endpoints at follow-ups. Conclusion. Patients with stable CHF patients did not exhibit enhanced levels of CD40L and the latter did not predict clinical events at follow-up. The lack of difference in CD40L levels between CHF and disease controls suggests that CD40L may not have a major role in CHF per se, but in the comorbidities associated with CHF.     

Assessment of mean platelet volume and soluble CD40 ligand levels in patients with non-dipper hypertension,dippers and normotensives

Abstract

Objective: Patients with a lack of nocturnal decline in blood pressure (BP) are at an increased risk for cardiovascular events. Mean platelet volume (MPV) and soluble CD40 ligand (sCD40L) are accepted biomarkers of platelet activation and considered as a risk factor for cardiovascular disease. The aim of this study was to determine whether MPV and sCD40L levels are higher in non-dipper hypertensive (NDHT) patients than in dipper hypertensive (DHT) patients and healthy controls.

Methods: 124 consecutive patients were included to this study. Patients were divided into three groups: NDHT patient group [n?=?43; mean age 51.8?±?6.6; 31?males (72.1%)]; DHT patient group [n?=?41; mean age 50.2?±?7.3; 22?males (53.7%)]; and normotensive group [n?=?40; mean age 49.9?±?6.7; 22?males (55%)]. Physical examination, laboratory work-up and 24-h ABPM were performed for all participants.

Results: The sCD40L and MPV levels were significantly higher in the NDHT group than in the DHT and normotensive groups (p?<?0.05). In correlation analysis, MPV, 24-h systolic blood pressure (SBP), 24-h diastolic blood pressure (DBP), night-time SBP and night-time DBP were positively correlated with sCD40L.

Conclusion: Our study demonstrated that MPV and sCD40L levels were significantly higher in NDHT patients compared to DHT and normotensive patients. sCD40L levels were positively correlated with MPV, 24-h SBP, 24-h DBP, night-time SBP and night-time DBP.     

Association of platelet activation markers with recurrence of atrial fibrillation after pulmonary vein isolation

Atrial fibrillation (AF) is known to cause platelet activation. AF and its degree of thrombogenesis could be associated with monocyte-platelet aggregates (MPAs). We investigated on whether the content of MPAs or other platelet activation markers is associated with the recurrence of AF after pulmonary vein isolation (PVI). A total of 73 patients with symptomatic AF underwent PVI. After 6 months, all patients were evaluated for episodes of AF recurrence. At the same time, flow-cytometric quantification analyses were performed to determine the content of MPAs. Further platelet activation parameters were detected by using either cytometric bead arrays or quantitative immunological determination. Patients with recurrent AF (n = 20) compared to individuals without AF relapse (n = 53) were associated with an increased content of MPAs (43 ± 3% vs. 33 ± 2%, p = 0.004), as well as an increased CD41 expression on monocytes (191 ± 20 vs. 113 ± 6, p = 0.001). The level of the soluble platelet activation markers such as D-dimer, sCD40L, and sP-selectin did not differ between these groups. The content of MPAs correlated weakly with the level of sCD40L (r = 0.26, p = 0.03), but not with sP-selectin and D-dimer, whereas sP-selectin and sCD40L correlated with each other (r = 0.38, p = 0.001). Only the cellular marker of platelet activation, the content of MPAs, was increased in patients with recurrent AF after PVI. In contrast, soluble markers remained unaltered. These data indicate a distinct mechanism and level of platelet activation in AF. The clinical relevance of MPAs in identifying AF recurrence or in guiding the therapy with anticoagulants remains to be elucidated.     

Platelet activation in coronary artery disease: intracardiac vs peripheral venous levels and the effects of angioplasty

BACKGROUND: Platelet activation and aggregation play a key role in coronary artery disease, with antiplatelet therapies leading to improved clinical outcomes. Limited data exist as to whether peripheral venous blood measurements of platelet physical indexes (eg, platelet count, volume, and granularity) and soluble markers of platelet activation (eg, P-selectin [sP-sel] and CD40 ligand [CD40L]) reflect the local (intracardiac) coronary environment. Furthermore, how percutaneous coronary interventions (PCIs) affect levels of peripheral/cardiac platelet indexes is unclear. METHODS: Blood samples were sequentially acquired from the coronary os, aortic root, coronary sinus, and the femoral vein, and where relevant, pre-PCI and post-PCI. Eighty-seven patients undergoing coronary angiography were recruited (mean [+/-SD] age, 59.8+/-10.8 years; 54 men [62%]), of whom 36 proceeded to PCI. Platelet physical indexes and plasma sP-sel and CD40L levels were measured (by enzyme-linked immunosorbent assay). RESULTS: At baseline, no intracardiac vs peripheral differences were noted in sP sel levels, while CD40L levels were elevated in the aorta compared to the coronary sinus and femoral venous. The mean platelet count (MPC) was similar at all four sites, but within the coronary sinus blood, mean platelet volume (MPV) was significantly lower and mean platelet granularity (MPG) was higher when compared to arterial levels. Though aortic and femoral levels of sP-sel were raised following PCI, transcardiac gradients of plasma sP-sel levels were unaffected. PCI was associated with lower CD40L, MPC, and MPV levels but with a higher MPG level in all sampling sites. CONCLUSIONS: sP-sel levels measured peripherally reflect the cardiac environment, unlike CD40L, MPC, MPV, and MPG. PCI leads to further platelet activation (raised sP-sel) despite aggressive antiplatelet therapy.     

Enhanced P-selectin expression and increased soluble CD40 Ligand in patients with Type 1 diabetes mellitus and microangiopathy: evidence for platelet hyperactivity and chronic inflammation

Aims/hypothesis Platelet activation, endothelial dysfunction and inflammation may be involved in early stages of diabetic microangiopathy. We therefore investigated patients with Type 1 diabetes mellitus, without (n=19) and with (n=20) microangiopathy, matched for glycaemic control and duration of disease, and matched with healthy control subjects (n=27).Methods Platelet activation was measured as platelet P-selectin expression using whole blood flow cytometry and as soluble P-selectin by immunoassay. Von Willebrand factor antigen in plasma, serum soluble E-selectin, CD40 ligand (sCD40L) and C-reactive protein (CRP) served as markers for endothelial function and inflammation.Results Thrombin-induced platelet P-selectin expression was enhanced, and soluble P-selectin and sCD40L concentrations were increased in patients with microangiopathy compared with the control subjects (p<0.01 for both) and with patients without microangiopathy (p<0.05 for P-selectin expression and sP-selectin), whereas all three parameters were similar in patients without microangiopathy and in the control subjects. CRP and soluble E-selectin were increased in patients with microangiopathy, compared with the control subjects (p<0.01 and p<0.05), whereas von Willebrand factor did not differ between the groups.Conclusions/interpretation Microangiopathy in Type 1 diabetes is associated with platelet hyperactivity, endothelial dysfunction and low-grade inflammation, indicating an increased risk for cardiovascular disease.Abbreviations sP-selectin Soluble P-selectin - sCD40L soluble CD40 Ligand - CRP C-reactive protein     

The effects of coronary artery disease severity on time-dependent changes in platelet activation indices in stored whole blood

Background Platelets play a pivotal role in the pathogenesis of the thrombotic complications in cardiovascular disease (CVD). Abnormal platelet activation indices are evolving as potentially useful markers in CVD risk stratification. Whilst there has been some investigation into the effects of storage time on several of these indices, the effects of underlying disease severity on these temporal changes have not been previously studied. Methods Using the ADVIA^TM120 haematology analyser, we assessed the effects of time-dependent storage of whole blood in EDTA, on a number of platelet activation indices: mean platelet volume (MPV), mean platelet component (MPC, measure of platelet density) and platelet component distribution width (PCDW, a marker of platelet shape change. We studied three age- and sex-matched patient groups: (i) healthy controls (n = 10), (ii) stable patients with coronary artery disease (CAD, n = 9); and (iii) patients with acute myocardial infarction (n = 8). Whole blood samples were processed at exactly 5 min following venesection and at 15, 30, 60 and 120 min later in storage in EDTA tubes at room temperature. Results There was a significant and stepwise increase in MPV (P = 0.01) and decrease in PCDW (P = 0.03), with a non-significant trend to increasing MPM and decreasing MPC with increasing underlying disease (that is healthy, ‘stable’ and ‘acute’ artery disease). There was a significant time-dependent increase in MPV and decrease in MPC and PCDW (all P < 0.05), which were all significant on ‘post-hoc’ analyses by 30 min. There were no significant changes in platelet count or MPM with time. There was no interaction of underlying disease with whole-blood storage time for any of the platelet indices reported (P = NS). Conclusion There is a temporal increase in MPV and decrease in MPC and PCDW in venous blood stored over 2 h in EDTA. These changes are not influenced by the underlying CVD disease severity.     

Circulating levels of soluble EMMPRIN (CD147) correlate with levels of soluble glycoprotein VI in human plasma

Abstract

Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147), which binds to the platelet-specific collagen receptor glycoprotein (GP) VI, is expressed in a range of cell types including platelets and leukocytes, and has been implicated in neoplastic disease and atherosclerotic coronary disease. Both CD147 and GPVI can be shed from cell membranes and detected in plasma. However, while the relationship between soluble CD147 (sCD147), soluble GPVI (sGPVI) and standard markers of platelet activation has received little attention, such analysis may help reveal pathways mediating release of sCD147. We investigated the relationship between sCD147 and platelet markers including sGPVI, soluble and platelet-bound CD62P (P-selectin), active αIIbβ3 (assessed by PAC-1 binding) and platelet CD147 in 25 patients with stable angina pectoris (SAP), 13 patients with no coronary artery disease (CAD) and 10 healthy donors. Plasma levels of sCD147 significantly correlated with sGPVI (r?=?0.46, p?=?.004), but did not correlate with any other platelet markers examined. Linear regression analysis identified that sCD147 levels could be predicted by sGPVI levels (β?=?.445, p?=?0.003) and age (β?=?0.304, p?=?0.038), but were independent of potential clinical confounders such as CAD, diabetes and medication usage. As sCD147 strongly correlates with platelet-specific sGPVI, a common platelet source and/or mechanism of release may contribute to sCD147 levels in vivo.     

Clinically apparent atherosclerotic disease in diabetes is associated with an increase in platelet microparticle levels.

BACKGROUND: The commonest cause of mortality in patients with Type 2 diabetes is atherothrombosis, which can be related to abnormalities in the coagulation and fibrinolytic pathways, as well as in platelet function. Platelet microparticles (PMPs) may contribute to the prothrombotic state and may promote the progression of atherosclerosis. We hypothesized that PMPs are elevated in Type 2 diabetes and that patients with Type 2 diabetes and clinically apparent atherosclerosis would have the highest levels. Similarly, we hypothesized that soluble plasma P-selectin (sPsel) and CD40L (both molecules which are released by activated platelets), as well as %CD62P (P-selectin) and %CD63 positivity on platelets quantified by flow cytometry, would be highest in patients with Type 2 diabetes and clinically apparent atherosclerotic disease, and might be correlated to PMP levels. METHODS: Venous blood was obtained from 21 Type 2 diabetic patients without atherosclerotic complications, 18 diabetic patients with clinically apparent atherosclerotic disease and 21 non-diabetic control subjects. PMPs, as well as %CD62P and %CD63 positivity on platelets, were quantified by flow cytometry. sPsel and CD40L were measured using ELISA. RESULTS: Patients with Type 2 diabetes and clinically apparent atherosclerotic disease had the highest PMP (P=0.045) and sPsel (P=0.046) levels, compared with patients without complications (who had intermediate PMP levels) and control subjects. Control subjects had the lowest CD40L levels (P<0.001) when compared with patients with Type 2 diabetes, with no difference in sCD40L levels between the two diabetic subgroups. %CD62P and %CD63 positivity did not differ between the groups. PMP levels correlated with %CD62P positivity (P=0.026) but not to %CD63 positivity (P=0.089), sCD40L (P=0.407) or sP-sel (P=0.163); sCD40L levels did not correlate with any other marker of platelet activation. CONCLUSION: PMPs are elevated in Type 2 diabetes. In addition, patients with clinically apparent atherosclerosis had the highest levels of PMPs and sPsel. Thus, PMPs may be a marker of symptomatic atherosclerotic vascular disease in Type 2 diabetes, and may both represent a useful risk stratification tool as well as a novel therapeutic target for anti-thrombotic drugs.     

Comparison of diverse platelet activation markers as indicators for left atrial thrombus in atrial fibrillation

Atrial fibrillation (AF) is well known for being a major risk factor of thromboembolic stroke. We could recently demonstrate an association of monocyte–platelet aggregates (MPAs) with the degree of thrombogenicity in patients with AF. This study investigated platelet activation markers, as potential biomarkers for the presence of left atrial (LA) thrombus in patients with AF. One hundred and eight patients with symptomatic AF underwent transesophageal echocardiography (TEE) before scheduled cardioversion or pulmonary vein isolation. In order to determine the content of MPAs by flow-cytometric quantification analyses, blood was drawn on the day of TEE. The soluble CD40 Ligand (sCD40L) and soluble P-selectin (sP-selectin) were obtained by Cytometric Bead Arrays (CBA). D-dimer levels were detected by quantitative immunological determination of fibrin degradation products. Clinical, laboratory, and echocardiographic standard parameters were obtained from all patients, including the determination of the flow in the left atrial appendage (LAA). Patients with detected LA thrombus (n = 28) compared with patients without thrombus (n = 80) showed an increased number of common risk factors, such as age, diabetes, heart failure, and coronary artery disease (CAD). The presence of LA thrombus was associated with significantly increased levels of MPAs (147 ± 12 vs. 304 ± 29 per µl; p < 0.00), sCD40L (106.3 ± 31.0 vs. 33.5 ± 2.1 pg/ml, p = 0.027), and D-dimer (0.13 ± 0.02 vs. 0.69 ± 0.21 mg FEU/l, p = 0.015). In contrast, sP-selectin showed no association with LA thrombus. A multivariate regression analysis showed that MPAs, sCD40L as well as D-dimers were independent indicators for the existence of LA thrombus. MPAs above 170 cells/µl indicated LA thrombus with a high sensitivity of 93% and a specificity of 73% (OR 62, 95% CI. 6.9–557.2, p < 0.001) in patients with AF, whereas the D-dimer lost their quality as independent indicator by using the conventional cut-off of 0.5 mg/l within the regression analysis. MPAs, as well as the D-dimer, correlated significantly negatively with the flow in the LAA measured during TEE. The content of MPAs, sCD40L, and D-dimer, but not sP-selectin showed an increased dependence on LA thrombus in patients with AF. In our study group, MPAs showed the best diagnostic test accuracy of the compared platelet markers. The different results of the examined platelet activation markers could be an indication of diverse mechanisms of LA thrombus in AF. Further studies should evaluate whether determination of MPAs in clinical routine may suffice to indicate the presence of LA thrombus in patients with AF.     

Inverse correlation between soluble CD40 ligand and soluble CD40 is absent in patients with unstable angina

The CD40/CD40 ligand (CD40L) system mediates inflammatory processes important in atherogenesis and plaque instability. The expression of CD40L on activated T cells was suppressed by soluble CD40 (sCD40) in vitro. However, the relationship between soluble CD40L (sCD40L) and sCD40 in unstable angina (UA) is still unknown. Thirty-seven consecutive patients with recent chest pain or discomfort were recruited. Patients with both Braunwald's class IB–IIIB and with coronary stenosis (or stenoses) of >75% were assigned to the UA group (n = 19, aged 67.2 ± 8.2 years), and the rest to the control group (n = 18, aged 63.4 ± 8.7 years). The serum levels of sCD40L and sCD40, and the plasma levels of matrix metalloproteinase (MMP)-9, were measured by enzyme-linked immunosorbent assays. A significantly inverse correlation between sCD40L and sCD40 was shown in the controls (r = −0.72, P = 0.0007), but was absent in the UA group (r = −0.16, P not significant), although there was no statistical significance between these groups in terms of serum levels of sCD40L or sCD40. The difference of the regression slopes of these regression lines was statistically significant (P < 0.01). Additionally, there was a significant correlation between sCD40 and plasma levels of MMP-9 in the patients with and without UA (r = 0.58, P = 0.0096), but no significant correlation between sCD40L and MMP-9 levels (r = 0.00, P not significant). The balance between CD40 and CD40L may be lost in patients with UA. Soluble CD40 expression may also be related to MMP-9 expression in atherosclerotic tissues.     

Association of platelet activation markers with cancer-associated venous thromboembolism

Venous thromboembolism (VTE) is a frequent complication in cancer patients. Platelet activation is thought to be involved in cancer-associated VTE. Here, we determined the association between evolving markers of platelet activation (soluble P-selectin [sP-selectin], soluble CD40 ligand [sCD40L], thrombospondin-1 [TSP-1] and platelet factor-4 [PF-4]) and the development of cancer-associated VTE. A nested matched case–control study was applied within a cohort of 1779 patients with different types of cancer that had been included in the Vienna Cancer and Thrombosis Study (CATS), a prospective, observational study on patients with newly diagnosed or progressive cancer after remission. Primary endpoint is symptomatic VTE during a maximum follow-up of 2 years. Cases (patients who developed VTE during follow-up) were matched in a 1:2 ratio to controls without VTE during follow-up with respect to tumor type, stage and time of observation in the study. In total, 131 VTE cases were compared to 262 controls. In logistic regression analysis, only sP-selectin was associated with risk of VTE. The odds ratios (OR) per double increase of sP-selectin, sCD40L, TSP-1 and PF-4 were 1.66 (95% confidence interval: 1.17–2.35, p?=?0.005), 1.04 (0.89–1.21, p?=?0.635), 1.09 (0.90–1.32, p?=?0.360) and 1.03 (0.87–1.21, p?=?0.737), respectively. In conclusion, sP-selectin, but not sCD40L, TSP-1 or PF-4 were associated with risk of VTE in cancer patients in this nested case–control study.     

Increased platelet activation markers in rheumatoid arthritis: Are they related with subclinical atherosclerosis?

Atherosclerotic cardiovascular mortality is increased in rheumatoid arthritis (RA) patients. We evaluated the association of inflammatory response with platelet, endothelial, coagulation activation parameters; and subclinical atherosclerosis in RA patients. We included 27 RA patients (21 female; six male) and 19 healthy subjects (14 female; five male). Disease activity score (DAS28) in RA patients was calculated; and patients were divided into two groups as active and inactive. Flow cytometry was used to determine platelet CD62P expression, platelet microparticles (PMP), platelet-monocyte (PMC) and platelet-neutrophil complexes (PNC). Plasma E-selectin, thrombin-antithrombin (TAT) complex, and serum sCD40L levels were determined by ELISA. The intima-media thickness (IMT) of carotid arteries was determined by B-mode ultrasonography. In RA patients, platelet CD62P expression (p < 0.001), PMC (p = 0.037) and sCD40L (p < 0.001) levels were increased when compared to the control group. PNC (p = 0.07) and TAT levels (p = 0.1) were non-significantly higher, and PMP level (p = 0.075) was nonsignificantly lower in RA patients. Soluble E-selectin level was significantly higher in the active RA group than in the inactive RA group (p = 0.009). There was no correlation between carotid IMT and activity markers, the evaluated parameters (p > 0.05).The increase in markers of active platelets, CD62P and sCD40L, and PMC levels might be associated with the increased cardiovascular mortality in RA. Nevertheless, none of these parameters were associated with carotid IMT: this suggests that one cross-sectional value might not be a good marker for atherosclerosis.     

Incremental predictive value of mean platelet volume/platelet count ratio in in-hospital stroke after acute myocardial infarction

Stroke is a serious complication after acute myocardial infarction (AMI) and is associated with an increased risk of death. Though the pathophysiological mechanisms are not exactly known, increased inflammation and platelet reactivity could play an important role in the occurrence of stroke during AMI. We aimed to investigate the relationship between both mean platelet volume (MPV), a parameter of platelet function, and C-reactive protein (CRP) and the occurrence of in-hospital ischemic stroke (IHS) after AMI. Data were obtained from a French regional survey for AMI that included 5976 patients admitted to an intensive care unit (ICU) between 2001 and 2010. Patients were divided into two groups according to the occurrence of IHS. MPV, platelet count (PC), and CRP were routinely measured at admission to the ICU; 99 (1.6%) IHSs were recorded during hospitalization after admission for AMI. In multivariate analysis, IHS was independently associated with a history of stroke (OR: 1.99%, CI: 1.1–3.49, p = 0.01), impaired left ventricular ejection fraction <40% (OR: 1.88, 95% CI: 1.20–2.94, p = 0.006), impaired renal function (OR: 1.94, 95% CI: 1.27–2.95, p = 0.002), CRP > 10 mg/l (OR: 2.19, 95% CI: 1.44–3.33, p < 0.001), and MPV/PC ratio (OR: 1.04, 95% CI: 1.01–1.08, p = 0.023). Compared with the first to fourth quintiles, the last quintile of the MPV/PC ratio was associated with higher rates of IHS on survival curve analysis (p = 0.014). At hospital admission, a high MPV/PC ratio and a high level of CRP might help to identify patients at increased risk of IHS. Moreover, these results provide new insights into the potential role played by increased inflammation and platelet reactivity in the occurrence of stroke after AMI.     

Platelet activation in patients with Familial Mediterranean Fever

Increased platelet activation and aggregation are central processes in the pathophysiology of atherosclerosis. Increased platelet activity is associated with increased platelet volume. Mean platelet volume (MPV), a determinant of platelet function, is a newly emerging risk factor for atherothrombosis. Familial Mediterranean Fever (FMF) is an autosomal recessive disease characterized by recurrent inflammatory febrile attacks of serosal and synovial membranes. Recently few studies have shown that FMF is associated with increased atherosclerosis risk. The present study was designed to evaluate levels of MPV in FMF patients compared with healthy subjects. We selected 35 FMF patients and 35 healthy control subjects matched for age, gender, and body mass index. Metabolic parameters and MPV levels were measured in all groups. Metabolic parameters were not different among the study groups (p > 0.05). The levels of MPV were significantly higher in the FMF group than in the control group (8.6 ± 0.9 fl vs 7.8 ± 0.5 fl, p = 0.001). The MPV levels were negatively correlated with duration of colchicine treatment (r = ?0.40, p = 0.017). Also MPV levels showed positive correlation with delay of diagnosis (r = 0.58, p = 0.001). In conclusion, our results suggest that patients with FMF tend to have an increased platelet activation. Increased platelet activity could contribute to increasing the atherosclerotic risk in FMF patients.     

Cone and platelet analyser (CPA): a new test for the prediction of bleeding among thrombocytopenic patients

The risk of bleeding among thrombocytopenic patients was evaluated using our new cone and platelet analyser (CPA) test. Using this test, adherence of platelets was quantitated on extracellular matrix and expressed as percent of surface coverage (SC) and the average size (AS) of aggregates. 42 thrombocytopenic patients with ITP (n=23), post chemotherapy (n=12) and others (n=7) were tested over a total of 82 visits. On each visit, complete blood count and CPA tests were performed and patients were evaluated for evidence of bleeding (found in 40 visits). Bleeding patients had significantly lower platelet counts (27.4 ± 22.0 v 47.1 ± 21.0 × 10⁹/l), lower haematocrit values (30.2 ± 8.1 v 35.2 ± 6.6%), lower MPV (6.83 ± 1.89 v 8.98 ± 1.13 fl), and lower SC (4.87 ± 3.95 v 10.33 ± 5.48%) and AS (33.99 ± 14.94 v 52.9 ± 24.34 μm²). Univariate analysis yielded platelet count 20.0 × 10⁹/l, MPV 8fl, haematocrit <35%, SC < 5%, AS 40 μm² as significantly associated with bleeding, whereas only MPV and SC were associated with bleeding (OR 6.95, CI 2.25–21.46 and OR 4.27, CI 1.29–14.16, respectively) by multivariate analysis. When taken together, 21/22 of patients (95%) with both low SC (<5%) and low MPV (<8.0 fl) had bleeding symptoms, whereas only 9/43 (21%) patients with both these parameters above these values experienced bleeding symptoms. We conclude that the CPA test and the parameter SC (<5%) together with MPV (8 fl) might be used as independent predictors of bleeding in the management of thrombocytopenic patients.     

Clinical implications of serum levels of soluble CD23 and tumor necrosis factor alpha in low-grade non-Hodgkin's lymphoma

Abstract: In the last few years the research for new biological features in low-grade non-Hodgkin's lymphoma has provided important results. Several biological parameters are under evaluation and, in particular, cytokines and soluble receptors levels are showing their importance as prognostic parameters. In the present study, serum levels of tumor necrosis factor alpha (TNF-α) and soluble CD23 (sCD23) were measured at the time of diagnosis and after induction polychemotherapy in 40 patients with newly diagnosed low-grade non-Hodgkin's lymphoma (LG-NHL). The treaments were CIOP (cyclophosphamide, idarubicin, vincristine, prednisone) regimen for 28 patients and FMP (fludarabine, mitoxantrone, prednisone) scheme for 12 patients. Pretreatment levels of TNF-α were highly elevated in patients with LG-NHL compared with healthy controls (p=0.005) and were significantly correlated with the Ann Arbor stage (p=0.001). sCD23 was detected in 35 patients at diagnosis and were markedly increased in LG-NHL patients when compared to healthy controls (p=0.005); patients with advanced stage presented higher values than those with early stage disease (p=0.002). All the complete responders (20/40, 50%) showed a decrease of TNF-α and sCD23 levels. By contrast, the combination of high levels of TNF-α and sCD23 correspond to a group of non-responders. Our results suggest that TNF-α and sCD23 are specific prognostic parameters for LG-NHL, and that they could be used as tumor markers within a potential biological prognostic index.     

Soluble CD40 ligand and atrial fibrillation: relationship to platelet activation, and endothelial damage/dysfunction

Increased plasma soluble CD40L (sCD40L) is present in many cardiovascular diseases and predicts poor outcome, but levels in atrial fibrillation (AF) are unknown. Although the platelet is frequently cited as the source of sCD40L, this view is not universal. We hypothesised (a) raised sCD40L in non-rheumatic AF, and (b) that sCD40L correlates with platelet, but not endothelial, markers, thus suggesting a platelet origin. Plasma sCD40L, platelet marker soluble P-selectin and endothelial markers von Willebrand factor (vWf) and soluble E-selectin were measured by ELISA in 54 AF patients free of diabetes or major cardiovascular disease, and in 28 age/sex matched controls. Median (inter-quartile range) sCD40L in AF was 0.82 (0-4.8) ng/mL compared to 0.21 (0-5.5 ng/mL) in controls (p=0.0397). vWf and soluble P-selectin (p<0.005), but not soluble E-selectin, were raised in AF, but none of the indices inter-correlated significantly. We find that sCD40L is marginally raised in AF but the stimulus for this is unclear. The lack of clear correlation with relevant plasma markers suggests that the source is unlikely to be the endothelium or platelet alone.     

Relationship between plasma inflammatory markers and platelet aggregation in patients with clopidogrel resistance after angioplasty

We evaluated the relationship between plasma inflammation markers and clopidogrel resistance in patients after stent implantation. The plasma levels of C-reactive protein (CRP), P-selectin, platelet soluble CD40 ligand (sCD40L), interleukin 6 (IL-6) and platelet aggregation were measured in 352 patients undergoing percutaneous coronary intervention (PCI) at baseline and after 6 months. The plasma levels of CRP, P-selectin, sCD40L, IL-6 was higher in 65 (18.5%) patients with clopidogrel resistance than in those with normal responsiveness at 6 months after PCI. There was a significant positive correlation between soluble CD40L levels and platelet aggregation (r = .28, P < .05). Diabetes (DM) and sCD40L level were independent predictors for unresponsiveness after stent implantation according to stepwise multivariate analyses. The hazard ratio (HR) for sCD40L level was 3.02 (95% CI = 1.28 to 3.25; P = .036) and for DM 2.53 (95% CI = 1.28 to 6.55, P = .03). We conclude that sCD40L and DM may influence clopidogrel resistance.     

The levels of sCD30 and of sCD40L in a group of patients with systemic lupus erythematodes and their diagnostic value

CD30/CD30L and CD40/CD40L are molecules from the tumor necrosis factor (TNF) superfamily. They have a major effect on communications between the B and T cells, which leads to control of maturation, proliferation, and apoptosis of those cells. The aim of this study was to compare the levels of a soluble form of CD30 (sCD30) and a soluble ligand CD40 (sCD40L) in patients with systemic lupus erythematosus (SLE) (n=65) and healthy controls (sCD30 n=20, sCD40L n=10) with other parameters of SLE activity. Patients were divided into subgroups according to presence or absence of lupus nephritis (LN; 33 with LN, 32 without LN). The serum levels of selected parameters were assessed also in the subgroups with low active disease characterized by European Lupus Activity Measure (ECLAM) at most 3(n=29) and active disease with ECLAM more than 3 (n=36). The serum levels of sCD30 were 66.0±40.2 UI/ml in the whole group. The mean serum levels were 60.0±45.2 UI/ml in the subgroups with LN, 67.1±38.9 UI/ml in the subgroup without LN, 80.2±51.9 UI/ml in the subgroup with active disease, 55.4±24.1 UI/ml in the subgroup with low active disease, and finally, 40.1±19.2 U/ml in the controls. Significant differences were found between the SLE patients and controls (p=0.0001) and between the active and nonactive groups (p=0.002). A correlation was found between levels of CD30 and ECLAM (r=0.25, p≤0.05), SLEDAI (SLE Disease Activity Index) (r=0.25, p≤0.05), C4 component of the complement system (r=0.24, p=0.02), and anti-C1q antibodies (r=0.42, p=0.0001). The levels of sCD40L were 7.4±6.7 ng/ml in whole SLE group, 7.0±8.1 ng/ml in the subgroup with LN, 8.0±4.9 ng/ml in the subgroup without LN, 7.1±5.0 ng/ml in the group of patients with active disease, 7.73±7.8 ng/ml in the subgroup with low activity, and 2.96±1.39.0 ng/ml in the controls. The difference in sCD40L serum levels between patients with SLE and controls was statistically significant (p=0.02). A correlation was found with the anti-C1q antibodies (r=0.21, p=0.05); no other correlations were found. These findings indicate some potentional role of both serum parameters in measurement or SLE disease activity, although their usage in the diagnostic of disease requires further investigation.     

Platelet activation in subjects with impaired glucose tolerance

Impaired glucose tolerance (IGT), a prediabetic state, is associated with an increased risk of cardiovascular disease. Mean platelet volume (MPV), a determinant of platelet activation, is a newly emerging risk factor for atherothrombosis. This study was designed to answer the following questions: (i) Do MPV levels change in IGT? (ii) Is there any relation between MPV levels and 2 h plasma glucose levels after 75 g oral glucose tolerance test. We selected 48 subjects with IGT, and 48 healthy subjects with normal glucose tolerance matched for age, gender, and body mass index. MPV was significantly higher in IGT group than in control group (9.06 ± 1.5 fl vs. 8.28 ± 0.8 fl, p = 0.002). Also, MPV was positively correlated with 2 h plasma glucose concentration in IGT group (r = 0.39, p = 0.006). In conclusion, our results suggest that subjects with IGT tend to have increased platelet activation. Increased platelet activity could contribute to increasing the risk of cardiovascular disease in IGT.