Human Blood-Clotting Factor VIII

Factor VIII is one of the several clotting factors needed for normal blood coagulation, and its gene sits on the X chromosome; a genetic defect there causes Haemophilia A, a sex-linked bleeding disorder marked by prolonged clotting time and dangerous internal bleeding. For years, Factor VIII purified from the blood of normal donors was the only treatment, but this demanded very large volumes of donor blood and carried a real risk of transmitting blood-borne infections such as HIV. Recombinant DNA technology now supplies Factor VIII grown in cultured mammalian cell lines — first in Chinese Hamster ovary cells and baby hamster kidney cells, and more recently in a human-origin cell line — sidestepping both the do …