Reduced Titers of Hageman Factor (Factor XII) in Orientals

doi:10.1059/0003-4819-95-6-697

Reduced Titers of Hageman Factor (Factor XII) in Orientals

Cleveland and Cincinnati, Ohio

Abstract

Hageman factor (factor XII) is a procoagulant upon which the surface-mediated generation of fibrinolytic activity and kinin formation depends. We found that the clot-promoting activity and antigenic properties of Hageman factor were present in lower levels in the plasma of a small group of Oriental subjects than in that of American whites, whereas the levels of plasma prekallikrein (Fletcher factor), high-molecular-weight kininogen (Fitzgerald factor), and plasma thromboplastin antecedent (factor XI) in plasma samples from Oriental subjects did not significantly differ from those from normal white subjects. In one family, there was an excess of plasma Hageman factor antigens with respect to functional activity. These findings stress the importance of defining the racial characteristics of subjects used to establish standards for clotting assays.

Article and Author Information

▸From the Departments of Pediatrics and Medicine, Case Western Reserve University School of Medicine, Rainbow Babies and Childrens Hospital, and University Hospitals of Cleveland; Cleveland, Ohio; and the Departments of Pediatrics and Medicine, University of Cincinnati, Children's Hospital Research Foundation; Cincinnati, Ohio.
Grant support: in part by grants HL 01661 and HL 15690, National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Public Health Service; and grants from the American Heart Association, and its Northeast Ohio affiliate. Dr. Ratnoff is a Career Investigator of the American Heart Association.
▸Requests for reprints should be addressed to Oscar D. Ratnoff, M.D.; Department of Medicine, University Hospitals of Cleveland; Cleveland, OH 44106.