The doctor injected himself with the blood of a sufferer of idiopathic thrombocytopenic purpura, or ITP—a condition that causes excessive bruising and bleeding, leading to purplish spots or regions on everything from skin to tongue and lips. The condition is caused by a low level of platelets, which cause clotting, and the doctor and his colleagues surmised this was because the body’s own immune system was attacking the platelets.
