Characterization of anti-factor VIII antibody in a patient with acquired hemophilia A.
- Author:
Jisu OH
1
;
Yeongmin LIM
;
Moon Ju JANG
;
Ji Young HUH
;
Midori SHIMA
;
Doyeun OH
Author Information
- Publication Type:Case Report
- Keywords: Acquired hemophilia A; Factor VIII autoantibody; Epitope
- MeSH: Antibodies; Enzyme-Linked Immunosorbent Assay; Factor VIII; Female; Hemophilia A; Hemorrhage; Humans; Immunoblotting; Immunoglobulins; Korea; Light; Partial Thromboplastin Time; Phospholipids; von Willebrand Factor
- From:Blood Research 2013;48(1):58-62
- CountryRepublic of Korea
- Language:English
- Abstract: Acquired hemophilia A (AHA) is a bleeding disorder caused by the development of an auto-antibody against endogenous factor VIII (FVIII). In this study, the epitope of the autoantibody was identified in a 67-year-old female patient with AHA. A prolonged activated partial thromboplastin time (77.4 s) that failed to correct in an incubation mixing test (68.2 s), a decreased FVIII activity, and a high FVIII inhibitor (14.6 Bethesda units/mL) were observed. Enzyme-linked immunosorbent assay demonstrated that the antibody belonged to the immunoglobulin G4 subclass. An immunoblotting assay revealed the light chain (A3/C1/C2 domain) of FVIII as the binding region of the antibody. The bleeding experienced by our patient resulted from the interference of FVIII binding to both FIX by anti-A3 antibodies and phospholipids and von Willebrand factor by anti-C2 antibodies. To the best of our knowledge, this is the first study in Korea characterizing an autoantibody in the context of AHA.
