Endothelial microparticles and platelet and leukocyte activation in patients with the metabolic syndrome

Accumulating evidence has shown a strong association between the metabolic syndrome (MS) and a chronic inflammatory state predisposing to atherosclerosis. We investigated leukocyte, platelet, and endothelial activation markers and cellular interactions in 33 patients with the MS and 25 healthy controls. Using flow cytometry, we measured: (1)P-selectin expression in platelets; (2) platelet microparticles identified by CD31 expression; (3) endothelial microparticles (EMPs) identified by expression of CD31 (EMP(31)), CD62E (EMP(62E)), and CD51 (EMP(51)); (4) conjugates of leukocytes with platelet microparticles/platelets and with EMPs identified by CD54 (EMP(54)); and (5) CD11b expression in leukocytes. Patients with the MS had markedly elevated EMP(31), although EMP(62E) levels were normal, suggesting that EMP(31) levels were increased because of endothelial cell apoptosis, rather than activation. EMP(51), EMP(54)-lymphocyte conjugates, platelet expression of P-selectin, CD11b expression in leukocytes, and platelet-lymphocyte conjugates were also increased in patients with the MS. Platelet-leukocyte conjugates correlated with leukocyte activation, suggesting that platelet binding to leukocytes regulates leukocyte activation in vivo. In conclusion, our data demonstrate endothelial cell microparticle release, platelet and leukocyte activation, and increased binding of EMPs and platelets to leukocytes in patients with the MS.     

Elevation of monocyte-derived microparticles in patients with diabetic retinopathy

Diabetic retinopathy is associated with microvascular damage and capillary occlusions which are common features of the microangiopathy in diabetes. Monocyte-derived microparticles (MDMPs) are released from activated monocytes and enhance the procoagulant activity, and also activate adhesion reactions. These are key events in the development of capillary occlusion. The MDMPs level in the blood, and platelet activation markers (platelet-derived microparticles (PDMPs), CD62P and CD63) were measured by flow cytometry in 72 diabetic patients. The plasma levels of intracellular adhesion molecule-1 (ICAM-1) and P-selectin were analyzed by ELISA. The level of MDMPs was significantly correlated with the levels of PDMPs (r=0.52, P<0.001), CD62P (r=0.37, P=0.001), CD63 (r=0.31 and P=0.007), P-selectin (r=0.38, P=0.001), and ICAM-1 (r=0.31, P=0.009). The MDMPs level increased with the progression of the diabetic retinopathy: 81+/-14/10(4)platelets (plts) in patients without retinopathy (n=10); 88+/-8/10(4)plts with mild or moderate non-proliferative diabetic retinopathy (NPDR, n=12); 95+/-8/10(4)plts with severe NPDR (n=24); and 112+/-9/10(4)plts with proliferative diabetic retinopathy (PDR) (n=26). The MDMPs level in patients with areas of capillary occlusion (123+/-10/10(4)plts, n=25) was significantly higher than that in patients without areas of capillary occlusion (84+/-5/10(4)plts, n=25; P=0.0008). These correlations suggest that increased levels of MDMPs may accelerate the progression of diabetic retinopathy.     

High-shear-stress-induced activation of platelets and microparticles enhances expression of cell adhesion molecules in THP-1 and endothelial cells

Lipid rich, soft plaques in the clinic are a common forerunner to occlusive thrombus formation, even with modest arterial stenosis. Animal models of atherosclerosis, obtained by various methods, do not generally allow direct in vivo evaluation of the lesion and, furthermore, cannot be examined more than once. The aim of the study was the generation of a rabbit model of atherosclerosis, with morphological characteristics similar to human lipid-rich, soft atheromatous plaques, and the evaluation of the reliability of intravascular ultrasound (IVUS) technology in the study of the development of atherosclerotic lesions in this model. Briefly, New Zealand white rabbits undergo perivascular electrical injury at both common carotid arteries, together with a 1.5% cholesterol diet for up to 90 days. The lesioned arterial segments show progressive changes, from diffuse cellular mortality, to macrophage infiltration in the media, up to the final migration of macrophages to the neointima, resulting in bulky, eccentric, macrophage and lipid-rich lesions. At IVUS, the produced lesions clearly resemble those described as 'soft plaques' in the clinical setting, with minimal calcification and reduced echo-reflectivity versus the adventitial layer. Quantitative and morphometric analysis of plaques shows a significant correlation between histological and IVUS measurements at each time point. In conclusion, vascular injury in the common carotids of rabbits generates atherosclerotic lipid-rich, soft plaques, that can be properly assessed by the IVUS methodology. The easy accessibility of the arterial lesion allows serial IVUS investigations and the direct evaluation of a number of locally or generally delivered therapeutic agents.     

Factor Xa inhibition in the prevention of venous thromboembolism and treatment of patients with venous thromboembolism

Venous thromboembolism (VTE) is a life-threatening complication following orthopedic surgery. Selective factor Xa inhibition is a new antithrombotic approach designed to avoid difficulties associated with heparins and other current anticoagulants. Several antifactor Xa compounds are in early investigation, but fondaparinux (Arixtra; NV Organon, Oss, The Netherlands; Sanofi-Synthelabo, Paris, France) is the first and most advanced compound in the development of a new class of synthetic antithrombotic agents--the selective factor Xa inhibitors. Fondaparinux has a highly favorable pharmacokinetic profile; four large phase 3 trials comparing subcutaneous fondaparinux 2.5 mg once daily with the low molecular weight heparin (LMWH) enoxaparin in doses approved by regulatory bodies showed that fondaparinux reduced the overall risk of VTE in major orthopedic surgery by > 50% without increasing clinically relevant bleeding. Fondaparinux also appears to be a very promising candidate for the treatment of patients with existing VTE.     

Treating venous thromboembolism in patients with cancer

Venous thromboembolism (VTE) is a major cause of morbidity and mortality among patients with cancer. Although much is known about the factors that contribute to VTE risk, pre-emptive therapy in high-risk populations is clearly indicated in only a few clinical situations. Low-molecular-weight heparin is still the recommended class of anticoagulants for cancer-associated VTE. Management of VTE in patients with renal failure, hemorrhagic brain metastases, thrombocytopenia and coagulopathy remains challenging with few safe and effective alternatives. Novel oral agents are currently being investigated and may play a role in the future in the treatment of cancer-associated VTE.     

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.     

Gastroduodenal ulcer incidence in patients with venous thromboembolism

The presence of peptic ulcer disease implies a high risk of bleeding in patients on heparin therapy. We reviewed our experience with 166 consecutive patients admitted because of venous thromboembolism. Of these 166 patients, 29 were referred for upper gastrointestinal endoscopy in order to detect the presence of any lesion that might contraindicate heparin therapy. A gastric ulcer was found in 10 patients, a duodenal ulcer in 11, and gastric erosions with signs of bleeding in 3 patients. Given the unexpectedly high frequency of ulcer in these patients, an upper gastrointestinal endoscopy was routinely performed early in the course of admission in 50 consecutive patients with venous thromboembolism. A gastric ulcer was found in 5 patients (10%), a duodenal ulcer in 7 (14%), and erosions in 2. Five of these patients had an unsuspected ulcer. A case can be made for prophylactic antiulcer therapy for all patients placed on anticoagulants for venous thromboembolism. Upper gastrointestinal endoscopy is indicated in patients with ulcer symptoms, in those with a previous history of peptic ulcer disease, and perhaps, in patients developing occult blood in the stools while on treatment with anticoagulants.     

Incidence of venous thromboembolism in patients hospitalized with cancer

Background

There are sparse data on the frequency of venous thromboembolism in patients with various types of cancer. We sought to determine the incidence and relative risk of venous thromboembolism, pulmonary embolism, and deep venous thrombosis in patients with malignancies.

Subjects and methods

The number of patients discharged with a diagnostic code for 19 types of malignancies, pulmonary embolism or deep venous thrombosis from 1979 through 1999 was obtained from the National Hospital Discharge Survey. Patients studied were men and women of all ages and races.

Results

In patients with any of the 19 malignancies studied, 827 000 of 40 787 000 (2.0%) had venous thromboembolism, which was twice the incidence in patients without these malignancies, 6 854 000 of 662 309 000 (1.0 %). The highest incidence of venous thromboembolism was in patients with carcinoma of the pancreas, 51 000 of 1 176 000 (4.3%), and the lowest incidences were in patients with carcinoma of the bladder and carcinoma of the lip, oral cavity or pharynx. The overall incidences of pulmonary embolism and deep venous thrombosis were also twice the rates in noncancer patients. Incidences with cancer were not age dependent. The incidence of venous thromboembolism in patients with cancer began to increase in the late 1980s.

Conclusion

Patients with cancer had twice the incidence of venous thromboembolism, pulmonary embolism and deep venous thrombosis as patients without cancer. The incidence of venous thromboembolism, pulmonary embolism and deep venous thrombosis associated with cancer differed according to the type of cancer, was comparable in elderly and younger patients, and increased in the late 1980s and 1990s.     

The treatment of venous thromboembolism in patients with cancer

Advances in neuroimaging have modified our knowledge on cerebral vein thrombosis (CVT). This disease is now diagnosed more frequently, and increasing evidence as to what are the most common risk factors and on the natural history of the disease is becoming available. Most patients with CVT have a benign prognosis: only a minority of patients die during the acute phase or in the following months. Most patients surviving CVT recover completely, or have only mild functional or cognitive deficits. Unfractionated or low-molecular weight heparin is widely used as a first-line therapy of CVT, despite the absence of conclusive evidence about the safety and efficacy in this setting. Vitamin K antagonists are usually prescribed for secondary prevention, but the optimal duration of treatment remains unknown. Because most patients with CVT have partial or complete recanalization of the vessels within the first few months after the index event, and because recurrences of CVT after a first episode appear to be uncommon, routine use of long-term therapy or event life-long secondary prevention seem to be unnecessary.     

Burden of venous thromboembolism in patients with pancreatic cancer

Pancreatic cancer (PC) is a devastating malignancy with fewer than 10% of patients being alive at 5 years after diagnosis. Venous thromboembolism (VTE) occurs in approximatively 20% of patients with PC, resulting in increased morbidity, mortality and significant health care costs. The management of VTE is particularly challenging in these frail patients. Adequate selection of the most appropriate anticoagulant for each individual patient according to the current international guidelines is warranted for overcoming treatment challenges. The International Initiative on Thrombosis and Cancer multi-language web-based mobile application (downloadable for free at www.itaccme.com) has been developed to help clinicians in decision making in the most complex situations. In this narrative review, we will discuss the contemporary epidemiology and burden of VTE in PC patients, the performances and limitations of current risk assessment models to predict the risk of VTE, as well as evidence from recent clinical trials for the primary prophylaxis and treatment of cancer-associated VTE that support up-dated clinical practice guidelines.     

Increased platelet,leukocyte and endothelial microparticles predict enhanced coagulation and vascular inflammation in pulmonary hypertension

Pulmonary hypertension (PH) is associated with platelet activation, vascular inflammation and endothelial dysfunction leading to often life threatening thrombo-embolic complications. Microparticles (MPs) are cell vesicles with strong coagulatory and inflammatory effects being released during cell activation and apoptosis. As there are currently no established surrogate markers predicting platelet activation and pro-coagulation in PH patients, the aim of the study was to analyze different pro-coagulatory MP populations that might be related to thrombo-embolic complications in PH patients. Circulating MPs from platelet- (PMP, CD31⁺/61⁺), leukocyte- (LMP, CD11b⁺) and endothelial- (EMP, CD62E⁺) origin were measured by flow cytometry in 19 PH patients and were compared to 16 controls. PH patients had increased levels of PMP (PH vs. control 1,016 ± 201 vs. 527 ± 59 counts per min [cpm], P = 0.032), LMP (PH vs. control 31 ± 3 cpm vs. 18 ± 2 cpm, P = 0.001) and EMP (PH vs. control 99 ± 14 cpm vs. 46 ± 6 cpm, P = 0.001). Furthermore, PMP correlated to LMP (PMP vs. LMP: r = 0.75, P < 0.001) and LMP correlated to EMP levels (LMP vs. EMP, r = 0.74, P < 0.001) indicating a functional interaction between the different types of MP. In comparison to non-embolic PH patients, patients with a thrombo-embolic PH suffered from enhanced endothelial cell dysfunction as represented by significantly increased EMP levels (thrombo-embolic PH vs. non-embolic PH 137 ± 27 vs. 72 ± 10, P = 0.02). PH patients have increased levels of platelet-, leukocyte- and endothelial MP indicating an increased vascular pro-coagulation and inflammation which might be related to thrombo-embolic complications as well as PH progression.     

Circulating endothelial microparticles in patients with acute myocardial infarction

BACKGROUND: Circulating endothelial microparticles (EMPs), the small vesicles released from altered endothelial cells, have been established as markers of endothelial injury. The elevated count of EMPs has been described in different conditions involving endothelial injury, including acute myocardial infarction (AMI). AIM: To assess the presence of EMP in patients with acute MI in relation to early clinical outcome and coronary angiography results. MATERIALS AND METHODS: EMPs counts were determined in 66 patients pts (23 women, 43 men) with documented ST elevation AMI and in 10 control patients with no evidence of coronary artery disease. All pts with AMI underwent coronary angiography with attempted primary angioplasty. EMPs were assayed by flow cytometry in platelet-poor plasma with combinations of fluorescent antibodies (anti CD31, -51, -42) allowing distinction of EMPs from platelet microparticles. Clinical and angiography results were compared with EMP levels. RESULTS: Three kinds of EMPs were measured: CD31+, CD51+ and CD31+/51+. The percentage of EMPs CD31+/CD51 was significantly (p=0,042) higher in patients with AMI in comparison with control subjects. However, a marker, which distinguished both groups the most, was the level of EMPs CD51+. It was significantly (p=0,024) higher in pts with AMI than in control pts. The levels of CD31+ were similar in both groups. There was no correlation between EMP levels, clinical and angiography results. CONCLUSION: The presence of circulating EMPs provides direct evidence of endothelial injury in AMI. The clinical and practical value of these results, however, needs further exploration.     

恶性肿瘤并发静脉血栓栓塞症的临床分析

目的分析并发静脉血栓栓塞症(VTE)恶性肿瘤患者的原发肿瘤种类、分期、分化程度等,以识别高危患者,提高防治意识,减少VTE的发生。方法回顾性分析北京医院2003年1月至2013年1月期间并发静脉血栓栓塞症的恶性肿瘤患者的年龄、性别、基础疾病、原发肿瘤种类、病理类型、分化程度、TNM分期、化疗方案及预后等临床信息。结果在所有18 531例恶性肿瘤患者中,280例并发VTE,其中男性157例,女性123例,年龄(66.60±12.60)岁。包括单纯肺栓塞(PTE)41例,单纯下肢深静脉血栓形成(DVT)189例,PTE合并DVT 50例。肺癌82例,消化道肿瘤78例,泌尿系肿瘤32例,妇科肿瘤27例,血液科肿瘤27例,乳腺癌12例,其他部位肿瘤22例。相比未并发VTE肿瘤患者,并发VTE多见于肺癌、妇科肿瘤和其他肿瘤患者,差异有统计学意义(P0.05)。151例(53.9%)并发VTE肿瘤患者病理类型为腺癌;206例(73.6%)患者发生VTE时,肿瘤处于进展期;247例有明确TNM分期患者中Ⅲ~Ⅳ期患者187例(66.8%);144例有明确病理组织分化程度报告,中、低度分化程度者120例(85.4%)。至随访结束,共有130例患者死亡,中位生存时间为(24.0±7.8)个月,明确诊断VTE后3,6,9,12个月的累积死亡率分别为46.9%、69.2%、80.0%和82.3%。导致死亡的主要原因是肿瘤本身、肺栓塞和感染。结论肿瘤与VTE密切相关,腺癌、进展期肿瘤、分化程度低的肿瘤患者和化疗方案中含铂类药物者更易发生VTE,临床医师应注意对这部分患者进行VTE风险评估,采取必要的预防措施,减少VTE的发生。