Immunological characterization of factor VIII autoantibodies in patients with acquired hemophilia A in the presence or absence of underlying disease.
The development of a factor VIII autoantibody results in a severe hemorrhagic diathesis known as acquired hemophilia A. Underlying pathologies, such as autoimmune disease or chronic inflammatory disease, are observed in about half of the patients. We have investigated a total of 16 cases with acquired hemophilia A and divided the patients into two groups according to the presence or absence of other clinical conditions. Group A comprised nine cases with no detectable associated pathology. Group B consisted of seven cases with other clinical diagnoses. Significant levels of factor VIII activity (FVIII:C) and factor VIII antigen (FVIII:Ag) were detected in Group A and the pattern of FVIII:C inactivation was characteristic of Type 2 inhibitors. In contrast, no FVIII:C was detected in Group B and, in five of seven cases, the inhibitory pattern was Type 1. IgG(4) antibody subclass specificity was dominant in both groups. IgG1 antibody reactivity was higher in Group B than in Group A. Our results suggested a close relationship between the presence of underlying disease and immunological and coagulation characteristics in acquired hemophilia A.
Matsumoto
T
T
Department of Pediatrics, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan.
Shima
M
M
Fukuda
K
K
Nogami
K
K
Giddings
J C
JC
Murakami
T
T
Tanaka
I
I
Yoshioka
A
A
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D001324:Autoantigens / Q000097:blood / Q000737:chemistry / Q000276:immunology; D000939:Epitopes; D005169:Factor VIII / Q000737:chemistry / Q000276:immunology*; D005260:Female; D006467:Hemophilia A / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood; D007132:Immunoglobulin Isotypes / Q000032:analysis / Q000097:blood; D008297:Male; D008875:Middle Aged; D017434:Protein Structure, Tertiary
D001323:Autoantibodies; D001324:Autoantigens; D000939:Epitopes; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D005169:Factor VIII