title: Challenges of the management of severe hemophilia A with inhibitors: two case reports emphasizing the potential interest of a high-purity human Factor VIII/von Willebrand factor concentrate and individually tailored prophylaxis guided by thrombin-generation test.
abstract: Severe hemophilia A is an X-linked bleeding disorder. Immune tolerance induction (ITI) is the best strategy of treatment when patients develop inhibitors. The objective is to illustrate the benefit of a high-purity human factor VIII/von Willebrand factor (VWF) concentrate (Octanate) in the management of ITI. We also wanted to raise the potential interest of laboratory assays such as thrombin-generation test (TGT) and epitope mapping. Two patients were treated during ITI, first with a recombinant FVIII and then with plasma-derived factor VIII without success, and, finally, with Octanate. Bypassing agents were used based on the results of TGT. Epitope mapping was performed during ITI therapy. These observations suggest the potential contribution of Octanate in the management of ITI in difficult cases. The use of bypassing agents can be necessary in prophylaxis or to treat bleedings, and may be guided by TGT results. Epitope mapping is used to describe the inhibitor. This article shows a decrease of the inhibitor directed against the C2 domain after initiation of Octanate. A high-purity human factor VIII/von Willebrand factor concentrate (Octanate) may be a valuable therapeutical option for ITI therapy. TGT and epitope mapping could be of help in the management of ITI.
authors.affiliation: aHematology and Oncology Pediatric Unit, CHU Saint Etienne bHematology Laboratory, CHU Caremeau, Nimes cResearch Unit on Hemophilia, UFR Laennec dClinical Hemostasis Unit, Hôpital Edouard Herriot, Lyon eHemostasis Laboratory, CHU, Saint Etienne, France fHZRM - Hemophilia Centre Rhein Main, Frankfurt-Mörfelden, Germany.
authors.forename: Sophie
authors.initials: S
authors.lastname: Mathieu
authors.forename: Carine
authors.initials: C
authors.lastname: Crampe
authors.forename: Yesim
authors.initials: Y
authors.lastname: Dargaud
authors.forename: Géraldine
authors.initials: G
authors.lastname: Lavigne-Lissalde
authors.forename: Carmen
authors.initials: C
authors.lastname: Escuriola-Ettingshausen
authors.forename: Brigitte
authors.initials: B
authors.lastname: Tardy
authors.forename: Roland
authors.initials: R
authors.lastname: Meley
authors.forename: Sandrine
authors.initials: S
authors.lastname: Thouvenin
authors.forename: Jean L
authors.initials: JL
authors.lastname: Stephan
authors.forename: Claire
authors.initials: C
authors.lastname: Berger
mesh_terms: D001779:Blood Coagulation Factors / Q000627:therapeutic use; D002648:Child; D003029:Coagulants / Q000737:chemistry / Q000276:immunology / Q000627:therapeutic use*; D019468:Disease Management; D004338:Drug Combinations; D018604:Epitope Mapping; D005169:Factor VIII / Q000737:chemistry / Q000276:immunology / Q000627:therapeutic use*; D015942:Factor VIIa / Q000627:therapeutic use; D006467:Hemophilia A / Q000097:blood / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007108:Immune Tolerance; D008297:Male; D057285:Precision Medicine; D011994:Recombinant Proteins / Q000627:therapeutic use; D012720:Severity of Illness Index; D013917:Thrombin / Q000096:biosynthesis*; D014841:von Willebrand Factor / Q000737:chemistry / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D001779:Blood Coagulation Factors; D003029:Coagulants; D004338:Drug Combinations; D011994:Recombinant Proteins; C509423:factor VIII, von Willebrand factor drug combination; D014841:von Willebrand Factor; D005169:Factor VIII; C103587:recombinant FVIIa; C065655:anti-inhibitor coagulant complex; D015942:Factor VIIa; D013917:Thrombin