Characteristics of factor V and protein C based on results from Korean testing centers

OBJECTIVE

The global incidence of thrombosis is increasing. However, research on thrombosis in the context of Korea is scarce. We aimed to analyze the relationship between factor V and protein C test results and thrombosis in Koreans through a domestic commissioned testing institution conducting mass examinations.

METHODS

Results of factor V and protein C tests of 1386 individuals referred simultaneously to EONE Laboratories (Incheon, Republic of Korea) from January 2017 to July 2023 were analyzed retrospectively to identify the association with thrombotic disease. The tests were performed using a STAR MAX (Diagnostica Stago, Asnieres, France) automatic blood coagulation analyzer. The results were analyzed by age and sex.

RESULTS

The inspection rate increased gradually from 2017 to 2022. Women (70.0%) demonstrated a higher test rate than did men (30.0%). Young women reported high test rates; the test rate and age distribution differed by sex. Women aged between 20 and 49 years reported lower factor V and higher protein C concentrations than did men between 20 and 49 years of age.

CONCLUSIONS

The tests were more commonly performed in women than in men. Women aged between 20 and 49 years reported lower factor V concentrations and higher protein C concentrations than men between 20 and 49 years of age. This study will facilitate recognizing and preventing thrombotic diseases in women.

The link between high factor VIII to protein C ratio values and poor liver function after major hepatectomy

Our goal was to assess the coagulation profile in the immediate postoperative time after major liver surgery and its association with the liver function. Our hypothesis is that a decreased synthesis of the coagulation factor levels reflects an impaired liver synthesis following hepatic resection and will be associated with poor outcomes. This is a prospective, observational study recruiting consecutive patients scheduled for major liver resection in a tertiary hospital. Coagulation profile was assessed by conventional assays, viscoelastic assays and coagulation factor levels preoperatively and, on postoperative days 1, 2 and 6. Factor VIII to protein C (FVIII/PC) ratio has been used as a surrogate marker of hemostatic imbalance. Liver function was measured with conventional and indocyanine green (ICG) clearance tests, which were obtained preoperatively and on postoperative days 1 and 2. Sixty patients were recruited and 51 were included in the study. There is a clear increase in FVIII/PC ratio after surgery, which was significantly associated with low liver function, being more pronounced beyond postoperative day 2 and in patients with poorer liver function ( P  < 0.001). High FVIII/PC ratio values were significantly associated with higher postoperative morbidity, prolonged ICU and hospital stay and less survival ( P  < 0.05). High FVIII/PC ratio on postoperative day 2 was found to be predictor of posthepatectomy liver failure (PHLF; area under the ROC curve = 0.8129). Early postoperative high FVIII/PC ratio values are associated with low liver function, PHLF and poorer outcomes in patients undergoing major hepatic resection.

Anticoagulant effects of protein C, protein S, and antithrombin levels on the protein C pathway in young children

The protein C (PC) pathway involves physiological anticoagulant factors (PC, protein S [PS], and factor V) and performs major anticoagulant functions in adults. Variations in overall PC pathway function due to dynamic changes in PC and PS in early childhood are poorly understood. We aimed to evaluate the contributions of PC pathway function during early childhood by measuring changes in plasma thrombin generation (TG) after administration of the PC activator protac. We evaluated correlations between anticoagulant factors and percentage of protac-induced coagulation inhibition (PiCi%). Before protac addition, TG in newborns (n = 35), infants (n = 42), young children (n = 35), and adults (n = 20) were 525 ± 74, 720 ± 96, 785 ± 53, and 802 ± 64 mOD/min, and PiCi% were 42.1 ± 9.9, 69.8 ± 11.0, 82.9 ± 4.4, and 86.9 ± 3.4%, respectively. The distribution of PiCi% on the two axes of TG (with or without protac) changed continuously with age and differed from that of warfarin-treated plasma and adult PC- or PS-deficient plasma. PiCi% increased dynamically during infancy and correlated with PS levels in newborns and PC levels in young children. Addition of PC or fresh frozen plasma equivalent to approximately 25% PC to PC-deficient plasma improved PiCi%. This automatic measurement requires only a small sample volume and is useful for analysis of developmental hemostasis.

The Relationship between Z-Protein Level and other Parameters in Pregnant Women with Intrauterine Growth Retardation in Third Trimester

BACKGROUND

Protein Z is a glycoprotein which acts as an anticoagulant factor. A deficiency of protein Z is associated with thrombotic events and adverse obstetric outcomes. The association between protein Z deficiency and adverse obstetric outcomes has previously been demonstrated in several studies. However, none of them have investigated each complication independently. The aim of this study was to evaluate serum levels of protein Z in pregnancies complicated by intrauterine growth restriction (IUGR).

METHODS

Pregnant and nonpregnant healthy women between the ages of 18 and 40 years were included in the study. There were three groups: One: Study group: pregnant women with IUGR fetuses; Two: Control group 1: pregnant women with normal fetuses; Three: Control group 2: nonpregnant, healthy women. Plasma protein levels of protein Z, protein S, and protein C were measured for each group.

RESULTS

Women with IUGR had significantly higher mean plasma concentrations of protein Z compared to women with normal pregnancies. This is in contrast to previous studies.

CONCLUSIONS

The results of this study indicate that the association between protein Z levels and IUGR is still controversial.

Effect of poor glycaemic control on plasma levels and activity of protein C, protein S, and antithrombin III in type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) patients are predisposed to several diabetes-related complications. Dysregulation of the haemostatic mechanisms have been implicated. There are however no current studies assessing the levels and activity of protein C (PC), protein S (PS), and antithrombin III (AT III), which are essential in haemostatic regulation, in a single cohort of T2DM patients. This study evaluated the effect of poorly-managed T2DM on the levels and activity of PC, PS, and AT III.

METHODS

This cross-sectional study was conducted at the Diabetes Clinic, Cocoa Clinic in Kumasi, Ghana. A total of 242 T2DM patients, comprising 152 patients with poorly-managed diabetes and 90 well-managed diabetes patients, were recruited for the study. Fasting blood glucose, liver function tests and lipid profile were performed for each respondent. Glycated haemoglobin (HbA1c) was estimated by turbidimetric inhibition immunoassay. The levels and activity of PC, PS and AT III were measured by solid phase sandwich ELISA method.

RESULTS

There was a negative correlation between HbA1c and the levels and activity of PC, PS and AT III. The levels and activity of PC [(5.78 vs 4.64 μg/ml, p<0.0001) and (42.22 vs 36.21 U/ml, p = 0.01) respectively], PS [(22.55 vs 20.29 μg/ml, p = 0.010) and (235.94 vs 211.67 U/ml, p<0.0001) respectively] and AT III [(16.28 vs 14.41μg/ml, p<0.0001) and (176.01 vs 160.09 U/ml, p = 0.03) respectively] were significantly increased in patients with well-managed T2DM compared to the poorly-managed diabetes patients. Likewise, the levels and activity of PC, PS, and AT III was higher among T2DM patients using statins than patients who were statin-naïve. Among patients with well-managed T2DM, those who were on statins had significantly higher levels and activities of PC, PS, and AT III compared to well-managed T2DM patients not on statins. However, there no statistically significant differences between the level and activity of PC, PS, and AT III among poorly-managed T2DM patients with respect to statin status.

CONCLUSION

Poorly-managed type 2 diabetes mellitus is associated with reduced levels and activity of PC, PS and AT III compared to well-managed T2DM. Though use of statins may improve the levels and activity of the PC, PS and AT III in T2DM, their effect is limited in the presence of poorly-controlled T2DM. Proper management of diabetes is essential to reduce the likelihood of thrombotic events among T2DM patients.

Two Novel Mutations Cause Hereditary Antithrombin Deficiency in a Chinese Family

OBJECTIVE

To study the molecular basis of hereditary antithrombin (AT) deficiency in a Chinese family. It will help us understand the pathogenesis of this type of disease.

METHOD

AT activity (AT:A) and the AT antigen (AT:Ag) level were tested by chromogenic substrate and immunoturbidimetry, respectively. To identify the novel mutations, SERPINC1 gene sequencing was carried out. The possible impact of the mutations was analyzed by model and bioinformatic analyses.

RESULTS

AT:A and the AT:Ag level of the proband were 43% and 113 mg/L (normal range: 98-119% and 250-360 mg/L), respectively. Sequencing analysis revealed compound heterozygous mutations, including a frameshift mutation (c.318_319insT) resulting in Asn75stop and a missense mutation (c.922G>T) resulting in Gly276Cys. The bioinformatic and model analyses indicated that these mutations may disrupt the function and structure of the AT protein.

CONCLUSION

We detected 2 novel heterozygous mutations (c.318_319insT and c.922G>T) in the proband, and these were associated with decreased AT:A.

Bariatric surgery in morbidly obese individuals affects plasma levels of protein C and thrombomodulin

Obesity is associated with a prothrombotic milieu and an increased risk for thrombotic events. Bariatric surgery is the most effective treatment for obesity resulting in dramatic weight loss and reduced inflammation and extrinsic coagulation pathway activation. Blood samples were drawn from 60 patients undergoing Roux-en-Y gastric bypass surgery before and 1 year after the intervention. Protein C (PC), activated PC (APC), soluble thrombomodulin (TM), soluble E-selectin (E-Sel), prothrombin time (PT) and activated partial thromboplastin time (aPTT) were evaluated. Both PC (187.4 ± 64.5% before surgery to 118.1 ± 48% 1 year after surgery, p < 0.001) and APC (138.7 ± 64.4% before surgery to 69.1 ± 65.7% after surgery, p < 0.001) were reduced following surgical intervention. TM showed a similar behavior with a reduction of soluble TM after the procedure from 5.7 ± 2.6 to 3.2 ± 1.4 ng/ml (p < 0.001). Similarly, soluble E-Sel was reduced after surgery from 26.6 ± 12.7 to 5.5 ± 4.1 ng/ml (p < 0.001). In contrast, aPTT was not shortened but slightly increased from 29.1 ± 4.8 s. before surgery to 31 ± 4.4 s. (p = 0.001) after surgery and levels of PT were reduced after surgery to 89.6 ± 15.5% from an initial 97.5 ± 13.5% (p < 0.001). In conclusion, we demonstrate a reduction of PC and APC 1 year after bariatric surgery accompanied by a reduction in soluble TM and soluble E-Sel. The reduction of PC and APC is not paralleled by a reduction but in contrast by a prolongation of aPTT suggesting a compensatory upregulation of PC during obesity. The reduction of TM and E-Sel might hint towards an improved endothelial function in this cohort of patients.

Serum proteins C and S levels as early biomarkers for kidney dysfunction in hemophilic patients

BACKGROUND

Hemophilia is an inherited genetic disease characterized by the inability to coagulate blood after injury. The rationale of the current study was to evaluate serum proteins S and C and correlate to kidney function test in hemophilic patients for early diagnosis of abnormality in renal function.

SUBJECTS AND METHODS

This study was conducted on 80 males subjects divided into four groups. Group I: Control: Healthy subjects. Group II: Renal dysfunction (serum Creatinine >2mg/dl): Group III: Hemophilic patients. Group IV: Hemophilic patients with renal disorder. Serum urea, creatinine, sodium, potassium, protein C and protein S level were determined.

RESUTS

Protein C and S levels showed a significant decrease in hemophilic/and with renal dysfunction (P < 0.001, p<0.001). The level of plasma protein C and S levels were positively correlated with increased urinary albumin (P < 0.01). Urinary albumin was increased about 15 folds in hemophilic patients with renal dysfunction and nephrotic patients as compared with the control group. The cut-off value in 90% patients at the hemophilic patients with renal dysfunction 70%. Positive correlations were observed between urinary albumin (r=0.66), and creatinine (r=0.73).

CONCLUSION

These biomarkers showed good predictive values with regard to ROC-AUC (0.41 and 0.75 for Proteins C and S, respectively).

Prothrombotic markers in Thalassemia major patients: A paradigm shift

BACKGROUND

It is being increasingly recognised that thalassemia major patients, like intermedia, have increased propensity for thromboembolism. Deficiency of natural anticoagulants is more recently defined finding contributing to the hypercoagulable state. The aim this study is to determine natural anticoagulants levels and their correlation with maternal characteristics, haematological and biochemical markers.

METHODS

This is a prospective case-control study. We registered 80 patients and 60 healthy controls from Jan 2009 to Dec 2013. Complete blood counts, prothrombin time, activated partial thromboplastin time, protein C, protein S, antithrombin, serum ferritin, liver enzymes; HbsAg and Anti- HCV were evaluated.

RESULT

There were 42 males and 38 females with mean age of 12.30±5.50 years. The mean protein C, protein S and antithrombin in patients and control were 58.25±22.5 versus 110.67±22.60, 67.90±19.58 versus 98.70±21.54 and 89.73±18.09 versus 104.0±10.98 (p<0.001) respectively. Protein C was predominantly deficient in 65% followed by protein S and antithrombin in 35% and 20% respectively. Protein C deficiency divulged positive correlation with protein S deficiency (p = 0.035) and antithrombin deficiency with hemoglobin of ≤8gm% (p<0.0025). No significant correlation of prothrombotic markers was established with maternal characteristics, hepatic dysfunction, hepatitis and serum ferritin.

CONCLUSION

Substantial decrement in prothrombotic markers, primarily protein C, may be implicated in elevated thrombosis; however follow-up data is required to establish definitive thromboembolic events.

Factor VIII, Protein C and Cardiovascular Disease Risk: The REasons for Geographic and Racial Differences in Stroke Study (REGARDS)

BACKGROUND

 Haemostatic balance represented by low protein C (PC) and elevated factor VIII (FVIII) has been inconsistently associated with stroke and coronary heart disease (CHD) risk.

OBJECTIVE

 This article assesses whether an elevated FVIII and a low PC would increase cardiovascular risk more than either individually.

PATIENTS AND METHODS

 REGARDS recruited 30,239 black and white U.S. participants aged ≥ 45 years between 2003 and 2007. FVIII and PC were measured in a case-cohort sample of 646 stroke, 654 CHD, and a 1,104-person random sample with follow-up for approximately 4.5 years. Hazard ratios (HRs) were estimated using Cox models adjusted for demographic and cardiovascular risk factors.

RESULTS

 Elevated FVIII (per standard deviation [SD] increase) was associated with increased risk of both stroke (HR, 1.26; 95% confidence interval [CI], 1.08, 1.46) and CHD (HR, 1.52; 95% CI, 1.29, 1.79), while there was no association of PC per SD decrease. For PC, there was a trend towards increased cardiovascular disease risk in the lowest values (bottom 5%). For stroke, there was no interaction between FVIII and low PC (pinteraction = 0.55). For CHD, the adjusted HR of FVIII per SD increase was significantly greater with PC in the bottom 5% (HR, 3.59; 95% CI, 1.39, 8.29) than PC in the upper 95% (HR, 1.45; 95% CI, 1.23, 1.71; pinteraction = 0.07).

CONCLUSION

 Higher FVIII was associated with both CHD and stroke risk and the risk potentiated by low PC for CHD. Findings demonstrate that risks for cardiovascular diseases conferred by adverse levels of haemostasis biomarkers may be augmented by levels of other biomarkers.

Closed Or Open after Source Control Laparotomy for Severe Complicated Intra-Abdominal Sepsis (the COOL trial): study protocol for a randomized controlled trial

Background

Severe complicated intra-abdominal sepsis (SCIAS) has an increasing incidence with mortality rates over 80% in some settings. Mortality typically results from disruption of the gastrointestinal tract, progressive and self-perpetuating bio-mediator generation, systemic inflammation, and multiple organ failure. Principles of treatment include early antibiotic administration and operative source control. A further therapeutic option may be open abdomen (OA) management with active negative peritoneal pressure therapy (ANPPT) to remove inflammatory ascites and ameliorate the systemic damage from SCIAS. Although there is now a biologic rationale for such an intervention as well as non-standardized and erratic clinical utilization, this remains a novel therapy with potential side effects and clinical equipoise.

Methods

The Closed Or Open after Laparotomy (COOL) study will constitute a prospective randomized controlled trial that will randomly allocate eligible surgical patients intra-operatively to either formal closure of the fascia or use of the OA with application of an ANPTT dressing. Patients will be eligible if they have free uncontained intra-peritoneal contamination and physiologic derangements exemplified by septic shock OR a Predisposition-Infection-Response-Organ Dysfunction Score ≥ 3 or a World-Society-of-Emergency-Surgery-Sepsis-Severity-Score ≥ 8. The primary outcome will be 90-day survival. Secondary outcomes will be logistical, physiologic, safety, bio-mediators, microbiological, quality of life, and health-care costs. Secondary outcomes will include days free of ICU, ventilation, renal replacement therapy, and hospital at 30 days from the index laparotomy. Physiologic secondary outcomes will include changes in intensive care unit illness severity scores after laparotomy. Bio-mediator outcomes for participating centers will involve measurement of interleukin (IL)-6 and IL-10, procalcitonin, activated protein C (APC), high-mobility group box protein-1, complement factors, and mitochondrial DNA. Economic outcomes will comprise standard costing for utilization of health-care resources.

Discussion

Although facial closure after SCIAS is considered the current standard of care, many reports are suggesting that OA management may improve outcomes in these patients. This trial will be powered to demonstrate a mortality difference in this highly lethal and morbid condition to ensure critically ill patients are receiving the best care possible and not being harmed by inappropriate therapies based on opinion only.

Trial registration

ClinicalTrials.gov, NCT03163095.

Predictors Of Thrombogenesis By The State Of Pro- And Anticoagulant Components Of Hemostasis In The Patients With Stage Vd Chronic Kidney Disease

OBJECTIVE

Introduction: One of the major complications of stage V chronic kidney disease (CKD), treated by program hemodialysis, are hemostatic system disturbances resulting in thrombosis development. To detect early predictors of potential thrombosis in study category of patients is rather difficult because of inflammatory process, accumulation of antibodies, continuous damage of blood elements. The aim: To estimate potential applicability of activators and inhibitors of thrombogenesis as thrombophilia markers in the patients with stage V CKD, treated by program hemodialysis.

PATIENTS AND METHODS

Materials and methods:88 patients (52 males and 36 females) with stage V CKD, treated by program hemodialysis, were studied. Hemostatic profile was estimated in all the patients (soluble fibrin, D-dimer, protein C, fibrinogen).

RESULTS

Results: Two thirds of the patients with stage V CKD, treated by program hemodialysis, had significant increase in soluble fibrin and fibrinogen concentration against the background of decrease of natural anticoagulant - protein C and disparate response of D-dimer (tendency to decrease). It was established that comprehensive estimation of activators and inhibitors of thrombogenesis can become an indicator of thrombophilias in the patients with stage V CKD, treated by long term hemodialysis.

CONCLUSION

Conclusions: The majority of patients (68.2%) with stage VD CKD, treated by long term hemodialysis, had significant increase of soluble fibrin level (р <0.02) along with decreased D-dimer to borderline values. In general group of patients there was significant decrease of protein C (р<0.05) on the background of great increase of fibrinogen concentration in the majority of patients (62%) (р <0.001). The females were found to have significant increase of D-dimer level (р <0.05) along with the increase of soluble fibrin concentration. Comprehensive determination of activators and inhibitors of thrombogenesis can serve an indicator of thrombophilias in the patients with stage VD CKD, treated by program hemodialysis.

"ProC Global": A functional screening test that predicts recurrent venous thromboembolism

Abnormalities of the Protein C (PC) pathway are found in the majority of patients with thrombophilia. ProC Global is a coagulation assay that reflects the net effect of the PC pathway by measuring the activated partial thromboplastin time (APTT) of patient and control plasma, before and after activation of endogenous PC by Protac, a snake venom. Previous studies have suggested that abnormalities in this test are associated with an increased risk of venous thromboembolism (VTE). A retrospective analysis was performed using frozen plasma samples from 140 patients with confirmed VTE to determine whether an abnormal ProC Global result (in the presence and in the absence of known abnormalities in the PC pathway) is a predictor of initial and recurrent VTE. Patients were tested for the presence of activated protein C resistance, Factor V Leiden, PC and protein S (PS) deficiency, and non-specific inhibitor positivity. Mean ProC Global results were significantly lower in patients with recurrent VTE than in patients without recurrent VTE. The association between abnormal ProC Global result and recurrent VTE showed a strong trend, before (odds ratio, OR 3.6) and after (OR 3.1) exclusion of known thrombophilic abnormalities. Patients with a first episode of idiopathic VTE also expressed significant lower ProC Global results than those with secondary VTE. After exclusion of known PC pathway abnormalities, there was a statistically significant association between abnormal ProC Global and initial idiopathic VTE (p=0.04). These results suggest that ProC Global may serve as a predictor of recurrent VTE and potentially for first episode of idiopathic VTE. ProC Global may help identify patients at increased risk of initial and recurrent VTE.

Plasma homocysteine concentration is not associated with activated protein C resistance in patients investigated for hypercoagulability

Homocysteine and activated protein C (aPC) resistance are known risk factors for thromboembolism, but how elevated homocysteine influences thrombogenicity is not fully understood. The possibility that homocysteine may exert a prothrombotic effect by inducing aPC resistance has been addressed, with conflicting conclusions. The aim of this study is to evaluate the possible relationship of serum homocysteine concentration to aPC resistance in a cohort of patients investigated for hypercoagulability. Laboratory records from 1011 consecutive patients referred to the Haemostasis Laboratory at the Health Sciences Centre (Winnipeg, Canada) were reviewed from February 1997 to November 2002. Homocysteine levels, normalized aPC sensitivity ratio (aPCSR), and Factor V Leiden genotype were recorded for all 1011 patients. 394 patients had aPC-SR determined by mixing the patient plasma in 4 parts FV deficient plasma (FV-deficient-mix assay), and 617 patients had aPC-SR calculated without mixing (neat assay). Homocysteine did not significantly influence the aPC-SR when using the FV deficient assay. When aPC-SR was measured using the neat assay, homocysteine was found to correlate inversely with the degree of aPC resistance. The mean aPC-SR of FV Leiden-negative subjects measured using the neat assay was substantially lower than the expected normalized value of 1.0 that was obtained when aPC-SR was measured with the FV-deficient-mix assay. aPC resistance is common in patients being evaluated for possible hypercoagulability. In these patients, elevated plasma homocysteine levels is not associated with aPC resistance regardless of FV Leiden genotype suggesting that this is not the mechanism by which homocysteine exerts a prothrombotic effect.

A preliminary estimation of tissue factor pathway inhibitor (TFPI) and protein C in patients with intracranial tumors

BACKGROUND

In patients with intracranial tumors, hypercoagulability is observed due to brain tissue and tumor cells being the source of tissue factor.

OBJECTIVES

The aim of the study was to assess tissue factor (TF), tissue factor pathway inhibitor (TFPI) and protein C in the plasma and tumor tissue homogenate in patients with intracranial tumors.

MATERIAL AND METHODS

The study included 77 patients; 24 patients were diagnosed with glioma, 20 patients with meningioma and 33 patients with metastatic tumors; mean age - 54 years. The material for the study was the plasma and tumor tissue homogenate sampled during surgery. The control group consisted of 30 controls; mean age - 51 years. In the plasma of all the participants and in tumor tissue homogenate, the concentrations of TF-Ag, TFPI-Ag and protein C activity, and the concentration of total protein were measured. The results were converted per mg of protein.

RESULTS

In patients with intracranial tumors, elevated concentrations of TF-Ag, TFPI-Ag and protein C activity were noted, also after the conversion per mg of protein. A 100-fold higher concentration of TF per 1 mg of protein was found in tumor tissue compared to the patients' plasma. In tumor tissue homogenate, a lower TFPI concentration and a lower protein C activity were recorded.

CONCLUSIONS

The study confirmed the essential prothrombotic properties in patients with intracranial tumors, expressed with an elevated TF level, as well as a tremendous amount of TF in tumor tissue homogenate derived from tumors. The elevated concentration of TFPI and protein C activity converted per mg of total protein should be analyzed in terms of their pleiotropic function, along with the participation in hemostasis control. It seems that the reduced protein C activity and low TFPI level are associated with the enormous TF value in tumor tissue homogenates.

A randomized trial of restarting warfarin at maintenance versus loading doses following an elective procedure

Guidelines suggest restarting warfarin at known maintenance doses, although this may result in a delay to achieving therapeutic anticoagulation. As such, we compared the time to achieve an INR ≥ 2.0 between those restarting warfarin maintenance vs loading doses after transient interruption, and the impact on protein C, S and factor II levels. Patients requiring interruption of warfarin for elective procedures without hospitalization were randomized 1:1 to receive warfarin maintenance or loading doses (1.5 times the maintenance dose for 3 days followed by pre-procedural warfarin maintenance dosing). Protein C, S and Factor II were drawn at baseline (prior to warfarin interruption), 7 and 14 days after restarting warfarin. Among 19 patients randomized to maintenance and 20 to loading doses, nearly half in each group had mechanical heart valves with gastrointestinal endoscopic procedures most commonly performed (41%). The median number of days to reach an INR ≥ 2.0 was 7.8 days in the loading and 9.0 in the maintenance group (difference between medians 1.2 days, 95% CI -3.1 to 4.9; P = 0.19). Although levels of protein C, S and factor II were lower in the loading vs maintenance dose group, all remained above that of baseline. Warfarin resumption with loading doses shortened the time to achieve a therapeutic INR by a median of 1.2 days. Prompt warfarin dose escalation should be done in response to the INR. Protein C and S remained above pre-warfarin interruption levels, implying a lack of depletion with restarting warfarin.

Endogenous thrombin potential changes during the first cycle of oral contraceptive use

OBJECTIVES

Venous thromboembolism (VTE) risk increases within months of combination oral contraceptive (COC) initiation. Because elevated endogenous thrombin potential (ETP) has been found in several studies to be a VTE risk factor, we evaluated the extent of ETP changes during the initial cycle of an ethinyl estradiol (EE) and levonorgestrel (LNG) COC. We also assessed the relationship between ETP changes and systemic EE and LNG concentrations.

STUDY DESIGN

Participants provided multiple blood samples during a first 21-day cycle of a 30-mcg EE/150-mcg LNG COC and after a further 7 days without an active COC. Thrombin generation measured with and without addition of activated protein C (APC) yielded ETP+APC and ETP-APC and the normalized APC sensitivity ratio (nAPCsr). EE and LNG pharmacokinetic analyses were conducted over 24 h after the first COC tablet and again at steady state.

RESULTS

Thrombin generation was determined in 16 of the 17 women who completed the study. Mean ETP-APC increased steadily to 21% above baseline at 24 h after the 6th COC tablet (COC624; p<.001) and to 28% above baseline at steady state (COC21; p<.001). The percentage increase in mean ETP+APC was considerably more - 54% at COC624 and 79% at steady state. Mean nAPCsr increased by 28% at COC624 and by 41% at steady state. Higher concentrations of EE or LNG were not correlated with greater increases in ETP.

CONCLUSIONS

ETP increases during the first COC cycle were substantial.

IMPLICATIONS

The early increases in ETP may provide biological support for the rapid increase in VTE risk during initial COC use. The lack of association between this clotting system perturbation and the systemic EE concentration is surprising and deserves further study.

Assessment of Hereditary Thrombophilia: Performance of Protein C (PC) Testing

Protein C (PC) is a plasma Vitamin K-dependent pro-enzyme protein that is synthesized in the liver. Upon activation, PC regulates the coagulation process by neutralizing the procoagulant activities of factors V and VIII in the presence of the cofactor Protein S. PC is a major regulator of the coagulation process. The clotting based Protein C assay, the protocol described in this chapter, quantitates the amount of functional PC present in the specimen in a proportional fashion based on the prolongation of the Activated Partial Thromboplastin Time (APTT). Other methods for assessing PC are also available, including chromogenic and antigenic assays, but protocols for these assays are not provided.

Microcontact imprinted quartz crystal microbalance nanosensor for protein C recognition

Detection of protein C (PC) in human serum was performed by quartz crystal microbalance (QCM) based on molecular imprinting technique (MIP). The high-resolution and mass-sensitive QCM based sensor was integrated with high sensitivity and selectivity of the MIP technique. The PC microcontact imprinted (PC-μCIP) nanofilm was prepared on the glass surface. Then, the PC-μCIP/QCM sensor was prepared with 2-hydroxyethyl methacrylate (HEMA), ethylene glycol dimethacrylate (EGDMA) and N-methacryloyl l-histidine methylester (MAH) as the functional monomer with copper(II) ions. The polymerization was performed under UV light (100W and 365nm) for 20-25min under nitrogen atmosphere. The characterization studies of QCM sensor were done by observation using atomic force microscopy (AFM), contact angle measurements, ellipsometry and fourier transform infrared spectroscopy (FTIR). Detection of PC was investigated in a concentration range of 0.1-30μg/mL. Selectivity of PC-μCIP and PC non-imprinted/QCM (PC-non-μCIP) sensors for PC determination was investigated by using proteins namely hemoglobin (Hb), human serum albumin (HSA) and fibrinogen solutions. QCM sensor was also used for detection of PC molecules in aqueous solutions and human plasma. The detection limit was determined as 0.01μg/mL for PC analysis. The PC-μCIP/QCM sensor was used for five consecutive adsorption-desorption cycles. According to the results, the PC-μCIP/QCM sensor had obtained high selectivity and sensitivity for detection of PC molecules.

Racial differences in coagulation studies in stroke

Racial differences in stroke are known to exist with persons in the black race having a higher morbidity, mortality and incidence of stroke compared to whites. We evaluated coagulation factors in black and white stroke patients and compared the results between races. D-dimer was elevated more frequently in blacks than whites to a statistically significant degree. There were non-significant trends for blacks to have a positive lupus anticoagulant, low protein C and protein S, higher platelet factor 4, and hyporesponsive platelets to 10 microM epinephrine. The significance of these findings in understanding racial differences in stroke is discussed.

Antithrombin and Protein C in Systemic Inflammatory Response Syndrome

Coronary artery bypass grafting with cardiopulmonary bypass can induce systemic inflammatory response syndrome. To assess the prevalence of preoperative antithrombin and protein C deficiencies in relation to the incidence of this syndrome, antithrombin and protein C levels were measured in 130 patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. Systemic inflammatory response syndrome developed in 36 (27.7%) patients who were predominantly male, had a lower EuroSCORE, longer cardiopulmonary bypass time, higher pre-bypass temperature, and shorter activated coagulation time. Logistic regression showed that predictive factors included bypass duration and pre-bypass temperature; however, low antithrombin levels appeared to be a negative predictive factor. Antithrombin levels were < 80% in 33.8% of patients, and 11.6% had protein C levels < 80%. Postoperative antithrombin and protein C deficiencies are not uncommon in adults undergoing cardiac surgery with cardiopulmonary bypass, but detection of these deficits did not identify patients at increased risk of systemic inflammatory response syndrome.

PIVKA-II correlates with INR but not protein C or protein S concentrations in cord blood among newborns

BACKGROUND

Protein induced by vitamin K absence (PIVKA)-II, inactive precursor of prothrombin, is elevated in vitamin K (VK) deficiency. Our aims were to find the prevalence of VK deficiency in neonates, assess the utility of international normalized ratio (INR) as a screening tool, and explore the relationship between PIVKA-II, activated partial thromboplastin time (aPTT) and VK dependent anticoagulants.

METHODS

INR, aPTT, PIVKA-II, and proteins C and S activities were measured in neonatal cord blood prior to VK administration.

RESULTS

We found 45% of neonates had subclinical VK deficiency based on PIVKA-II levels and 7% based on INR. Receiver operating characteristic (ROC) analysis assessed the utility of INR in detecting >4 ng/mL of PIVKA-II and ROC of the area under the curve was 0.70 (95% CI 0.46-0.92, p = 0.07). Proteins C and S activities were normal for age and did not correlate with PIVKA-II [(r = 0.40, p = 0.14) and (r = 0.29, p = 0.29), respectively]. There was no association between aPTT and PIVKA-II (p = 0.83).

CONCLUSION

PIVKA-II seems to be a sensitive indicator of mild VK deficiency. Further studies are needed to investigate the lack of relationship between PIVKA-II and functional protein C or S levels.

[Identification of Target Extracellular Proteases--Activators of Proteins of Haemostasis System Produced by Micromycetes Aspergillus ochraceus and Aspergillus terreus]

Effects of extracellular proteases of Aspergillus ochraceus and Aspergillus terreus on plasma hemostasis proteins, consist of initiating the activation of prothrombin complex proteins, was detected. Was discovered, that A. ochraceus proteases have a direct influence on protein C and coagulation factor X, and A. terreus proteases causes their activation indirectly through kallikrein system stimulation. The ability of extracellular proteases of micromycetes activate prekallikrein in human blood plasma on the example of A. terreus was first demonstrated.

Prospective evaluation of protein C and factor VIII in prediction of cancer-associated thrombosis

Venous thromboembolism (VTE) is a preventable disease, yet it is one of the leading causes of death among patients with cancer. Improving risk stratification mechanisms will allow us to personalize thrombo-prophylaxis strategies. We sought to evaluate Collagen and Thrombin Activated Platelets (COAT-platelets) as well as protein C and factor VIII as biomarkers predictive of cancer-associated thrombosis in a prospective cohort of patients with cancer. Protein C was selected as a candidate based on bioinformatics prediction. Blood samples were collected before chemotherapy. All specimen processing was blinded to clinical data. Surveillance and adjudication of the main outcome of VTE was performed for up to 1 year. We used Cox proportional hazard regression to measure the association of biomarkers and incident events using SAS 9.2 for all statistical analysis. Death was modeled as a competing event. Among 241 patients followed for an average of 10.4 months, 15% died and 13% developed a VTE. COAT-platelets were not predictive of VTE. Low levels of pre-chemotherapy protein C (<118%) (HR 2.5; 95% CI 1.1-5.5) and high baseline factor VIII (>261% I) (HR 3.0; 95% CI 1.1-8.0) were predictive of VTE after adjusting for age, Khorana prediction risk, metastatic disease and D dimer. In addition, low protein C was predictive of overall mortality independent of age, metastatic disease and functional status (HR 2.8; 95% CI 1.3-6.0). Addition of these biomarkers to cancer-VTE risk prediction models may add to risk stratification and patient selection to optimize thrombo-prophylaxis.

[Estimation of venous thromboembolism risk with thrombotic biomarkers in cancer patients]

OBJECTIVE

To assess the value of thrombotic biomarkers in estimation of venous thromboembolism (VTE) risk in cancer patients.

METHODS

A total of 1473 cancer patients treated in the Tianjin Medical University General Hospital from 2009 to 201 were selected, including 845 males and 628 females in the age of 56 ± 17 years. The activities of von Willebrand factor antigen (vWF:Ag), factor VII (F VII:A), factor VIII (F VIII:A), antithrombin (AT:A), protein C (PC:A) and protein S (PS:A) were assayed using an ACL TOP 700 blood coagulation analyzer. The level of D-dimer (D-D) was assayed using the Biomerieux Mini Vidas Automated Immunoassay Analyzer. Receiver operating characteristic curve (ROC) was used to analyze the diagnostic performance of the parameters. Cox regression analysis model was applied to evaluate the effect on prognosis, and Kaplan-Meier curve was used to implement the survival analysis.

RESULTS

The levels of vWF:Ag, D-D, and F VIII:A were significantly higher in all the specified tumor groups ( except the other tumor group ) than that of the control groups (P < 0.05). F VIII:A was significantly higher than that in the control group in all tumor groups except the renal carcinoma, prostatic cancer, lymphoma groups and the other tumor group (P < 0.05). The PC:A level was significantly lower in all tumor patients groups than in the control group, except glioma, breast cancer, gastric carcinoma, renal carcinoma and the other tumors groups (P < 0.05). The PS: A level was significantly lower in all tumor groups than in the control group, except the glioma, breast cancer, prostatic cancer, lymphoma and the other tumors groups (P<0.05). The AT: A level was significantly lower in all tumor groups than in the control group (P<0.05). When the optimum cut-off point of vWF:Ag for VTE diagnosis was 192% in the cancer group, the area under ROC curve = 0.828 (95% CI: 0.716 to 0.939). When the optimum cut-off point of D-dimer for VTE diagnosis was 1484 ng/ml in the cancer group, the area under ROC curve = 0.915 (95% confidence interval: 0. 840 to 0.988). When the optimum cut-off point of PC: A for VTE diagnosis was 75.2% in the cancer group, the area under ROC curve = 0.764 (95% confidence interval: 0.630 to 0.898). The Cox analysis showed that age, surgery, chemotherapy and D-dimer were independent risk factors for VTE event within three months in cancer patients. The cumulative probability of VTE was increased significantly in the cancer patients if whose plasma D-dimer level was over the cut-off value.

CONCLUSIONS

The plasma D-dimer level is obviously increased in cancer patients, and there is a relevance to thrombosis risk stratification and VTE cumulative probability. It is with good diagnostic performance, and may be used as an effective marker in estimation of VTE risk within 3 months in cancer patients.