Pharmacokinetic Study of Coagulation Factor Ⅷ in Adults with Severe Hemophilia A
Objective:To detect the pharmacokinetic(PK)parameters of coagulation factor Ⅷ(FⅧ)in adult patients with severe hemophilia A,identify the potential factors influencing FⅧ PK,and optimize the use of FⅧ in individual prophylaxis regimens.Methods:PK characteristics of FⅧ were studied in a total of 23 severe hemophilia A adults.The correlation of patients'characteristics including age,von Willebrand factor antigen(vWF:Ag),blood group,weight,body mass index(BMI)and FⅧ genotype,with FⅧ PK were evaluated.Individual prophylaxis regimens were given based on FⅧ PK parameters.Results:The mean terminal half-life(t1/2)of FⅧ was 20.6±9.3 h,ranged from 11.47 h to 30.12 h.The age(r=0.580)and vWF:Ag(r=0.814)were significantly positively correlated with t1/2 of FⅧ.The mean area under the plasma concentration curve(AUC)of FⅧ was 913±399(328-1 878)IU h/dl,and the AUC of FⅧ was positively correlated with age(r=0.557)and vWF:Ag(r=0.784).The mean residence time(MRT)of FⅧ was 24.7±12.4(13.2-62.2)h,and the MRT of FⅧ was positively correlated with age(r=0.664)and vWF:Ag(r=0.868).The mean in vivo recovery(IVR)of FⅧ was 2.59±0.888(1.5-4.29)IU/dl per IU/kg,the mean clearance(CL)of FⅧ was 3±1.58(0.97-7.18)ml/(kg·h),and there was no significant correlation of IVR and CL with age and vWF:Ag.According to the individual PK parameters,ultra low-dose,low-dose and moderate-dose FⅧ were applied to 15,6,2 adults patients with severe hemophilia A for prophylaxis,respectively.Conclusion:There are significant individual differences in the FⅧ half-life of adult patients with severe hemophilia A.The older the patient,the higher the vWF:Ag level,and the longer the FⅧ half-life.Individual administration is required based on the FⅧ PK parameters to optimize prophylaxis treatment.
severe hemophilia Acoagulation factor Ⅷadultspharmacokineticshalf-life