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Risk prediction of chemotherapy-associated venous thromboembolism (VTE) is a compelling challenge in contemporary oncology, as VTE may result in treatment delays, impaired quality of life, and increased mortality. Current guidelines do not recommend thromboprophylaxis for primary prevention, but assessment of the patient's individual risk of VTE prior to chemotherapy is generally advocated. In recent years, efforts have been devoted to building accurate predictive tools for VTE risk assessment in cancer patients. This review focuses on candidate biomarkers and prediction models currently under investigation, considering their advantages and disadvantages, and discussing their diagnostic performance and potential pitfalls.

Aim: To investigate the possible predictive role of routinely used glycemic parameters for a first venous thromboembolism (VTE) episode in gastrointestinal (GI) cancer ambulatory patients - with or without clinically diagnosed type 2 diabetes (T2D) or obesity - treated with chemotherapy., Methods: Pre-treatment fasting blood glucose, insulin, glycated hemoglobin (HbA 1c ) and homeostasis model of risk assessment (HOMA) were retrospectively evaluated in a cohort study of 342 GI cancer patients. Surgery was performed in 142 (42%) patients with primary cancer, 30 (21%) and 112 (79%) of whom received neoadjuvant and adjuvant therapies, respectively. First-line chemotherapy was administered in 200 (58%) patients with metastatic disease. The study outcome was defined as the occurrence of a first symptomatic or asymptomatic VTE episode during active treatment., Results: Impaired glucose tolerance (IGT) or T2D were diagnosed in 30% of GI cancer patients, while overweight/obesity had an incidence of 41%. VTE occurred in 9.4% of patients (7% of non-diabetic non-obese), especially in those with a high ECOG score ( P = 0.025). No significant association was found between VTE incidence and T2D, obesity, different tumor types, metastatic disease, Khorana class of risk, or different anti-cancer drugs, although VTE rates were substantially higher in patients receiving bevacizumab (17% vs 8%, P = 0.044). Conversely, all glucose metabolic indexes were associated with increased VTE risk at ROC analysis. Multivariate Cox proportional analyses confirmed that HOMA index (HR = 4.13, 95%CI: 1.63-10.5) or fasting blood glucose (HR = 3.56, 95%CI: 1.51-8.39) were independent predictors of VTE occurrence during chemotherapy., Conclusion: The results here reported demonstrate that evaluating glucose metabolic asset may allow for VTE risk stratification in GI cancer, helping to identify chemotherapy-treated patients who might benefit from thromboprophylaxis. Further multicenter prospective studies involving a larger number of patients are presently needed., Competing Interests: Conflict-of-interest statement: All the Authors have no conflict of interest related to the manuscript.

The hypothesis that increased oxidative stress in breast cancer (BC) patients could induce enhanced lipid peroxidation, which, in turn, would contribute to platelet activation and poor clinical outcome is attractive. To address this issue, we investigated pre-surgical urinary 8-iso-prostaglandin (PG)F 2α (marker of in vivo oxidative stress) and 11-dehydro-thromboxane (TX)B 2 (marker of in vivo platelet activation) levels in patients with primary BC (n = 115) compared with control women paired for comorbidities and their association with patients' metabolic profile and clinical prognostic factors. The results obtained showed that presurgical urinary excretion of both biomarkers was enhanced in BC patients compared to controls and was associated with patients' estrogen receptor (ER) expression, but not HER2 status or Ki67 proliferation index. Accordingly, both urinary biomarkers were increased in patients with luminal-like BC molecular subtypes compared with triple negative or HER2-enriched tumors. ER status was an independent predictor of 8-iso-PGF 2α urinary levels, which, in turn, significantly predicted 11-dehydro-TXB 2 urinary levels together with disease stage and ER status. The prognostic value of 11-dehydro-TXB 2 was then evaluated showing a significant correlation with BC pathological response to neoadjuvant treatment. Furthermore, among relapsing patients, those with elevated urinary biomarker levels were more likely to develop distant metastasis rather than local recurrence. In conclusion, we may speculate that enhanced oxidative stress due to estrogen-related mechanisms might cause a condition of persistent platelet activation capable of sustaining BC growth and progression through the release of bioactive stored molecules, ultimately contributing to tumor invasiveness. Further studies specifically addressing this hypothesis are presently needed., (© 2016 UICC.)

Objective: To design a precision medicine approach aimed at exploiting significant patterns in data, in order to produce venous thromboembolism (VTE) risk predictors for cancer outpatients that might be of advantage over the currently recommended model (Khorana score)., Design: Multiple kernel learning (MKL) based on support vector machines and random optimization (RO) models were used to produce VTE risk predictors (referred to as machine learning [ML]-RO) yielding the best classification performance over a training (3-fold cross-validation) and testing set., Results: Attributes of the patient data set ( n = 1179) were clustered into 9 groups according to clinical significance. Our analysis produced 6 ML-RO models in the training set, which yielded better likelihood ratios (LRs) than baseline models. Of interest, the most significant LRs were observed in 2 ML-RO approaches not including the Khorana score (ML-RO-2: positive likelihood ratio [+LR] = 1.68, negative likelihood ratio [-LR] = 0.24; ML-RO-3: +LR = 1.64, -LR = 0.37). The enhanced performance of ML-RO approaches over the Khorana score was further confirmed by the analysis of the areas under the Precision-Recall curve (AUCPR), and the approaches were superior in the ML-RO approaches (best performances: ML-RO-2: AUCPR = 0.212; ML-RO-3-K: AUCPR = 0.146) compared with the Khorana score (AUCPR = 0.096). Of interest, the best-fitting model was ML-RO-2, in which blood lipids and body mass index/performance status retained the strongest weights, with a weaker association with tumor site/stage and drugs., Conclusions: Although the monocentric validation of the presented predictors might represent a limitation, these results demonstrate that a model based on MKL and RO may represent a novel methodological approach to derive VTE risk classifiers. Moreover, this study highlights the advantages of optimizing the relative importance of groups of clinical attributes in the selection of VTE risk predictors.

Using kernel machine learning (ML) and random optimization (RO) techniques, we recently developed a set of venous thromboembolism (VTE) risk predictors, which could be useful to devise a web interface for VTE risk stratification in chemotherapy-treated cancer patients. This study was designed to validate a model incorporating the two best predictors and to compare their combined performance with that of the currently recommended Khorana score (KS). Age, sex, tumor site/stage, hematological attributes, blood lipids, glycemic indexes, liver and kidney function, BMI, performance status, and supportive and anticancer drugs of 608 cancer outpatients were all entered in the model, with numerical attributes analyzed as continuous values. VTE rate was 7.1%. The VTE risk prediction performance of the combined model resulted in 2.30 positive likelihood ratio (+LR), 0.46 negative LR (-LR), and 4.88 HR (95% CI: 2.54-9.37), with a significant improvement over the KS [HR 1.73 (95% CI: 0.47-6.37)]. These results confirm that a ML approach might be of clinical value for VTE risk stratification in chemotherapy-treated cancer outpatients and suggest that the ML-RO model proposed could be useful to design a web service able to provide physicians with a graphical interface helping in the critical phase of decision making.

Pre-clinical and clinical studies have investigated the role of a dysregulated metabolism in the sustainability of tumor initiation and progression. One of the most familiar metabolic alterations encountered in several types of cancers is the upregulation of glycolysis, which is also maintained in conditions of normal oxygen tension (aerobic glycolysis, Warburg effect) while oxidative phosphorylation is apparently reduced. As a result, cancer cells convert most incoming glucose to lactate. Although more rapid, adenosine triphosphate (ATP) production by glycolysis is less efficient in terms of ATP generated per unit of glucose consumed than oxidative phosphorylation. The consequence is that tumor cells require an abnormally higher rate of glucose compared to the normal counterpart. New evidence shows that other metabolic substrates such as glutamine may also have an important role in cancer metabolism. Ketogenic diet (KD) replaces all but non-starchy vegetable carbohydrates with low to moderate amounts of proteins and high amounts of monounsaturated and polyunsaturated fats. The rationale of KD is valid both because it lowers carbohydrate uptake possibly leading to cancer cell starvation and apoptosis and, at the same time, increases the levels of ketone bodies available for energy production in normal cells but not in cancer cells which have an allegedly downregulated oxidative phosphorylation. For this reason, several authors speculate on the possibility to evaluate KD as a novel approach in the treatment of cancer. In this review we will assess the data supporting the use of such alimentary regimen and its impact on tumor development and progression., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Venous thromboembolism (VTE) is a commonly diagnosed multifactorial condition with significant morbidity and mortality, occurring in up to 20% of cancer patients. Indeed, patients with cancer are in a higher pro-thrombotic state due to alterations in their haemostatic- coagulative system, stasis and blood flow slowdown, endothelial dysfunction, vascular inflammation and platelet activation. Moreover, several cancer-dependent factors can sum up to trigger a first episode of VTE or to cause its recurrence in the course of anticoagulant treatment. Such a pro-thrombotic condition is further worsened by additional favoring risks such as immobilization, infection, surgery, or insertion of a central venous catheter, and anti-cancer therapy. Furthermore, in the secondary prevention setting, the anticoagulant therapy is accompanied by a high incidence of bleeding complications. Given the above, understanding and identifying the factors associated with the incidence and clinical outcome of VTE in cancer patients might be of great value in the prevention and management of VTEattributable complications, including death. Differences associated to gender on cancerrelated VTEs are not yet fully defined; many of the studies that addressed the question have been biased by erroneous/non homogeneous inclusion criteria. In the present review, we analyzed the potential differences in VTEs occurrence in cancer patients, by reporting the most significant findings in the recent literature. The identification of a differential clinical approach according to patient sex, might prompt the design of personalized treatment options tailored and optimized according to algorithms for oncological VTE prevention., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Background: Neo-angiogenesis, a key step in cancer progression, is a highly regulated process, in which Vascular Endothelial Growth Factor (VEGF) plays a fundamental role, thus representing the most suitable anti-angiogenic target. In the last year, a number of anti-VEGF drugs have been developed and approved for therapeutic use, especially in combination with standard chemotherapy. VEGF, however, is not only crucial for physiological and pathological angiogenesis, but also for the maintenance of vascular homeostasis, at a point that its pharmacological blockade may lead to endothelial dysfunction and adverse vascular effects, such as venous thromboembolism. The picture is further complicated by the understanding that the amount of VEGF production is influenced by genetic factors, with environmental ones accounting only for 20-30% of its variations. This has recently prompted the design of various pharmacogenetic studies to investigate the role of VEGF polymorphisms in determining the pharmacological response and safety profile of various anti-angiogenic drugs, suggesting that the analysis of VEGF genetic variants in cancer patients may further help personalize anti-angiogenic pharmacological strategies., Conclusion: In this review, we initially focused on the biological mechanisms involved in vascular maintenance and angiogenesis. Then, discussed the efficacy and toxicity profile of some of the antiangiogenic drugs most commonly used in the treatment of solid cancer, with a particular focus on the thromboembolic complications of anti-angiogenic treatments in cancer patients. Finally, the impact of VEGF gene polymorphisms on clinical outcome and toxicity was briefly reviewed., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Aim: To investigate the clinical significance of routinely used glycemic parameters in a cohort of colorectal cancer (CRC) patients., Methods: Pre-treatment fasting blood glucose, insulin, HbA 1c and homeostasis model of risk assessment (HOMA-IR) were retrospectively evaluated in a case-control study of 224 CRC and 112 control subjects matched for sex, obesity and diabetes frequency and blood lipid profile. Furthermore, the prognostic value of routinely used glycemic parameters towards progression-free (PFS) and overall survival (OS) was prospectively evaluated., Results: Fasting blood glucose, insulin, HOMA-IR and HbA 1c (all P < 0.0001) levels were higher in non-diabetic CRC patients compared with obesity-matched controls. All parameters were associated with increased CRC risk at ROC analysis, but no relationship with clinical-pathological variables or survival outcomes was observed for glycemia, insulinemia or HOMA-IR. Conversely, advanced CRC stage ( P = 0.018) was an independent predictor of increased HbA 1c levels, which were also higher in patients who had disease progression compared with those who did not ( P = 0.05). Elevated HbA 1c levels showed a negative prognostic value both in terms of PFS (HR = 1.24) and OS (HR = 1.36) after adjustment for major confounders, which was further confirmed in a subgroup analysis performed after exclusion of diabetic patients., Conclusion: HbA 1c might have a negative prognostic value in CRC, thus suggesting that glycemic metabolic markers should be carefully monitored in these patients, independently of overt diabetes., Competing Interests: Conflict-of-interest statement: All the Authors have no conflict of interest related to the manuscript.

Background: High Neutrophil/Lymphocyte ratio (NLR), as a measure of enhanced inflammatory response, has been negatively associated with prognosis in patients with localized pancreatic ductal adenocarcinoma (PDA)., Objective: In the present study, we aimed at investigating the prognostic value of NLR in two homogeneous groups of chemotherapy-naïve metastatic PDA patients. Patients were treated with either gemcitabine (GEM) or gemcitabine/oxaliplatin (GEMOXA). We also assessed whether NLR could identify patients benefiting from the use of oxaliplatin., Methods: Consecutive PDA patients treated at the Medical Oncology Unit of Tor Vergata University Hospital of Rome with either GEM or GEMOXA were included (n= 103). NLR was assessed before and during chemotherapy and correlated with outcome together with common clinical and biochemical variables., Results: Among 17 analyzed variables NLR, Karhofsky Perfomance Status (KPS), d-dimer and erythrocyte sedimentation rate were found to be significantly associated with median Overall Survival (mOS) at the univariate analysis. Only NLR and KPS were independent prognosticator at multivariate analysis, with NLR displaying the highest statistical significance. NLR was also predictive of oxaliplatin activity, as only patients with NLR > 2.5 (cutoff determined upon ROC analysis) derived benefit from GEMOXA over GEM., Conclusions: NLR is both an independent prognostic and predictive factor in metastatic PDA, since only patients with high NLR seem to benefit from the addition of oxaliplatin. NLR may help select patients for whom a particularly poor prognosis might justify more intensive, yet less tolerable, combination regimens.

Background: Based on the hypothesis that impaired glucose metabolism might be associated with survival outcomes independently of overt diabetes, we sought to investigate the prognostic value of routinely used glycemic parameters in a prospective study of breast cancer (BC) patients., Patients and Methods: Fasting blood glucose, insulin and HbA1c levels, and insulin resistance (assessed by the Homeostasis Model Assessment [HOMA] index) at diagnosis were evaluated in 286 nondiabetic BC patients (249 with primary cancer, 37 with metastatic) with respect to those parameters' possible associations with clinicopathological features and survival outcomes. As a control group, 143 healthy women matched in a 2:1 ratio for age, blood lipid levels, and body mass index were also investigated., Results: Fasting blood glucose level (mean ± SD: 99 ± 26 vs. 85 ± 15 mg/dL), insulin level (median: 10.0 vs. 6.8 μIU/mL), and HOMA index (median: 2.2 vs. 1.4), but not HbA1c level, were significantly elevated in BC patients compared with control subjects. Receiver operating characteristics analysis showed comparable areas for blood glucose and insulin levels, and HOMA index (ranging from 0.668 to 0.671). Using a cutoff level of 13 μIU/mL, insulin had the best specificity (92%) and sensitivity (41%), was significantly associated with disease stage, and acted as a negative prognostic marker of progression-free survival (hazard ratio: 2.17; 95% confidence interval: 1.13-4.20) independently of menopausal status, disease stage, hormone receptor status, and human epidermal growth factor receptor 2 and Ki67 expression., Conclusion: These results suggest that insulin determination might provide prognostic information in BC and support the hypothesis that lifestyle and/or pharmacological interventions targeting glucose metabolism could be considered to improve survival outcome of selected BC patients., Implications for Practice: Pretreatment insulin levels may represent a biomarker of adverse prognosis in nondiabetic women with breast cancer, independently of other well-established prognostic factors (i.e., stage, hormone receptors, HER2/neu, and Ki67). This finding has important implications, because it provides the rationale for lifestyle or insulin-targeting pharmacologic interventions as a means of improving breast cancer outcomes not only in early stages, but also in advanced-stage breast cancer patients with aggressive tumor phenotypes (HER2-negative hormone-resistant, or triple-negative breast cancer), in which treatments are still challenging. The possibility of using insulin as a biomarker to guide insulin-targeted interventions also should be taken into account., Competing Interests: of potential conflicts of interest may be found at the end of this article., (©AlphaMed Press.)

An impairment of the activated protein C (APC) system has been occasionally reported in breast cancer (BC). However, the clinical significance and prognostic value of an impaired APC functionality in BC patients is still poorly understood. Thus, the present study was aimed at investigating the prognostic value of altered APC functionality for progression-free (PFS) and overall survival (OS) in a cohort study of BC patients. APC functionality was retrospectively analyzed by a coagulation inhibition assay (ThromboPath) in 290 consecutive patients with primary (n=246) or relapsing/recurrent (n=44) BC. All patients were prospectively followed for a median time of 3.5 years (14% recurrence rate). As control group, 145 age-matched healthy women were also investigated. The results obtained demonstrated that APC function was impaired in roughly 20% of all BC at baseline. BC women with stage I/II had a significantly lower rate of APC impairment (13%) than women with stage III (22%) or distant metastases (44%, p=0.001). At univariate analyses, an impairment of APC function had a negative prognostic impact in terms of PFS (5-year PFS rates 53% vs. 70%; HR=2.5; p<0.001) and OS (5-year OS rates 79% vs. 93%; HR=3.9; p=0.005). However, prognostic significance was retained in multivariate models only for PFS (HR=2.0; p=0.017). We may, thus, conclude that BC patients are in a prothrombotic condition, which could play a role in the progression of the disease. Monitoring coagulation changes in BC women could provide important prognostic information especially in patients with advanced stages.

Among the possible genetic contributors to cancer-related venous thromboembolism (VTE), vascular endothelial growth factor (VEGFA) could play an important role, as an imbalance of the VEGFA system (either disease-related or drug-induced) may result in a disturbance of vascular homeostasis. Thus, this study was designed to investigate the predictive role of eight different VEGFA gene promoter single nucleotide polymorphisms (SNPs) for a first VTE episode in cancer out-patients undergoing chemotherapy. To this purpose, VEGFA gene promoter polymorphisms were analysed in 297 cancer patients using polymerase chain reaction amplification and direct DNA sequencing analysis. One hundred forty unrelated healthy subjects from the same geographical area were also analysed in order to evaluate and compare genotype/haplotype frequencies in our ethnicity. VTE occurred in 26 (9%) of cancer patients with a median time-to-event of 3.4 months. Association analyses showed that -1154G/A polymorphism was significantly associated with the risk of chemotherapy-triggered VTE, with the A allele exerting a protective role both in the overall population (hazard ratio [HR]: 0.21; 95% confidence interval [CI]: 0.07-0.58) or in bevacizumab-treated metastatic patients (HR: 0.09, 95%CI: 0.01-0.86) in whom VEGFA -1154AA genotype also conferred a reduced risk of early progression (HR: 0.58, 95%CI: 0.34-0.98). These results suggest that VEGFA may represent a candidate gene contributing to VTE development in chemotherapy treated cancer patients and that -1154G/A SNP might provide useful clinical information on the efficacy and toxicity of bevacizumab in metastatic patients. Validation studies are needed for translation into clinical practice.

Neutrophil/lymphocyte (NLR) and platelet/lymphocyte (PLR) ratios might represent a yet unrecognized risk factor for venous thromboembolism (VTE) in cancer out-patients receiving chemotherapy. Accordingly, this study was aimed at analyzing the significance of these novel markers in the risk prediction of a first VTE episode in a population representative of a general practice cohort. To this purpose, a mono-institutional cohort study was conducted to retrospectively analyze NLR and PLR in 810 consecutive cancer out-patients with primary or relapsing solid cancer at the start of a new chemotherapy regimen. Over a median follow-up of 9.2 months, VTE occurred in 6.7% of patients. Incidental VTE was diagnosed at time of restaging in 47% of cases. Median pre-chemotherapy NLR (p = 0.015) and PLR (p = 0.040) were significantly higher in patients with intermediate risk class who developed symptomatic VTE with a twofold increased VTE risk for both inflammation-based markers (NLR: p = 0.022; PLR: p = 0.037) and a worst 1-year VTE-free survival for patients with high NLR or PLR. However, only PLR (HR = 2.4, p = 0.027) confirmed to be an independent predictor of future VTE in patients in the intermediate risk class in multivariate analysis, together with ECOG performance status (HR = 3.4, p = 0.0002) and bevacizumab use (HR = 4.7, p = 0.012). We may, thus, conclude that PLR, but to a lesser extent NLR, could represent useful clinical predictors of VTE, especially in selected categories of patients such as those in the intermediate risk class in whom the assessment of PLR could allow a better risk stratification of VTE without additional costs to the national health systems., (© 2014 UICC.)

Vascular endothelial growth factors (VEGFs) are the key regulators in angiogenesis and have been shown to play a significant role in the progression and prognosis of angiogenesis-related diseases, such as cancer. VEGF inhibitors are a current pharmacological tumoral strategy. However, despite the strong association between aging and cancer incidence and progression, recent findings suggest impaired angiogenesis accompanied by a reduced expression of VEGF in cells derived from aging subjects. Specific variations of VEGF genes have been demonstrated to be genetic determinants for susceptibility, outcome and therapy response, especially for the solid tumors. Considering the complications present in frail elderly patients, analysis of VEGF genetic polymorphisms in these subjects may further help in tailoring an angiogenic pharmacological strategy, and in improving our ability to better understand prognosis during therapy-related to cancer.

Metabolic disorders, especially type 2 diabetes and its associated complications, represent a growing public health problem. Epidemiological findings indicate a close relationship between diabetes and many types of cancer (including breast cancer risk), which regards not only the dysmetabolic condition, but also its underlying risk factors and therapeutic interventions. This review discusses the advances in understanding of the mechanisms linking metabolic disorders and breast cancer. Among the proposed mechanisms to explain such an association, a major role is played by the dysregulated glucose metabolism, which concurs with a chronic proinflammatory condition and an associated oxidative stress to promote tumour initiation and progression. As regards the altered glucose metabolism, hyperinsulinaemia, both endogenous due to insulin-resistance and drug-induced, appears to promote tumour cell growth through the involvement of innate immune activation, platelet activation, increased reactive oxygen species, exposure to protumorigenic and proangiogenic cytokines, and increased substrate availability to neoplastic cells. In this context, understanding the relationship between metabolic disorders and cancer is becoming imperative, and an accurate analysis of these associations could be used to identify biomarkers able to predict disease risk and/or prognosis and to help in the choice of proper evidence-based diagnostic and therapeutic protocols.

Obesity-associated diseases account for a large portion of public health challenges. Among obesity-related disorders, a direct and independent relationship has been ascertained for colorectal cancer (CRC). The evidence that adipocyte hypertrophy and excessive adipose tissue accumulation (mainly visceral) can promote pathogenic adipocyte and adipose tissue-related diseases, has led to formulate the concept of "adiposopathy", defined as adipocyte and adipose tissue dysfunction that contributes to metabolic syndrome. Adipose tissue can, indeed, be regarded as an important and highly active player of the innate immune response, in which cytokine/adipokine secretion is responsible for a paracrine loop between adipocytes and macrophages, thus contributing to the systemic chronic low-grade inflammation associated with visceral obesity, which represents a favorable niche for tumor development. The adipocyte itself participates as a central mediator of this inflammatory response in obese individuals by secreting hormones, growth factors and proinflammatory cytokines, which are of particular relevance for the pathogenesis of CRC. Among adipocyte-secreted hormones, the most relevant to colorectal tumorigenesis are adiponectin, leptin, resistin and ghrelin. All these molecules have been involved in cell growth and proliferation, as well as tumor angiogenesis and it has been demonstrated that their expression changes from normal colonic mucosa to adenoma and adenocarcinoma, suggesting their involvement in multistep colorectal carcinogenesis. These findings have led to the hypothesis that an unfavorable adipokine profile, with a reduction of those with an anti-inflammatory and anti-cancerous activity, might serve as a prognostic factor in CRC patients and that adipokines or their analogues/antagonists might become useful agents in the management or chemoprevention of CRC.

Reduced estimated glomerular filtration rate (eGFR) has been associated with increased venous thromboembolism (VTE) risk in the general population. VTE incidence significantly increases in cancer patients, especially those undergoing chemotherapy. Despite the evidence that a substantial number of cancer patients have unrecognized renal impairment, as indicated by reduced eGFR in the presence of serum creatinine levels within the reference value, chemotherapy dosage is routinely adjusted for serum creatinine values. Among chemotherapies, platinum-based regimens are associated with the highest rates of VTE. A cohort study was designed to assess the value of pretreatment eGFR in the risk prediction of a first VTE episode in cancer outpatients without previous history of VTE who were scheduled for platinum-based chemotherapy. Methods. Serum creatinine and eGFR were evaluated before the start of standard platinum-based chemotherapy in a cohort of 322 consecutive patients with primary or relapsing/recurrent solid cancers, representative of a general practice population. Results. Patients who experienced a first VTE episode in the course of chemotherapy had lower mean eGFR values compared with patients who remained VTE free. Multivariate Cox analysis demonstrated that eGFR had an independent value for risk prediction of a first VTE episode during treatment, with a 3.15 hazard ratio. Indeed, 14% of patients with reduced eGFR had VTE over 1-year follow-up compared with 6% of patients with normal eGFR values. Conclusion. The results suggest that reductions in eGFR, even in the presence of normal serum creatinine, are associated with an increased VTE risk in cancer outpatients undergoing platinum-based chemotherapy regimens. Determining eGFR before chemotherapy could represent a simple predictor of VTE, at no additional cost to health care systems.

Background: Signaling pathways triggered by increased thrombin or plasminogen activator inhibitor-1 (PAI-1) expression drastically alter the tumor microenvironment, contributing to an adverse outcome. This study aimed to evaluate the prognostic value of coagulation/fibrinolytic activities in breast cancer (BC)., Materials and Methods: Coagulation/fibrinolytic activities were investigated in 187 patients with breast cancer, with respect to possible associations with clinicopathological features and survival outcomes., Results: Levels of plasma PAI-1 (p<0.001), D-dimer (p=0.037) and activated protein C-dependent thrombin generation (p=0.003) were higher in women with breast cancer compared to 187 healthy women. PAI-1 directly correlated with D-dimer levels (p=0.009) and Ki67 expression (p=0.027), which were both predictors of elevated PAI-1 levels at multivariate regression analysis. Cox analysis demonstrated that an elevated plasma PAI-1 level had a negative prognostic impact in terms of relapse-free (hazard ratio=2.5, p=0.021) and overall survival (hazard ratio=2.7, p=0.002)., Conclusion: Determination of plasma PAI-1 levels might provide important prognostic information in risk stratification and survival outcomes for patients with breast cancer.

Chemotherapy has been associated with an increased risk of venous thromboembolism (VTE). However, the prevalence of coagulation abnormalities or VTE occurrence as a consequence of different anti-cancer agents or treatment schemes is largely uncharacterized. Thus, this study was aimed at analyzing the impact of different anticancer drugs on the prothrombotic status of cancer out-patients scheduled for chemotherapy. To this purpose, a mono-institutional study was prospectively conducted to monitor serial changes of activated protein C (APC) function in 505 consecutive cancer out-patients with primary or relapsing solid cancer at the start of a new chemotherapy regimen. The results obtained showed that age >65 years (p = 0.01), ECOG performance status (p = 0.01), platinum-based (p = 0.035) and fluoropyrimidine-based regimens (p = 0.008) were independent predictors of an acquired APC resistance during the first chemotherapy cycle. Multivariate model of Cox proportional hazards survival analysis demonstrated that a decline in APC functionality (HR = 2.4; p = 0.013) and platinum-based regimens (HR = 2.2; p = 0.042) were both capable of predicting the occurrence of a first VTE episode during chemotherapy. Indeed, 14% of patients with platinum-associated APC impairment had VTE over a 1-year follow-up, compared to 3% of patients treated with other regimens and in whom APC functionality remained stable (HR = 1.5; p = 0.003). We may, thus, conclude that use of platinum-based regimens is responsible for induction of an acquired thrombophilic condition and represents a predictor for VTE even after adjustment for other risk factors., (Copyright © 2013 UICC.)

Thiazolidinediones (TZDs) represent a class of peroxisome proliferator-activated receptor (PPAR)γ agonists widely used as insulin-sensitizers in the treatment of type 2 diabetes mellitus (T2DM). The beneficial effects of hypoglycemic drugs, including TZDs, on the hemostatic abnormalities associated to T2DM have been formerly related to improved metabolic control, rather than to direct effects. However, in recent years the pleiotropic effects of PPARγ agonists on hemostatic function have become evident. In particular, the role of platelets as a pivotal player in diabetes complications by stimulating and sustaining inflammation has been lately acknowledged. Upon activation platelets synthesize and release many bioactive substances such as thromboxane A2 (TXA2) or pro-inflammatory mediators including CD40 ligand (CD40L) that exert autocrine and paracrine activation processes in vascular inflammation leading to cardiovascular disease (CVD). Although PPARγ is a nuclear hormone receptor, anucleate platelets also highly express this receptor and treatment with synthetic PPARγ ligands dampens the release of soluble(s)CD40L and TXA2 in thrombin-activated platelets. Moreover, PPARγ through Sirtuin1 pathway has been implicated in modulating inflammatory and atherosclerotic processes in patients with T2DM. Therefore, in T2DM, where platelet activation contributes to the pathogenesis of CVD, TZDs may have an enhanced therapeutic role, despite some potentially serious adverse side effects. This review will discuss the pleiotropic effects of PPARγ treatment on the hemostatic abnormalities associated with T2DM, with particular focus on platelet activation.

Purpose: The purpose of this study was to investigate the possible association between tumor necrosis factor-α (TNF-α) levels and defects in the activated protein C (APC) system as a determinant of venous thromboembolism (VTE) in metastatic colorectal cancer patients (mCRC) undergoing chemotherapy., Methods: TNF-α levels (measured by immunoassay) and abnormalities in the APC system [evaluated by an APC-dependent thrombin generation assay (ThromboPath-ThP)] were evaluated in 45 mCRC patients undergoing chemotherapy. VTE events were recorded during follow-up., Results: TNF-α levels were increased (p < 0.01), and APC functionality was decreased (p < 0.0001) in mCRC patients compared to age- and sex-matched controls. An inverse correlation was observed between TNF-α and APC impairment in mCRC (p < 0.0001). TNF-α was confirmed as an independent predictor (p = 0.007) for APC abnormalities at multivariate regression analysis. Nine (20 %) of 45 mCRC patients experienced VTE during chemotherapy. Bayesian analysis of combined ThP/TNF-α showed a positive predictive value of 0.67 in predicting VTE (p = 0.01). Cox proportional hazards survival analysis confirmed the predictive value of combined ThP/TNF-α determination in VTE risk assessment of mCRC patients (either negative vs. both positive: HR = 0.02; p = 0.001), and Kaplan-Meier analysis demonstrated that mCRC patients with either negative TNF-α or ThP values prior to chemotherapy were less likely to experience VTE (13 %) than patients with abnormalities of both markers (67 %, p = 0.002)., Conclusions: These results suggest that the host inflammatory response to cancer cells and/or tumor-derived cytokines could be responsible for an impairment of the APC system and a switch toward a pro-thrombotic state, which might predispose to the occurrence of VTE in mCRC patients undergoing chemotherapy.

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.

Increased oxidative stress appears to be of fundamental importance in the pathogenesis and development of several disease processes. Indeed, it is well known that reactive oxygen species (ROS) exert critical regulatory functions within the vascular wall, and it is, therefore, plausible that platelets represent a relevant target for their action. Platelet activation cascade (including receptor-mediated tethering to the endothelium, rolling, firm adhesion, aggregation, and thrombus formation) is tightly regulated. In addition to already well-defined platelet regulatory factors, ROS may participate in the regulation of platelet activation. It is already established that enhanced ROS release from the vascular wall can indirectly affect platelet activity by scavenging nitric oxide (NO), thereby decreasing the antiplatelet properties of endothelium. On the other hand, recent data suggest that platelets themselves generate ROS, which may evoke pro-thrombotic responses, triggering many biological processes participating in atherosclerosis initiation, progression, and complication. That oxidative stress may alter platelet function is conceivable when considering that antioxidants play a role in the prevention of cardiovascular disease, although the precise mechanism accounting for changes attributable to antioxidants in atherosclerosis remains unknown. It is possible that the effects of antioxidants may be a consequence of their enhancing or promoting the antiplatelet effects of NO derived from both endothelial cells and platelets. This review focuses on current knowledge regarding ROS-dependent regulation of platelet function in health and disease, and summarizes in vitro and in vivo evidence for their physiological and potential therapeutic relevance.

Biobanks provide stored material to basic, translational, and epidemiological research and this material should be transferred without institute-dependent intrinsic bias. The ISBER Biospecimen Science Working Group has released a "Standard PREanalytical Code" (SPREC), which is a proposal for a standard coding of the preanalytical options that have been adopted in order to track and make explicit the preanalytical variations in the collection, preparation, and storage of specimens. In this paper we address 2 issues arising in any biobank or biolaboratory aiming at adopting SPREC: (i) reducing the burden required to adopt this standard coding, and (ii) maximize the immediate benefits of this adoption by providing a free, dedicated software tool. We propose SPRECware, a vision encompassing tools and solutions for the best exploitation of SPREC based on information technology (www.sprecware.org). As a first step, we make available SPRECbase, a software tool useful for generating, storing, managing, and exchanging SPREC-related information associated to specimens. Adopting SPREC is useful both for internal purposes (such as finding the samples having some given preanalytical features), and for exchanging the preanalytical information associated to biological samples between Laboratory Information Systems. In case of a common adoption of this coding, it would be easy to find out whether and where, among the participating Biological Resource Centers, the specimens for a given study are available in order to carry out a planned experiment.

We propose a new data analysis approach for reactive oxygen species detection using Dihydrorhodamine 123 in blood monocytes and neutrophils. This approach, based on data transformation using lymphocytes as internal standard, allows to appreciate free radical production by monocytes also without Phorbol 12-myristate 13-acetate (PMA) activation. In addition, this method is sensitive to differences in healthy subjects due to sub-pathological conditions, such as hypercholesterolemia., (Copyright © 2012 Elsevier B.V. All rights reserved.)

This study was designed to analyze the changes in circulating factor seven activating protease (FSAP) levels in association with the thrombophilic state of 40 women with recurrent pregnancy loss (RPL). All women were trying to conceive and were prospectively followed up until the achievement of spontaneous pregnancy. The results obtained showed that plasma FSAP activity levels were higher in RPL than in fertile women (P < .001) and represented an adverse predictor of pregnancy at multivariate analysis (P = .002). In 7 consenting RPL women, FSAP activity levels increased continuously during pregnancy until the third trimester, remained elevated immediately after delivery, and declined 6-week postpartum, although at levels that were still above the range of control women. These results suggest that FSAP activity levels might provide useful information during pregnancy progression in at-risk women, possibly acting as a predictive factor for adverse pregnancy outcome in RPL even in the absence of other well recognized thrombophilic conditions.

Purpose: Progressive functional impairments develop with chronic repetitive tasks possibly involving inflammatory mediators. Aim of this study was to analyze systemic inflammatory changes in relation to the possible occurrence of pain and/or disability in video terminal operators (VTOs) undergoing upper-extremity repetitive stress due to chronic overuse., Methods: Pain assessments, classification, and grade of impairment relied on self-report questionnaires administered to 21 VTOs and to 21 matched controls. The inflammatory status of the enrolled subjects was analyzed by determination of serum high sensitive C-reactive protein (hs-CRP) as well as systemic levels or monocyte expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)., Results: Serum levels of both cytokines were increased in VTOs compared to controls (P = 0.005 for TNF-α and P = 0.004 for IL-6). TNF-α levels correlated to IL-6 (P = 0.019), which, in turn, was associated to increased hs-CRP (P = 0.012). DASH score allowed to categorize VTOs according to disability. VTOs with mild (DASH = 22) or moderate (DASH = 46) disability (n = 10) had higher serum hs-CRP (P = 0.001) and IL-6 (P = 0.035) levels than VTOs without disabilities (DASH < 17) (n = 11). Monocyte stimulatory TNF-α expression was increased in individuals with mild/moderate disability. Monocyte expression of TNF-α was independently associated to that of IL-6, which, in turn, was associated to increased systemic hs-CRP levels together with mild/moderate functional impairment and weekly commitment to the display screen., Conclusions: The results here reported indicate the occurrence of a low-grade inflammatory condition in VTOs with mild/moderate disability, which might allow the early recognition of arising musculoskeletal disorders induced by repetitive stress.

Background: Biospecimen quality is crucial for clinical and translational research and its loss is one of the main obstacles to experimental activities. Beside the quality of samples, preanalytical variations render the results derived from specimens of different biobanks or even within the same biobank incomparable. Specimens collected along the years should be managed with a heterogeneous life cycle. Hence, we propose to collect detailed data concerning the whole life cycle of stored samples employing radio-frequency identification (RFID) technology.?, Methods: We describe the processing chain of blood biosamples that is operative at the biobank of IRCSS San Raffaele, Rome, Italy (BioBIM). We focus on the problem of tracing the stages following automated preanalytical processing: we collected the time stamps of all events that could affect the biological quality of the specimens by means of RFID tags and readers.?, Results: We developed a pilot study on a fragment of the life cycle, namely the storage between the end of the preanalytics and the beginning of the analytics, which is usually not traced by automated tools because it typically includes manual handling. By adopting RFID devices we identified the possible critical time delays. At 1, 3 and 6 months RFID-tagged specimens cryopreserved at -80°C were successfully read.?, Conclusions: We were able to record detailed information about the storage phases and a fully documented specimen life cycle. This will allow us to promote and tune up the best practices in biobanking because i) it will be possible to classify sample features with a sharper resolution, which allows future utilization of stored material; ii) cost-effective policies can be adopted in processing, storing and selecting specimens; iii) after using each aliquot, we can study the life cycle of the specimen with a possible feedback on the procedures.

Objectives: We investigated the possible involvement of vascular endothelial growth factor (VEGF-A) gene promoter polymorphisms in essential hypertension (EH)., Design and Methods: 1225bp of the VEGF-A gene promoter were screened for polymorphisms using PCR amplification and direct DNA sequence analysis in 62 EH and 62 normotensive (HS) individuals. Circulating VEGF-A levels were determined by immunoassay., Results: -152G/A (p=0.009) and -116G/A (p=0.016) polymorphisms were correlated to hypertension (p<0.05). Median platelet VEGF-A load in EH was 2.10fg/plt. Patients with microvascular complications (MC) had higher platelet VEGF-A load than those without (p=0.005). Multivariate analyses showed that -116 A allele was an independent predictor of microalbuminuria (p=0.014) and increased platelet VEGF-A load (p=0.009) in EH. Platelet VEGF-A load independently predicted MC (p=0.049) in addition to -116G/A polymorphism (p=0.035)., Conclusions: Abnormal regulation of VEGF-A due to polymorphism at position -116 might represent a genetic factor for increased VEGF-A production and MC in EH., (Copyright (c) 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to investigate the relationship between serum tumor necrosis factor alpha (TNF-alpha) levels and single nucleotide polymorphisms (SNPs) of the TNFA gene promoter (-376G/A, -308G/A, and -238G/A) in 100 Italian Caucasian women with reproductive failure and 100 fertile controls. Molecular analysis of TNFA SNPs showed higher frequencies of -238G allele (P = .028) as well as the presence of a 3-loci haplotype (-376G/-308A/-238G; P = .020) in fertile controls compared to women with reproductive failure. Serum TNF-alpha levels were higher in study women compared to controls ( P = .001). Of interest, the TNFA -376G/-308A/-238G haplotype was an independent predictor of low TNF-alpha levels (P = .021) and miscarriage (P = .023) in multivariate analyses. In conclusion, these findings support the concept of an association of TNFA polymorphisms and recurrent pregnancy loss (RPL). In particular, the TNFA -238GG variant and the TNFA -376G/-308A/-238G haplotype might represent protective factors, probably through reduced TNF-alpha production and/or mediated responses.

Objectives: To investigate whether sCD40L dosage might represent a useful tool to explore in vivo platelet function., Design and Methods: sCD40L and sP-selectin levels and light transmission aggregometry (LTA) were analyzed in 69 healthy donors. Immunoassays were performed on platelet-depleted citrate plasma samples. The effects of in vitro aspirin treatment on the release of sCD40L were investigated in 15 subjects following platelet stimulation. The effects of a 1-month therapeutic course of low-dose aspirin on sP-selectin and sCD40L levels were also investigated., Results: A significant correlation was observed between sCD40L and sP-selectin (p<0.01). In vitro aspirin treatment remarkably decreased sCD40L levels following platelet activation by exogenous agonists. sCD40L directly correlated with LTA (Rho=0.62, p<0.0001). In vivo aspirin treatment significantly reduced both sP-selectin and sCD40L levels (both p<0.01) in a direct correlation (Rho=0.66, p<0.05)., Conclusions: Citrated plasma samples reflect sCD40L released from platelets, thus yielding the most valid estimates of in vivo circulating levels of this platelet activation markers., (2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

MYH9-related disease ( MYH9-RD) is an autosomal dominant thrombocytopenia with giant platelets variably associated with young-adult onset of progressive sensorineural hearing loss, presenile cataract, and renal damage. MYH9-RD is caused by mutations of MYH9 , the gene encoding for non-muscle heavy-chain myosin-9. Wild-type and mutant myosin-9 aggregate as cytoplasmic inclusions in patients' leukocytes, the identification of which by immunofluorescence has been proposed as a suitable tool for the diagnosis of MYH9-RD. Since the predictive value of this assay, in terms of sensitivity and specificity, is unknown, we investigated 118 consecutive unrelated patients with a clinical presentation strongly consistent with MYH9-RD. All patients prospectively underwent both the immunofluorescence assay for myosin-9 aggregate detection and molecular genetic analysis of the MYH9 gene. Myosin-9 aggregates were identified in 82 patients, 80 of which (98%) had also a MYH9 mutation. In the remaining 36 patients neither myosin-9 aggregates nor MYH9 mutations were found. Sensitivity and specificity of the immunofluorescence assay was evaluated to be 100% and 95%, respectively. Except for the presence of aggregates, we did not find any other significant difference between patients with or without aggregates, demonstrating that the myosin-9 inclusions in neutrophils are a pathognomonic sign of the disease. However, the identification of the specific MYH9 mutation is still of importance for prognostic aspects of MYH9-RD.

Background: A condition of maternal thrombophilia, either inherited or acquired, can compromise the success of implantation and foetal survival., Methods: Malfunctions in protein C pathway were evaluated using a novel assay [HemosIL ThromboPath (ThP)] in a case-control study of 172 women with a history of recurrent miscarriage or infertility and 86 age-matched unrelated fertile women., Results: Thrombophilia was ascertained in 13% of the cases. ThP values were lower in women either with or without thrombophilia compared to controls (both p<0.0001). Abnormal ThP values (below the mean minus 1SD of controls) were found in 62% of cases compared to 12% of controls (p<0.0001). Non-thrombophilic women who achieved spontaneous pregnancy had higher ThP values compared to those who did not (p<0.05). Elevated ThP values were an independent predictor for pregnancy (p<0.01) in women without thrombophilia. A decrease of ThP values was observed during pregnancy progression, which correlated with that of protein S (p<0.05). Miscarriage or major complications occurred in women in whom ThP percent change was approximately 2-fold higher than that observed in women who achieved successful pregnancy (p<0.05)., Conclusions: ThP might represent an efficient assay for screening women with pregnancy complications and might provide prognostic information during pregnancy progression.

Background: Homocysteinemia has been associated with oncogenic risk. This study was designed to investigate the homocysteine (Hcy) genotype/phenotype interactions together with the inflammatory and nutritional status of cancer patients., Patients and Methods: The Hcy levels were analyzed in 47 cancer patients in association with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, folate and inflammatory markers., Results: The MTHFR C677T and A1298C genotype distributions did not differ from those predicted by the Hardy-Weinberg distribution. Conversely, the Hcy levels were higher in the cancer patients (p=0.04), who were also characterized by low-grade inflammation. The Hcy levels correlated with the interleukin-6 (IL-6) (p=0.001), tumor necrosis factor-alpha (TNF-alpha) (p=0.042) and folate (p<0.0001) levels of the patients. Multivariate analysis showed that TNF-alpha (p=0.014) and folate (p=0.019) were independent predictors of elevated Hcy levels in the cancer patients., Conclusion: The MTHFR polymorphisms do not significantly contribute to tHcy (total Hcy) levels in cancer patients, and cancer-related inflammation may be associated with elevated tHcy levels, possibly involving a TNF-alpha mediated pathway.

Background: Adipokines may significantly influence the growth and proliferation of tumor stroma and malignant cells within. Reduced adiponectin and increased leptin serum levels were found in colorectal cancer (CRC) patients. Recently, it has been demonstrated that tumor necrosis factor-alpha (TNF-alpha) is able to induce dose-dependent changes in serum adipokine levels. Thus, aims of this study were to evaluate the possible associations between adipokines, TNF-alpha and clinicopathological variables of CRC patients and to analyze their possible prognostic value in predicting relapse-free and overall survival., Materials and Methods: Baseline leptin, adiponectin and TNF-alpha levels were analyzed in 90 patients with histologically diagnosed primary or newly diagnosed metastatic CRC treated at 'Tor Vergata' Clinical Center and followed up for a median period of 3 years., Results: Serum leptin levels were higher in CRC patients than in controls (p<0.0001). Conversely, serum adiponectin levels were lower in CRC patients than in controls (p<0.0001). Leptin inversely correlated with adiponectin (p<0.005). The leptin/adiponectin (L/A) ratio was eight-fold greater in CRC compared to controls (p<0.0001). Kaplan-Meier analysis of relapse-free and overall survival time showed that the L/A ratio was an independent predictor for adverse outcome in CRC., Conclusion: Serum adipokine levels might have a role in the biology of CRC and the combined measurement of leptin and adiponectin levels might provide useful prognostic information in the management of patients with CRC.

Statin interference has been suggested among the mechanisms of reduction of the antiplatelet effect of clopidogrel. We thus sought to assess the influence of rosuvastatin on clopidogrel antiplatelet action in high-risk (HR) cardiovascular patients. To set the level of platelet inhibition by combined antithrombotic treatments we retrospectively studied two populations of HR patients, one under aspirin alone, the other under aspirin plus rosuvastatin, before and after addition of clopidogrel. The effects of rosuvastatin compared with atorvastatin were then prospectively investigated in patients who underwent percutaneous coronary intervention (PCI), under clopidogrel and aspirin treatment. Light transmission platelet aggregation (LTA) was studied in response to adenosine diphosphate (ADP) (5 microM) or arachidonic acid (0.5 mM). The inhibitory effect of clopidogrel in reducing ADP-induced LTA was similar in the two HR groups of patients. No difference in ADP-induced platelet aggregation was observed in the two PCI groups of patients with either atorvastatin or rosuvastatin. In conclusion, rosuvastatin does not interfere with the antiplatelet effect of clopidogrel in patients with cardiovascular disease.

Background: Platelets are the major source of circulating sP-selectin. Elevated levels of this protein have been found in many atherothrombotic disorders. Thus, we investigated whether sP-selectin dosage might reflect platelet function in patients with risk factors for or with established cardiovascular diseases and whether its levels can be modulated by aspirin therapy., Methods: Plasma sP-selectin levels and light transmission platelet aggregometry (LTA) were analyzed in 152 outpatients. The effects of a 6-month aspirin therapeutic course on sP-selectin levels and LTA in 51 consecutive patients have been also investigated., Results: Significant correlations were observed between sP-selectin and Mx% LTA in response to epinephrine (p=0.022) and arachidonic acid (p=0.006), or between sP-selectin and collagen lag-phase (p=0.016). Multiple regression analysis showed that the only predictors of sP-selectin levels were platelet number (p<0.001) and collagen-induced lag-phase (p<0.01). Aspirin-treated patients showed a significant reduction of sP-selectin levels by 13% (p=0.021) which significantly correlated with collagen-induced lag-phase (p=0.005)., Conclusions: sP-selectin dosage could be proposed as a reliable marker of platelet activation in patients with major atherosclerotic risk factors either in the absence of clinically overt disease, and might represent a valid tool to asses in vivo platelet behavior.

Introduction: There is emerging evidence of a considerable variability of the impact of aspirin on clinical outcome and laboratory findings. Persistent TxA2 production seems to be the most likely reason. Aim of this study was to determine whether the mechanism responsible for TxA2 persistent production is, at least partially, dependent upon aspirin-insensitive platelet COX-2 enzymatic pathway., Methods and Results: In 100 consecutive patients, under chronic aspirin anti-platelet treatment (100-160 mg/day) selected on the basis of detectable plasma salicylate levels, serum and Arachidonic Acid (AA)-induced platelet TxA2 production, immunoblot analysis of platelet COX-1/COX-2 expression and COX-2 activity were studied. Immunoblot revealed COX-2 expression in 46% patients, in an amount that was markedly lower than COX-1. In 10 COX-2 positive patients with TxA2 levels over the median, AA-induced TxA2 production performed in vitro in the presence of the COX-2 inhibitor CAY10404 and aspirin demonstrated that COX-2 dependent TxA2 production is less than 2%., Conclusion: Our data demonstrate that the inter-individual variability of platelet sensitivity to aspirin is due to a reduced efficacy of aspirin on platelet COX-1 despite ascertained patient compliance. We suggest that serum TxA2 assay might be performed in future clinical studies to improve our knowledge on the residual TxA2 production in aspirin-treated patients.

The clinical history of patients with heart failure (HF) is complicated by arterial thromboembolism. Platelet activation is reported in this population, but the underlying mechanism has not been clarified. Forty-two patients with HF scored according to New York Heart Association (NYHA) classification had higher levels of collagen-induced platelet aggregation, platelet tumor necrosis factor-alpha (TNF-alpha) receptor expression, and serum thromboxane B2 and higher circulating levels of TNF-alpha than 20 healthy subjects. Coincubation of platelets from HF patients with an inhibitor of TNF-alpha receptors significantly reduced collagen-induced platelet aggregation. In vitro study demonstrated that TNF-alpha amplified the platelet response to collagen; this effect was inhibited by TNF-alpha receptor antagonist and inhibitors of arachidonic acid metabolism. This study showed that TNF-alpha behaves as a trigger of platelet activation through stimulation of the arachidonic acid pathway.

Shape change is the earliest response of platelets to stimuli; it is mainly dependent upon Ca(2+)/calmodulin interaction subsequent to Ca(2+) mobilization and is mediated by myosin light chain kinase (MLCK) activation. It has been recently suggested that collagen itself is not able to elicit platelet shape change in the absence of ADP and thromboxane A(2) costimulation but is capable of inducing MLCK activation. Since we hypothesize that the morphological changes of the few platelets that adhere to collagen might not be revealed by turbidimetry, the aim of this study was to assess platelet shape change using transmission electron microscopy, in the absence of the amplificatory feedback pathways of ADP and thromboxane A(2). Our results demonstrated that only the platelets in contact with insoluble collagen fibers underwent a typical shape change, whereas those further away remained quiescent. Moreover, since cAMP enhances Ca(2+) mobilization in response to collagen, in the present study, we also investigated whether cAMP is involved in the inhibition of collagen-induced platelet shape change and MLC phosphorylation. Platelets were thus treated with iloprost (28 nm) prior to stimulation. Electron microscopy studies demonstrated that iloprost did not modify collagen-induced shape change, whereas immunoblotting studies showed a slight inhibition of MLC phosphorylation in the presence of enhanced cAMP levels. We can thus conclude that collagen is able to cause platelet shape change through activation of Ca(2+)/calmodulin-dependent MLCK, without the involvement of amplificatory pathways. Enhanced cytosolic cAMP levels do not inhibit collagen-induced platelet shape change but exert a weak inhibitory action on MLCK.

Objectives: We sought to investigate, during a two-year follow-up period, the effects of aspirin on platelet aggregation., Background: The platelets of patients given aspirin may be less sensitive to antiplatelet treatment, although the extent of such phenomenon over long-term follow-up is unclear., Methods: Adenosine diphosphate (ADP) and collagen-induced platelet aggregation was periodically monitored before and after 2, 6, 12, and 24 months of treatment with aspirin (n = 150) or ticlopidine (n = 80) in patients matched for gender, age, and risk factors for atherothrombosis., Results: Compared with baseline values, two months of aspirin treatment significantly inhibited platelet aggregation; thereafter, this inhibitory effect progressively decreased. At 24-month follow-up, collagen-induced platelet aggregation was significantly higher than that observed at two months (p < 0.05); a more pronounced difference was observed when collagen-induced lag phase was considered (p < 0.01). Restoration of platelet aggregation was less evident when ADP was used as an agonist. Conversely, the inhibition induced by ticlopidine was constant throughout follow-up with both agonists., Conclusions: The study demonstrates that a long-term treatment with aspirin is associated with a progressive reduction in platelet sensitivity to this drug.

Experimental studies have suggested that TNF alpha, a pro-inflammatory cytokine, may contribute to the deterioration of cardiovascular function through various mechanisms, including the generation of reactive oxygen species. It has not yet been demonstrated whether TNF alpha has prooxidant activity in patients with heart failure, and what the mechanism eventually resulting in this effect are. We analyzed 42 patients (38 men and 4 women, aged 26 to 74 years) with heart failure, secondary to idiopathic dilated cardiomyopathy (n=21), coronary artery disease (n=15), and valve disease (n=6), and 20 controls (18 men and 2 women, aged 49 to 67 years). Ten patients were in class I, 9 in class II, 15 in class III and 8 in class IV according to NYHA Classification. Blood samples were obtained from each patient to evaluate basal and collagen-induced platelet O(2)(-) production, and plasma TNF alpha. In vivo results showed increased platelet O(2)(-) production and plasma TNF alpha levels in NYHA class III-IV compared with that in controls or in NYHA I-II (p<0,001); platelet O(2)(-) production correlated significantly (R=0,6; p<0,01) with TNF alpha plasma levels. In vitro studies showed TNF alpha dose-dependently (5-40 pg/ml) induced platelet O(2)(-) production, and that this effect was significantly inhibited by its specific inhibitor, WP9QY (1 microM); aspirin (100 microM), AACOCF(3), a specific PLA(2) inhibitor (14 microM), and DPI, an inhibitor of NADPH oxidase, significantly inhibited TNF alpha-mediated platelet O(2)(-) production. This study suggests that in patients with heart failure, enhanced platelet O(2)(-) production is mediated by TNF alpha via activation of arachidonic acid and NADPH oxidase pathways.

Once platelets are activated, the first event to occur is a rapid change in shape, associated with Ca2+/calmodulin-dependent myosin light chain (MLC) phosphorylation and with Rho kinase activation. The purpose of this study was to investigate which is the biochemical pathway that leads to platelet shape change in response to convulxin, a selective GpVI activator, and to verify whether MLC phosphorylation is essential for this process. The inhibition of the Ca2+-dependent pathway by means of the Ca2+ chelator BAPTA, the Ca2+/calmodulin inhibitor W-7 or the cAMP enhancing drug iloprost reduced about 50% of platelet shape change in response to convulxin. The treatment with either the Rho kinase inhibitors Y27632 or HA 1077 had no effect on platelet shape change induced by convulxin. When both Ca2+/calmodulin-dependent and Rho kinase-dependent pathways were concomitantly inhibited by the combined use of Y27632 plus BAPTA, W-7 or iloprost, platelet shape change was completely abolished. Our findings suggest that convulxin-induced platelet shape change occurs via both pathways, the Ca2+/calmodulin-dependent, which appears to be more important, and the Rho kinase-dependent one. The pattern of MLC phosphorylation was not modified by Rho kinase inhibitors. Conversely, the inhibition of the Ca2+-dependent pathway caused a strong reduction of MLC phosphorylation in BAPTA-treated platelets, and a total inhibition in W-7 or iloprost-treated platelets. Our results demonstrate that following Rho kinase-dependent pathway platelet shape change can occur without the involvement of MLC phosphorylation.

Cyclic nucleotides, such as cAMP, are known to inhibit the multistep cascade that results in platelet aggregation. In the present study we provide evidence that it is possible to bypass cAMP inhibitory effect on fibrinogen binding site exposure induced by the thromboxane A2 synthetic analogue U46619, the snake venom toxin convulxin, or by the direct PKC activator OAG, by concomitantly activating a G1-coupled receptor by means of epinephrine or by inducing cytosolic calcium influx by means of ionomycin. In fact, in our study we demonstrate that, in iloprost-treated platelets, the inhibition of both platelet aggregation and fibrinogen binding was overcome by adding epinephrine or ionomycin. To further confirm this, we used the cAMP analogue dibutyryl cAMP and we obtained platelet aggregation in response to U46619, convulxin or OAG plus epinephrine. Moreover, a complete inhibition of platelet aggregation in the presence of high concentrations of cAMP was observed only in the case of U46619, while a small percentage of aggregation persisted when convulxin or OAG were used, due to the small amount of ADP that both convulxin and OAG are able to release. Since PKC inhibition didn't allow platelet aggregation to occur in response to the concomitant activation of U46619 or convulxin, plus epinephrine or ionomycin, we can conclude that cAMP-induced inhibition of aggregation can be counteracted by the simultaneous activation of PKC in the presence of an activated G1-coupled receptor or of an induced calcium influx.