Thrombin generation, thrombin-antithrombin complex, and prothrombin fragment F1+2 as biomarkers for hypercoagulability in cancer patients

Coagulation and fibrinolytic markers offer utility when distinguishing between benign and malignant gallbladder tumors: A cross-sectional study

BACKGROUND

The metabolic or proliferative abnormalities that are characteristic of tumor cells can lead to abnormal fibrinolysis or coagulation system activity, with certain tumors exhibiting hypercoagulability or existing in a fibrinolytic state. However, the utility of biomarkers of coagulation and fibrinolysis when seeking to differentiate between benign gallbladder disease and malignant gallbladder tumors remains uncertain.

METHODS

This study included a total of 81 patients with benign gallbladder polyps and 94 patients with malignant gallbladder tumors. Pre-biopsy or pretreatment levels of PT, APTT, FIB, D-dimer, FDP, PLT, PIC, TAT, TM, and t-PAIC from these patients were compared using Mann-Whitney tests. The baseline data of the patients were analyzed using chi-square tests, and the diagnostic utility of these biomarkers in distinguishing between benign and malignant gallbladder lesions was evaluated using ROC curves, and Spearman correlation analysis was employed to assess the correlation between these indicators and tumor parameters.

RESULTS

The average age of malignant gallbladder tumor group was higher than benign gallbladder polyp group. And the base line analysis showed that there was a statistic difference in age, history of smoking, drinking, biliary tract disease, BMI of over weight between these two groups. In patients with malignant gallbladder tumors, FIB, D-dimer, FDP, PIC, TAT, TM, and t-PAIC levels were significantly elevated relative to those in patients affected by benign gallbladder polyp. The AUC for FIB, D-dimer, and FDP was 0.8469, 0.6514, 0.5950, while for PIC, TAT, TM, t-PAIC and four biomarker combined diagnosed was 0.8455, 0.6554, 0.7130, 0.6806, and 0.8859. Among these, TM was associated with the vascular invasion of tumor patients; TAT and t-PAIC were associated with neural invasion; D-dimer and FDP were related to the maximum tumor diameter; and FDP had a certain correlation with the tumor stage.

CONCLUSIONS

In gallbladder tumor patients, conventional coagulation metrics like FIB, D-dimer, and FDP, as well as newer thrombotic indicators such as PIC, TAT, TM, and t-PAIC, were obviously increased. Correlations with tumor parameters suggested their potential as biomarkers to distinguish benign from malignant gallbladder growths.

Cancer progression and tumor hypercoagulability: a platelet perspective

Venous thromboembolism, which is common in cancer patients and accompanies or even precedes malignant tumors, is known as cancer-related thrombosis and is an important cause of cancer- associated death. At present, the exact etiology of the elevated incidence of venous thrombosis in cancer patients remains elusive. Platelets play a crucial role in blood coagulation, which is intimately linked to the development of arterial thrombosis. Additionally, platelets contribute to tumor progression and facilitate immune evasion by tumors. Tumor cells can interact with the coagulation system through various mechanisms, such as producing hemostatic proteins, activating platelets, and directly adhering to normal cells. The relationship between platelets and malignant tumors is also significant. In this review article, we will explore these connections.

Cellular Components Contributing to the Development of Venous Thrombosis in Patients with Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive type of cancer and has a poor prognosis. Patients with PDAC are at high risk of developing thromboembolic events, which is a leading cause of morbidity and mortality following cancer progression. Plasma-derived coagulation is the most studied process in cancer-associated thrombosis. Other blood components, such as platelets, red blood cells, and white blood cells, have been gaining less attention. This narrative review addresses the literature on the role of cellular components in the development of venous thromboembolism (VTE) in patients with PDAC. Blood cells seem to play an important role in the development of VTE. Altered blood cell counts, i.e., leukocytosis, thrombocytosis, and anemia, have been found to associate with VTE risk. Tumor-related activation of leukocytes leads to the release of tissue factor-expressing microvesicles and the formation of neutrophil extracellular traps, initiating coagulation and forming a scaffold for thrombi. Tissue factor-expressing microvesicles are also thought to be released by PDAC cells. PDAC cells have been shown to stimulate platelet activation and aggregation, proposedly via the secretion of podoplanin and mucins. Hypofibrinolysis, partially explained by increased plasminogen activator inhibitor-1 activity, is observed in PDAC. In short, PDAC-associated hypercoagulability is a complex and multifactorial process. A better understanding of cellular contributions to hypercoagulability might lead to the improvement of diagnostic tests to identify PDAC patients at highest risk of VTE.

A diagnostic biomarker of acid glycoprotein 1 for distinguishing malignant from benign pulmonary lesions

BACKGROUND

The acid glycoprotein 1 (AGP1) is downregulated in lung cancer. However, the performance of AGP1 in distinguishing benign from malignant lung lesions is still unknown.

METHODS

The expression of AGP1 in benign diseases and lung cancer samples was detected by Western blot. The receiver operating characteristic curves, bivariate correlation, and multivariate analysis was analyzed by SPSS software.

RESULTS

AGP1 expression levels were significantly downregulated in lung cancer and correlated with carcinoembryonic antigen (CEA), CA199, and CA724 tumor biomarkers. The diagnostic performance of AGP1 for distinguishing malignant from benign pulmonary lesions was better than the other four clinical biomarkers including CEA, squamous cell carcinoma-associated antigen, neuron-specific enolase, and cytokeratin 19 fragment 21-1, with an area under the curve value of 0.713 at 88.8% sensitivity. Furthermore, the multivariate analysis indicated that the variates of thrombin time and potassium significantly affected the AGP1 levels in lung cancer.

CONCLUSIONS

Our study indicates that AGP1 expression is decreased in lung cancer compared to benign samples, which helps distinguish benign and malignant pulmonary lesions.

Coagulation Factor Expression and Composition of Arterial Thrombi in Cancer-Associated Stroke

BACKGROUND

Cancer is associated with an increased risk of stroke. Tumor cells activate platelets, induce a coagulation cascade, and generate thrombin. The composition of thrombi may reflect the mechanism of thrombosis, aiding the determination of the treatment strategy. Here, we investigated the composition and expression of coagulation factors in the thrombi of patients with cancer-associated stroke.

METHODS

Patients with stroke who underwent endovascular thrombectomy between September 2014 and June 2020 and whose cerebral thrombi were obtained were divided into those with cancer-associated stroke (cancer group) and propensity score-matched patients without cancer (control group), using 1:1 matching based on age and sex. Immunohistochemistry was performed of the thrombi, and the composition and expression of coagulation factors were compared between groups.

RESULTS

Among the 320 patients who underwent endovascular thrombectomy and who had thrombi obtained, this study included 23 patients with cancer and 23 matched controls. In both groups, the median age was 65 years, and 12 patients (52.2%) were men. Platelet composition was significantly higher in the cancer group than in the control group (median [interquartile range], 51.3% [28.0%-61.4%] versus 9.5% [4.8%-14.0%]; P<0.001). Among coagulation factors, thrombin (26.2% [16.2%-52.7%] versus 4.5% [1.3%-7.2%]; P<0.001) and tissue factors (0.60% [0.34%-2.06%] versus 0.37% [0.22%-0.60%]; P=0.024) were higher and factor X was lower (1.25% [0.39%-3.60%] versus 2.33% [1.67%-4.48%]; P=0.034) in the cancer group. There was a positive correlation between thrombin and platelets in the cancer group (r=0.666; P=0.001) but not in the control group (r=-0.167; P=0.627).

CONCLUSIONS

Cerebral thrombi in patients with cancer-associated stroke showed higher proportions of platelets, thrombin, and tissue factors, suggesting their key roles in arterial thrombosis in cancer and providing a therapeutic perspective for preventing stroke in patients with cancer-associated stroke.

A prediction nomogram for deep venous thrombosis risk in patients undergoing primary total hip and knee arthroplasty: a retrospective study

INTRODUCTION

Deep venous thrombosis (DVT) prediction after total hip and knee arthroplasty remains challenging. Early diagnosis and treatment of DVT are crucial. This research aimed to develop a nomogram for early DVT prediction.

METHODS

A total of 317 patients undergoing primary total hip and knee arthroplasty in Sun Yat-sen Memorial Hospital were enrolled between May 2020 and September 2022. Data from May 2020 to February 2022 were used as the development datasets to build the nomogram model (n = 238). Using multivariate logistic regression, independent variables and a nomogram for predicting the occurrence of DVT were identified. Datasets used to validate the model for internal validation ranged from March 2022 to September 2022 (n = 79). The nomogram's capacity for prediction was also compared with the Caprini score.

RESULTS

For both the development and validation datasets, DVT was found in a total of 38 (15.97%) and 9 patients (11.39%) on post-operative day 7 (pod7), respectively. 59.6% patients were symptomatic DVT (leg swelling). The multivariate analysis revealed that surgical site (Knee vs. Hip), leg swelling and thrombin-antithrombin complex (TAT) were associated with DVT. The previously indicated variables were used to build the nomogram, and for the development and validation datasets, respectively. In development and validation datasets, the area under the receiver operating characteristic curve was 0.836 and 0.957, respectively. In both datasets, the predictive value of the Nomogram is greater than the Caprini score.

CONCLUSIONS

A proposed nomogram incorporating surgical site (Knee vs. Hip), leg swelling, and thrombin antithrombin complex (TAT) may facilitate the identification of patients who are more prone to develop DVT on pod7.

Bleeding patients on extracorporeal membrane oxygenation have reduced platelet aggregation and plasma fibrinogen: a longitudinal observational study

This study investigated changes in coagulation and associations with occurrence of bleeding and thrombosis during extracorporeal membrane oxygenation (ECMO) therapy. The study included 100 adult ECMO-patients. Standard coagulation parameters, platelet aggregation and thromboelastometry (ROTEM®) were compared with healthy controls. Data on bleeding and thrombosis were collected until recovery or death. Mortality data were collected 30 days after weaning from ECMO. During ECMO therapy, 53 patients experienced at least one moderate or major bleed. Among these, 42 (79%) patients experienced the first bleeding on day 1 or 2. Platelet aggregation and ROTEM® revealed a hypocoagulable state in ECMO patients when compared with healthy controls. Patients bleeding on day 1 or 2, had lower platelet count (p = 0.04), poorer platelet aggregation and lower levels of fibrinogen (p < 0.01) than patients not bleeding on day 1 or 2. Further, ROTEM® clot propagation was reduced in bleeding patients (p < 0.001). Mortality was higher among bleeding patients than patients not bleeding on day 1 or 2 (67% versus 34%, p < 0.01). Congruity existed between ROTEM® measurements and standard coagulation assays, but plasma fibrinogen had a stronger association with bleeding than ROTEM® measurements. The present study does not support ROTEM® analysis as a routine part of coagulation monitoring during ECMO therapy.

[Application Value of Novel Coagulation Markers in Predicting Postoperarative Complications in the Early Stage After Liver Transplantation]

Objective

To investigate the relationship between thrombin-antithrombin complex (TAT), plasmin-α 2-plasmininhibitor complex (PIC), soluble thrombomodulin (sTM), and tissue plasminogen activator-inhibitor complex (tPAIC) and postoperative complications in the early stage after liver transplantation (LT).

Methods

We analyzed the perioperative clinical data, including plasma TAT, PIC, sTM, and tPAIC, of 130 post-LT patients admitted to the intensive care unit (ICU), West China Hospital, Sichuan University between December 2021 and November 2022. Patients were divided into two groups, a complication group and a non-complication group, according to whether they experienced complications of Clavien-Dindo (CD) grade Ⅲb and above within 30 days after the surgery. Univariate analysis and binary multivariate logistic regression models were used to determine the risk factors for complications within 30 days post-LT.

Results

The incidence of complications of CD grade Ⅲb and above within 30 days post-LT was 33.1% (43/130). Patients in the complication group had significantly higher scores for the Model for End-Stage Liver Disease (MELD), operative time, intraoperative red blood cell transfusion volume, intraoperative plasma transfusion volume, and plasma TAT, PIC, sTM and tPAIC measured at the time of admission to ICU after the operation than those in the non-complication group did (all P<0.05). Logistic regression showed that for every single U of red blood cells transfused during the transplant surgery, the probabilities of complications within 30 days post-LT increased by 15.1% (95% confidence interval [ C I]: 1.070-1.239, P<0.001) and for the increase of every single TU/mL of plasma sTM measured upon post-LT admission to ICU, the probabilities of complications increased by 13.7% (95% CI: 1.060-1.220, P<0.001).

Conclusion

Plasma sTM measured upon admission to ICU after LT is an independent risk factor for complications within 30 days post-LT, and additional assessment of sTM may help predict complications in the early stage post-LT.

Overestimation of fibrinogen concentration in cryoprecipitate by repeated freeze-thawing with long thawing period as used in the Clauss method

BACKGROUND

Cryoprecipitate (CRY) is widely used for treating acquired hypofibrinogenemia. During our study to determine an optimal preparation method, we noticed that the measurement of fibrinogen concentration in CRY had a risk of overestimation. We analyzed this condition and mechanism.

STUDY DESIGN AND METHODS

CRY was prepared from fresh frozen plasma (FFP) under four conditions: A, 30 h thawing time, 2 cycles; B, 24 h thawing time, 2 cycles; C, 30 h thawing time, 1 cycle; and D, 24 h thawing time, 1 cycle. Then, fibrinogen concentrations in CRY and cryosupernatant (CS) were measured by the Clauss method.

RESULTS

Purification (CRY/CRY+CS) and recovery (CRY/FFP) rates in CRY prepared under 2-cycle conditions were higher than those under 1 cycle. However, recovery rates often exceeded 100%, particularly in the case of CRY prepared under A condition, and fibrinogen concentrations calculated by direct measurement were higher than those indirectly calculated from FFP and CS, suggesting an overestimation of fibrinogen values. The level of soluble fibrin monomer complex was considerably higher in CRY prepared under A than under D condition, indicating that CRY adopted a hypercoagulated state. We further found that repeated thawing/freezing increased fibrinogen values as measured by the Clauss method while mechanical vortexing did not.

DISCUSSION

Our findings suggest that direct assessment of fibrinogen contents in CRY prepared by repeated freeze-thawing with a longer thawing period presents a higher risk of overestimation. For the purpose of quality control, we propose an alternative method to indirectly estimate fibrinogen concentrations in CRY from those of CS and FFP.

Nucleic acid aptamer-based biosensors and their application in thrombin analysis

Thrombin is a multifunctional serine protease that plays an important role in coagulation and anticoagulation processes. Aptamers have been widely applied in biosensors due to their high specificity, low cost and good biocompatibility. This review summarizes recent advances in thrombin quantification using aptamer-based biosensors. The primary focus is optical sensors and electrochemical sensors, along with their applications in thrombin analysis and disease diagnosis.

A cohort study on blood coagulation in childhood cancer survivors

Cancer survivors are at an increased risk of thromboembolism compared to the general pediatric population. Anticoagulant therapy decreases the risk of thromboembolism in cancer patients. We hypothesized that pediatric cancer survivors are in a chronically hypercoagulable state compared to healthy controls. Children who survived for more than five years from cancer diagnosis at the UT Health Science Center at San Antonio Cancer Survivorship Clinic were compared to healthy controls. The exclusion criteria were recent NSAID use or a history of coagulopathy. Coagulation analysis included platelet count, thrombin-antithrombin complexes (TAT), plasminogen activator inhibitor (PAI), routine coagulation assays, and thrombin generation with and without thrombomodulin. We enrolled 47 pediatric cancer survivors and 37 healthy controls. Platelet count was significantly lower in cancer survivors at a mean of 254 × 10⁹/L (95%CI: 234-273 × 10⁹/L) compared at 307 × 10⁹/L (283-331 × 10⁹/L) in healthy controls (p < 0.001), although not outside the normal range. Routine coagulation assays showed no differences, except for a significantly lower prothrombin time (PT) in cancer survivors (p < 0.004). Cancer survivors has significantly elevated biomarkers of the procoagulant state, such as TAT and PAI, compared to healthy controls (p < 0.001). A multiple logistic regression model controlling for age, BMI, gender, and race/ethnicity documented that a low platelet count, short prothrombin clot time, and higher procoagulant biomarkers (TAT and PAI) were significantly associated with past cancer therapy. Survivors of childhood cancer have a persistent procoagulant imbalance for more than five years after diagnosis. Further studies are needed to establish whether procoagulant imbalance increases the risk of thromboembolism in childhood cancer survivors.

Thromboinflammatory response is increased in pancreas transplant alone versus simultaneous pancreas-kidney transplantation and early pancreas graft thrombosis is associated with complement activation

Background

Pancreas transplant alone (PTA) recipients are more affected by pancreas graft thrombosis, and graft loss compared to simultaneous pancreas-kidney (SPK) recipients. The pathophysiology is unknown, but an increased immune response has been suggested in the PTA recipients. In this observational study, we compared perioperative thromboinflammation between PTA (n=32) and SPK (n=35) recipients, and between PTA recipients with (n=14) versus without (n=18) early graft thrombosis.

Methods

We measured C-reactive protein (CRP), plasma markers of activated coagulation and complement, and cytokines preoperatively and daily during the first postoperative week.

Results

Preoperatively, coagulation and complement activation markers were comparable between PTA and SPK recipients, while cytokine concentrations were higher in SPK recipients (TNF, IL-8, IP-10, MCP-1, MIP-1α; all p&lt;0.05). On the first postoperative day, PTA recipients had higher coagulation activation, measured as thrombin-antithrombin complex (TAT), than SPK recipients (p=0.008). In the first postoperative week, PTA recipients showed higher relative cytokine release (IL-6, IL-8, G-CSF, IP-10, MCP-1, and MIP-1α; all p&lt;0.05) while SPK recipients showed higher absolute cytokine concentrations (TNF, IL-1ra, IL-8, MIP-1α, and IL-4; all p&lt;0.05). PTA and SPK recipients showed similar terminal complement complex (TCC, sC5b-9) activation. On the first postoperative day, TCC (OR 1.2 [95% CI 1.0-1.5] for 0.1 CAU/ml increase, p=0.02) and CRP (OR 1.2 [95% CI 1.0-1.3] for 10 mg/L increase, p=0.04) were associated with an increased risk of early graft thrombosis. TCC was specific for graft thrombosis, while CRP increased with several complications. PTA recipients with compared to those without graft thrombosis had higher TCC pre- (p=0.04) and postoperatively (p=0.03).

Conclusion

The relative increase in postoperative thromboinflammatory response was more pronounced in PTA recipients. Complement activation was associated with an increased risk of graft thrombosis. This study indicates that innate immune activation rather than elevated levels may affect early postoperative pancreas graft thrombosis.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT01957696, identifier NCT01957696

Preparation of magnetic poly(ethylene glycol dimethacrylate-N-Methacryloyl-(L)-glutamic acid) particles for thrombin purification

In this study, magnetic poly(ethylene glycol dimethacrylate-N-methacryloyl-(L)-glutamic acid) (mPEGDMA-MAGA) particles were prepared by the dispersion polymerization in order to purify thrombin effectively. mPEGDMA-MAGA particles were synthesized by adding different ratios of magnetite (Fe₃O₄) to the medium in addition to the monomer phases EGDMA and MAGA. The characterization studies of mPEGDMA-MAGA particles were used by fourier transform infrared spectroscopy, zeta size measurement, scanning electron microscopy and electron spin resonance. mPEGDMA-MAGA particles were used in thrombin adsorption studies from aqueous thrombin solutions in both batch and magnetically stabilized fluidized bed (MSFB) system. Maximum adsorption capacity in pH 7.4 phosphate buffer solution is 964 IU/g polymer and 134 IU/g polymer in MSFB system and batch system, respectively. The developed magnetic affinity particles enabled the separation of thrombin from different patient serum samples in one step. It has also been observed that magnetic particles can be used repeatedly without significant reduction in adsorption capacity.

Increased In Vivo Thrombin Generation in Patients with Localized Non-Small Cell Lung Cancer Unfit for Surgery

Patients with lung cancer face a substantially increased risk of thromboembolic disease. Patients with localized non-small cell lung cancer (NSCLC) who are unfit for surgery due to age or comorbidity have additional thrombotic risk factors. Thus, we aimed to investigate markers of primary and secondary hemostasis, since this could assist in treatment decisions. We included 105 patients with localized NSCLC. Ex vivo thrombin generation was determined by calibrated automated thrombogram and in vivo thrombin generation was determined by measurement of thrombin-antithrombin complex (TAT) levels and prothrombin fragment F1 + 2 concentrations (F1 + 2). Platelet aggregation was investigated by impedance aggregometry. Healthy controls were used for comparison. TAT and F1 + 2 concentrations were significantly higher in NSCLC patients than in healthy controls (P < .001). The levels of ex vivo thrombin generation and platelet aggregation were not increased in the NSCLC patients. Patients with localized NSCLC considered unfit for surgery had significantly increased in vivo thrombin generation. This finding should be further investigated as it could be relevant for the choice of thromboprophylaxis in these patients.

Age-dependent thrombin generation predicts 30-day mortality and symptomatic thromboembolism after multiple trauma

Trauma-induced coagulopathy (TIC) is a risk factor for death and is associated with deviations in thrombin generation. TIC prevalence and thrombin levels increase with age. We assayed in vivo and ex vivo thrombin generation in injured patients (n = 418) to specifically investigate how age impacts thrombin generation in trauma and to address the prognostic ability of thrombin generation. Biomarkers of thrombin generation were elevated in young (< 40 years) and older (≥ 40 years) trauma patients. In vivo thrombin generation was associated with Injury Severity Score (ISS) and this association was stronger in young than older patients. In vivo thrombin generation decreased faster after trauma in the young than the older patients. Across age groups, in vivo thrombin generation separated patients dying/surviving within 30 days at a level comparable to the ISS score (AUC 0.80 vs. 0.82, p > 0.76). In vivo and ex vivo thrombin generation also predicted development of thromboembolic events within the first 30 days after the trauma (AUC 0.70-0.84). In conclusion, younger trauma patients mount a stronger and more dynamic in vivo thrombin response than older patients. Across age groups, in vivo thrombin generation has a strong ability to predict death and/or thromboembolic events 30 days after injury.

In vitro Effect of Dalteparin and Argatroban on Hemostasis in Critically Ill Sepsis Patients with New-Onset Thrombocytopenia

Thrombocytopenia is common among critically ill sepsis patients, while they also hold an increased risk for thromboembolic events. Thus, the choice of anticoagulant prophylaxis for this patient population is challenging. We investigated the in vitro effect of low-molecular-weight heparin (dalteparin) and direct thrombin inhibitor (argatroban) on the hemostasis in blood from sepsis patients with new-onset thrombocytopenia. Thrombocytopenia was defined as a platelet count drop of ≥30% and/or from >100 × 10 ⁹ /L to 30 to 100 × 10 ⁹ /L within 24 hours prior to inclusion. We included five healthy individuals and ten patients. Analyses of thrombin generation (Calibrated Automated Thrombogram), thrombin-antithrombin (TAT) complex levels, prothrombin fragment 1+2 (F1+2), and rotational thromboelastometry (ROTEM) were performed. Based on dose-response relationships investigated in healthy blood, patient samples were spiked with prophylactic (0.25 IU/mL) and therapeutic (0.75 IU/mL) dalteparin and low (0.25 µg/mL) and high (0.50 µg/mL) argatroban concentrations, each with a sample without anticoagulant. In patients, the endogenous thrombin potential was markedly lower in therapeutic dalteparin samples than in samples without anticoagulant [median (range): 29 (0-388) vs. 795 (98-2121) nM × min]. In high argatroban concentration samples, thrombin lag time was longer than in samples without anticoagulant [median (range): 15.5 (10.5-20.2) versus 5.3 (2.8-7.3) min]. Dalteparin and argatroban both increased clotting time but did not affect maximum clot firmness in the ROTEM INTEM assay. Six patients had elevated TAT and eight patients had elevated F1 + 2. In conclusion, dalteparin mainly affected the amount of thrombin generated and argatroban delayed clot initiation in critically ill sepsis patients with new-onset thrombocytopenia. Neither anticoagulant affected clot strength.

Clinical study on the feasibility of new thrombus markers in predicting massive cerebral infarction

Objective

This study investigated the diagnostic performance of the thrombin-antithrombin complex (TAT), plasmin-α2 plasmin inhibitor complex (PIC), tissue plasminogen activator-plasminogen activator inhibitor complex (t-PAIC), and thrombomodulin (TM) in the early identification of massive cerebral infarction.

Method

A total of 423 patients with cerebral infarction confirmed by imaging examination were divided into the massive cerebral infarction (MCI) group and the non-massive cerebral infarction (NMCI) group. TAT, PIC, t-PAIC, and TM were measured immediately after admission. The diagnostic performance was analyzed by the receiver characteristic operating curve (ROC).

Result

The median plasma concentrations of TAT, PIC, and t-PAIC in patients with MCI at early onset were 5.10 ng/ml, 1.11 μg/ml, and 8.80 ng/ml, respectively, which were higher than those in patients with NMCI (2.20 ng/ml, 0.59 μg/ml, and 7.35 ng/ml), and the difference was statistically significant (P < 0.001). TAT was shown to be an independent risk factor for the development of massive cerebral infarction by a multivariate logistic regression analysis (OR = 1.138). A ROC curve analysis showed that PIC had the best performance in identifying MCI at an early stage (AUC = 82.8%), with a sensitivity of 80.7% and a specificity of 76.2% when the PIC concentration was ≥0.8 μg/ml; TAT had the highest specificity in identifying MCI, with a specificity of 80.6% when the TAT concentration was ≥3.97 ng/ml.

Conclusion

The detection of PIC, TAT, t-PAIC, and TM is a comprehensive assessment of vascular endothelial damage and activation of the coagulation and fibrinolytic systems and has diagnostic value for early identification of patients with MCI, which, together with its ease of detection, can be used as a plasma marker for early identification of large vessel occlusion.

Impact of Stereotactic Body Radiotherapy on Thrombin Generation and Platelet Aggregation in Patients with Non-Small Cell Lung Cancer

Patients with localized non-small cell lung cancer (NSCLC) considered unfit for surgery are at substantially increased risk of venous thromboembolism. Radiotherapy may further increase this risk. We aim to investigate the impact of stereotactic body radiotherapy (SBRT) on thrombin generation and platelet aggregation. We included 110 patients with localized NSCLC treated with SBRT. Blood samples were obtained prior to SBRT, immediately after SBRT completion, and 4-6 weeks following SBRT. Ex vivo and in vivo thrombin generations were analyzed using a calibrated automated thrombogram and commercial enzyme-linked immunosorbent assays. Platelet aggregation was evaluated using multiple electrode aggregometry. No significant differences were found in ex vivo or in vivo thrombin generation between blood samples before and immediately after SBRT treatment. Platelet aggregation was lower immediately after SBRT than before SBRT (TRAP: P = 0.04 and ASPI: P = 0.02) but remained within the reference interval. SBRT did not affect in vivo and ex vivo thrombin generation or platelet aggregation. SBRT did not cause prothrombotic changes in the coagulation in this study population of SBRT-treated patients with localized NSCLC.

Do coagulation or fibrinolysis reflect the disease condition in patients with soft tissue sarcoma?

BACKGROUND

Coagulation and fibrinolysis are distinct processes that are highly correlated. Cells control coagulation and fibrinolysis by expression of tissue factor and urokinase-type plasminogen activator receptor on their surface. Tumor cells express these proteins, adjust their microenvironment and induce tumor exacerbation. We hypothesized that the expression of plasma markers for coagulation and fibrinolysis in patients with soft tissue sarcomas (STSs) was dependent on the level of tumor malignancy. To elucidate which markers are predictive of recurrence, metastasis and prognosis, coagulation or fibrinolysis, we analyzed the correlation between plasma levels of thrombin-antithrombin III complex (TAT), soluble fibrin (SF), plasmin-α2 plasmin inhibitor complex (PIC), D-dimer (DD) and clinical parameters in patients with STSs.

METHODS

TAT, SF, PIC or DD were measured in pre-treatment blood samples from 64 patients with primary STSs and analyzed with clinicopathological parameters, and 5-year recurrence free survival (RFS), 5-year metastasis free survival (MFS) and 5-year overall survival (OS) were evaluated.

RESULTS

The metastasis group had significantly higher DD (p = 0.0394), PIC (p = 0.00532) and SF (p = 0.00249) concentrations than the group without metastasis. The group that died of disease showed significantly higher DD (p = 0.00105), PIC (p = 0.000542), SF (p = 0.000126) and TAT (p = 0.0373) than surviving patients. By dividing the patients into low and high groups, the group with high DD, PIC, SF and TAT showed significantly lower 5-year MFS and 5-year OS than the corresponding low group. Furthermore, in multivariate COX proportional hazard analysis of continuous variables for 5-year MFS, only PIC was found to be a significant factor (HR: 2.14).

CONCLUSION

Fibrinolysis was better than coagulation at reflecting the disease condition of patients with STS. Notably, PIC levels ≥ 1.1 can not only predict the risk of metastasis and poor prognosis, but also increasing PIC levels correspond to further increases in risks of metastasis and poor prognosis.

Changes in thrombosis-related parameters after AstraZeneca COVID-19 vaccination in a male volunteer: a case report

Background

We speculated that subclinical thrombosis may occur frequently through crosstalk between immune/inflammatory reactions and hemostasis after corona virus disease-2019 (COVID-19) vaccination. To test this hypothesis, we measured thrombosis-related parameters after COVID-19 vaccination in a volunteer for 21 days.

Case presentation

The following parameters were measured in a 72-year-old Korean man at 1 day before vaccination and on days 1, 3, 7, 14, and 21 post vaccination (AstraZeneca COVID-19 vaccine: ChAdOx1-S/nCoV-19, CTMAV563): complete blood count, platelet indices, thrombin receptor-activating peptide-induced platelet aggregation, prothrombin time, activated partial thromboplastin time, D-dimer, thrombin–antithrombin III complex (TAT), plasmin-α2 antiplasmin complex (PAP), von Willebrand factor (vWF) antigen and activity, plasminogen activator inhibitor-1 (PAI-1), protein C and protein S antigen and activity, lupus anticoagulant, fibrinogen degradation product, and plasminogen. We found that the TAT had significantly increased from 0.7 ng/mL (baseline) to 21.7 ng/mL (day 1). There was a transient increase in the PAI-1 level from 7.2 ng/mL (baseline) to 10.9 ng/mL (day 3), followed by a decrease in PAP level from 0.9 ng/mL (baseline) to 0.3 μg/mL (day 7), suggesting that plasmin generation is suppressed by PAI-1.

Conclusions

Increased thrombotic factors (such as decreased protein S) and decreased fibrinolytic activity due to increased PAI-1 were potential factors causing thrombogenesis after COVID-19 vaccination. Sequential measurement of platelet indices, TAT, PAP, protein C, protein S, vWF, D-dimer, and PAI-1 following COVID-19 vaccination was informative.

Arterial and venous blood sampling is equally applicable for coagulation and fibrinolysis analyses

OBJECTIVES

No consensus exists upon whether arterial and venous blood samples are equivalent when it comes to coagulation analyses. We therefore conducted a comparative cohort study to clarify if arteriovenous differences affect analyses of primary and secondary hemostasis as well as fibrinolysis.

METHODS

Simultaneous paired blood samplings were obtained from a cannula in the radial artery and an antecubital venipuncture in 100 patients immediately before or one day after thoracic surgery. Analyses of platelet count and aggregation, International Normalized Ratio (INR), activated partial thromboplastin time (APTT), antithrombin, thrombin time, fibrinogen, D-dimer, rotational thromboelastometry (ROTEM), thrombin generation, prothrombin fragment 1 + 2, and an in-house dynamic fibrin clot formation and lysis assay were performed.

RESULTS

No differences were found between arterial and venous samples for the far majority of parameters. The only differences were found in INR, median (IQR): venous, 1.1 (0.2) vs. arterial, 1.1 (0.2) (p<0.002) and in prothrombin fragment 1 + 2: venous, 289 (209) pmol/L vs. arterial, 279 (191) pmol/L (p<0.002).

CONCLUSIONS

The sampling site does not affect the majority of coagulation analyses. Small differences were found for two parameters. Due to numerically very discrete differences, they are of no clinical relevance. In conclusion, the present data suggest that both samples obtained from arterial and venous blood may be applied for analyses of coagulation and fibrinolysis.

Thrombin antithrombin complex concentration as an early predictor of deep vein thrombosis after total hip arthroplasty and total knee arthroplasty

Aim

Early predictive markers of venous thromboembolism (VTE) after total hip arthroplasty (THA)/total knee arthroplasty (TKA) remain unclear. Our study identified early predictive markers for VTE after THA/TKA.

Methods

A single-institution retrospective review study was conducted between May 2020 and April 2022 (n = 256). All patients underwent Doppler ultrasounds exam in preoperation and seventh day after surgery. Deep vein thrombosis (DVT) was defined by Doppler ultrasound of the lower extremities, which revealed thrombosis. Thrombin-antithrombin complex (TAT), thrombomodulin (TM), and plasmin-antiplasmin complex (PIC) concentration were tested from each patient’s preoperative and postoperative days 1, 4, 7, 14. These values were then accessed via receiver operating characteristic (ROC) curve analysis and further quantified the level of this risk by concentration.

Results

On postoperative day 1 (pod-1), all patients’ TAT and PIC concentrations were significantly higher than those preoperatively (p < 0.05). The levels of TAT and PIC in patients in the DVT group on pod-1 were significantly higher than those in the non-DVT group (p < 0.05). At pod-1, the TAT concentration for DVT patients was 49.47 ng/mL compared to 20.70 ng/mL for non-DVT patients, PIC was 3.72μg/mL compared to 1.65μg/mL. ROC curve analysis demonstrated that a TAT concentration of 24.3 ng/mL had a sensitivity of 87.9% and a specificity of 69.1%.

Conclusion

TAT levels on pod-1 may predict DVT early after THA/TKA, which makes it possible for early intervention to decrease the incidence of DVT.

Biomarkers of Venous Thromboembolism Recurrence after Discontinuation of Low Molecular Weight Heparin Treatment for Cancer-Associated Thrombosis (HISPALIS-Study)

The most appropriate duration of anticoagulant treatment for cancer-associated venous thromboembolism (CAT) remains unclear. We have conducted a prospective multicenter study in CAT patients with more than 6 months of anticoagulant treatment to predict the risk of venous thromboembolism (VTE) recurrence after anticoagulation discontinuation. Blood samples were obtained when patients stopped the anticoagulation, at 21 days and at 90 days. In each sample we assessed different coagulation-related biomarkers: D-dimer (DD), high-sensitivity C-reactive protein (hs-CRP), P-selectin (PS), phospholipids, soluble tissue factor, factor VIII and the thrombin generation test. It was evaluated 325 CAT patients and 166 patients were included in the study, mean age 64 ± 17 years. VTE recurrence until 6 months after stopping anticoagulation treatment was 9.87% [95% confidence interval (CI): 6−15]. The biomarkers sub-distribution hazard ratios were 6.32 for ratio DD basal/DD 21 days > 2 (95% CI: 1.82−21.90), 6.36 for hs-CRP > 4.5 (95% CI: 1.73−23.40) and 5.58 for PS > 40 (95% CI: 1.46−21.30) after 21 days of stopping anticoagulation. This is the first study that has identified the DD ratio, hs-CRP and PS as potential biomarkers of VTE recurrence in cancer patients after the discontinuation of anticoagulation treatment. A risk-adapted strategy may allow the identification of the optimal time to withdraw the anticoagulation in each CAT patient.

Performance and reference intervals of thrombin generation test: results from the Brazilian longitudinal study of adult health (ELSA-Brasil). A cross-sectional study

BACKGROUND

The thrombin generation test (TGT) has shown promise for investigation of hemorrhagic and thrombotic diseases. However, despite its potential, it still needs standardization. Moreover, few studies have established reference values for TGT parameters. In Brazil, these values have not yet been established.

OBJECTIVE

To determine TGT performance and reference intervals for TGT parameters in healthy individuals.

DESIGN AND SETTING

Cross-sectional study conducted among participants in the Brazilian Longitudinal Study of Adult Health (Estudo Longitudinal de Saúde do Adulto, ELSA-Brasil).

METHODS

The reference sample consisted of 620 healthy individuals. The calibrated automated thrombogram (CAT) method, under low and high tissue factor (TF) conditions, was used to assess thrombin generation. Test performance was analyzed using intra and interassay coefficients of variation (CV) and reference intervals were calculated using the nonparametric method proposed by the International Federation of Clinical Chemistry and the Clinical and Laboratory Standards Institute.

RESULTS

The intraassay CV ranged from 1.4% to 2.2% and the interassay CV, 6.8% to 14.7%. The reference intervals for TGT parameters under low and high TF conditions were, respectively: lagtime: 3.0-10.3 and 1.4-3.7 min; endogenous thrombin potential (ETP): 1134.6-2517.9 and 1413.6-2658.0 nM.min; normalized ETP: 0.6-1.3 and 0.7-1.4; peak: 103.2-397.7 and 256.4-479.0 nM; normalized peak: 0.3-1.3 and 0.7-1.2; and time-to-peak: 5.6-16.0 and 3.4-6.7 min. These parameters were categorized relative to sex.

CONCLUSION

TGT performance was adequate and the proposed reference intervals were similar to those of other studies. Our findings may be useful for consolidating the TGT, through contributing to its standardization and validation.

Tumor-Educated Platelets Facilitate Thrombus Formation Through Migration

Platelets are small anucleate cells that circulate in the blood and form thrombi. Tumor-educated platelets are the platelets derived from cancer patients. Although many have reported that tumor-educated platelets are associated with cancer-associated thrombosis, their function in this process is poorly understood. Here we first collect the clinical data from 100 different cancer patients, showing that cancer patients are in a hypercoagulable state. Our experiment shows that tumor-educated platelets from melanoma-burdened mouse models can migrate faster and longer, forming more clots (thrombus). However, the plasma from tumor mice can inhibit platelet migration. The RNA sequence profile of tumor-educated platelets shows that many genes associated with cell migration and cell skeleton expressed significantly higher. Our research offers a new insight into the tumor-educated platelets to better understand the thrombus formation.

Markers of hypercoagulability in children with newly diagnosed acute lymphoblastic leukemia

BACKGROUND

Venous thromboembolism (VTE) is a known complication for children with acute lymphoblastic leukemia (ALL). The aim of this study was to identify laboratory biomarkers that predict which children with ALL are at risk for VTE during induction chemotherapy.

MATERIALS AND METHODS

Newly diagnosed ALL patients admitted to Children's Hospital Los Angeles with a central venous catheter (CVC) were eligible to participate. Participants' blood samples (complete blood count [CBC], quantitative D-dimer, prothrombin fragment 1.2 [PTF 1.2], and thrombin-antithrombin complexes [TAT]) were collected at day 0 (baseline/prior to induction), day 7 (±2 days), day 14 (±2 days), day 21 (±2 days), and day 28 (±2 days) of induction chemotherapy or until participants presented with a symptomatic VTE.

RESULTS

Seventy-five participants aged 1-21 years were enrolled and included in the final analysis. Twenty-six (35%) of the 75 participants were diagnosed with a CVC-associated VTE (22 asymptomatic and four symptomatic). There was a statistically significant difference between VTE and non-VTE participants for D-dimer (odds ratio [OR] 1.61, 95% confidence interval [CI]: 1.59-1.64), TAT (OR 1.34, 95% CI: 1.32-1.38), and PTF 1.2 (OR 1.31, 95% CI: 1.25-1.37) at all time points. Participants >10 years had a significantly higher risk of developing a VTE compared to participants <4 years (p = .007).

CONCLUSION

Older children with ALL as well as those with an elevated TAT, PTF 1.2, or D-dimer showed an increased risk of VTE, which may hold potential for predicting VTE in future studies.

Human endothelial cells and fibroblasts express and produce the coagulation proteins necessary for thrombin generation

In a previous study, we reported that human endothelial cells (ECs) express and produce their own coagulation factors (F) that can activate cell surface FX without the additions of external proteins or phospholipids. We now describe experiments that detail the expression and production in ECs and fibroblasts of the clotting proteins necessary for formation of active prothrombinase (FV-FX) complexes to produce thrombin on EC and fibroblast surfaces. EC and fibroblast thrombin generation was identified by measuring: thrombin activity; thrombin-antithrombin complexes; and the prothrombin fragment 1.2 (PF1.2), which is produced by the prothrombinase cleavage of prothrombin (FII) to thrombin. In ECs, the prothrombinase complex uses surface-attached FV and γ-carboxyl-glutamate residues of FX and FII to attach to EC surfaces. FV is also on fibroblast surfaces; however, lower fibroblast expression of the gene for γ-glutamyl carboxylase (GGCX) results in production of vitamin K-dependent coagulation proteins (FII and FX) with reduced surface binding. This is evident by the minimal surface binding of PF1.2, following FII activation, of fibroblasts compared to ECs. We conclude that human ECs and fibroblasts both generate thrombin without exogenous addition of coagulation proteins or phospholipids. The two cell types assemble distinct forms of prothrombinase to generate thrombin.

Dynamic Hemostasis and Fibrinolysis Assays in Intensive Care COVID-19 Patients and Association with Thrombosis and Bleeding-A Systematic Review and a Cohort Study

Patients admitted to the intensive care unit (ICU) with coronavirus disease 2019 (COVID-19), the infectious pathology caused by severe acute respiratory syndrome coronavirus 2, have a high risk of thrombosis, though the precise mechanisms behind this remain unclarified. A systematic literature search in PubMed and EMBASE identified 18 prospective studies applying dynamic coagulation assays in ICU COVID-19 patients. Overall, these studies revealed normal or slightly reduced primary hemostasis, prolonged clot initiation, but increased clot firmness. Thrombin generation assay parameters generally were equivalent to the control groups or within reference range. Fibrinolysis assays showed increased clot resistance. Only six studies related their findings to clinical outcome. We also prospectively included 51 COVID-19 patients admitted to the ICU. Blood samples were examined on day 1, 3-4, and 7-8 with platelet function tests, rotational thromboelastometry (ROTEM), in vivo and ex vivo thrombin generation, and clot lysis assay. Data on thrombosis, bleeding, and mortality were recorded during 30 days. Primary hemostasis was comparable to healthy controls, but COVID-19 patients had longer ROTEM-clotting times and higher maximum clot firmness than healthy controls. Ex vivo thrombin generation was similar to that of healthy controls while in vivo thrombin generation markers, thrombin-antithrombin (TAT) complex, and prothrombin fragment 1 + 2 (F1 + 2) were higher in ICU COVID-19 patients than in healthy controls. Impaired fibrinolysis was present at all time points. TAT complex and F1 + 2 levels were significantly higher in patients developing thrombosis (n = 16) than in those without. In conclusion, only few previous studies employed dynamic hemostasis assays in COVID-19 ICU-patients and failed to reveal a clear association with development of thrombosis. In ICU COVID-19 patients, we confirmed normal platelet aggregation, while in vivo thrombin generation was increased and fibrinolysis decreased. Thrombosis may be driven by increased thrombin formation in vivo.

Aptamer-Based Solution-Gated Graphene Transistors for Highly Sensitive and Real-Time Detection of Thrombin Molecules

Thrombin is an important biomarker for various diseases and biochemical reactions. Rapid and real-time detection of thrombin that quickly neutralizes in early coagulation in the body has gained significant attention for its practical applications. Solution-gated graphene transistors (SGGTs) have been widely studied due to their higher sensitivity and low-cost fabrication for chemical and biological sensing applications. In this paper, the ssDNA aptamer with 29 bases was immobilized on the surface of the gate electrode to specifically recognize thrombin. The SGGT sensor achieved high sensitivity with a limit of detection (LOD) up to fM. The LOD was attributed to the amplification function of SGGTs and the suitable aptamer choice. The ssDNA configuration folding induced by thrombin molecules and the electropositivity of thrombin molecules could arouse the same electrical response of SGGTs, helping the device obtain a high sensitivity. The channel current variation of sensors had a good linear relationship with the logarithm of thrombin concentration in the range of 1 fM to 10 nM. The fabricated device also demonstrated a short response time to thrombin molecules, and the response time to the 1 fM thrombin molecules was about 150 s. In summary, the sensing strategy of aptamer-based SGGTs with high sensitivity and high selectivity has a good prospect in medical diagnosis.

New Insights in Coagulation and Fibrinolysis in Patients with Primary Brain Cancer: A Systematic Review

Patients with primary brain tumors have a high incidence of thrombosis and hemorrhage. The underlying mechanism is believed to be derangement of their hemostatic system. To get nearer a clarification of this, we aimed to systematically review the existing literature regarding primary and secondary hemostasis as well as fibrinolysis in patients with primary brain tumor. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The databases PubMed, Embase, and Web of Science were searched on December 15, 2020, without time restrictions. Studies were included if they evaluated at least one blood coagulation and/or fibrinolysis parameter in patients with primary brain cancer. In total, 26 articles including 3,288 patients were included. Overall, increased activity of secondary hemostasis was observed as increased prothrombin fragment 1 + 2 and endogenous thrombin generation levels were found in glioma patients compared with controls. Furthermore, data showed a state of hypofibrinolysis with increased plasminogen activator inhibitor 1 and prolonged clot lysis time in glioma patients. In contrast, no consistent increase in the primary hemostasis was identified; however, data suggested that increased sP-selectin could be a biomarker of increased venous thromboembolism risk and that increased platelet count may be prognostic for survival. Lastly, data indicated that fibrinogen and D-dimer could hold prognostic value. In conclusion, this review indicates that an increased activity of secondary hemostasis and impaired fibrinolysis could be important players in the pathogeneses behind the high risk of thromboembolisms observed in brain cancer patients. Thus, long-term thromboprophylaxis may be beneficial and additional studies addressing this issue are wanted.

Thrombin: A Pivotal Player in Hemostasis and Beyond

The serine protease thrombin, a naturally derived enzyme, plays a key role in hemostasis by converting fibrinogen to fibrin and activating coagulation factor XIII whereby the fibrin clot is stabilized. Furthermore, thrombin activates platelets through protease-activated receptors on the platelet surface. Conversely, thrombin also exerts anticoagulant effects, enhancing the protein C activity while complexed with thrombomodulin. During recent years, it has become evident that thrombin has significant effects beyond hemostasis, as it contributes also to modulation of the endothelium, promotes inflammation and angiogenesis, and plays a role in tumor progression. Yet, due to the very short half-life and almost immediate inhibition in fluid phase by antithrombin, thrombin itself remains elusive, and only indirect measurement of thrombin generation is possible. This review provides a description of structure and mechanisms of action of thrombin both in physiological and pathological processes. Furthermore, it summarizes laboratory tests that measure in vivo or ex vivo thrombin generation, and presents knowledge on the value of these biomarkers in bleeding disorders, cardiopulmonary bypass surgery, and thromboembolic risk assessment in different patient populations. Finally, this review outlines further perspectives on using thrombin generation biomarkers for research purposes and in clinical practice.

Risk Factors and Prediction Models for Venous Thromboembolism in Ambulatory Patients with Lung Cancer

Venous thromboembolism (VTE) is a significant cause of mortality in patients with lung cancer. Despite the availability of a wide range of anticoagulants to help prevent thrombosis, thromboprophylaxis in ambulatory patients is a challenge due to its associated risk of haemorrhage. As a result, anticoagulation is only recommended in patients with a relatively high risk of VTE. Efforts have been made to develop predictive models for VTE risk assessment in cancer patients, but the availability of a reliable predictive model for ambulate patients with lung cancer is unclear. We have analysed the latest information on this topic, with a focus on the lung cancer-related risk factors for VTE, and risk prediction models developed and validated in this group of patients. The existing risk models, such as the Khorana score, the PROTECHT score and the CONKO score, have shown poor performance in external validations, failing to identify many high-risk individuals. Some of the newly developed and updated models may be promising, but their further validation is needed.

Significance of coagulation and fibrinolysis markers for benign and malignant soft tissue tumors

Background

The intimate relationship between coagulation and fibrinolysis in malignant tumors is a well-known phenomena, with the malignant phenotype enhancing coagulation and fibrinolysis. We hypothesized that soft tissue sarcoma (STS) affects the expression of coagulation and fibrinolysis markers, which could be used to distinguish STS from benign soft tissue tumors. We analyzed the correlations between plasma levels of D-dimer (DD), plasmin-α2 plasmin inhibitor complex (PIC), soluble fibrin (SF), and thrombin-antithrombin III complex (TAT) in benign soft tissue tumors and STS to elucidate whether these markers can be used to predict STS.

Methods

Plasma DD, PIC, SF and TAT levels in primary soft tissue tumors (benign 67, STS 68) were measured before biopsy or treatment. The marker levels were analyzed and compared to various clinicopathological parameters.

Results

In malignancy (STS), the average DD, PIC and SF levels were significantly higher than in benign tumors. Multivariate logistic analysis of continuous variables indicated that only PIC exhibited a significant difference (OR: 24.5, 95%CI: 3.55–170, p = 0.0012). Receiver operating characteristic curve analysis produced area under the curve values for DD: 0.691, PIC: 0.784, SF: 0.734 and TAT: 0.588. Youden’s index was used to establish thresholds of 0.37 (DD), 0.80 (PIC), 0.90 (SF) and 0.82 (TAT). Threshold values for PIC and SF indicated high specificity (0.881, 0.791) and high positive predictive value (0.818, 0.745), respectively. The highest accuracy value among the markers was observed for PIC (0.704). Significant differences in multivariate analysis of binary variables were demonstrated by categorizing low and high groups based on their threshold, PIC (≥0.80) (OR: 3.36, 95%CI: 1.19–9.43, p = 0.0212) and SF (≥0.90) (OR: 2.63, 95%CI: 1.04–6.66, p = 0.0404) .

Conclusions

Of the coagulation and fibrinolysis markers studied, increased PIC levels were related to STS and over 0.80 PIC was the most suitable for the prediction of STS, which, along with other diagnostic tools, represents a helpful subsidiary tool for the prediction of STS.

Added Value of Blood Cells in Thrombin Generation Testing

The capacity of blood to form thrombin is a critical determinant of coagulability. Plasma thrombin generation (TG), a test that probes the capacity of plasma to form thrombin, has improved our knowledge of the coagulation system and shows promising utility in coagulation management. Although plasma TG gives comprehensive insights into the function of pro- and anticoagulation drivers, it does not measure the role of blood cells in TG. In this literature review, we discuss currently available continuous TG tests that can reflect the involvement of blood cells in coagulation, in particular the fluorogenic assays that allow continuous measurement in platelet-rich plasma and whole blood. We also provide an overview about the influence of blood cells on blood coagulation, with emphasis on the direct influence of blood cells on TG. Platelets accelerate the initiation and velocity of TG by phosphatidylserine exposure, granule content release and surface receptor interaction with coagulation proteins. Erythrocytes are also major providers of phosphatidylserine, and erythrocyte membranes trigger contact activation. Furthermore, leukocytes and cancer cells may be important players in cell-mediated coagulation because, under certain conditions, they express tissue factor, release procoagulant components and can induce platelet activation. We argue that testing TG in the presence of blood cells may be useful to distinguish blood cell-related coagulation disorders. However, it should also be noted that these blood cell-dependent TG assays are not clinically validated. Further standardization and validation studies are needed to explore their clinical usefulness.