Anticoagulants ; pharmacokinetics ; Child ; Hemophilia A ; drug therapy ; Hemophilia B ; drug therapy ; Humans ; Precision Medicine

Factor IX/therapeutic use* ; Factor VIII ; Hemophilia A/drug therapy* ; Hemophilia B/drug therapy* ; Humans ; Recombinant Proteins/therapeutic use*

Adolescent ; Child ; Child, Preschool ; Factor IX ; administration & dosage ; therapeutic use ; Factor VIII ; administration & dosage ; therapeutic use ; Hemophilia A ; drug therapy ; prevention & control ; Hemophilia B ; drug therapy ; prevention & control ; Humans

OBJECTIVETo analyze the clinical features of hemophilia A (HA), and the factors associated with the factor VIII (FVIII) inhibitor development.

METHODSOne huandred and thirteen patients with HA were recruited in this retrospective study, among whom, 85 were treated with FVIII replacement therapy. The FVIII inhibitor levels and factors associated with the inhibitor development were correspondingly investigated in these 85 patients.

RESULTSFVIII inhibitor developed in 28.24% of the 85 severe and moderate patients treated with FVIII. Factors of statistical significance (P < 0.05) associated with the low-titer FVIII inhibitor development were as follows: the first enduring adminstration of FVIII, the situation of the patients, and the high dose FVIII used in severe bleeding or major operation.

CONCLUSIONThe development of FVIII inhibitor by Bethesda assay in Chinese hemophilia A patients is not rare, especially that with low-titer. Most of them are severe and moderate patients. The inhibitor development was associated with the following factors: the first adminstration of FVIII for more than 5 days, the severe or moderate conditions of patients, the high dose FVIII used in severe bleeding or major operation.

Hemophilia B is an X chromosome linked hereditary hemorrhagic disease, which is caused by the lose function mutation of factor IX (FIX), and significantly affects the patients' lifespan and life quality. The severity of hemophilia B depends on the FIX level in the plasma. By referring to the relevant literatures, we reviewed and summarized hemophilia B replacement therapies. Specifically, we focus on recombinant factor IX products on the market and those in the pipeline, especially on the long-acting factor IX drugs, to provide the basis for researches of new hemophilia B drugs.
Factor IX ; genetics ; therapeutic use ; Hemophilia B ; drug therapy ; Humans ; Mutation ; Recombinant Proteins ; therapeutic use

Aneurysm, False ; surgery ; Factor VIII ; therapeutic use ; Hemophilia A ; drug therapy ; Humans ; Uremia

Adult ; Antibodies, Monoclonal, Murine-Derived ; administration & dosage ; therapeutic use ; Female ; Hemophilia A ; drug therapy ; Humans ; Rituximab

BACKGROUND: Risk factors for the development of inhibitors in previously untreated patients (PUPs) have been reported; this is not the case in previously treated patients (PTPs) owing to fewer studies. Risk factors may differ for the development of PTP versus PUP inhibitors. We aimed to identify risk factors for PTP inhibitor development. METHODS: Participants were patients at a hemophilia treatment center in Korea with current or past history of factor VIII or factor IX alloantibodies. Observed inhibitors were classified as PUP or PTP inhibitors based on the cumulative number of exposure days. We compared the type and severity of hemophilia, mutation type, and family history of inhibitor between PUPs and PTPs. Events within 3 months before the first inhibitor detection, such as change of the factor concentrate used, short-term high exposure or continuous infusion of factor concentrate, history of surgery, infection, diagnosis of cancer, use of immunosuppressive or immunomodulator agents, and vaccination were compared between PUPs and PTPs. RESULTS: We observed 5 PUP inhibitors and 5 PTP inhibitors in 115 patients with hemophilia A. Events that might be related to the development of inhibitors within 3 months prior to the first inhibitor detection were observed in all 5 PTPs. On the contrary, no such events were observed in any PUPs. The observed events included a change in the factor concentrate used, subsequent chemotherapy, and short-term high exposure to factor concentrates for controlling hemorrhage and surgeries. CONCLUSION: Our results suggest a greater role of nongenetic factors in PTP inhibitor development.
Diagnosis ; Drug Therapy ; Factor IX ; Factor VIII ; Hemophilia A ; Hemorrhage ; Humans ; Isoantibodies ; Korea ; Prevalence ; Risk Factors ; Vaccination

Objective To evaluate the performance of myPKFiT,a tool guiding the dosing of antihemophilic factor (recombinant) plasma/albumin-free method (rAHF-PFM),in maintaining the coagulation factor Ⅷ (FⅧ) level above a target threshold at the steady state and estimating the pharmacokinetics (PK) parameters in hemophilia A patients in China. Methods The data of 9 patients with severe hemophilia A in a trial (CTR20140434) assessing the safety and efficacy of rAHF-PFM in the Chinese patients with hemophilia A were analyzed.The myPKFiT was used to predict the adequate dose to maintain a patient's FⅧ level above target threshold at the steady state.Furthermore,the performance of myPKFiT in estimating the pharmacokinetics parameters of individuals was evaluated. Results Twelve combinations of two dosing intervals and six sparse sampling schedules were investigated,and 57%-88% of the patients remained the FⅧ level above the target threshold of 1 U/dl (1%) for at least 80% of the dosing interval.The clearance and time to FⅧ level of 1% obtained from sparse sampling by myPKFiT were similar to those obtained from extensive sampling. Conclusions The myPKFiT can provide adequate dose estimates to maintain the FⅧ level above the target threshold at the steady state in Chinese patients with severe hemophilia A.Moreover,it demonstrates good performance for estimating key pharmacokinetics parameters,including clearance and time to FⅧ level of 1%.
Humans ; China ; East Asian People ; Factor VIII/pharmacokinetics* ; Hemophilia A/drug therapy*

Objective: To reveal the related factors of inhibitors and differences ofhemorrhage and joint disease before and after the production of inhibitors in children with hemophilia A (HA) . Methods: Retrospective analyses of the clinical data of 381 children with HA under the age of 16 registered in the Registration Management Center of Hemophilia in Henan Provincial from January 2015 to August 2018. Results: A total of the 381 children were enrolled with 116 (30.4%) mild, 196 (51.4%) moderate, and 69 (18.1%) severe cases; 54 patients (14.2%) had inhibitors, including 22 high and 32 low titer inhibitors. Positive family history was positively associated with inhibitors[P<0.001, OR=3.299 (95%CI 1.743-5.983) ], and high-intensity exposure was associated with inhibitors[P=0.002, OR=2.587 (95%CI 1.414-4.731) ]. High-intensity exposure was associated with high titer inhibitor production[P=0.001, OR=8.689 (95%CI 2.464-30.638) ], and high-intensity exposure increased the risk of high titer inhibitors in HA patients. After inhibitors occurred in 54 patients with HA, the rates of overall joint annual bleeding (z=-3.440, P=0.001) and traumatic annual bleeding (z=-2.232, P=0.026) increased, but the rates of the annual joint bleeding (z=-1.342, P=0.180) and spontaneous annual bleeding (z=-1.414, P=0.157) remained to be not statistically significant. The joint ultrasound score did not change significantly after the inhibitor information (z=-0.632, P=0.527) . Conclusions: Positive family history and high-intensity exposure could increase the risk of F Ⅷ inhibitors in HA patients, and high-intensity exposure increased the risk of high titer inhibitors. The rates of the overall joint annual bleeding and traumatic annual bleeding increased after the inhibitor information.
Child ; Factor VIII/therapeutic use* ; Hemarthrosis ; Hemophilia A/drug therapy* ; Hemorrhage ; Humans ; Retrospective Studies