title: The antigenic binding sites of autoantibodies to factor XII in patients with recurrent pregnancy losses.
abstract: Recently, numerous studies have suggested an association between factor XII (FXII) deficiency and recurrent pregnancy losses, and between autoantibodies to FXII and recurrent pregnancy losses. Autoantibodies to FXII rather than FXII deficiency may be a risk factor for recurrent pregnancy losses. To know the pathogenesis of autoantibodies to FXII, epitope mapping study was done. Seventeen anti-FXII antibody positive recurrent pregnancy loss patients were chosen for this study. We used synthetic peptides in inhibition and direct binding studies to identify the antigenic binding site of autoantibodies to FXII. Among plasmas from 17 recurrent pregnancy loss patients who were positive for autoantibodies to FXII, 13 patients (76.5%) recognized amino acids 1-30, the amino-terminal heavy chain region that is known as factor XII binding site to platelet glycoprotein Ibalpha.
authors.affiliation: Department of Obstetrics and Gynecology, Specialized Clinical Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Inomo
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Sugi
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Fujita
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Matsubayashi
authors.forename: Shun-ichiro
authors.initials: S
authors.lastname: Izumi
authors.forename: Mikio
authors.initials: M
authors.lastname: Mikami
mesh_terms: D000026:Abortion, Habitual / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood* / Q000378:metabolism; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D005174:Factor XII / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D010455:Peptides / Q000378:metabolism; D011247:Pregnancy; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D001323:Autoantibodies; D010455:Peptides; D005174:Factor XII