Russell Viper Venom: A Journey from the Bedside to the Bench and Back to the Bedside.

Russel Viper Venom (RVV) is widely used as a diagnostic test for antiphospholipid syndrome (APS). But the history of how this venom came to be discovered is well known. Dr Patrick Russel is responsible for the identification of the venom during his work on snake bites in India while Dr Robert Macfarlane used it to staunch bleeding in persons with haemophilia. The ability to directly activate factor X led RVV to the laboratory diagnosis of APS. More recently, it has come back to clinical world with a potential for an engineered factor X activator from RVV to be used in the treatment of haemophilia.