kaolinite and Thrombophilia

Age, race, and gender differences in coagulation status of healthy volunteers have been reported in previous case series; however, rigorous multivariate analysis adjusting for these factors is lacking. We aimed to investigate the effects of age, race, and gender on baseline coagulation status in healthy volunteers.. Thirty healthy volunteer controls with no history of bleeding or thrombotic events and no previous anticoagulant or antiplatelet use were recruited. Citrated and heparinized blood samples were drawn, and kaolin and platelet-mapping thromboelastography (TEG) assays performed.. Thirty participants had a mean age of 37, mean body mass index of 29 kg/m. Women at baseline have relatively hypercoagulable fibrin deposition kinetics, platelet contributions to clot formation, and overall clot strength compared to men, even when adjusted for age and race. Additional research is needed to specifically detail the key patient-level factors, clinical implications, and opportunities for tailored therapy related to gender-associated hypercoagulability.

Topics: Adult; Anticoagulants; Female; Fibrin; Humans; Kaolin; Male; Thrombelastography; Thrombophilia; Thrombosis

OBJECTIVE To validate that dogs become hypocoagulable following rattlesnake envenomation and to determine whether thromboelastographic abnormalities are correlated with envenomation severity for dogs bitten by rattlesnakes native to southern California. ANIMALS 14 dogs with observed or suspected rattlesnake envenomation (envenomated dogs) and 10 healthy control dogs. PROCEDURES For each dog, a citrate-anticoagulated blood sample underwent kaolin-activated thromboelastography. For each envenomated dog, a snakebite severity score was assigned on the basis of clinical findings, and prothrombin time, activated partial thromboplastin time, and platelet count were determined when the attending clinician deemed it necessary and owner finances allowed. RESULTS For 12 of 14 envenomated dogs, the thromboelastographically determined clot strength was below the 25th percentile for the clot strength of control dogs, which was indicative of a hypocoagulable state. No envenomated dog had thromboelastographic results indicative of a hypercoagulable state. One envenomated dog had a prolonged prothrombin time, but the activated partial thromboplastin time and all thromboelastographic variables were within the respective reference ranges for that dog. Seven of 13 envenomated dogs were thrombocytopenic (platelet count, ≤ 170,000 platelets/μL). Snakebite severity score was negatively correlated with platelet count but was not correlated with any thromboelastographic variable. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dogs generally become hypocoagulable following rattlesnake envenomation. Thromboelastography might provide an objective measure of the coagulation status of envenomated dogs and aid in the identification of dogs that are in a hypocoagulable state and in need of antivenin treatment prior to the onset of progressive clinical signs.

Topics: Animals; Antivenins; Blood Coagulation; California; Crotalus; Dog Diseases; Dogs; Female; Humans; Kaolin; Male; Partial Thromboplastin Time; Platelet Count; Prospective Studies; Prothrombin Time; Snake Bites; Thrombelastography; Thrombophilia

Energy drink consumption in the United States has more than doubled over the last decade and has been implicated in cardiac arrhythmias, myocardial infarction, and even sudden cardiac death. We hypothesized that energy drink consumption may increase the risk of adverse cardiovascular events by increasing platelet aggregation, thereby resulting in a relatively hypercoagulable state and increased risk of thrombosis.. Thirty-two healthy volunteers aged 18-40 y were given 16 oz of bottled water or a standardized, sugar-free energy drink on two separate occasions, 1-wk apart. Beverages were consumed after an overnight fast over a 30-min period. Coagulation parameters and platelet function were measured before and 60 min after consumption using thrombelastography and impedance aggregometry.. No statistically significant differences in coagulation were detected using kaolin or rapid thrombelastography. In addition, no differences in platelet aggregation were detected using ristocetin, collagen, thrombin receptor-activating peptide, or adenosine diphosphate-induced multiple impedance aggregometry. However, compared to water controls, energy drink consumption resulted in a significant increase in platelet aggregation via arachidonic acid-induced activation (area under the aggregation curve, 72.4 U versus 66.3 U; P = 0.018).. Energy drinks are associated with increased platelet activity via arachidonic acid-induced platelet aggregation within 1 h of consumption. Although larger clinical studies are needed to further address the safety and health concerns of these drinks, the increased platelet response may provide a mechanism by which energy drinks increase the risk of adverse cardiovascular events.

Topics: Adult; Arachidonic Acid; Energy Drinks; Female; Healthy Volunteers; Humans; Kaolin; Male; Platelet Aggregation; Platelet Function Tests; Random Allocation; Thrombelastography; Thrombophilia; Young Adult

Inflammation is implicated in the progression of coronary artery disease and the molecular processes of inflammation and thrombosis are closely intertwined. Elevated levels of C-reactive protein (CRP) have been associated with an elevated risk of adverse ischaemic events after coronary stenting and hypercoagulability. Heightened whole blood clot strength measured by thrombelastography (TEG) has been associated with adverse ischaemic events after stenting. We intended to examine the relationship of CRP to plasma fibrin clot strength in patients after coronary stenting. Plasma fibrin clot strength was measured by TEG in 54 patients 16-24 h after undergoing elective percutaneous coronary intervention (PCI). Coagulation was induced in citrated plasma by addition of kaolin and CaCl2. Plasma levels of CRP and fibrinogen were measured by enzyme-linked immunoassay. Increasing quartiles of CRP were associated with increasing levels of maximal plasma fibrin clot strength measured by TEG (P < 0.001) and increasing BMI (P = 0.04). Patients in the highest quartile of CRP had significantly higher maximal fibrin clot strength (G) than the patients in the lowest quartile (G: 3438 ± 623 vs. 2184 ± 576 dyn/cm, P < 0.0001). Fibrinogen concentration was not significantly different across quartiles of CRP (P = 0.97). Patients with established coronary artery disease undergoing coronary stenting who have elevated CRP after PCI exhibit heightened maximal plasma fibrin clot strength as compared with those with low CRP. Thrombotic risk associated with elevated CRP may be linked to procoagulant changes and high tensile fibrin clot strength independent of fibrinogen concentration.

Topics: Aged; Angioplasty, Balloon, Coronary; Blood Coagulation; C-Reactive Protein; Calcium Chloride; Coronary Artery Disease; Female; Fibrin; Fibrinogen; Humans; Inflammation; Kaolin; Male; Middle Aged; Risk Factors; Stents; Thrombelastography; Thrombophilia; Thrombosis

Thromboelastography (TEG) evaluates the visco-elastic properties of whole blood to assess clot formation and hemostasis. When blood cannot be analyzed immediately, it is stored in citrated tubes to be analyzed after recalcification. In this study, we evaluated the results of TEG analysis performed on citrated blood and compared these results to values obtained from activated (kaolin and tissue factor) and non activated, fresh blood samples, obtained at various time intervals (one, two, and three hours).. Four blood samples were collected from each of ten healthy volunteers. The following TEG analyses were performed on each sample: reaction time (r), k time (k), alpha angle (alpha), and maximum amplitude (MA). Studies were done using fresh, non citrated blood, obtained within five minutes of collection, and using citrated blood, one, two, and three hours after collection. Samples were analyzed, with and without activation, using kaolin and tissue factor.. Tissue factor activated and non activated, citrated samples had shorter r and k times (P=0.03, P=0.008, P<0.0001, and P<0.0001, respectively) and higher alpha angle and MA values (P<0.0001, P<0.0001, P=0.79, and P=0.03, respectively) compared to fresh, non citrated samples. These findings were consistent with a hypercoagulable state. Conversely, citrated samples, activated with kaolin, yielded results similar to those obtained from fresh, non citrated samples. The TEG measurements were similar among citrated samples stored from one to three hours.. Our results demonstrate that TEG measures, performed on citrated blood samples, yield results that are consistent with a hyperocoagulable state. Using kaolin to activate citrated samples, on the other hand, yields results similar to those obtained from non citrated, fresh blood samples.

Topics: Adult; Blood Coagulation; Blood Specimen Collection; Citrates; Female; Humans; Kaolin; Male; Thrombelastography; Thrombophilia; Thromboplastin; Time Factors; Treatment Outcome; Whole Blood Coagulation Time

Antiprothrombin and anti-beta2-glycoprotein I (beta2-GPI) antibodies belong to the family of antiphospholipid (APL) antibodies and represent the phospholipid-dependent inhibitors of coagulation. They may be distinguished by analyzing the coagulation profiles generated by the comparison of the ratios of two coagulation tests, the Kaolin Clotting Time (KCT) and the dilute Russell's Viper Venom Time (dRVVT), commonly adopted for their diagnosis. The KCT profile is caused by antiprothrombin antibodies, whereas anti-beta2-GPI antibodies are responsible for the dRVVT coagulation profile. The presence of aPL antibodies is frequently associated with acquired resistance to activated Protein C (APC-R), but limited information is available regarding the role of the different antibodies in its development. We studied the time-course of activated Factor V (FVa) generation and inactivation in the plasma of 42 patients with well-defined phospholipid-dependent inhibitors of coagulation: 24 displayed the dRVVT coagulation profile, whereas the other 18 cases showed the KCT profile. In normal pooled plasma, the peak values of FVa (mean +/- standard deviation, [SD]: 16.307 +/- 4.372 U/mL) were reached in 4 to 5 minutes and an almost complete inactivation (0.088 +/- 0.123 U/mL) was obtained within 20 minutes. At this time point, values of residual FVa exceeding 2 SD the mean of controls (0.344 U/mL) were considered abnormal. Patients belonging to the KCT coagulation profile group reached the maximal amount of FVa in plasma (22.740 +/- 7.693 U/mL, P = not significant v controls) within 4 to 5 minutes; at 20 minutes, the residual amount of FVa in plasma ranged from 0 to 1.09 U/mL (0.293 +/- 0.298; P = .027), but it was found abnormal in only six of the 18 cases. The time-course of FVa in plasma of patients belonging to the dRVVT coagulation profile group differed from that of normal controls in that the peak values (10.955 +/- 5.092 U/mL) were reached at 10 minutes and the amount of residual FVa at 20 minutes ranged from 0.320 to 14.450 U/ml (2.544 +/- 3.580 U/mL; P = .0191 v normal controls and P = . 0114 v KCT group patients). Twenty of the 24 patients belonging to the dRVVT profile group had an abnormal inactivation of FVa (chi2 = 0.001 v KCT group patients). History of venous thrombosis was experienced by 15 patients: an abnormal rate of FVa inactivation was found in 11 of them (73%) versus 15 of the 27 cases without thrombosis (56%) (x2 = 0.2556). The effect of affinity-pu

Topics: Adult; Aged; Antibodies, Antiphospholipid; Antibody Specificity; Antiphospholipid Syndrome; Autoimmune Diseases; beta 2-Glycoprotein I; Blood Coagulation; Blood Coagulation Tests; Enzyme Activation; Factor Va; Female; Glycoproteins; Humans; Immunoglobulin G; Immunoglobulin M; Kaolin; Male; Middle Aged; Protein C; Prothrombin; Prothrombin Time; Thrombophilia