Role of Thromboelastogram in monitoring the activation of the coagulation pathway and assessing the associated risk factors for hypercoagulable state in transfusion dependent thalassemia patients.

BACKGROUND: Thromboembolic events are rare but one of the fatal complications in thalassemia. Assessment of the hypercoagulable state is not done regularly, and we have assessed the utility of Thromboelastography (TEG) for monitoring the activation of the coagulation pathway in patients with thalassemia. METHODOLOGY: A prospective single-center cohort study was conducted in a tertiary care set-up. Transfusion Dependent Thalassemia patients registered with the pediatric unit were screened for hypercoagulability using TEG during six months of the study period and followed up for three years for the development of thromboembolic events. Patient demographics, history of splenectomy, Serum ferritin levels and annual red cell transfusion requirement (mL/kg/year) were assessed. TEG parameters used were R time, K time, alpha angle, Maximum amplitude, Clot index, and Lysis 30. The thrombin generation test (V Curve) obtained from the first-degree derivate of the TEG velocity curve was also used for analysis. RESULTS: A total of 34 patients were recruited during the six months study period with an average age of 10.6 years ( ± 5.47). The average pre-transfusion hemoglobin level and the volume of packed red cells received were 7.24 g/dL and 152.82 mL/kg/year respectively. The TEG tracing was suggestive of a hypercoagulable state in 58.82% of patients. The mean values of angle (70.74), MA (64.16), CI (2.65) and TG (774.43) in TDT patients compared to age matched reference range (62.81, 57.99, 0.8, 577.83 respectively) was suggestive of prothrombotic changes. Annual blood transfusion requirement was negatively correlated with hypercoagulable status (-0.344, CI= -0.68 to 0.08). One out of 34 patients developed corona radiata infarct (with annual blood requirement; 112.7 mL/kg/Year). The risk to develop a hypercoagulable state appeared to be higher when the volume of RBCs transfused was less than 154 mL/kg/Year. CONCLUSION: TDT patients are at risk of developing thromboembolism, and screening with TEG may be useful to identify those at high risk.

Age- and gender-related reference ranges for thromboelastography from a healthy Indian population.

INTRODUCTION: Thromboelastography (TEG) is a whole blood clotting assay largely used in major surgeries and trauma to monitor patients' in vivo hemostatic status. Standardization of kaolin-activated citrated whole blood thromboelastography is not done in the Indian population. This study primarily aims to derive reference ranges of kaolin-activated TEG for healthy volunteers in the Indian population. Secondarily, it aims to study the age- and gender-related hemostatic changes in the study population. METHODS: A total of 120 healthy volunteers were enrolled (55 adult males, 32 adult females, and 33 children). The volunteers were interviewed for any bleeding history or drug intake which affects coagulation. Kaolin-activated TEG was performed on citrated whole blood, and parameters including R-time, K-time, angle, MA, LY30, and CI were analyzed. RESULTS: Derived reference range for total volunteers irrespective of age and sex were as follows: R-time: 3.8-10.6, K-time: 1.2-3.1, angle: 44.9-72.0, MA: 41.2-64.5, LY30: 0-9.9, and CI: -3.7 to 3.4. Statistically significant difference was observed in different age and sex groups for R-time, K-time, and angle. About 40% of the volunteers had at least one abnormal parameter according to the manufacturer's reference range which decreased to 12.5% when the derived reference ranges were considered. CONCLUSION: Gender- and age-related variances were observed in reference ranges of our population and which was also differed from the other ethnic population. Many of our healthy volunteers were categorized as coagulopathic when manufacturer's reference range was considered. So, it is important to derive the reference range of the target population before using the TEG into clinical practice.

Can the methanolic extract of Andrographis paniculata be used as a supplement to anti-snake venom to normalize hemostatic parameters: A thromboelastographic study.

ETHNOPHARMACOLOGICAL RELEVANCE OF ANDROGRAPHIS PANICULATA: The whole plant (including leaves and roots) is used in traditional Ayurveda and Siddha medicine to treat various clinical conditions such as fever, respiratory tract infections, colic pain, liver disorders, diabetes, hypertension, and inflammation. It is also used as an antidote for snake-bite, poisonous bites of insects and recommended as a dietary supplement to boost immunity. AIM OF THE STUDY: In-vitro thromboelastographic evaluation of the efficacy of methanolic extract of Andrographis paniculata (MAP) and polyvalent anti-snake venom (ASV) in neutralizing the Naja naja (N.N) venom-induced changes in hemostatic parameters. MATERIALS AND METHODS: Thromboelastographic evaluation of hemostatic parameters was initiated by adding 3µg N.N venom to citrated whole blood from healthy volunteers. The effect of different concentrations of ASV and MAP in neutralizing the toxicity of N.N venom were studied in two groups. In group 1 experiments, citrated whole blood (340µl) was mixed with N.N venom (3µg), immediately followed by successive addition of ASV (5µl, 8µl and 15µl) or MAP (15µg, 30µg, 60µg and 120 µg) or combination of ASV and MAP (3µl ASV+30µg MAP and 3µl ASV+60µg MAP). In group 2 experiments, N.N venom was incubated with whole blood for 90 minutes at 37°C, followed by successive addition of ASV (5µl, 10µl, and 15µl) or MAP (30µg and 60µg) or combination of ASV and MAP (5µl ASV+30µg MAP and 5µl ASV+60µg MAP). RESULT: In Group 1 experiments, N.N venom caused significant (p<0.05) increase in R-time, K-time, LY30% and a decrease in angle and MA. Optimum effect on hemostatic parameters was observed at a concentration of 8µl ASV, where all the deleterious effects of the venom were completely reversed. Similarly, the addition of MAP to the assay system could reproduce results as ASV, in reversing the deleterious effects of the venom. This occurred in a concentration-dependent manner, from 15µg-60µg, with the optimum results at 60µg. When ASV concentration was reduced to 3µl and supplemented with MAP (30µg or 60µg), the positive supplementary effect of MAP was demonstrated. In Group 2 experiments, N.N venom caused significant (p<0.05) changes in all TEG parameters, with most deleterious changes observed in MA and LY30% compared to Group 1 experiments. ASV when added in increasing concentrations (5-15µl), had beneficial effects only on K-time, angle, and MA. When added together with ASV, MAP (30µg or 60µg) could significantly (p<0.05) supplement the effect of ASV (5µl) in improving R-time, K-time, and angle. CONCLUSION: This in-vitro study demonstrates the effectiveness of MAP as a supplement to ASV in combating the deleterious effects of N.N venom on hemostasis. However, further in-vivo experiments in animal models are required to substantiate these effects.

Clinico-hematological and thromboelastographic profiles in glanzmann's thrombasthenia.

: Glanzmann's thrombasthenia is a rare inherited bleeding disorder characterized by the quantitative or qualitative defect of glycoprotein IIb/IIIa receptor on platelets which leads to ineffective aggregation. Light transmittance aggregometry is considered as the gold standard for diagnosis of Glanzmann's thrombasthenia. Thromboelastography (TEG) is a global hemostatic assay which measures clot formation, clot strengthening and fibrinolysis. This study evaluates the clinical, laboratory and TEG profiles in patients with Glanzmann's thrombasthenia. Bleeding score by (International Society on Thrombosis and Haemostasis) ISTH-bleeding assessment tool (bleeding score), laboratory tests to diagnose Glanzmann's thrombasthenia, and TEG parameters were correlated in 11 Glanzmann's thrombasthenia patients. Seventeen participants with normal bleeding score were included as controls. Bleeding score was increased in all patients. The highest bleeding score was in an adult female (26), whereas the lowest score (4) was in two children of less than 1 year. Majority of TEG parameters (except R-time) showed a statistically significant difference between Glanzmann's thrombasthenia patients and controls (K-time: P < 0.001, angle: P < 0.001, maximum amplitude: P < 0.001). The average time required to record the maximum amplitude was 23 min. Maximum amplitude was markedly reduced in all Glanzmann's thrombasthenia patients with an average of 20.9 mm (reference range 44-68 mm) having 100% sensitivity. The thromboelastographic profile of Glanzmann's thrombasthenia showed a consistently reduced maximum amplitude. Hence reduced maximum amplitude with a normal platelet count, significant bleeding score and prolonged bleeding time could potentially be used as a preliminary algorithm for the diagnosis of Glanzmann's thrombasthenia.