The Incidence Of Antithrombin Cambridge Ⅱ Mutation And The Association With Deep Venous Thrombosis In Chinese Deep Venous Thrombosis Patients And Cerabral Infarction Patients

Background: The thrombotic disease, especially ischemic vessel disease of heart and brain, has become the leading cause of death in Chinese population. Deep venous thrombosis(DVT) is a common blood vessel thrombotic disease of limbs, with the incidence increasing, DVT impairs human's health severly. It was reported that, about 250,000 -500,000 people were affected by the venous thrombosis embolism disease every year. In our country , the morbidity of DVT ranks among the top three diseases following the ischemic heart disease and stroke . It was reported by VITAE that , over 1,500,000 patients suffered fatal or non-fatal venous thrombosis embolism (VTE) in European Union every year, and 543,500 cases of them died. In Europe, the number of patients died from DVT has surpassed sum of breast cancer, prostate cancer, AIDS and the traffic accidents. As it is frequently symptomless, venous thrombosis embolism may be lead to die at its first presentation. Therefore, further investigation for the etiology and pathogenesis of venous thromboembolism, and performing interventatin as soon as possible is very significant and useful to reduce the morbidity and mortality rate of DVT.DVT is a kind of monogenic or polygene genetic diseases. Many mutations of anti-coagulation or procoagulant are related to DVT. Among these mutations, the anti-thrombin III (AT-III) mutation is reported to be closely association with DVT. Recently, Correl reported that the antithrombin Cambridge II (A384S) mutation is a major genetic risk factor of venous thrombosis in the United Kingdom, besides, it is the main antithrombin defect in the Caucasian.To find out the distribution frequencies of A384S mutations in different ethnic, 60 normal controls, 50 cases of DVT, 60 cases of cerebral infarction were enrolled into the study. Ploymerase chain reacion(PCR) method combined with restriction endonuclease map from the PCR products were used to determine the mutation site, and the AT-III activity in DVT and cerebral infarction patients was detected by chromogenic methods. This setting provides a basis for screening the risk factors of DVT and obtaining the distribution frequency of thrombotic disease in Chinese population .Part I Identification of the Mutation Site of Antithrombin Cambridge II (A384S) in patients with thrombotic disorderObjective: To obtain the incidence of antithrombin Cambridge II (A384S)mutation and its association with thrombosis in Chinese deep venous thrombosis patients and cerebral infarction patients.Method: Peripheral blood samples were collected for genome DNA extraction. DNA was extraced by standard procedure, and DNA samples were amplified by polymerase chain reaction(PCR), using primers5'-TGAGGAATTGCTGTGTCTGTG-3' and 5'-AGAGGTGCAAAGAATAAGAA -3'. The fragment containing antithrombin Cambridge IIA384S nucleotide sites, PCR products would be digested by therestriction enzyme PvuII, by which determine the existence ofantithrombin Cambridge II A384S mutation.Results: Antithrombin Cambridge II A384S mutation was not foundamong 60 normal controls , 50 DVT patients and 60 cerebral infarctionpatients.Conclusion: Antithrombin Cambridge II A384S mutation is not the highrisk factor of DVT and cerebral infarction patients in China.Part II The changes And Significance of Antithrombinactivity in the Deep Venous Thrombosis and CerebralInfarction patients.Objective: Detecting the AT-III activity level in deep venous thrombosispatients and cerebral infarction patients, screening deep venousthrombosis-related risk factors.Methods: Separation of peripheral blood plasma were performed on 60normal controls, 50 cases of DVT and 60 cases of cerebral infarctionpatients. Determination of plasma antithrombin III activity were carryingout using chromogenic methods. Results: Compared with the control group, the average of AT-III activity was significantly lower in DVT patients (P <0.01), and 13(26%) patiens showed reduced AT-III activity in DVT group. The level of AT-III activity in cerebral infarction patients and the ratio of who showed reduced AT-III activity(n=3, 5%) were not different from the controls with statistical significance.Conclusion: Reduced AT-III activity is one of the risk factors of deep venous thrombosis, but is not related to the cerebral artery thrombosis.