Clinical Manifestations Of Severe Hemophilia Heterogeneity Relationship With Anticoagulant And Fibrinolytic Protein Related Proteins

Background&PurposeThere is considerable clinical heterogeneity among severe hemophilia patients. About10%to15%of these patients with severe hemophilia have relatively mild clinical presentations. Genetic mutations, variations of the global hemostasis system (including antithrombotic and fibrinolytic proteins), local inflammation and angiogenic factors, pharmacokinetics of administered clotting factor concentrates, and environmental factors can affect the clinical heterogeneity of severe hemophilia. In foreign countries, the conclusive opinion is that if the patient has concurrent prothrombotic factors, such as FV Leiden or prothrombin G20210A mutations, the bleeding can be considerably diminished. But such gene mutations are very rare in Chinese population, so the genetic and environmental factors affecting clinical phenotype of severe hemophilia are still unknown.In this research, by analyzing clinical characteristics of Chinese hemophilia patients and detecting the plasma levels of protein C (PC), protein S (PS), antithrombin (AT), tissue type plasmonogen activator (t-PA), plasminogen activator inhibitor-1(PAI-1) and thromobin activatable fibrinolysis inhibitor (TAFI), we initially investigate the impact of these antithrombotic and fibrinolytic proteins on the clinical heterogeneity of severe hemophilia.MethodsWe collect blood samples of hemophilia patients who came to the hemophilia clinic of Peking Union Medical College Hospital from December2008to March2010and record clinical data of these patients. FVIII Activity (FVIII:C) or FIX Activity (FIX:C) were measured by one-stage coagulation assay; FVIII Inhibitor (FVIII:I) or FIX Inhibitor (FIX:I) measured by the Bethesda assay; AT, PC and TAFI activity measured by chromogenic assay; PS activity measured by clotting assay; the antigen of vWF, t-PA and PAI-1determined by ELISA. The clinical and laboratory data are analyzed by SPSS PASW Statistics18software.Results1. Characteristics of hemophilia patients in this research:Among234hemophilia patients,206(88%) were hemophilia A, hemophilia B accounted for12%; Severe, moderate and mild cases were215(91.9%),16(6.8%) and3(1.3%), respectively. The median age was20years (quartile range13.8-30years). Ten hemophilia A patients (4.9%) were FⅧ:Ⅰ positive and one hemophilia B patients (3.6%) were FIX:I positive.3%(4/133) of the patients carried HbsAg and up to38.8%(52/134) of the patients had positive results in HCV-Ab detection. HIV-Ab were measured in132patients and all of them had negative results.2. There is considerable clinical heterogeneity among severe hemophilia patients. The median age of first bleeding episode was0.92year (0.5-2years). The median annual bleeding were18(7.5-36) episodes. The median number of joint deformities was2with quartile range1-4.3. The frequencies of the deficiency of PC, PS and AT among234hemophilia patients were6.8%,6.4%and6.0%, respectively, which were significant higher than those from Chinese healthy population (1.1%,1.2%,2.3%, respectively, P≤0.001). The median antigen levels of t-PA and PAI-1were13(6-21) ng/ml and35.5(14～56) ng/ml, respectively, and significantly higher than reference range which were1～12ng/ml and5-45ng/ml respectively. The average level of TAFI activity was114.04%(95%interval54.82～173.26), and significantly higher than reference range which is108(60～156)%(P=0.046).4. The plasma level of t-PA in HCV-Ab positive hemophilia patients was17(10.8～25) ng/ml, and significantly higher than the negative ones which was11(4-15) ng/ml (P=0.005). It appeared that the plasma level of PC, PS, AT, PAI-1and TAFI were not related to chronic HCV infection.5. Among severe hemophilia patients, the plasma level of AT in clinically severe group was105(100.3～110)%, and significantly lower than clinically mild group which was114(106-117)%(P=0.010). It had not been found that there were differences of PC, PS, t-PA, PAI-1and TAFI levels between the two groups.Conclusions1. There were considerable clinical heterogeneity among severe hemophilia patients in this research, which was mainly represented by the variations in the age of first bleeding episode, bleeding frequency, bleeding sites and joint deformities.2. The deficiency frequencies of the activities of PC, PS and AT in this group of hemophilia patients were significantly higher than those in the healthy population.3. The plasma antigen levels of t-PA and PAI-1in this group of hemophilia patients increased significantly. The elevation of t-PA level was partially related to the high rate of HCV infection among those patients. The TAFI activity of hemophilia patients in this research also significantly elevated.4. The clinical heterogeneity in severe hemophilia was probably related to the plasma activity of AT, since the plasma activity of AT remarkably descended in clinically severe patients.