An Evaluation of Platelet Factor 4, Beta-Thromboglobulin and Mean Platelet Volume in the Assessment of Thrombotic Risks in Subjects with Diabetes Mellitus at Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria.

BACKGROUND: Beta-thromboglobulin and platelet factor 4 are known platelet-specific proteins that are stored in the platelet alpha-granules and released during platelet activation. The measurement of these proteins can reflect the degree of platelet activation and indirectly suggest a pro-thrombotic state. This study aimed at determining serum levels of Betathromboglobulin, mean platelet volume, and platelet factor 4 in diabetes mellitus and control subjects in Lagos, Nigeria. MATERIALS AND METHODS: Using enzyme-linked immunosorbent assay at Lagos State University Teaching Hospital, Ikeja, this study evaluated serum concentrations of Beta-thromboglobulin, and platelet factor 4, the mean platelet volume was also determined from a Full Blood Count of all participants. Data were analyzed using Statistical Package for Social Sciences, Inc., Chicago, Ill; version 26.0. The continuous variables were given as mean ± standard deviation. The P-value was considered to be statistically significant when ≤0.05. RESULTS: Beta-thromboglobulin concentration was higher and statistically significant (7.82 ± 1.54ng/ml and 6.70 ± 2.23 ng/ml; P = 0.01), platelet factor 4 (39.86 ± 11.25 ng/ml and 47.73 ± 21.73ng/ml, P = 0.06) and mean platelet volume (10.26± 1.06fl and 10.29 ± 1.02fl P = 0.89) were not statistically significant in the diabetes mellitus group compared with non-diabetic participants, platelet factor 4 was higher in the older than younger diabetes mellitus participants. CONCLUSION: Elevated Beta-thromboglobulin may suggest a possible increase in thrombotic risks among diabetes mellitus.

CONTEXTE: La bêta-thromboglobuline et le facteur plaquettaire 4 sont des protéines spécifiques des plaquettes qui sont stockées dans les alpha-granules plaquettaires et libérées lors de l'activation des plaquettes. La mesure de ces protéines peut refléter le degré d'activation des plaquettes et suggérer indirectement un état prothrombotique. Cette étude visait à déterminer les taux sériques de bêta-thromboglobuline, le volume plaquettaire moyen et le facteur plaquettaire 4 chez des sujets atteints de diabète sucré et des sujets témoins à Lagos, au Nigéria. MATÉRIEL ET MÉTHODES: En utilisant le dosage immunoenzymatique au Lagos State University Teaching Hospital, Ikeja, cette étude a évalué les concentrations sériques de bêtathromboglobuline et de facteur plaquettaire 4, le volume plaquettaire moyen a également été déterminé à partir d'une numération globulaire complète de tous les participants. Les données ont été analysées à l'aide du logiciel Statistical Package for Social Sciences, Inc, Chicago,Ill ; version 26.0. Les variables continues ont été exprimées en moyen ± écart-type. La valeur P a été considérée comme statistiquement significative lorsqu'elle était inférieure à ≤0,05. RÉSULTATS: La concentration de bêta-thromboglobuline était plus élevée et statistiquement significative (7,82±1,54ng/ml et 6,70±2,23 ng/ml ; P=0,01), le facteur plaquettaire 4 (39,86±11,25 ng/ml et 47,73±21,73 ng/ml, P=0,06) et le volume plaquettaire moyen (10. 26± 1.06fl et 10.29±1.02fl P= 0.89) n'étaient pas statistiquement significatifs dans le groupe diabète sucré par rapport aux participants non-diabétiques, le facteur plaquettaire 4 était plus élevé chez les participants diabétiques plus âgés que chez les plus jeunes. CONCLUSION: Un taux élevé de bêta-thromboglobuline peutsuggérer une augmentation possible des risques thrombotiques chez les personnes atteintes de diabète sucré. Mots-clés: Bêta-thromboglobuline, facteur plaquettaire 4, volume plaquettaire moyen.

Exploring the changes of brain immune microenvironment in Alzheimer's disease based on PANDA algorithm combined with blood brain barrier injury-related genes.

Studies have shown that the specific entry of peripheral cells into the brain parenchyma caused by BBB injury and the imbalance of the immune microenvironment in the brain are closely related to the pathogenesis of Alzheimer's disease (AD). Because of the difficulty of obtaining data inside the brain, it is urgent to find out the relationship between the peripheral and intracerebral data and their influence on the development of AD by machine learning methods. However, in the actual algorithm design, it is still a challenge to extract relevant information from a variety of data to establish a complete and accurate regulatory network. In order to overcome the above difficulties, we presented a method based on a message passing model (Passing Attributes between Networks for Data Assimilation, PANDA) to discover the correlation between internal and external brain by the BBB injury-related genes, and further explore their regulatory mechanism of the brain immune environment for AD pathology. The Biological analysis of the results showed that pathways such as immune response pathway, inflammatory response pathway and chemokine signaling pathway are closely related to the pathogenesis of AD. Especially, some significant genes such as RELA, LAMA4, PPBP were found play certain roles in the injury of BBB and the change of permeability in AD patients, thus leading to the change of immune microenvironment in AD brain.

Increased Plasma Levels of Platelet Factor 4 and ß-thromboglobulin in Women with Recurrent Pregnancy Loss.

Thrombosis in decidual vessels is one of the mechanisms of pregnancy loss. However, few studies have assessed the relation between platelet activation, which is known to cause of thrombosis, and recurrent pregnancy loss (RPL). We investigated platelet activation in women with RPL compared to controls by measuring plasma levels of platelet factor 4 (PF4) and ß-thromboglobulin (ßTG), and assessed correlations between PF4/ßTG and coagulative risk factors associated with RPL. The study group included 135 women who had experienced two or more consecutive pregnancy losses. The control group included 28 age-matched healthy women who had never experienced pregnancy loss. PF4 and ßTG plasma levels were significantly higher in the women with RPL than controls (PF4: 14.0 [8.0-20.0] vs. 9.0 [6.0-12.0] ng/ml, p=0.043; ßTG: 42.0 [24.3-59.8] vs. 31.5 [26.6-36.4] ng/ml, p=0.002). There was a significant association between ßTG and anti-phosphatidylethanolamine antibody immunoglobulin M (aPE IgM) (p=0.048). Among the women with RPL, 18 of those who were positive for PF4 (45%) and 18 of those who were positive for ßTG (37%) were negative for all known coagulative risk factors associated with RPL. Measurements of PF4 and ßTG may be important because they help identify women who are at risk of RPL.

Comprehensive lipidomic, metabolomic and proteomic profiling reveals the role of immune system in vitiligo.

BACKGROUND: Vitiligo is a common depigmentation disorder resulting from destruction of melanocytes, and has both genetic and environmental influences. Although genomic analyses have been performed to investigate the pathogenesis of vitiligo, the lipidomics, metabolomics and proteomics of serum have not been reported, and the role of small molecules and serum proteins in vitiligo remains unknown. AIM: To study the metabolite and protein profiles in patients with vitiligo and healthy controls (HCs). METHODS: Plasma samples from 60 participants (29 patients with vitiligo and 31 HCs) were analysed. Untargeted lipidomics, metabolomics and isobaric tags for relative and absolute quantification-based proteomics were performed using high performance liquid chromatography-tandem mass spectrometry. In addition, to validate differentially expressed metabolites in patients with vitiligo, plasma enzyme-linked immunosorbent assay was performed. RESULTS: We identified differential expression of several metabolites and proteins involved in the immune system. Among these metabolites and proteins, lysophosphatidylcholine, platelet-activating factor, sn-glycerol-3-phosphocholine, succinic acid, CXCL4 and CXCL7 were significantly elevated in the plasma of patients with vitiligo, while aspartate was downregulated. CONCLUSION: Our study has characterized several serum metabolites and proteins that could be potential candidate biomarkers in vitiligo, and provides a comprehensive insight into the role of immune system and aspartate metabolism in vitiligo.

Platelet Depletion Impairs Host Defense to Pulmonary Infection with Pseudomonas aeruginosa in Mice.

Platelets have been implicated in pulmonary inflammatory cell recruitment after exposure to allergic and nonallergic stimuli, but little is known about the role of platelets in response to pulmonary infection with Pseudomonas aeruginosa. In this study, we have investigated the impact of the experimental depletion of circulating platelets on a range of inflammatory and bacterial parameters, and their subsequent impact on mortality in a murine model of pulmonary infection with P. aeruginosa. P. aeruginosa infection in mice induced a mild, but significant, state of peripheral thrombocytopenia in addition to pulmonary platelet accumulation. Increased platelet activation was detected in infected mice through increased levels of the platelet-derived mediators, platelet factor-4 and ß-thromboglobulin, in BAL fluid and blood plasma. In mice depleted of circulating platelets, pulmonary neutrophil recruitment was significantly reduced 24 hours after infection, whereas the incidence of systemic dissemination of bacteria was significantly increased compared with non-platelet-depleted control mice. Furthermore, mortality rates were increased in bacterial-infected mice depleted of circulating platelets. This work demonstrates a role for platelets in the host response toward a gram-negative bacterial respiratory infection.

rLj-RGD3, a novel recombinant toxin protein from Lampetra japonica, prevents coronary thrombosis-induced acute myocardial infarction by inhibiting platelet functions in rats.

Recombinant Lampetra japonica RGD-peptide (rLj-RGD3), a soluble protein containing three RGD sequences, was acquired from the oral salivary glands of Lampetra japonica using recombinant DNA technology. The aim of this study was to investigate the protective effects of rLj-RGD3 against acute myocardial infarction (AMI) induced by coronary artery thrombosis, as well as the underlying mechanisms. A rat model of AMI caused by ferric chloride-induced thrombosis on the surface of the left anterior descending (LAD) coronary artery was successfully established. Rats were given various doses of rLj-RGD3 (12 µg/kg, 24 µg/kg and 48 µg/kg) via sublingual intravenous delivery 10 min before AMI. ST segment elevation was recorded by electrocardiogram (ECG) until the end of the model. Left ventricular Evans blue content and histopathological changes were examined. Blood samples were collected to determine 5-hydroxytryptamine (5-HT), ß-thromboglobulin (ß-TG), platelet factor 4 (PF4) and cAMP levels. The effects of rLj-RGD3 on platelet aggregation, adhesion and intracellular calcium concentrations were also measured. rLj-RGD3 significantly reduced ST segment elevation, prevented thrombus formation in the coronary artery and decreased Evans blue content in the left ventricular myocardium. Meanwhile, rLj-RGD3 exerted an inhibitory effect on adenosine diphosphate (ADP)-induced platelet aggregation and blocked platelet adhesion to collagen. Treatment with rLj-RGD3 prevented 5-HT, ß-TG and PF4 release and significantly elevated intracellular cAMP levels in a dose-dependent manner but decreased the level of cytosolic-free Ca2+, an aggregation-inducing molecule. These results show that rLj-RGD3 can effectively reduce coronary thrombosis in AMI rats by strongly inhibiting platelet function, indicating that the recombinant RGD toxin protein rLj-RGD3 may serve as a potent clinical therapeutic agent for AMI.

CXCL7 is a predictive marker of sunitinib efficacy in clear cell renal cell carcinomas.

BACKGROUND: Sunitinib is one of the first-line standard treatments for metastatic clear cell renal cell carcinoma (ccRCC) with a median time to progression shorter than 1 year. The objective is to discover predictive markers of response to adapt the treatment at diagnosis. METHODS: Prospective phase 2 multi-centre trials were conducted in ccRCC patients initiating sunitinib (54 patients) or bevacizumab (45 patients) in the first-line metastatic setting (SUVEGIL and TORAVA trials). The plasmatic level of CXCL7 at baseline was correlated with progression-free survival (PFS). RESULTS: The cut-off value of CXCL7 for PFS was 250 ng ml-1. Patients with CXCL7 plasmatic levels above the cut-off at baseline (250 ng ml-1) had a significantly longer PFS (hazard ratio 0.323 (95% confidence interval 0.147-0.707), P=0.001). These results were confirmed in a retrospective validation cohort. The levels of CXCL7 did not influence PFS of the bevacizumab-treated patients. CONCLUSIONS: CXCL7 may be considered as a predictive marker of sunitinib efficacy for ccRCC patients.

Higher platelet reactivity and platelet-monocyte complex formation in Gram-positive sepsis compared to Gram-negative sepsis.

Platelets may play a role in the high risk for vascular complications in Gram-positive sepsis. We compared the platelet reactivity of 15 patients with Gram-positive sepsis, 17 with Gram-negative sepsis and 20 healthy controls using a whole blood flow cytometry-based assay. Patients with Gram-positive sepsis had the highest median fluorescence intensity (MFI) of the platelet membrane expression of P-selectin upon stimulation with high dose adenosine diphosphate (ADP; P = 0.002 vs. Gram-negative and P = 0.005 vs. control groups) and cross-linked collagen-related peptide (CRP-XL; P = 0.02 vs. Gram-negative and P = 0.0001 vs. control groups). The Gram-positive group also demonstrated significantly higher ADP-induced fibrinogen binding (P = 0.001), as wll as platelet-monocyte complex formation (P = 0.02), compared to the Gram-negative group and had the highest plasma levels of platelet factor 4, ß-thromboglobulin and soluble P-selectin. In contrast, thrombin-antithrombin complex and C-reactive protein levels were comparable in both patient groups. In conclusion, common Gram-positive pathogens induce platelet hyperreactivity, which may contribute to a higher risk for vascular complications.

ß-Thromboglobulin may not reflect platelet activation during haemodialysis with the HeprAN membrane.

BACKGROUND: When blood passes through the extracorporeal circuit during haemodialysis (HD) undesirable effects including platelet degranulation and coagulation activation take place. ß-thromboglobulin (ß-TG) is a sensitive marker of platelet activation. The aim of this study was to investigate platelet degranulation and coagulation activation during HD with the heparin-coated dialysis membrane HeprAN. METHODS: Four HD sessions were evaluated in each of 12 chronic HD patients. None of the patients used oral warfarin, other anticoagulants or antiplatelet drugs. In the first session the HeprAN membrane or a conventional polyflux membrane was used in a randomized manner and thereafter alternately in a cross-over design, and 50% of the conventional dalteparin dose was given at start of HD. Prothrombin fragment 1 + 2 (PF1 + 2), ß-TG and anti-factor Xa activity were measured repeatedly. RESULTS: No dialysis sessions were terminated early due to clotting of the extracorporeal system. Activation of intravascular coagulation as assessed by change in PF1 + 2 during 4 hours of HD was the same with the two membranes. ß-TG concentration decreased significantly during 4 hours of HD with the HeprAN membrane but remained stable with the polyflux membrane. CONCLUSION: There were no differences in clotting scores or coagulation activation with the two membranes. The decrease in ß-TG during HD with the HeprAN membrane suggests ß-TG to be an inferior marker of platelet degranulation when using a heparin-coated dialysis membrane. A possible mechanism for the decline in ß-TG concentration may be adherence of this heparin-binding protein to the heparin-coated dialysis membrane.

PPBP and DEFA1/DEFA3 genes in hyperlipidaemia as feasible synergistic inflammatory biomarkers for coronary heart disease.

BACKGROUND: Coronary heart disease (CHD) is an important complication of atherosclerosis. Biomarkers, which associate with CHD development, are potential to predict CHD risk. To determine whether genes showing altered expression in hyperlipidaemia (H) and coronary heart disease (CHD) patients compared with controls could be CHD risk biomarkers. METHODS: Control, H, and CHD groups represented atherosclerosis to CHD development. Gene profiling was investigated in peripheral blood mononuclear cells using DNA microarrays. Eight selected genes expressed only in H and CHD groups were validated by real-time quantitative reverse transcription PCR and plasma protein determination. RESULTS: α-defensin (DEFA1/DEFA3), pro-platelet basic protein (PPBP), and beta and alpha2 hemoglobin mRNA expression was significantly increased in H and CHD groups compared with controls, but only plasma PPBP and α-defensin proteins were correspondingly increased. CONCLUSION: PPBP and DEFA1/DEFA3 could be potential CHD biomarkers in Thai hyperlipidaemia patients.

Structural Basis of Native CXCL7 Monomer Binding to CXCR2 Receptor N-Domain and Glycosaminoglycan Heparin.

CXCL7, a chemokine highly expressed in platelets, orchestrates neutrophil recruitment during thrombosis and related pathophysiological processes by interacting with CXCR2 receptor and sulfated glycosaminoglycans (GAG). CXCL7 exists as monomers and dimers, and dimerization (~50 µM) and CXCR2 binding (~10 nM) constants indicate that CXCL7 is a potent agonist as a monomer. Currently, nothing is known regarding the structural basis by which receptor and GAG interactions mediate CXCL7 function. Using solution nuclear magnetic resonance (NMR) spectroscopy, we characterized the binding of CXCL7 monomer to the CXCR2 N-terminal domain (CXCR2Nd) that constitutes a critical docking site and to GAG heparin. We found that CXCR2Nd binds a hydrophobic groove and that ionic interactions also play a role in mediating binding. Heparin binds a set of contiguous basic residues indicating a prominent role for ionic interactions. Modeling studies reveal that the binding interface is dynamic and that GAG adopts different binding geometries. Most importantly, several residues involved in GAG binding are also involved in receptor interactions, suggesting that GAG-bound monomer cannot activate the receptor. Further, this is the first study that describes the structural basis of receptor and GAG interactions of a native monomer of the neutrophil-activating chemokine family.

Chemokine CXCL7 Heterodimers: Structural Insights, CXCR2 Receptor Function, and Glycosaminoglycan Interactions.

Chemokines mediate diverse fundamental biological processes, including combating infection. Multiple chemokines are expressed at the site of infection; thus chemokine synergy by heterodimer formation may play a role in determining function. Chemokine function involves interactions with G-protein-coupled receptors and sulfated glycosaminoglycans (GAG). However, very little is known regarding heterodimer structural features and receptor and GAG interactions. Solution nuclear magnetic resonance (NMR) and molecular dynamics characterization of platelet-derived chemokine CXCL7 heterodimerization with chemokines CXCL1, CXCL4, and CXCL8 indicated that packing interactions promote CXCL7-CXCL1 and CXCL7-CXCL4 heterodimers, and electrostatic repulsive interactions disfavor the CXCL7-CXCL8 heterodimer. As characterizing the native heterodimer is challenging due to interference from monomers and homodimers, we engineered a "trapped" disulfide-linked CXCL7-CXCL1 heterodimer. NMR and modeling studies indicated that GAG heparin binding to the heterodimer is distinctly different from the CXCL7 monomer and that the GAG-bound heterodimer is unlikely to bind the receptor. Interestingly, the trapped heterodimer was highly active in a Ca2+ release assay. These data collectively suggest that GAG interactions play a prominent role in determining heterodimer function in vivo. Further, this study provides proof-of-concept that the disulfide trapping strategy can serve as a valuable tool for characterizing the structural and functional features of a chemokine heterodimer.

Expression of chemokines CXCL4 and CXCL7 by synovial macrophages defines an early stage of rheumatoid arthritis.

BACKGROUND AND OBJECTIVES: For our understanding of the pathogenesis of rheumatoid arthritis (RA), it is important to elucidate the mechanisms underlying early stages of synovitis. Here, synovial cytokine production was investigated in patients with very early arthritis. METHODS: Synovial biopsies were obtained from patients with at least one clinically swollen joint within 12 weeks of symptom onset. At an 18-month follow-up visit, patients who went on to develop RA, or whose arthritis spontaneously resolved, were identified. Biopsies were also obtained from patients with RA with longer symptom duration (>12 weeks) and individuals with no clinically apparent inflammation. Synovial mRNA expression of 117 cytokines was quantified using PCR techniques and analysed using standard and novel methods of data analysis. Synovial tissue sections were stained for CXCL4, CXCL7, CD41, CD68 and von Willebrand factor. RESULTS: A machine learning approach identified expression of mRNA for CXCL4 and CXCL7 as potentially important in the classification of early RA versus resolving arthritis. mRNA levels for these chemokines were significantly elevated in patients with early RA compared with uninflamed controls. Significantly increased CXCL4 and CXCL7 protein expression was observed in patients with early RA compared with those with resolving arthritis or longer established disease. CXCL4 and CXCL7 co-localised with blood vessels, platelets and CD68(+) macrophages. Extravascular CXCL7 expression was significantly higher in patients with very early RA compared with longer duration RA or resolving arthritis CONCLUSIONS: Taken together, these observations suggest a transient increase in synovial CXCL4 and CXCL7 levels in early RA.

Comparative study to evaluate the effects of peritoneal and hemodialysis on peripheral nerve function.

INTRODUCTION: There is no specific treatment for neuropathy in chronic kidney disease (CKD). We compared nerve function across hemodialysis (HD) and peritoneal dialysis (PD). METHODS: Subjects underwent neurological assessment and neurophysiological testing using nerve excitability studies. Pre- and postdialysis studies were undertaken in HD (n = 10) and PD (n = 10) patients and were compared with stage 4 CKD patients (n = 12) and healthy controls (n = 20). RESULTS: There were prominent differences in nerve excitability between the groups (P < 0.001). The HD group was significantly abnormal compared with all groups for excitability parameters, while the PD group demonstrated results similar to the CKD group. Pre- and postdialysis fluctuations were pronounced in the HD group, while the PD group showed less severe fluctuations. CONCLUSIONS: PD patients demonstrated greater normality of nerve excitability compared with the HD group despite similar duration of dialysis. These results suggest PD may provide greater homeostatic stability and may be neurologically beneficial. Muscle Nerve 54: 58-64, 2016.

Elevated levels of the neutrophil chemoattractant pro-platelet basic protein in macrophages from individuals with chronic and allergic aspergillosis.

BACKGROUND: Aspergillus fumigatus causes chronic cavitary pulmonary aspergillosis (CCPA) and allergic bronchopulmonary aspergillosis (ABPA) in overtly immunocompetent and atopic individuals, respectively. Disease mechanisms are poorly understood but may be related to increased neutrophil presence and activation. Pro-platelet basic protein (PPBP) is a potent neutrophil chemoattractant and activator whose expression is repressed by interleukin 10 (IL-10). METHODS: PPBP expression by monocyte-derived macrophages from patients with ABPA or CCPA and asthmatic and healthy controls (10 individuals per group) was analyzed using reverse-transcription polymerase chain reaction. PPBP and IL-10 protein levels in cell culture supernatants were measured by enzyme-linked immunosorbent assay. Two PPBP single-nucleotide polymorphisms (SNPs) were genotyped in 638 individuals. The gene was resequenced in 20 individuals. RESULTS: PPBP expression and protein levels were significantly increased in the ABPA (19.7-fold) and CCPA (27.7-fold) groups, compared with the control groups. PPBP SNPs were not associated with disease. IL-10 protein levels were significantly lower in the ABPA and CCPA groups, compared with the healthy group, suggesting that differences in PPBP levels may result from regulatory mechanisms. CONCLUSIONS: The results suggest a role for increased PPBP expression in ABPA and CCPA. Repression of PPBP expression may benefit some patients. Increased PPBP expression in ABPA and CCPA may be useful as a future diagnostic tool or possible target for novel therapeutics.

Dynamics and thermodynamic properties of CXCL7 chemokine.

Chemokines form a family of signaling proteins mainly responsible for directing the traffic of leukocytes, where their biological activity can be modulated by their oligomerization state. We characterize the dynamics and thermodynamic stability of monomer and homodimer structures of CXCL7, one of the most abundant platelet chemokines, using experimental methods that include circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy, and computational methods that include the anisotropic network model (ANM), molecular dynamics (MD) simulations and the distance constraint model (DCM). A consistent picture emerges for the effects of dimerization and Cys5-Cys31 and Cys7-Cys47 disulfide bonds formation. The presence of disulfide bonds is not critical for maintaining structural stability in the monomer or dimer, but the monomer is destabilized more than the dimer upon removal of disulfide bonds. Disulfide bonds play a key role in shaping the characteristics of native state dynamics. The combined analysis shows that upon dimerization flexibly correlated motions are induced between the 30s and 50s loop within each monomer and across the dimer interface. Interestingly, the greatest gain in flexibility upon dimerization occurs when both disulfide bonds are present, and the homodimer is least stable relative to its two monomers. These results suggest that the highly conserved disulfide bonds in chemokines facilitate a structural mechanism that is tuned to optimally distinguish functional characteristics between monomer and dimer.

Circulating levels of platelet α-granule cytokines in trauma patients.

OBJECTIVE AND DESIGN: To elucidate whether platelets differentiate cytokine release following trauma, we prospectively measured three major platelet-derived cytokines in 213 trauma patients on hospital arrival. METHODS: We measured plasma levels of the anti-inflammatory ß-thromboglobulins (ßTGs), transforming growth factor-ß1 (TGFß1) and the pro-inflammatory platelet factor 4 (PF4) cytokines. We also measured soluble glycoprotein VI (sGPVI), procoagulant platelet microparticles (PMPs) and white blood cell (WBC) counts, and evaluated in vitro platelet function in primary and secondary haemostasis by aggregometry and thromboelastometry, respectively. We evaluated associations of each cytokine by multivariate regression including injury severity score (ISS), WBC counts, sGPVI and platelet counts as explanatory variables. RESULTS: Severely injured patients (ISS > 15) had higher levels of ßTGs and TGFß1 (both p < 0.01) but lower levels of PF4 (p = 0.02). GPVI and PMPs levels correlated with TGFß1 and PF4 whereas we found no significant association between cytokine levels and measures of haemostasis. By multivariate regression, a high WBC count was associated with high levels of TGFß1 (p = 0.01) and ßTGs (p < 0.01) but with low levels of PF4 (p = 0.03). CONCLUSION: Severely injured patients had higher levels of ßTGs and TGFß1 but lower levels of the PF4; a high WBC count predicted this anti-inflammatory profile of platelet cytokines.

[Hormonal and Metabolic Differences in Patients With Coronary Artery Disease].

OBJECTIVE: To prove the involvement of the autonomic nervous system in the formation of thrombotic status of the patients. 24 patients with myocardial infarction were enrolled in the study. Catecholamines levels were compared duing pain episodes and at rest. Patients were divided in to 2 groups according to the level of norepinephrine during the pain episode: Group 1-12 persons with the level of norepinephrine more than 500 pg/ml, and group 2-12 persons with a level below 500 pg/ml. Patients in group 1 the level of beta thromboglobulin and thromboxane were elevated, as well as there are changes of cAMP and cGMP, indicating increased thrombogenic activity. Particular attention was paid to the 8 patients in Group 1, in which the level of norepinephrine is maintained above 500 pg/ml both during pain and at rest (disseminated intravascular coagulation).

Venous plasma serotonin is not a proper biomarker for pulmonary arterial hypertension.

OBJECTIVES: Serotonin (5-HT) most likely plays an important role in the pathogenesis of pulmonary arterial hypertension (PAH). We aimed to test if venous plasma 5-HT is a potential biomarker of PAH. We also measured venous blood ß-thromboglobulin (ß-TG) in all participants to ensure that any increase in serotonin levels measured is due to platelet release. DESIGN: Blood samples from patients (n = 9) with pulmonary arterial hypertension (Group 1 of the World Health Organization classification of pulmonary hypertension) as well as healthy volunteers (n = 9) were analyzed. We used enzyme-linked immunosorbent assay (ELISA) to measure venous platelet-poor plasma 5-HT and ß-TG in patients with pulmonary arterial hypertension (PAH) and in age-matched normal controls. RESULTS: Venous platelet-free plasma 5-HT and ß-TG were almost similar in patients with PAH and healthy controls with only a slight trend toward increased 5-HT levels in patients with PAH. No correlation was found between venous platelet-poor plasma 5-HT and disease severity. There was no association between venous plasma 5-HT and the mean pulmonary artery pressure. CONCLUSIONS: Our data suggest that 5-HT is not significantly elevated in venous platelet-free plasma in patients with PAH and may accordingly not be a useful biomarker in this condition.

Molecular Biomarkers for In Vitro Thrombogenicity Assessment of Medical Device Materials.

To develop standardized in vitro thrombogenicity test methods for evaluating medical device materials, three platelet activation biomarkers, beta-thromboglobulin (ß-TG), platelet factor 4 (PF4), soluble p-selectin (CD62P), and a plasma coagulation marker, thrombin-antithrombin complex (TAT), were investigated. Whole blood, drawn from six healthy human volunteers into Anticoagulant Citrate Dextrose Solution A was recalcified and heparinized over a concentration range of 0.5-1.5 U/mL. The blood was incubated with test materials with different thrombogenic potentials for 60 min at 37°C, using a 6 cm2/mL material surface area to blood volume ratio. After incubation, the blood platelet count was measured before centrifuging the blood to prepare platelet-poor plasma (PPP) and platelet-free plasma (PFP) for enzyme-linked immunosorbent assay analysis of the biomarkers. The results show that all four markers effectively differentiated the materials with different thrombogenic potentials at heparin concentrations from 1.0 to 1.5 U/mL. When a donor-specific heparin concentration (determined by activated clotting time) was used, the markers were able to differentiate materials consistently for blood from all the donors. Additionally, using PFP instead of PPP further improved the test method's ability to differentiate the thrombogenic materials from the negative control for ß-TG and TAT. Moreover, the platelet activation markers were able to detect reversible platelet activation induced by adenosine diphosphate (ADP). In summary, all three platelet activation markers (ß-TG, PF4, and CD62P) can distinguish thrombogenic potentials of different materials and detect ADP-induced reversible platelet activation. Test consistency and sensitivity can be enhanced by using a donor-specific heparin concentration and PFP. The same test conditions are applicable to the measurement of coagulation marker TAT.