The N-terminal 1-16 peptide derived in vivo from protein seminal vesicle protein IV modulates alpha-thrombin activity: potential clinical implications

We have previously shown that seminal vesicle protein IV (SV-IV) and its 1-70 N-terminal fragment have anti-inflammatory activity and modulate anti-thrombin III (AT) activity. Moreover, mass spectrometry analysis of purified SV-IV has shown that the protein was found to be highly heterogeneous and 14% of the total SV-IV molecules are truncated forms, of particular interest the 1-16, 1-17, and 1-18 peptides. In this work we report experimental data which demonstrate that the 1-16 peptide (P1-16) possesses a marked effect on the AT activity by preventing the formation of the thrombin-AT complex. We found that the formation of thrombin-AT complex is markedly decreased in the presence of P1-16 used at equimolar concentration with thrombin as evaluated with SDS-PAGE. We also monitored the conformational changes of thrombin in the presence of different P1-16 concentrations, and calculated the K(d) of thrombin/P1-16 system by circular dichroism technique. The probable interaction sites of P1-16 with thrombin have been also evaluated by molecular graphics and computational analyses. These results have potential implications in the treatment of sterility and thrombotic diseases.

Combination of thrombophilia markers in acute myocardial infarction of the young.

BACKGROUND: The pathogenesis of arterial thrombotic disease involves multiple genetic and environmental factors related to atherosclerosis and thrombosis. But, there have been very few studies in India which have investigated some of the thrombophilia markers. AIM: To look for combined thrombophilia in MI patients. SETTINGS AND DESIGN: One hundred twenty patients of myocardial infarction (age below 40 yrs.) were recruited 8-10 weeks after stabilization. Hundred age and sex-matched healthy controls were also recruited in the present study. METHODS AND MATERIAL: Following thrombophilia markers were screened in these patients--plasma fibrinogen, protein C, protein S, antithrombin III, factor V Leiden, PT G20210A polymorphism, MTHFR C677T, homocysteine, fibrinogen b448 Arg/Lys polymorphism and CBS T833C mutation. STATISTICAL ANALYSIS: Statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 10.0, SPSS Inc., Chicago, USA. RESULTS AND CONCLUSION: Elevated fibrinogen levels, homocysteine (p< 0.001 and homocysteine with odds ratio 6.26) and factor V Leiden (p=0.038) were independently associated with MI in our patients. A total of 37 patients (42.5%) had the presence of more than one thrombophilia markers in combination. Out of these, 10 had the presence of three markers in combination and 1 had five thrombophilia markers in combination. Only 2 controls had prothrombotic markers in combination. Combined prothrombotic risk factors were significant in cases in comparison to controls (p< 0.001). Further larger studies on a nationwide basis recruiting a large number of young MI patients should be done to substantiate these findings.

Haemostatic disorders in nonsplenectomized and splenectomized thalassaemic children

A group of 40 thalassaemic patients [20 splenectomized and 20 nonsplenectomized] from the Haematology Unit of Tanta University Hospital [age range: 3-14 years] were studied to identify the mechanisms by which haemorrhagic and thrombotic complications occur in thalassaemic patients. The patients' levels of protein C, antithrombin III and in vitro platelet aggregation in response to collagen were compared with those of 20 controls. The study suggests that thrombocytosis, increased platelet aggregation and decreased natural coagulation inhibitors [protein C and antithrombin III] in splenectomized thalassaemic children may be significant in thrombotic complications in such patients. Defective platelet aggregation and prothrombin activity in nonsplenectomized children may also give rise to haemorrhagic tendencies

The imbalance between coagulation and fibrinolysis is related to the severity of the illness and the prognosis in sepsis

OBJECTIVES: The coagulation and fibrinolytic system appears to be activated by the septic process independently, leading to the syndrome of disseminated intravascular coagulation (DIC). In this study, we investigated the changes within the hemostatic system related to the severity of the illness and the prognosis in patients with sepsis. METHODS: Plasma thrombin-antithrombin III (TAT) and plasmin-alpha 2-antiplasmin (PAP) complexes were measured using ELISA methods in 32 patients with sepsis and 20 controls and were analyzed according to the APACHE III scores and survival of the patients. RESULTS: Plasma TAT and PAP in patients with sepsis were significantly higher than controls. Nonsurvivors showed greater levels of TAT (21.7 +/- 22.3 ng/mL) and lower levels of PAP (628.4 +/- 378.1 ng/mL) than survivors (TAT: 11.1 +/- 11.2 ng/mL; PAP: 857.1 +/- 364.1 ng/mL). The imbalance between coagulation and fibrinolysis described as TAT/PAP ratio was closely related with APACHE III scores in patients with sepsis (r = 0.47) and the TAT/PAP ratio in nonsurvivors was significantly higher compared with survivors (34.4 +/- 21.4 vs. 14.4 +/- 13.8). CONCLUSION: In sepsis, both coagulation and the fibrinolysis system are activated and the imbalance between coagulation and fibrinolysis predisposes to the hypercoagulation state and is closely related to the severity of the disease and the prognosis.

Haemostatic abnormalities in patients with liver disease associated with viral hepatitis.

Clinical and laboratory findings were studied in 56 patients with liver disease (10 acute hepatitis, 10 fulminant hepatitis and 36 cirrhosis). Spontaneous bleeding occurred in 19 patients (8 fulminant hepatitis, 11 cirrhosis) and another 8 cirrhotic patients had variceal bleeding. There were 22 deaths (36%), 12 of these patients had spontaneous bleeding. Depletion of antithrombin III (AT III) occurred in fulminant hepatitis (mean +/- S.D. = 27 +/- 16%) and cirrhosis (49 +/- 23%) but thrombin-antithrombin III complexes (TAT) were significantly higher in the former (45 +/- 22 vs 8.6 +/- 7.0 ng/ml; p = 0.006). Within subgroups of cirrhosis (with or without spontaneous bleeding or with variceal bleeding), there were no significant differences in levels of AT III or TAT. Of all patients, those with spontaneous bleeding had persistently lower AT III levels but had variable changes of other coagulation parameters (PT, PTT, TT, FDP, fibrinogen and platelet counts). This study showed that coagulopathic consumption is an important cause of AT III deficiency in fulminant hepatitis but not in cirrhosis. Serial changes in AT III levels correlated with bleeding risk in patients with liver disease.

Pregnancy induced hypertension and antithrombin-III.

This study was undertaken to determine the coagulation profile of women with pregnancy induced hypertension and to evaluate the changes in the level of AT-III in pre-eclampsia and eclampsia and its correlation with severity of disease in order to evaluate if it can be used as a marker for severity of PIH. 119 women with PIH in the third trimester of pregnancy constituted the study group. Age and parity matched 25 normal pregnant and 25 non-pregnant women were taken as control group. No significant difference between the coagulation profile of non-pregnant and normal pregnant women was seen. There is evidence of consumption coagulopathy in PIH patients and AT-III activity shows a gradual and almost linear reduction in various groups ranging from normal pregnant women to eclampsia. Reduction in AT-III activity has positive correlation with PIH and it can be a useful marker for severity of PIH.

Antithrombin III levels in pregnancy induced hypertension.

BACKGROUND. Antithrombin III deficiency is common as well as severe in both consumptive coagulopathy and conditions such as pregnancy induced hypertension. We determined antithrombin III levels in women suffering from pregnancy induced hypertension to determine its usefulness in assessing severity of the disease and outcome. METHODS. Forty-five pregnant women with mild and severe forms of pregnancy induced hypertension and 18 women with normal pregnancies matched for gestational age formed the study population. Fasting blood samples were collected and the plasma separated. Antithrombin III levels were estimated by the kinetic Berichrom antithrombin III method. RESULTS. The mean (SD) antithrombin III levels [0.76 (0.233) IU/ml] were significantly lower in pregnancy induced hypertension compared to the control group [0.97 (0.234) IU/ml]. Low antithrombin III and high diastolic blood pressure (> 110 mmHg) were related to poor pregnancy outcome in primigravidae. CONCLUSION. Mean antithrombin III levels were lower in pregnancy induced hypertension compared to a control group of women especially those who were primigravidae and had a diastolic blood pressure > 110 mmHg. Since low antithrombin III levels and a high diastolic blood pressure result in adverse pregnancy outcome monitoring of antithrombin III levels in pregnancy induced hypertension may help in assessing foetal jeopardy.

Significance of blood coagulation and platelet profiles in relation to pulmonary thrombosis in beta-thalassemia/Hb E.

In beta-Thalassemia hemoglobin E (beta-thal Hb E), hypoxemia with abnormal lung function was described and postmortem examination in these patients showed organized pulmonary trombi with thickened arterial wall, particularly in post-splenectomized cases. Coagulation and platelet profiles were studied in 58 beta-thal Hb E patients. In 35 cases with intact spleen, the fibrinolytic activity was significantly decreased with high antithrombin III activity, while coagulation tests revealed mild abnormality. The platelet aggregation to ADP, adrenaline, collagen and ristocretin were defective and platelet 5-hydroxytryptamine content was lower than normal. Twenty-three patients who had been splenectomized for 5-18 years, decreased fibrinolytic activity and high antithrombin III activity were also observed. The coagulation profiles and platelet aggregation in response to ADP, adrenaline and collagen showed better results. Fourteen cases exhibited thrombocytosis and their thrombin generation was in the hypercoagulable range. Platelet aggregation in response to ristocetin remained defective and platelet 5-hydroxytryptamine content was lower than in cases with intact spleens. Defective aggregation to ristocetin would indicate abnormal von Willebrand's factor (vWF). Decreased fibrinolysis should very likely have a role in the occurrence of thrombosis and the better hemostatic profiles in post-splenectomized cases would contribute to the more frequent thrombotic incidence in these cases.

Evaluation of factors predisposing to arterial thrombosis in coronary artery disease.

Estimation of antithrombin III, alpha 2 macroglobulin and alpha 1 antitrypsin in patients with stable and unstable angina and acute myocardial infarction (15 cases each) were carried out. Twenty age, sex and weight matched healthy subjects were included as controls. Mean platelet factor 4(PF4) levels measured in 10 cases of each subgroup were significantly elevated in myocardial infarction (MI) (48.4 +/- 15.16 ng/ml) and III unstable angina patients (44.7 +/- 15.9 ng/ml) as compared to controls (25.42 +/- 12.47 ng/ml; P less than 0.01). Mean antithrombin III (AT III) levels were markedly reduced in all patients with MI (39.65 +/- 12.8% of normal pooled plasma) and unstable angina (37.9 +/- 16.6% of normal pooled plasma) and in 9 patients with stable angina. Alpha I antitrypsin and alpha 2 macroglobulin levels in these cases showed no significant difference compared to normals. Reduced AT III in coronary artery disease suggests a prethrombotic tendency in these patients. Raised PF4 levels in acute phase of the disease suggests heightened platelet activation.

Antitrombina II en el plasma libre de globulina antihemofílica / Antithrombin III in cryoprecipitate depleted plasma

En una serie de 22 muestra de plasma fresco citratado (PFC) y sus correspondientes fracciones libres de globulina antihemofílica (PLGAH) recién preparadas, se determinó la concentración de antitrombina III (AT III) en mg/dl, por medio de inmunodifusión radial cuantitativa y su actividad en porcentaje mediante su capacidad de inactivar a la trombina. Ambos valores se determinaron tambiém periódicamente en alíquotas de PLGAH almacenadas a - 20-C. Los valores de AT III obtenidos en el PFC y en PLGAH recién preparado, no mostraron diferencias significativas ni en concentración ni en actividad. Durante el almacenamiento, el PLGAH mostró un decaimiento progresivo de la actividad de AT III desde la primera semana, llegando al 50% a las cuatro semanas. Durante el mismo lapso, la concentración de AT III también disminuyó significativamente desde la segunda semana sin caer a valores anormales bajos durante las 13 semans que duró el estudio. Se comentan estos hallazgos y se discute su utilidad práctica proponiéndose el empleo de PLGAH como fuente de AT III en la clínica