Oscar Ratnoff

Oscar Davis Ratnoff (1916 to 2008) was an American physician who researched blood coagulation and blood-related disorders. The son of a New York pediatrician, he trained at the Columbia University College of Physicians and Surgeons and at Johns Hopkins, served in the United States Army Air Corps during the Second World War, and in 1950 moved to Cleveland, where he spent his career at the Case Western Reserve University School of Medicine as professor, chief of hematology-oncology and interim chief of medicine. In 1954 he treated a railway worker named John Hageman, whose blood clotted slowly although he had never bled badly, and with the biochemist Earl Davie he identified the missing protein, called Hageman factor and later known as factor XII. In 1964 Ratnoff and Davie published a model of the clotting cascade, and Robert Gwyn Macfarlane at Oxford reported a similar cascade independently at about the same time. He also contributed to research on the complement system, to an assay that separates classic hemophilia from von Willebrand disease, and to early recognition of AIDS symptoms in hemophilia patients. He was president of the American Society of Hematology and was elected to the National Academy of Sciences in 1976.