Oscar Davis Ratnoff

BMJ 2008; 337 doi: (Published 02 July 2008) Cite this as: BMJ 2008;337:a606
  1. Caroline Richmond

    Discoverer of clotting factor XII and of the sequence of reactions in blood clotting

    Oscar Ratnoff discovered the Hageman and Fitzgerald clotting factors, now known as factor XII and high molecular weight kininogen. Long before genetic tests were available, he devised a method for detecting carriers of haemophilia. He co-discovered the sequence of chemical events in clotting, which he termed the waterfall hypothesis to distinguish it from the rival—but compatible—cascade hypothesis.

    In the early 1980s he realised that the AIDS epidemic among haemophiliac patients could be due to them receiving factor VIII from pooled donations, which he realised conformed to Koch’s postulates and could spread contamination from a single donor. He had seen the incidence of AIDS antibodies in haemophiliac patients rise from 15% in 1980 to 64% in 1984, and at a 1983 meeting of the Centers for Disease Control (CDC) he argued for screening donors for hepatitis B as a surrogate for AIDS. He also argued against using factor VIII concentrates in favour of cryoprecipitate from local, known donors. His objections were dismissed because of the need to produce enough factor VIII for the marketplace.

    Little was known about clotting at the start …

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