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Shinozawa K, Yada K, Kojima T, Nogami K, Taki M, Fukutake K, Yoshioka A, Shirahata A, Shima M. Spectrum of F8 Genotype and Genetic Impact on Inhibitor Development in Patients with Hemophilia A from Multicenter Cohort Studies (J-HIS) in Japan. Thromb Haemost 2020; 121:603-615. [PMID: 33254277 DOI: 10.1055/s-0040-1721385] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Some genetic and treatment-related factors are risk factors for inhibitor development in patients with hemophilia A (PwHA). However, the genotype distribution of the factor VIII gene (F8) and genetic impact on inhibitor development in Japanese PwHA remain unknown. In 2007, the Japan Hemophilia Inhibitor Study 2 (J-HIS2) was organized to establish a nationwide registry system for hemophiliacs and to elucidate risk factors for inhibitor development, designed for prospective investigation following a retrospective study (J-HIS1) which had already finished. Patients, newly diagnosed after January 2007, were enrolled in J-HIS2 and followed up for inhibitor development and clinical environments since 2008 onward. In the present study, F8 genotypes of PwHA were investigated in the patients recruited from the J-HIS2 cohort as well as those with inhibitor from the J-HIS1 cohort. F8 variants identified in 59 PwHA with inhibitor in J-HIS1 were: 20 intron-22 inversions, 5 intron-1 inversions, 9 large deletions, 4 nonsense, 8 missense, 11 small in/del, and 2 splice-site variants. F8 variants identified in 267 (67 with inhibitor) PwHA in J-HIS2 were: 76(28) intron-22 inversions, 3(2) intron-1 inversion, 1(0) duplication, 8(5) large deletions, 21(7) nonsense, 109(7) missense, 40(11) small in/del, and 9(7) splice-site variants. Forty variants were novel. The cumulative inhibitor incidence rate in the severe group with null changes was 42.4% (95% confidence interval [CI]: 33.7-50.8), higher than that with nonnull changes (15.6% [95%CI: 6.8-27.8]), in J-HIS2. Relative risk for inhibitor development of null changes was 2.89. The spectrum of F8 genotype and genetic impact on inhibitor development in Japanese PwHA were consistent with the previous reports.
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Affiliation(s)
- Keiko Shinozawa
- Department of Laboratory Medicine, Tokyo Medical University, Shinjuku, Tokyo, Japan
| | - Koji Yada
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan.,The Course of Hemophilia Education, Nara Medical University, Kashihara, Nara, Japan
| | - Tetsuhito Kojima
- Aichi Health Promotion Foundation, Nagoya, Aichi, Japan.,Department of Pathophysiological Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Keiji Nogami
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - Masashi Taki
- St. Marianna University School of Medicine, Yokohama City Seibu Hospital, Yokohama, Kanagawa, Japan
| | - Katsuyuki Fukutake
- Department of Laboratory Medicine, Tokyo Medical University, Shinjuku, Tokyo, Japan
| | - Akira Yoshioka
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - Akira Shirahata
- Department of Pediatrics, University of Occupational and Environmental Health Japan, Kitakyushu, Fukuoka, Japan
| | - Midori Shima
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan.,The Course of Hemophilia Education, Nara Medical University, Kashihara, Nara, Japan
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Yaoi H, Shida Y, Kitazawa T, Shima M, Nogami K. Activated factor VIII-mimicking effect by emicizumab on thrombus formation in type 2N von Willebrand disease under high shear flow conditions. Thromb Res 2020; 198:7-16. [PMID: 33248318 DOI: 10.1016/j.thromres.2020.11.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/24/2020] [Accepted: 11/19/2020] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Type 2N von Willebrand disease (2NVWD) is characterized by a mild to moderate reduction in plasma levels of factor (F)VIII associated with defective binding of von Willebrand factor (VWF) to FVIII and accelerated proteolysis and clearance of FVIII. The clinical phenotype in 2NVWD is often indistinguishable from mild/moderate hemophilia (H)A. Emicizumab is a bispecific antibody to FIX/FIXa and FX/FXa that mimics FVIIIa cofactor function, and emicizumab prophylaxis significantly reduces bleeding events in patients with severe HA. AIM We investigated the potential benefits of emicizumab in the hemostatic management of 2NVWD. PATIENTS/METHODS Perfusion chamber experiments were performed using whole blood from three 2NVWD patients with different clinical phenotypes (bleeding scores: 0, 6 and 20; mutations: p.R816W, p.R816W, and p.R365X/p.T791M, respectively). Furthermore, the impact of specific FVIII-VWF interactions on thrombus formation was investigated. RESULTS Defective thrombus formation that correlated with bleeding phenotype was evident in these 2NVWD patients. Emicizumab improved surface coverage and thrombus height in all cases. Multi-color immunostaining of thrombi further demonstrated that emicizumab enhanced thrombin generation and fibrin formation. The addition of FVIII alone to 2NVWD whole blood did not augment thrombus formation, while supplementation with FVIII/VWF complex enhanced platelet-fibrin interactions. Furthermore, an anti-FVIII monoclonal antibody known to interrupt the release of FVIIIa from VWF depressed these effects. CONCLUSIONS Emicizumab-induced enhancing effects of thrombus formation, independent on VWF, might be useful as an alternative therapy for 2NVWD patients. The extent of FVIII-VWF interaction should be optimal to deliver and release FVIII/FVIIIa on the activated platelet surface.
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Affiliation(s)
- Hiroaki Yaoi
- Dept. Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - Yasuaki Shida
- Dept. Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - Takehisa Kitazawa
- Chugai Pharmaceutical Co., Research Division, Gotemba, Shizuoka, Japan
| | - Midori Shima
- Dept. Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - Keiji Nogami
- Dept. Pediatrics, Nara Medical University, Kashihara, Nara, Japan.
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Nakajima Y, Nogami K, Yada K, Kawamura T, Ogiwara K, Furukawa S, Shimonishi N, Takeyama M, Shima M. Evaluation of clinical severity in patients with type 2N von Willebrand disease using microchip-based flow-chamber system. Int J Hematol 2019; 111:369-377. [DOI: 10.1007/s12185-019-02782-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/08/2019] [Accepted: 11/12/2019] [Indexed: 11/29/2022]
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The inhibitors - a challenge for the management of patients with hereditary haemophilia A. ACTA ACUST UNITED AC 2018; 56:143-152. [PMID: 29791318 DOI: 10.2478/rjim-2018-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Our research strategy was aimed at evaluating the possible implication of the type of factor VIII product administered as substitution treatment to haemophilia A patients in the occurrence of inhibitors and their consequences on the management. METHODS Scientific articles from July 2015 to July 2017 were searched using the PubMed and PubMed Central databases. The used search terms included "haemophilia A", "inhibitors", "plasma-derived factor VIII" and "recombinant factor VIII". RESULTS The risk factors for inhibitors occurrence may be patients-related (genetic and nongenetic) and treatment-related. The possibility of a correlation between the increased purity of factor VIII given as substitution treatment and the occurrence of inhibitors is discussed in the light of literature data. Plasma-derived factor VIII is less immunogenic, but not entirely safe from the point of view of the possibility of transmitting biological agents. It is obvious that there is not enough plasma-derived factor VIII for the planet's needs. Recombinant factor VIII products have revolutionized the treatment of patients with haemophilia A over the past 3 decades by the disappearance of transfusion-related infections and their complications. They are safer in terms of pathogens and the new long-acting factor VIII products are based on recombinant DNA technology. CONCLUSION Plasma-derived or recombinant factor VIII products must co-exist on the market for the benefit of haemophilic patients. Future solutions could be: less immunogenic factor VIII products, nonfactor replacement strategies, or bispecific antibody that mimics the function of coagulation factor VIII.
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