Lifestyle and biological factors influence the relationship between mental health and low-grade inflammation.

Mental health modulates the risk of common chronic conditions. Although inflammation is thought to partly explain this link, its relation with mental health is still unclear and largely unexplored. We investigated three scales assessing psychological resilience (CD-RISC), depression symptoms (PHQ9-6) and mental wellbeing (SF36-MCS) in an Italian adult population cohort (Nmax = 16,952). This showed a slightly higher frequency of men, more educated and younger participants, compared to samples with incomplete questionnaires. We performed stepwise generalized linear models to test the association between each scale and INFLA-score, a composite blood-based inflammation index. At each step, a class of potential mediators was included in the model, namely health conditions, lifestyle factors, or both (full model). Full model analysis was also conducted on single blood markers involved in the inflammatory process. In the baseline model, we observed significant associations of PHQ9-6 (standardized ß(SE) = 0.024(0.009), p = 8.9 × 10-3) and SF36-MCS (ß(SE) = -0.021(0.008), p = 7 × 10-3) with INFLA-score. These associations survived adjustment for health conditions but not for lifestyle factors, which explained 81% and 17% of the association with PHQ9-6 and SF36-MCS. Significant associations (p < 4.2 × 10-3) after mediator adjustment were observed for single low-grade inflammation markers, including platelet distribution width (with PHQ9-6 and CD-RISC), granulocyte- and neutrophil-to-lymphocyte ratios, monocyte and lymphocyte fractions (with SF36-MCS). After imputation of missing data, we observed substantially consistent associations. These findings suggest that the relationship between mental health and low-grade inflammation is largely influenced by lifestyle. However, the associations with specific biomarkers related to inflammation are partly independent and might be explained by biological factors.

Consumption of whole grain food and its determinants in a general Italian population: Results from the INHES study.

BACKGROUND AND AIMS: Whole grain (WG) food consumption is associated with lower risk of cardiovascular disease, cancer and neurological diseases. The aim of this study was to assess the consumption of WG food and its major demographic, socioeconomic, psychosocial and behavioral determinants in a general Italian population. METHODS AND RESULTS: Data were from the Italian Nutrition & Health Survey (INHES), a telephone-based survey established in 2010-2013 including 9422 participants aged ≥5 years from all over Italy. WG food intake was assessed by the European Food Propensity Questionnaire and included bread, pasta, breakfast cereals, biscuits and WG soups. WG consumption was categorized as none, occasional (<1 time/week) and regular (≥1 time/week). Overall, 26.9% of the sample reported a regular consumption of WG food (27.2% of adults aged 20-97 y, and 21.9% of children/adolescents aged 5-19 y). In both age-groups, the major food source contributing to total WG intake was WG bread followed by WG pasta. Among adults, greater consumption of WG was associated with healthier lifestyle (e.g. sport activity), and higher educational level. Eating meals outside of the house in adults, and spending >2 h/day watching TV in children/adolescents were inversely associated with WG intake. CONCLUSIONS: The percentage of WG consumers in Italy in 2010-2013 appears to be quite low and still below that recorded in other countries of Europe where consumption is frequently over 50 percent. WG consumption is likely to be influenced by socioeconomic status and is associated with a number of psychosocial factors, meal patterns and eating-related behaviors.

Impact of combined healthy lifestyle factors on survival in an adult general population and in high-risk groups: prospective results from the Moli-sani Study.

BACKGROUND: There is poor knowledge on the association between combined lifestyles with mortality risk among individuals at high risk, and little is known on the biological mechanisms that could be on the pathway. METHODS: Longitudinal analysis on 22 839 individuals from the Moli-sani Study (Italy, 2005-2010). Among them, we identified 5200 elderly individuals (≥65 year), 2127 subjects with diabetes and 1180 with cardiovascular disease (CVD) at baseline. A healthy lifestyle score (HLS) was calculated, allocating 1 point for each of the following: abstention from smoking; adherence to Mediterranean diet; physical activity; absence of abdominal obesity. Hazard ratios (HR) with 95% confidence intervals (95%CI) were calculated by multivariable Cox regression and competing risk models. RESULTS: During 8.2 years of follow-up, 1237 deaths occurred. In the general population, adherence to all four healthy lifestyles, compared with none or 1, was associated with lower risk of all-cause (HR = 0.53; 95%CI:0.39-0.72), CVD (HR = 0.54; 0.32-0.91), cancer (HR = 0.62; 0.39-1.00) and mortality from other causes (HR = 0.39; 0.19-0.81). A 1-point increase in HLS was associated with 20%, 22% and 24% lower risk of total mortality among the elderly, in subjects with diabetes or CVD, respectively. Traditional (e.g. blood lipids), inflammatory (e.g. C-reactive protein) and novel biomarkers (e.g. markers of cardiac damage) accounted for up to 24% of the association of HLS with all-cause mortality risk in the general population. CONCLUSIONS: The impact of combined four healthy lifestyles on survival was considerable, both in the general population and among high-risk subgroups. Inflammatory and novel biomarkers of CVD risk explained a substantial proportion of this association.

Learning by counting blood platelets in population studies: survey and perspective a long way after Bizzozero.

Platelet count represents a useful tool in clinical practice to discriminate individuals at higher risk of bleeding. Less obvious is the role of platelet count variability within the normal range of distribution in shaping the individual's disease risk profile. Epidemiological studies have shown that platelet count in the adult general population is associated with a number of health outcomes related to hemostasis and thrombosis. However, recent studies are suggesting a possible role of this platelet index also as an independent risk factor. In this review of adult population studies, we will first focus on known genetic and non-genetic determinants of platelet number variability. Next, we will evaluate platelet count as a marker and/or a predictor of disease risk and its interaction with other risk factors. We will then discuss the role of platelet count variability within the normal distribution range as a contribution to disease and mortality risk. The possibility of considering platelet count as a simple, inexpensive indicator of increased risk of disease and death in general populations could open new opportunities to investigate novel platelet pathophysiological roles as well as therapeutic opportunities. Future studies should also consider platelet count, not only platelet function, as a modulator of disease and mortality risk.

Serum vitamin D deficiency and risk of hospitalization for heart failure: Prospective results from the Moli-sani study.

BACKGROUND AND AIMS: Evidence indicates that Vitamin D deficiency may be associated with increased risk of cardiovascular disease, although findings on risk of heart failure (HF) are controversial. We investigated the relationship between serum Vitamin D and the incidence of hospitalization for HF in a large prospective cohort of Italian adults. METHODS AND RESULTS: 19,092 (49% men, age range 35-99 years) HF-free individuals from the Moli-sani study, with complete data on serum Vitamin D (25-hydroxyvitamin) levels and incident hospitalized HF, were analysed. The cohort was followed up for a median of 6.2 years. Baseline serum Vitamin D levels were categorized in deficient (<10 ng/mL), insufficient (10-29 ng/mL), and normal (≥30 ng/mL) Incident cases of hospitalization for HF were identified by linkage with the regional hospital discharge registry. Hazard ratios (HRs) were calculated using Cox-proportional hazard models. The prevalence of normal, insufficient or deficient levels of Vitamin D was 12.2%, 79.6% and 8.2%, respectively. During follow-up, 562 admissions to hospital for HF were identified. The incidence of HF was 1.6%, 2.9% and 5.3%, respectively in subjects with normal, insufficient and deficient levels of Vitamin D. After multivariable analysis, individuals with deficiency of Vitamin D had a higher risk of hospitalization for HF (HR: 1.61, 95%CI: 1.06-2.43) than those with normal levels. Further adjustment for subclinical inflammation did not substantially change the association between Vitamin D deficiency and HF. CONCLUSION: Deficiency of Vitamin D was associated, independently of known HF risk factors, with an increased risk of hospitalization for HF in an Italian adult population.

Mediterranean-type diet is associated with higher psychological resilience in a general adult population: findings from the Moli-sani study.

BACKGROUND/OBJECTIVE: Psychological resilience is a measure of stress coping ability and has been associated with favourable health outcomes. While evidence on the relationship of dietary habits with a number of psychosocial conditions is available, there is lack of studies on their association with psychological resilience in a general adult population. SUBJECTS/METHODS: Cross-sectional analysis on 10 812 subjects recruited within the cohort of the Moli-sani study (2005-2010). Psychological resilience was measured by the 25-item Connor-Davidson Psychological Resilience Scale. Food intake was recorded by the EPIC food frequency questionnaire and adherence to Mediterranean diet was appraised by both a Greek Mediterranean diet score and an Italian Mediterranean Index. Empirically derived dietary patterns were obtained by principal factor analysis. Multivariable linear regression analysis (95%CI) was used to test the association between dietary scores and psychological resilience. RESULTS: Higher adherence to Mediterranean-type diets or consumption of a vegetable-based dietary pattern (obtained from principal factor analysis) were positively associated with psychological resilience (ß=0.43; 95%CI: 0.19-0.66, ß=0.92; 0.69-1.16, and ß=1.18; 0.93-1.44, for Greek Mediterranean diet score, Italian Mediterranean Index and the 'Olive oil and vegetables pattern', respectively). Dietary polyphenol or antioxidant intakes and greater variety in fruit and vegetable consumption were also positively associated with psychological resilience, while the associations with Western-like diets were weak. CONCLUSIONS: In conclusion, Mediterranean diet, vegetable-based dietary patterns and better diet quality were all positively associated with higher psychological resilience, whereas Western-type diets were not.

Fish intake is associated with lower cardiovascular risk in a Mediterranean population: Prospective results from the Moli-sani study.

BACKGROUND AND AIMS: Fish consumption reportedly reduces the risk of heart disease, but the evidence of cardiovascular advantages associated with fish intake within Mediterranean cohorts is limited. The aim of this study was to test the association between fish intake and risk of composite coronary heart disease (CHD) and stroke in a large population-based cohort adhering to Mediterranean Diet. METHODS AND RESULTS: Prospective analysis on 20,969 subjects free from cardiovascular disease at baseline, enrolled in the Moli-sani study (2005-2010). Food intake was recorded by the Italian version of the EPIC food frequency questionnaire. Hazard ratios were calculated by using multivariable Cox-proportional hazard models. During a median follow-up of 4.3 years, a total of 352 events occurred (n of CHD = 287 and n of stroke = 66). After adjustment for a large panel of covariates, fish intake ≥4 times per week was associated with 40% reduced risk of composite CHD and stroke (HR = 0.60; 95%CI 0.40-0.90), and with 40% lower risk of CHD (HR = 0.60; 95%CI 0.38-0.94) as compared with subjects in the lowest category of intake (<2 times/week). A similar trend of protection was found for stroke risk although results were not significant (HR = 0.62; 95%CI 0.26-1.51). When fish types were considered, protection against the composite outcome and CHD was confined to fatty fish intake. CONCLUSIONS: Fish intake was associated with reduced risk of composite fatal and non-fatal CHD and stroke in a general Mediterranean population. The favourable association was likely to be driven by fatty fish.

Neuromedin U potentiates ADP- and epinephrine-induced human platelet activation.

Neuromedin U (NmU) is a pleiotropic hypothalamic neuropeptide involved in the gut-brain axis. It acts via both a Gαq/11-coupled receptor (NMUR1) and a Gαi-coupled receptor (NMUR2) in different cell types. Expression of both receptors was reported in platelets, but their significance for NmU signaling remains elusive. We studied the potential effects of NmU on human platelet activation. In platelet-rich plasma (PRP), NmU alone (up to 10µM) did not induce any measurable aggregation, but at nanomolar concentrations, it potentiated platelet aggregation by low (mean 0.47µM) ADP concentrations (from 25.9±3.6% to 74.8±2.7% maximal aggregation for ADP vs. ADP+NmU, 100nM, mean±SEM, n=13), accompanied by platelet P-selectin expression and intracellular calcium mobilization. Accordingly, platelet preincubation with NmU for 2min sensitized platelets for subsequent activation by ADP. When P2Y1 was inactivated by 50µM MRS2179, NmU comparably potentiated ADP-induced PRP aggregation, suggestive of cooperative activation with Gαi-coupled P2Y12. Likewise, NmU potentiated platelet aggregation by Gαi-operated epinephrine at subthreshold concentrations (99ng/ml, mean), but not that by Gαq-dependent serotonin (20µM). Platelet aggregation by NmU/epinephrine combination was fully inhibited by the Gαq inhibitor YM-254890 (1µM). qPCR detection and western blot analysis substantiated platelet expression of NMUR1 in different donors, a finding collectively complying with functionally relevant Gαq/11-mediated activation of platelet NMUR1 by NmU. Our findings advocate further studies on platelet sensitization by NmU, released during vascular activation and injury, to define its role as a modifier of platelet responsiveness to the physiological activation signals, operational in cardiovascular health and disease.

Food group consumption in an Italian population using the updated food classification system FoodEx2: Results from the Italian Nutrition & HEalth Survey (INHES) study.

BACKGROUND AND AIM: Dietary habits evolve over time, being influenced by many factors and complex interactions. This work aimed at evaluating the updated information on food group consumption in Italy. METHODS AND RESULTS: A total of 8944 (4768 women and 4176 men) participants aged >18 years from all over Italy recruited in 2010-13 (Italian Nutrition & HEalth Survey, INHES) was analyzed. The recruitment was performed using computer-assisted-telephone-interviewing and one-day 24-h dietary recall retrieved from all participants. The updated, second version, of FoodEx2 food classification system was applied to extract data on food group consumption. The participation rate was 53%; 6.2% of the participants declared to follow a special diet, the most prevalent being hypo-caloric diets (55.7% of special diets). Men compared to women presented significantly higher intakes of "grains and grain-based products", "meat and meat products", "animal and vegetable fats and oils and primary derivatives" and "alcoholic beverages" (P for all<0.001); moreover, men had lower intakes of "milk and dairy products", "water and water-based beverages" and "products for non-standard diets, food imitates and food supplements" (P for all<0.001). Differences in food group intake among age groups, geographical regions and educational level groups were also identified (P for all<0.05). CONCLUSIONS: Data on the consumption of more than 70 food groups and sub-groups were illustrated in different strata. The present analysis could be considered as an updated source of information for future nutrition research in Italy and in the EU.

Association of pasta consumption with body mass index and waist-to-hip ratio: results from Moli-sani and INHES studies.

BACKGROUND/OBJECTIVES: Pasta as a traditional component of Mediterranean diet (MeD) in Italy has not been studied in detail in the management of body weight. This study aimed at evaluating the association of pasta intake with body mass index (BMI) and waist-to-hip ratio, in two large epidemiological datasets. SUBJECTS/METHODS: A total of 14 402 participants aged ⩾35 years randomly recruited from the general population of the Molise region (Moli-sani cohort) and 8964 participants aged >18 years from all over Italy (Italian Nutrition & HEalth Survey, INHES) were separately analyzed. The European Prospective Investigation into Cancer and Nutrition (EPIC)-food frequency questionnaire and one 24-h dietary recall were used for dietary assessment. Weight, height, waist and hip circumference were measured in Moli-sani or self-reported in INHES. Residuals methodology corrected for either total energy intake or body weight was used for the analysis of pasta intake. RESULTS: Higher pasta intake was associated with better adhesion to MeD in both genders (P for both<0.001). In the Moli-sani study, after multivariable analysis, pasta-energy residuals were negatively associated with BMI in women but not in men (ß-coef=-0.007, P=0.003 for women and ß-coef=-0.001, P=0.58 for men). When pasta intake-body weight residuals were used, pasta intake was significantly and negatively associated with BMI in crude and multi-adjusted models (including adhesion to MeD) in both genders and Moli-sani and INHES studies (for all ß-coef<0, P<0.05). In the Moli-sani study, pasta-body weight residuals were significantly and negatively associated with waist and hip circumference and waist-to-hip ratio (for all ß-coef<0, P<0.05). CONCLUSIONS: As a traditional component of MeD, pasta consumption was negatively associated with BMI, waist circumference and waist-to-hip ratio and with a lower prevalence of overweight and obesity.

Effects of moderate beer consumption on health and disease: A consensus document.

A large evidence-based review on the effects of a moderate consumption of beer on human health has been conducted by an international panel of experts who reached a full consensus on the present document. Low-moderate (up to 1 drink per day in women, up to 2 in men), non-bingeing beer consumption, reduces the risk of cardiovascular disease. This effect is similar to that of wine, at comparable alcohol amounts. Epidemiological studies suggest that moderate consumption of either beer or wine may confer greater cardiovascular protection than spirits. Although specific data on beer are not conclusive, observational studies seem to indicate that low-moderate alcohol consumption is associated with a reduced risk of developing neurodegenerative disease. There is no evidence that beer drinking is different from other types of alcoholic beverages in respect to risk for some cancers. Evidence consistently suggests a J-shaped relationship between alcohol consumption (including beer) and all-cause mortality, with lower risk for moderate alcohol consumers than for abstainers or heavy drinkers. Unless they are at high risk for alcohol-related cancers or alcohol dependency, there is no reason to discourage healthy adults who are already regular light-moderate beer consumers from continuing. Consumption of beer, at any dosage, is not recommended for children, adolescents, pregnant women, individuals at risk to develop alcoholism, those with cardiomyopathy, cardiac arrhythmias, depression, liver and pancreatic diseases, or anyone engaged in actions that require concentration, skill or coordination. In conclusion, although heavy and excessive beer consumption exerts deleterious effects on the human body, with increased disease risks on many organs and is associated to significant social problems such as addiction, accidents, violence and crime, data reported in this document show evidence for no harm of moderate beer consumption for major chronic conditions and some benefit against cardiovascular disease.

Orange juice intake during a fatty meal consumption reduces the postprandial low-grade inflammatory response in healthy subjects.

BACKGROUND AND AIMS: Evidence associates polyphenol-rich foods to reduction of low-grade inflammation and mortality for cardiovascular disease, the mechanisms underlying such effects being still unclear. Consumption of a fatty meal by healthy volunteers induces rapid and reversible low-grade inflammation. The aim of the present study was to evaluate the effect of orange juice on cellular modifications induced by a fatty meal. METHODS AND RESULTS: 18 apparently healthy subjects consumed a fatty meal, during which they drunk orange juice, either blond or red, or water, according to a randomized cross-over design. Two hours after the end of the fatty meal, both white blood cell (WBC) and platelet counts significantly increased (12.5 and 5%, respectively), while mean platelet volume decreased and a 25% release of myeloperoxidase (MPO) from polymorphonuclear leukocyte occurred. Both juices significantly prevented WBC increase and MPO degranulation, in respect to control. Triglycerides significantly increased (42%) after the fatty meal, but at a lower extent when red orange juice was consumed with the meal (20%), in respect to blond orange juice or control. This effect was statistically significant in the subgroup of 8 subjects with hypertriglyceridemia. Vascular stiffness (augmentation index), measured by Endo-PAT2000, significantly decreased after the meal only in conjunction with red orange juice. CONCLUSION: In healthy subjects the concomitant intake of orange juice may prevent the low-grade inflammatory reaction induced by a fatty meal, at cellular and possibly at vascular function levels. The relative role of different polyphenols on the observed effects of orange juices remains to be established.

Recommendations for the Standardization of Light Transmission Aggregometry: A Consensus of the Working Party from the Platelet Physiology Subcommittee of SSC/ISTH.

Light transmission aggregometry (LTA) is the most common method used to assess platelet function. However, there is no universal standard for its performance. The Platelet Physiology Subcommittee of the Scientific and Standardization Committee (SSC) of the International Society on Thrombosis and Haemostasis formed a working party of experts with the aim of producing a series of consensus recommendations for standardizing LTA. Due to a lack of investigations that directly compared different methodologies to perform LTA studies, there were insufficient data to develop evidence-based guidelines. Therefore, the RAND method was used, which obtains a formal consensus among experts about the appropriateness of health care interventions, particularly when scientific evidence is absent, scarce and/or heterogeneous. Using this approach, each expert scored as "appropriate", "uncertain" or "inappropriate" a series of statements about the practice of LTA, which included pre-analytical variables, blood collection, blood processing, methodological details, choice of agonists and the evaluation and reporting of results. After presentation and public discussion at SSC meetings, the assessments were further refined to produce final consensus recommendations. Before delivering the recommendations, a formal literature review was performed using a series of defined search terms about LTA. Of the 1830 potentially relevant studies identified, only 14 publications were considered to be actually relevant for review. Based upon the additional information, 6 consensus statements were slightly modified. The final statements were presented and discussed at the SSC Meeting in Cairo (2010) and formed the basis of a consensus document, which is the subject of the present report. This article is protected by copyright. All rights reserved.

Heritability, genetic correlation and linkage to the 9p21.3 region of mixed platelet-leukocyte conjugates in families with and without early myocardial infarction.

BACKGROUND AND AIMS: Variations in mixed platelet-leukocyte conjugate formation in human whole blood could be genetically determined. We quantified platelet and leukocyte activation and interaction in families with or without early myocardial infarction and evaluated their heritability, genetic correlation and linkage to the 9p21.3 region. METHODS AND RESULTS: The study population included 739 subjects (≥ 15 years old) from 54 large pedigrees, 23 with and 31 without familial myocardial infarction. Mixed platelet-leukocyte conjugates and markers of platelet or leukocyte activation (P-selectin, CD11b and L-selectin surface expression) were measured both before and after in vitro blood stimulation with collagen-ADP. All traits had significant genetic components (17.5-65.3% of the phenotypic variability), while shared household effects (0-39.6%) and environmental covariates (0-10.2%) tended to be smaller. Stimulated platelet-polymorphonuclear leukocyte (PMN) and platelet-monocyte conjugates showed the highest linkage to the 9p21.3 region (LOD = 0.94 and 1.33, respectively; empirical p value = 0.017 and 0.009). PMN markers resulted strongly genetically correlated between them in bivariate analysis among pairs of quantitative traits. CONCLUSION: This study supports a genetic regulation of human mixed platelet-leukocyte conjugates.

Incomplete inhibition of platelet function as assessed by the platelet function analyzer (PFA-100) identifies a subset of cardiovascular patients with high residual platelet response while on aspirin.

Sixty-six patients with a history of ischemic events (myocardial infarction, unstable angina, or stroke) on chronic aspirin therapy were studied by different platelet function tests: 37 patients had suffered a recurrent event while on aspirin and 29 were without recurrences. Based on results from light transmission aggregometry (LTA) induced by arachidonic acid (AA) and serum TxB(2) both COX-1-dependent methods, only one patient could be identified as aspirin "resistant". However, when methods only partially-dependent on platelet COX-1 activity were considered, the prevalence of aspirin non-responders ranged, according to the different tests, from 0 to 52%. No difference was observed between patients with recurrences and those without. Among patients with recurrent events, those with an incomplete inhibition of platelet function, as assessed by the PFA-100, had significantly higher residual serum TxB(2) (2.4 ± 2.4 ng/mL vs 0.4 ± 0.1 ng/mL, p = 0.03), residual LTA-AA (9.2 ± 10.6% vs 2.0 ± 1.6%, p = 0.008), LTA-Coll (49.3 ± 14.6% vs 10.2 ± 8.3%, p = 0.007) and LTA-ADP (50.9 ± 16.2% vs 34.3 ± 11.0%, p = 0.04). In conclusion, laboratory tests solely exploring the AA-mediated pathway of platelet function, while being the most appropriate to detect the effect of aspirin on its pharmacologic target (platelet COX-1), may fail to reveal the functional interactions between minimal residual TxA(2) and additional stimuli or primers potentially leading to aspirin-insensitive platelet aggregation. High residual platelet response in platelet function tests only partially dependent on COX-1 may reveal a condition of persistent platelet reactivity in a subset of aspirin-treated patients characterizing them as a subgroup at higher vascular risk.

Genetic regulation of inflammation-mediated activation of haemostasis: family-based approaches in population studies.

Blood coagulation and inflammation play a key role in atherosclerosis and thrombosis. Candidate gene and genome wide association studies have identified potential specific genes that might have a causal role in these pathogenic processes. The analysis of quantitative traits is more powerful as they are closer to direct gene action than disease phenotypes. Thus linkage-based studies on extended families might be useful both to estimate the heritability and to map the genetic loci responsible for the regulation of the trait. Family-based studies may estimate high heritability for thrombosis and quantitative traits regarding both platelet aggregation and blood coagulation. Some specific loci relevant to thrombosis have been identified, with some of them showing a direct pleiotropic effect on the risk of thrombosis. Haemostasis factors can be activated by inflammatory stimuli. Fibrinogen level is genetically correlated with C-reactive protein levels with a link for both traits on chromosomes 12 and 21. Genes related to prostanoid biosynthesis, involved both in inflammation and thrombosis, show high heritability levels in both enzyme expression and prostanoid production. Considering that few large family-based linkage studies have as yet been performed on haemostasis and inflammation-related traits, additional studies are highly needed. We are performing a family-based linkage study on large pedigrees (750 subjects from 23 families with juvenile myocardial infarction and 31 control families), to identify genes responsible for quantitative traits involved in the pathway progressively going from inflammation to haemostasis, cell activation, thrombus formation and cardiovascular events.

Inhibition of tissue factor expression by hydroxyurea in polymorphonuclear leukocytes from patients with myeloproliferative disorders: a new effect for an old drug?

BACKGROUND: Polymorphonuclear leukocytes (PMN) from healthy subjects can produce and store tissue factor (TF), which is expressed on PMN surface upon in vitro stimulation with P-selectin. RESULTS: We report here that platelets and PMN from 12 patients with myeloproliferative disorders (MPD) (six with polycythemia vera, six with essential thrombocythemia) show up regulation of P-selectin and TF, respectively, in the absence of any in vitro challenge. The number of circulating mixed platelet-PMN aggregates was also increased. PMN TF expression as well as mixed platelet-PMN aggregates, but not platelet P-selectin, were significantly reduced in six MPD patients after treatment with hydroxyurea (HU). In vitro studies performed on PMN separated from healthy donors confirmed HU effects (0-1400 microm). HU prevented both P-selectin-induced TF expression and mixed cell aggregate formation. The inhibitory effect of HU was specific for P-selectin-induced PMN activation, as it did not affect formyl-methionyl-leucyl-phenylalanine-induced PMN TF expression. CONCLUSIONS: In MPD patients, platelet P-selectin-mediated TF expression on circulating PMN may play a role in thrombus formation and represents a novel target for the antithrombotic activity of HU.

Human polymorphonuclear leukocytes produce and express functional tissue factor upon stimulation.

BACKGROUND: Blood-borne tissue factor (TF) plays a crucial role in thrombogenesis. AIM: To study whether polymorphonuclear leukocytes (PMN) are a source of TF. METHODS AND RESULTS: Human PMN were carefully separated from other blood cells and stimulated for 3 min with purified P-selectin or the chemotactic peptide formyl-MetLeuPhe (fMLP): they expressed both TF procoagulant activity, as identified by specific TF MoAb and inactivated factor VIIa blockade; and TF:Ag (four to six times), as shown by flow-cytometry and immunocytochemistry. About 40% of permeabilized PMN, both resting and stimulated, contained TF:Ag, indicating that stimulation only modifies the location of TF:Ag within PMN. By real time-polymerase chain reaction (RT-PCR), a very low amount of TF mRNA was detectable in resting PMN, but a 3- to 5-fold increase was observed after 1-h stimulation with P-selectin or fMLP, respectively. CONCLUSIONS: These findings suggest that TF is not constitutively expressed in peripheral PMN, but can be up-regulated and produced upon stimulation and specific gene transcription, as for instance during contact with activated platelets or endothelium. The stored TF is rapidly expressed in vitro as a functional molecule on the surface of activated PMN. The availability of PMN TF supports the relevance of inflammatory cells and their interaction with platelets for fibrin deposition and thrombus formation.