Reciprocal stabilization of coagulation factor XIII-A and -B subunits is a determinant of plasma FXIII concentration.

ABSTRACT: Transglutaminase factor XIII (FXIII) is essential for hemostasis, wound healing, and pregnancy maintenance. Plasma FXIII is composed of A and B subunit dimers synthesized in cells of hematopoietic origin and hepatocytes, respectively. The subunits associate tightly in circulation as FXIII-A2B2. FXIII-B2 stabilizes the (pro)active site-containing FXIII-A subunits. Interestingly, people with genetic FXIII-A deficiency have decreased FXIII-B2, and therapeutic infusion of recombinant FXIII-A2 (rFXIII-A2) increases FXIII-B2, suggesting FXIII-A regulates FXIII-B secretion, production, and/or clearance. We analyzed humans and mice with genetic FXIII-A deficiency and developed a mouse model of rFXIII-A2 infusion to define mechanisms mediating plasma FXIII-B levels. Like humans with FXIII-A deficiency, mice with genetic FXIII-A deficiency had reduced circulating FXIII-B2, and infusion of FXIII-A2 increased FXIII-B2. FXIII-A-deficient mice had normal hepatic function and did not store FXIII-B in liver, indicating FXIII-A does not mediate FXIII-B secretion. Transcriptional analysis and polysome profiling indicated similar F13b levels and ribosome occupancy in FXIII-A-sufficient and -deficient mice and in FXIII-A-deficient mice infused with rFXIII-A2, indicating FXIII-A does not induce de novo FXIII-B synthesis. Unexpectedly, pharmacokinetic/pharmacodynamic modeling of FXIII-B antigen after rFXIII-A2 infusion in humans and mice suggested FXIII-A2 slows FXIII-B2 loss from plasma. Accordingly, comparison of free FXIII-B2 vs FXIII-A2-complexed FXIII-B2 (FXIII-A2B2) infused into mice revealed faster clearance of free FXIII-B2. These data show FXIII-A2 prevents FXIII-B2 loss from circulation and establish the mechanism underlying FXIII-B2 behavior in FXIII-A deficiency and during rFXIII-A2 therapy. Our findings reveal a unique, reciprocal relationship between independently synthesized subunits that mediate an essential hemostatic protein in circulation. This trial was registered at www.ClinicalTrials.com as #NCT00978380.

Platelet and cryoprecipitate transfusions from female donors improve coagulopathy in vitro.

BACKGROUND: Females are relatively hypercoagulable compared with males, with increased platelet aggregation and improved clot dynamics. However, sex differences in coagulation have not yet been considered in transfusion guidelines. Therefore, our objective was to evaluate hemostatic differences in sex concordant and sex discordant cryoprecipitate and platelet transfusions. We hypothesized that transfusion of blood products from female donors results in improved coagulopathy compared with male blood products. METHODS: This was a cohort study evaluating sex dimorphisms in coagulation assays and clotting factors in healthy volunteer plasma and cryoprecipitate. Sex dimorphisms in transfusions were evaluated using an in vitro coagulopathy model. Female or male platelets or single-donor cryoprecipitate was added to "recipient" whole blood after dilution of recipient blood with citrated saline to provoke a coagulopathic profile. Citrated native thromboelastography was then performed. Liquid chromatography/mass spectroscopy was performed on single-donor cryoprecipitate to evaluate sex dimorphisms in the proteome of cryoprecipitate. RESULTS: Females have an increased proportion of functional fibrinogen. Transfusion of female-donor platelets and cryoprecipitate induces a larger decrease in R time and greater increase in angle than male-donor platelets or cryoprecipitate. Female-donor cryoprecipitate has increased factor V and factor XIII compared with male cryoprecipitate, and comprehensive proteomics revealed sex differences in several proteins with potential immunological significance. CONCLUSION: Platelets and cryoprecipitate from female donors improve coagulopathy more than male blood products in vitro. Increased factor V and factor XIII activity as well as increased fibrinogen activity in female donors appears to drive this disparity. Sex differences in the proteome of cryoprecipitate may influence how transfusions modulate the thromboinflammation of trauma. The differing hemostatic profiles of female and male blood products suggest the potential role of sex-specific transfusions guidelines in hemostatic resuscitation.

More Pronounced Hypercoagulable State and Hypofibrinolysis in Patients With Cirrhosis With Versus Without HCC.

In patients with cirrhosis, particularly those with hepatocellular carcinoma (HCC), hypercoagulability may be associated with purported increased risks of portal vein thrombosis and cirrhosis progression. In this study, we extensively investigated hemostatic alterations potentially responsible for the thrombotic tendency in HCC, and evaluated whether such alterations were predictive of hepatic decompensation. Patients with cirrhosis at all stages were prospectively recruited and underwent an extensive hemostatic assessment, including all procoagulant factors and inhibitors, thrombin generation with and without thrombomodulin (TG), profibrinolytic and antifibrinolytic factors, and plasmin-antiplasmin complex. In study part 1 (case control), we compared alterations of coagulation and fibrinolysis in patients with cirrhosis with versus without HCC. In study part 2 (prospective), the subgroup of patients with decompensated cirrhosis was followed for development of further decompensation, and predictors of outcome were assessed by multivariate analysis. One-hundred patients were recruited (50 each with and without HCC). Severity of cirrhosis was comparable between groups. Median HCC volume was 9 cm3 (range: 5-16). Compared with controls, patients with HCC demonstrated a significantly more prothrombotic hemostatic profile due to increased TG and reduced activation of fibrinolysis, independent of cirrhosis stage. During a median follow-up of 175 days, 20 patients with decompensated cirrhosis developed further episodes of decompensation that were predicted by low FVII and high plasminogen activator inhibitor-1 levels, independent of Model for End-Stage Liver Disease score. Conclusion: Patients with cirrhosis with HCC have profound hyper-coagulable changes that can account for their increased thrombotic tendency. In contrast, hypercoagulability in patients with decompensated cirrhosis is more likely a consequence of chronic liver disease rather than a driver for cirrhosis progression.

Gelatin-thrombin hemostatic matrix in neurosurgical procedures: hemostatic effectiveness and economic value of clinical and surgical procedure-related benefits.

BACKGROUND: Gelatin-thrombin hemostatic matrix (FloSeal®) use is associated with shorter surgical times and less blood loss, parameters that are highly valued in neurosurgical procedures. We aimed to assess the effectiveness of gelatin-thrombin in neurosurgical procedures and estimate its economic value. METHODS: In a 6-month retrospective evaluation at 2 hospitals, intraoperative and postoperative information were collected from patients undergoing neurosurgical procedures where bleeding was controlled with gelatin-thrombin matrix or according to local bleeding control guidelines (control group). Study endpoints were: length of surgery, estimated blood loss, hospitalization duration, blood units utilized, intensive care unit days, postoperative complications, and time to recovery. Statistical methods compared endpoints between the gelatin-thrombin and control groups and resource utilization costs were estimated. RESULTS: Seventy-eight patients (38 gelatin-thrombin; 40 control) were included. Gelatin-thrombin was associated with a shorter surgery duration than control (166±40 versus 185±55 minutes, P=0.0839); a lower estimated blood loss (185±80 versus 250±95 mL; P=0.0017); a shorter hospital stay (10±3 versus 13±3 days; P<0.001); fewer intensive care unit days (10 days/3 patients and 20 days/4 patients); and shorter time to recovery (3±2.2 versus 4±2.8 weeks; P=0.0861). Fewer gelatin-thrombin patients experienced postoperative complications (3 minor) than the control group (5 minor; 3 major). No gelatin-thrombin patient required blood transfusion; 5 units were administered in the control group. The cost of gelatin-thrombin (€ 268.40/unit) was offset by the shorter surgery duration (difference of 19 minutes at € 858/hour) and the economic value of improved the other endpoint outcomes (i.e., shorter hospital stay, lesser blood loss/lack of need for transfusion, fewer intensive care unit days, and complications). CONCLUSIONS: The use of gelatin-thrombin hemostatic matrix in patients undergoing neurosurgical procedures was associated with better intra- and postoperative parameters than conventional hemostasis methods, with these parameters having substantial economic benefits.

Coagulant Effect and Tolerability of Yeast-Produced Recombinant Batroxobin in Healthy Adult Subjects.

BACKGROUND AND OBJECTIVE: Batroxobin, a snake venom thrombin-like enzyme, converts fibrinogen into fibrin by cleaving fibrinopeptide A. It is used for hemostasis; however, the supply of native batroxobin is limited. Therefore, we developed a recombinant batroxobin (r-batroxobin) from Pichia pastoris and evaluated its pharmacodynamics and safety in humans. METHODS: A randomized, double-blind, placebo-controlled, single ascending-dose study was performed. Eight healthy subjects were enrolled in each r-batroxobin dose group (2.5, 5.0, or 10.0 BU/2.0 mL administered intravenously), and randomized to receive r-batroxobin (n = 6) or matching placebo (n = 2). Safety was evaluated during the study, and pharmacodynamics was assessed using prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen level. RESULTS: All subjects in each cohort completed the study. No significant changes in PT or aPTT occurred after intravenous r-batroxobin administration. Compared with the placebo group, the fibrinogen level in all r-batroxobin dose groups decreased significantly to 8.68-33.57% from the baseline within 12 h (p ≤ 0.05). The TT in the 5.0 and 10.0 BU/2.0 mL groups significantly increased to 7.53-18.48% from baseline within 12 h compared with that of the placebo group (p ≤ 0.05), whereas that of the 2.5 BU/2.0 mL group exhibited non-significant changes compared with the placebo group. No serious adverse events occurred. CONCLUSIONS: A single intravenous injection of r-batroxobin within a dose range of 2.5-10.0 BU/2.0 mL was well tolerated and resulted in a significant decrease in fibrinogen and prolongation of TT. REGISTRATION: This study is registered at the Clinical Research Information Service (CRIS, http://cris.nih.go.kr ), number KCT0002518.

Global hemostasis in healthy bitches during pregnancy and at different estrous cycle stages: Evaluation of routine hemostatic tests and thromboelastometry.

This study assessed the global hemostasis (including prothrombin time [PT], activated partial thromboplastin time [aPTT], antithrombin activity [ATA], fibrinogen and d-Dimer concentrations, platelet count, plateletcrit and thromboelastometry) in healthy pregnant bitches, comparing the results with those of healthy bitches at different estrous cycle stages, and assessed whether hemostatic changes during pregnancy are associated with serum progesterone concentration or the presence of fetuses in utero. The results show that pregnant bitches have higher fibrinogen concentration, platelet count and platelatecrit, and that fibrin and global clot formations occur faster than in non-pregnant bitches at different estrous cycle stages. Additionally, clot strength was higher in pregnant bitches than in non-pregnant ones. There were no differences in PT, ATA, and D-dimer concentration between all study groups. The aPTT was significantly shorter in bitches at the fourth and last pregnancy weeks, compared to the anestrus group, and shorter in both the fourth and last pregnancy weeks groups, compared to diestrus group. These results all support a hypercoagulable state in healthy pregnant bitches, unassociated with progesterone concentration.

The effect of moderate alcohol consumption on biomarkers of inflammation and hemostatic factors in postmenopausal women.

BACKGROUND/OBJECTIVES: Inflammation and hemostasis contribute to the etiology of cardiovascular disease. We previously demonstrated that moderate alcohol consumption (1-2 drinks/day) may decrease risk for cardiovascular disease because of an improved lipid profile. In addition to these beneficial changes, the alcohol-mediated reduction in risk may be through its effect on inflammation and hemostasis. The objective of the study was to evaluate the effect of moderate alcohol consumption on biomarkers of inflammation and hemostasis in postmenopausal women. SUBJECTS/METHODS: As part of a controlled diet study, 53 postmenopausal women each consumed a weight-maintaining diet plus 0, 15 and 30 g/day of alcohol for 8 weeks, in a randomized crossover design. The controlled diet contained 15%, 53% and 32% of energy from protein, carbohydrate and fat, respectively. RESULTS: Soluble intercellular adhesion molecule-1 decreased by 5% (P<0.05) with consumption of both 15 and 30 g of alcohol. Fibrinogen concentrations decreased by 4% and 6% (P<0.05) after consumption of 15 and 30 g alcohol, respectively. Fibrin D-dimer decreased by 24% (P<0.05) after consumption of 30 g of alcohol. Plasminogen activator inhibitor-1 (PAI-1) concentrations were increased 27 and 54% (P<0.05) after consumption of 15 and 30 g of alcohol. Plasma high-sensitivity C-reactive protein, interleukin-6 and factor VII coagulant activity did not change with alcohol consumption. CONCLUSIONS: These data suggest that moderate alcohol consumption may have beneficial effects on inflammation and hemostasis in postmenopausal women, and this may be somewhat mitigated by an increase in PAI-1.

Hemostatic, inflammatory, and oxidative markers in pesticide user farmers.

The aim of this work was to investigate inflammatory, oxidative, and thrombotic parameters as biomarkers in farmers exposed to pesticides. Fifty farmers using chemical pesticides and 60 unexposed control men participated in this study. The Mediterranean diet compliance, the duration of pesticide use, and personal protection for pesticides handling were recorded using self-administered questionnaires. Serum biochemical parameters, oxidant/antioxidant, inflammatory, and thrombosis markers were determined. Our findings showed oxidative stress reflected by an increase in malondialdehyde, carbonyl proteins and superoxide anion levels and a decrease in vitamins C and E, glutathione, catalase, and superoxide dismutase activities in farmers. Serum C-reactive protein, prothrombin, and fibrinogen levels were enhanced in these farmers. In conclusion, inflammation, oxidative stress, and metabolic perturbations reflected the possibility of the effects of pesticides to farmers.

Modelling of vitamin K half-life in patients treated with vitamin K antagonists before hip fracture surgery.

BACKGROUND: Guidelines recommend treatment with vitamin K in patients requiring reversal of the effect of vitamin K antagonists (VKA) before semi-urgent surgery. In clinical practice, the time for reversal of the international normalized ratio (INR) to values adequate for surgery is often reported longer than the expected 12-24 hours, which may delay surgery and increase the risk of complications. METHODS: In order to optimize the management of elderly patients treated with VKA and undergoing hip fracture surgery, we aimed to model the vitamin K half-life in this specific population. Files for patients admitted between 2006 and 2008 for hip fracture surgery and chronically treated with VKA were retrospectively studied. Only patients with an INR superior to 1.5 upon arrival were included in the study. The effect of vitamin K on the decrease in INR was modelled after a PK/PD analysis using NONMEM. Thirty-one patients' files were analysed. RESULTS: Despite management in accordance with guidelines, 31% of the patients had a delayed return to INR values<1.5 resulting in delayed surgery. Time to INR<1.5 was longer than 24 hours in 50% of the patients. The calculated half-life of vitamin K was 24.7 hours in this population. CONCLUSION: The vitamin K half-life in elderly patients treated with VKA and undergoing hip fracture surgery was prolonged. The use of vitamin K or of a more rapid acting alternative should be discussed, depending on the urgency of the surgery.

Serum specific vasopressin-degrading activity is related to blood total cholesterol levels in men but not in women.

The role of vasopressin (AVP) in the pathophysiology of cardiovascular disease is controversial, but this peptide hormone is elevated in heart failure and some forms of hypertension. Also, AVP has vasoconstrictor, mitogenic, hyperplasic and renal fluid retaining properties which, by analogy with angiotensin II, may have deleterious effects when present in chronic excess. Furthermore, cholesterol blood levels are also associated with hypertension, although the underlying mechanism is not known. Here we analyze the relationship between blood total cholesterol levels and serum vasopressin- degrading cystyl-aminopeptidase activity (AVP-DA) in healthy humans, and the differences between men and women. Linear correlation coefficients were calculated to test relationships between AVP-DA and blood total cholesterol levels. Sex differences were observed for AVP-DA, being this activity higher in men than in women. According to the linear model of the regression analysis, AVP-DA showed a significant negative correlation with blood total cholesterol levels in men, whereas no correlation was observed in women. Several studies in humans demonstrate the existence of greater plasma AVP concentrations in normal men compared to normal women, which could explain the gender-differences observed in the present work in relation with AVP-DA. However, AVP-DA is related to blood cholesterol levels only in men, although in our hands, women showed higher blood cholesterol levels than men. This could indicate that the risk of high cholesterol-related hypertension is more probable in men than in women. Although AVP-DA misregulation could be involved in the pathogenesis of hypertension, its relation with cholesterol levels appears only in men, but not in women.

Recovery of fibrinogen after administration of fibrinogen concentrate to patients with severe bleeding after cardiopulmonary bypass surgery.

BACKGROUND: Normalization of plasma fibrinogen levels may be associated with satisfactory haemostasis and reduced bleeding. The aim of this retrospective study was to assess fibrinogen recovery parameters after administration of fibrinogen concentrate (Haemocomplettan P) to patients with diffuse bleeding in cardiovascular surgery. Data on transfusion and patient outcomes were also collected. METHODS: Patient characteristic and clinical data were obtained from patient records. RESULTS: of the thromboelastometry (FIBTEM)and of the standard coagulation tests, including plasma fibrinogen level, measured before surgery, before and after haemostatic therapy, and on the following day, were retrieved from laboratory records. Results Thirty-nine patients receiving fibrinogen concentrate for diffuse bleeding requiring haemostatic therapy after cardiopulmonary bypass were identified. The mean fibrinogen concentrate dose administered was 6.5 g. The mean fibrinogen level increased from 1.9 to 3.6 g litre(-1) (mean increment of 0.28 g litre(-1) per gram of concentrate administered); maximum clot firmness increased from 10 to 21 mm. The mean fibrinogen increase was 2.29 (sd 0.7) mg dl(-1) per mg kg(-1) bodyweight of concentrate administered. Thirty-five patients received no transfusion of fresh-frozen plasma (FFP) or platelet concentrate after receiving fibrinogen concentrate; the remaining four patients received platelet concentrate intraoperatively. Eleven patients received platelets, FFP, or both during the first postoperative day. No venous thromboses, arterial ischaemic events, or deaths were registered during hospitalization. CONCLUSIONS: In this retrospective study, fibrinogen concentrate was effective in increasing plasma fibrinogen level, and contributed to the correction of bleeding after cardiovascular surgery.

Aprotinin modifies left ventricular contractility and cytokine release after ischemia-reperfusion in a dose-dependent manner in a murine model.

BACKGROUND: Periods of ischemia-reperfusion (I/R) during cardiac surgery are associated with transient left ventricular (LV) dysfunction and an inflammatory response. In this study, we examined the potential dose-dependent effects of aprotinin (APRO) on LV contractility and cytokine release in the setting of I/R. METHODS: An index of LV contractility, LV maximal elastance (E(max)), was measured at baseline, 30 min of ischemia, and 60 min of reperfusion by microtransducer volumetry. Mice were randomized as follows: (a) APRO 20,000 kallikrein-inhibiting units (KIU)/kg (n = 11); (b) APRO 4 x 10(4) KIU/kg (n = 10); (c) APRO 8 x 10(4) KIU/kg (n = 10); and (d) vehicle (saline; n = 10). APRO doses were calculated to reflect half, full, and twice the clinical Hammersmith dosing schedule. After I/R, plasma was collected for cytokine measurements. RESULTS: After I/R, E(max) decreased from the baseline value by more than 40% in the vehicle group as well as in the APRO 4 x 10(4) KIU/kg and APRO 8 x 10(4) KIU/kg groups (P < 0.05). However, E(max) returned to near baseline values in the APRO 2 x 10(4) KIU/kg group. Tumor necrosis factor (TNF) increased 10-fold after I/R, but it was reduced with higher APRO doses. CONCLUSIONS: This study demonstrated that a low dose of APRO provided protective effects on LV contractility, whereas higher doses suppressed TNF release. These unique findings suggest that there are distinct and independent mechanisms of action of APRO in the context of I/R.

Is aprotinin safe to use in a cohort at increased risk for thrombotic events: results from a randomized, prospective trial in off-pump coronary artery bypass.

BACKGROUND: Multiple randomized trials have established a favorable safety profile for aprotinin use during cardiac surgery, but recent database analyses suggest an increased risk of adverse thrombotic events. Our group previously demonstrated that off-pump coronary artery bypass (OPCAB) is linked to a postoperative hypercoagulable state. In this study, we tested whether aprotinin influences thrombotic events after OPCAB. METHODS: Patients randomly received saline (n = 61) or aprotinin (2 x 10(6) kallikrein inhibiting units (KIU) loading dose, 0.5 x 10(6) KIU/hour [n = 59]) during OPCAB. Aprotinin levels (KIU/mL) were analyzed before, and 30 minutes (peak) and 4 hours after the loading dose. Estimated glomerular filtration rate (eGFR) was calculated daily based on Cockcroft equation with acute kidney injury (AKI) defined as eGFR less than 75% of baseline. Major adverse cardiac and cerebrovascular events (MACCE) were monitored during the first year, including acute graft failure by predischarge computed tomographic angiography. RESULTS: Compared with placebo, the aprotinin group developed a significantly lower eGFR on day 3 (p < 0.006), but this difference resolved by day 5. Peak aprotinin level correlated with the degree of eGFR decline noted on day 3 (r = 0.56, p < 0.03) and independently predicted postoperative AKI (odds ratio 8.8, p < 0.008). The receiver operating characteristic analysis demonstrated that peak aprotinin level strongly predicts AKI (area under the curve = 0.86, 95% confidence interval 0.69 to 1.00). The percentage of patients reaching the composite MACCE endpoint was significantly reduced in the aprotinin versus placebo group (12 vs 34%, p = 0.01). CONCLUSIONS: Compared with placebo, aprotinin use was associated with less MACCE but more AKI after OPCAB. The strong relationship between the peak aprotinin level and subsequent AKI suggests weight-based protocols for dosing aprotinin may reduce this risk.

Phase 3, randomized, double-blind study of plasma-derived human thrombin versus bovine thrombin in achieving hemostasis in patients undergoing surgery.

OBJECTIVE: To compare the effectiveness of plasma-derived human thrombin and bovine thrombin for achieving hemostasis during surgery. METHODS: Adults (N = 305) with > or = 1 mild or moderate bleeding site not manageable by conventional modalities during elective cardiovascular, neurologic, or general surgical procedures at multiple study centers were randomized to human (n = 153) or bovine (n = 152) thrombin, applied topically with an absorbable gelatin sponge. Bleeding was assessed 3, 6, and 10 min post-application. Other evaluations included laboratory assessments, vital signs, blood loss, blood transfusions, time in specialty-care units, procedure duration, and length of hospital stay. Blood samples for antibody assessment were collected at baseline and postoperative week 5. RESULTS: The proportion of patients achieving hemostasis within 10 min (primary outcome) was equivalent for human and bovine thrombin (97.4 vs. 97.4%, respectively; ratio, 1.00; 95% CI, 0.96-1.05). The proportions of patients achieving hemostasis at 6 min (94.8 vs. 92.8%) and 3 min (73.2 vs. 72.4%) were also equivalent. No clinically meaningful differences were noted for other variables. The products had similar adverse event profiles. More patients (12.7%) who received bovine thrombin demonstrated seroconversion for > or = 1 of the 4 antibodies assayed than patients who received human thrombin (3.3%). No patients in the human thrombin group developed seroconversion for anti-human thrombin or anti-human factor V/Va antibodies. Limitations of this study include the lack of a placebo-control group, the potential for inter-surgeon variability, and the fact that antibody assessment was not evaluable in all patients. CONCLUSIONS: Plasma-derived human thrombin and bovine thrombin were equivalent in achieving hemostasis within 10, 6, and 3 min and had comparable safety profiles. None of the patients receiving human thrombin developed seroconversion for antibodies to any of the human antigens.

V617F JAK-2 mutation in patients with essential thrombocythemia: relation to platelet, granulocyte, and plasma hemostatic and inflammatory molecules.

OBJECTIVE: This article evaluates patients with essential thrombocythemia (ET) to determine whether the V617F mutation in the JAK2 gene affects platelet hemostatic and adhesive molecules, platelet-polymorphonuclear leukocyte (PMN) interactions, and PMN-activation characteristics, as well as plasma hypercoagulation markers. PATIENTS AND METHODS: Thirty-seven ET patients with V617F JAK2 mutation and 38 wild-type, and 50 healthy controls were studied. RESULTS: Platelets from overall ET patients, compared to controls, expressed significantly higher membrane tissue factor (TF) and P-selectin (p < 0.01) and lower CD41 and CD42b (p < 0.01). TF appeared significantly higher in the V617F JAK2 carriers compared to wild-type, and total platelet TF antigen levels confirmed the same result. The presence of circulating platelet/PMN aggregates was significantly greater in the JAK2-mutation carriers than in the wild-type and controls (p < 0.05). PMN surface activation and inflammatory markers (i.e., CD14, TF, CD11b, and leukocyte alkaline phosphatase [LAP]) were all significantly higher in ET versus control subjects, with CD14 and LAP being the highest in the JAK2 mutation carriers. Finally, a significant increase in plasma hypercoagulation markers was found in ET patients, and the only difference for the V617F JAK2 carriers was higher plasma thrombomodulin levels (p < 0.01). Differences in white blood cell and PMN count, platelet TF, PMN CD14, and LAP, and plasma thrombomodulin remained significant after multivariate analysis. CONCLUSIONS: These results show that a correlation exists between the presence of V617F JAK2 mutation and selected hemostatic activation variables.

The efficacy and safety of aprotinin for hemostasis during intracranial surgery.

OBJECT: The aim of this study was to determine the safety and efficacy of prophylactic high-dose intravenous aprotinin in reducing intraoperative blood loss in the neurosurgical population. METHODS: A randomized, double-blind, placebo-controlled trial was conducted in parallel groups in two regional neurosurgical departments. One hundred patients with a preoperative diagnosis of intracranial meningioma or vestibular schwannoma subsequently confirmed on histological studies were included. All patients were older than 18 years of age, pregnancy had been excluded, there was no history of bleeding diathesis, no previous exposure to aprotinin, and no ingestion of antiplatelet or anticoagulant medications within the 2 weeks preceding surgery. Aprotinin was administered in doses of 30,000 kallikrein-inhibiting units (KIU)/kg body weight on induction of anesthesia and was continued as an infusion of 10,000 KIU/kg/hr until surgery was complete, or for a maximum of 8 hours. Intraoperative blood loss, blood transfusion, the Glasgow Outcome Scale score, and the Index of Independence were measured, and screening for deep vein thrombosis and the Mini-Mental State Examination were performed. CONCLUSIONS: Intraoperative blood loss was reduced from 1014 ml (geometric mean) to 508 ml (p = 0.028). Although this study was not designed to evaluate the need for blood transfusion, 37 U of blood was used in 11 patients in the aprotinin group and 58 U in 13 patients in the placebo group (not significant). There were no significant differences in postoperative thrombotic risk or other outcome measures between treatment groups. Aprotinin therefore can be safely used to reduce intraoperative blood loss in patients who are not receiving anticoagulation therapy.

Aprotinin reduces blood loss and the need for transfusion in orthognathic surgery.

A randomized, placebo-controlled, double-blind trial (n= 15 in each group) showed that patients given aprotinin intravenously (200 ml, [2000000 kallikrein inactivator units] before the operation and then 50 ml per h until the end of the operation) during simultaneous maxillary Le Fort 1 and mandibular sagittal split osteotomies, lost 52% less blood than controls (calculated by subtracting the volume of saline irrigant used from the volume of blood collected in the aspirator bottle and surgical drains). Patients given aprotinin lost a mean (SD) of 473 (190) ml compared with 986 (356) ml in controls. They also required significantly less transfused blood (1 was given 2 units in the aprotinin group compared with 9 given a mean of 1.5 units (range 1-4) in the control group). There were no complications attributable to this drug.

Effects of all-trans-retinoic acid and arsenic trioxide on the hemostatic disturbance associated with acute promyelocytic leukemia.

To study the in vivo effect of all-trans-retinoic acid (ATRA) and arsenic trioxide (As(2)O(3)) on the expression of tissue factor (TF) and the other hemostatic disturbance, a series of parameters were measured either in bone marrow blasts or plasma from acute promyelocytic leukemia (APL) patients. The plasma parameters were measured by ELISA or chromogenic studies. The TF transcription was assessed using reverse transcription-polymerase chain reaction (RT-PCR) technique. The results indicated that the blast cell procoagulant activity (PCA), TF antigen of APL cell lysate, as well as the transcription of APL TF mRNA elevated at diagnosis, were reduced after ATRA or As(2)O(3) therapy. The plasma level of P-selectin, TF, thrombin-antithrombin complex (TAT), soluble fibrinmonomer complex, thrombomodulin (TM), tissue factor pathway inhibitor (TFPI), plasmin-antiplasmin complex, tissue plasminogen activator (t-PA) activity, urokinase plasminogen activator (u-PA) and its receptor (u-PAR), and D-dimer (D-D) significantly increased. Fibrinogen (Fg), antigen level of protein C (PC), plasminogen (PLG) activity, alpha(2)-plasminogen inhibitor activity (alpha(2)-PI), and plasminogen activator inhibitor (PAI) activity were decreased at diagnosis. The protein C activity (PC:A) and protein S (PS) remained unchanged. All the parameters were restored to normal ranges after complete remission (CR) except elevation of TF and TAT in both groups, as well as PC:A, PS, and t-PA in the ATRA group. In conclusion, there existed activation of platelets and consumption of anticoagulants as well as activation of coagulation and fibrinolytic system before treatment. Both ATRA and As(2)O(3) therapy downregulated the expression of TF mRNA, decreased the PCA and TF level in APL cells, significantly inhibited coagulation activation, corrected secondary hyperfibrinolysis and the other hemostatic abnormalities, and thus greatly improved the bleeding symptom in early stage of the treatment.

Hemostatic changes in patients with malignancy.

Alterations of hemostasis commonly accompany the progression of malignant disease and every known component of the hemostatic mechanism may be affected by this disease process. Nearly all patients with an active neoplasm will exhibit at least subtle biochemical changes in hemostasis, and a minority of these patients will also develop clinical thrombosis or hemorrhage. In this paper, we will review intravascular coagulation and fibrinolysis, thrombocytopenia, and thrombocytosis, as well as more rare thrombotic and hemorrhagic events resulting from the direct interactions of neoplasms, or of their products, with the individual elements of hemostatic mechanisms. Thrombotic and hemorrhagic events resulting from the induction of autoimmune or thrombotic microangiopathic syndromes are also discussed. This review focuses on the clinical thrombotic and bleeding syndromes that may occur as a result of this interaction between neoplasia and hemostasis.

Hemostatic and fibrinolytic status in patients with ovarian cancer and benign ovarian cysts: could D-dimer and antithrombin III levels be included as prognostic markers for survival outcome?

We determined the hemostatic and fibrinolytic status in 60 patients with ovarian cancer and benign ovarian cysts. Hypercoagulation, increased platelets, and enhanced fibrinolysis were seen in patients with preoperative ovarian cancer compared to patients with benign ovarian cysts. Enhanced thrombin generation, evidenced by increased F1+2 and decreased antithrombin III (ATIII) levels with further enhanced fibrinolysis by elevated D-dimer, was seen in advanced cancer. Ten ovarian cancer patients died within 13 months after diagnosis and another died at 24 months, all from advanced stage of cancer, except one from stage IC cancer who died at 11 months. The survival rates from the disease at 13 months and 24 months were 66.7% and 45%, respectively. Most of the patients had gone through the complete course of chemotherapy, and those patients still alive have been disease free between 13 and 42 months. No statistical relationships for the hemostatic parameters studied in ovarian cancer patients could be found between those who died and those still living 13 and 24 months after diagnosis, except for ATIII and D-dimer levels. Elevated D-dimer levels were associated with those who died within 13 and 24 months from the disease, and the decreased ATIII levels only reached statistical significance by 24 months. It could be suggested that these two parameters might be useful as systemic prognostic markers in survival outcome from the disease for the first 24 months in advanced ovarian cancer, in addition to the known correlation with the International Federation of Gynecology and Obstetrics stage.