The Role Of Polymorphism And Promoter Methylation Of Factor Ⅶ In Coagulopathy After Traumatic Brain Injury

Two parts are in this study. We study the effect of coagulation factor Ⅶ (FⅦ) genepolymorphism and promoter methylation on activated FⅦ (FⅦa) and coagulopathy intraumatic brain injury (TBI) patients. Each part of the study is summarized as follows:Part1: The DNA polymorphisms of FⅦ in TBI patients:association with FⅦa and coagulopathyObjective: To study the effect of gene polymorphisms in FⅦ on FⅦa andcoagulopathy in patients with TBI.Methods: Eighty-four patients with isolated TBI were recruited between March2011and March2013. Genotyping of-323P0/P10, R353Q,-401G/T,-402G/A,-670A/C andIVS7polymorphisms of the FⅦ gene was performed by the method of polymerase chainreaction and restriction fragment length polymorphism (PCR-RFLP). Then collectedblood was analyzed with the international normalized ratio, activated partialthromboplastic time, platelet count, and FⅦa. The risks for FⅦa <77.5%andcoagulopathy were examined by logistic regression.Results: FⅦa in different phenotypes of-323P0/P10, R353Q,-401G/T and IVS7have significant differences (P <0.05), but there is no significant difference in-402G/A or-670A/C (P>0.05). Using the bivariate regression analysis, the P10allele of-323P0/P10,Q allele of R353Q and H7allele of IVS7are associated with a significantly higher risk forFⅦa <77.5%. The result shows that Q allele of R353Q (OR=4.401,95%CI=1.275-15.190, P=0.019) being associated with significant increased risk of FⅦa <77.5%.The result of Multivariate logistic regression analysis indicates P10allele of-323P0/P10is the independent risk factor of coagulopathy (OR=12.323,95%CI=1.445-105.062, P=0.022). For the risk of coagulopathy, the patients with the P10-H7-Q haplotype werehigher than patients with other haplotypes (OR=7.624,95%CI=1.325-43.888, P=0.037).Conclusion: Our research results show that Q allele of R353Q is associated with thedecline of plasma FⅦa, and P10allele of-323P0/P10in TBI patients is an independentrisk factor for coagulopathy. In addition, for the risk of coagulopathy, the patients with theP10-H7-Q haplotype were higher than patients with other haplotypes.Part2: The promoter methylation of FⅦ in patients with TBI:association with FⅦa and coagulopathyObjective: To study the effect of the promoter methylation in FⅦ on FⅦa andcoagulopathy in TBI patients.Methods: Blood was collected and analyzed with activated partial thromboplastictime, the international normalized ratio, platelet count, and FⅦa. The risks for FⅦa<77.5%and coagulopathy were examined by logistic regression. The promoter methylationin FⅦ in modulating FⅦa and coagulopathy were evaluated by Methylight. We used acutoff value of promoter methylation level (PMR)>4which has been validated in theliterature as a standard cutoff. Spearman’s rank correlation coefficient examined theassociation between continuous variables. Logisitic regression analysis was applied todetermine the association between the promoter methylation and activity of FⅦ orcoagulopathy. Then polymorphisms of FⅦ gene were added into the regression analysis.Results: Spearman correlation analysis show that PMR was significantly negativecorrelation with FⅦa (R=-0.249, P=0.027), and PMR in TBI patients with coagulopathywas (5.98±7.32), which is significantly higher than the patients without coagulopathy(2.09±1.98)(P=0.001). Increased PMR was a factor for FⅦa <77.5%and coagulopathyby using bivariate regression analysis. When polymorphisms of FⅦ gene were included inthe regression analysis:(1) Bivariate analysis was performed to identify risk factors for FⅦa <77.5%, which showed that P10allele of-323P0/P10, Q allele of R353Q, H7alleleof IVS7and PMR>4was associated with a significantly higher risk of FVIIa, whereas Tallele of-401G/T was not. Stepwise logistic regression analysis identified H7allele ofIVS7(OR=5.024,95%CI=1.143-22.076, P=0.033) was the independent risk factor forthe development of FⅦa <77.5%;(2) Bivariate analysis was performed to identify riskfactors for coagulopathy, which showed that platelet count <150×109/L, aPTT>32s andPMR>4were associated with a significantly higher risk, whereas the alleles of FⅦ genepolymorphisms were not. Stepwise logisitic regression analysis showed PMR>4was theidenpendent risk factor for the development of coagulopathy(OR=4.280,95%CI=1.398-13.104, P=0.011).Conclusion: Increased PMR was a factor for FⅦa <77.5%and coagulopathy in TBIpatients. When FⅦ gene polymorphisms were enrolled in the regression analysis, theresults showed that H7allele of IVS7was the independent risk factor for the developmentof FⅦa <77.5%and PMR>4was the independent risk factor for coagulopathy.