Prognostic value of thrombin generation assay and coagulation factor testing in postoperative deep venous thrombosis of lower extremities in elderly patients with traumatic fracture / 临床外科杂志

Objective To analyze the prognostic value of thrombin generation assay(TGA)and coagulation factor testing in postoperative deep venous thrombosis(DVT)of lower extremities in elderly patients with traumatic fracture.Methods A retrospective case-control study was conducted to collect traumatic patients older than 60 years old who underwent surgery in our department from March 2019 to March 2022.The number of patients was 104.According to the ultrasonic examination of DVT 5 days after operation,the patients were divided into DVT group and non-DVT group.The differences of general demographic data,previous chronic diseases,time from trauma to operation,related indexes of TGA and TF coagulation factors(F)between the two groups were analyzed.The indexes with statistical significance were analyzed by receiver operating curve(ROC);the indexes with statistically significant differences were analyzed by Logistic regression and the prediction probability was calculated by ROC curve analysis.Results The incidence of postoperative DVT was 21.12％.Compared with the non-DVT group,the time from trauma to operation was longer in the DVT group,and the peak value under 5 pmol/L TF activation was lower(258.13±40.88 vs 209.58±30.09).F V,F Ⅷ and Fib were higher(141.25(125.38,158.18)vs 176.12(150.65,186.34),145.49(133.36,147.48)vs 165.96(153.07,180.65),3.25± 0.55 vs 3.92±0.72,respectively).The differences were statistically significant(all P＜0.01).ROC curve analysis showed that the time from trauma to operation,the peak value of 5 pmol/L TF activation,F V,FⅧ and Fib combined had more predictive value for postoperative DVT,the AUC was 0.91(P＜0.01),the sensitivity was 0.82 and the specificity 0.92.Conclusion The time from trauma to operation,the peak value of TGA under the condition of 5 pmol/L TF activation,F V,F Ⅷ and Fib have excellent prognostic value for the postoperative DVT of lower extremities in elderly patients with traumatic fracture,and the combined detection is more significative.

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

ABSTRACT 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.

Benefits of Thromboelastography and Thrombin Generation Assay for Bleeding Prediction in Patients With Thrombocytopenia or Hematologic Malignancies

BACKGROUND: Thromboelastography (TEG) provides comprehensive information on the whole blood clot formation phases, whereas thrombin generation assay (TGA) reveals the endogenous thrombin levels in plasma. We investigated the potential significance of TEG and TGA parameters for prediction of clinical bleeding in hematologic patients on the basis of the patient's platelet levels. METHODS: TEG and TGA were performed in 126 patients with thrombocytopenia or hematologic malignancies. The bleeding tendencies were stratified on the basis of the World Health Organization bleeding grade. RESULTS: Maximum amplitude (MA) and clot formation in TEG and endogenous thrombin potential (ETP) in TGA showed significant associations with high bleeding grades (P=0.001 and P=0.011, respectively). In patients with platelet counts ≤10×10⁹/L, low MA values were strongly associated with a high bleeding risk. For bleeding prediction, the area under the curve (AUC) of MA (0.857) and ETP (0.809) in patients with severe thrombocytopenia tended to be higher than that of platelets (0.740) in all patients. Patients with platelet counts ≤10×10⁹/L displayed the highest AUC of the combined MA and ETP (0.929). CONCLUSIONS: Both TEG and TGA were considered to be good predictors of clinical bleeding in patients with severe thrombocytopenia. Combination of the ETP and MA values resulted in a more sensitive bleeding risk prediction in those with severe thrombocytopenia.

Activation of the Intrinsic Coagulation Pathway in Patients With Chronic Urticaria

PURPOSE: Although coagulation activation has been reported in chronic urticaria, data pertaining to detailed changes in coagulation factors and global coagulation status are lacking. The current study evaluated global coagulation status in patients with chronic urticaria using thrombin generation assay (TGA) and the levels of individual coagulation factors. METHODS: Patients with chronic urticaria (n=57) and 20 healthy controls were enrolled. TGA was performed under stimulation with 2 concentrations of tissue factor (TF). Coagulation factors and conventional coagulation assays were also analyzed. RESULTS: Although patients with chronic urticaria showed prolonged activated partial thromboplastin time, prothrombin time did not differ significantly between patients and controls. In both 1 pM and 5 pM TF-stimulated TGA, peak thrombin and endogenous thrombin potential (ETP) levels were markedly decreased in patients with chronic urticaria. As expected, intrinsic coagulation factors (VIII, IX, and XII), as well as coagulation factors of the common pathway (II, V, and X), were consistently decreased. Additionally, D-dimer was significantly increased in patients as compared to controls. In multivariate regression analysis, the presence of chronic urticaria was the only significant independent contributor to the low ETP value. CONCLUSIONS: Chronic urticaria is characterized by in vivo coagulation activation through the intrinsic coagulation pathway, which can be measured with sensitivity using TGA.