Autoimmune Folate Deficiency and the Rise and Fall of “Horror Autotoxicus”

Abstract

In 1904, a little more than a century ago, Julius Donath, a senior physician working in the Vienna Merchants' Hospital, and Karl Landsteiner, the chair of the pathology department at the University of Vienna and one of the founders of immunochemistry, reported the first known autoimmune disease in humans, paroxysmal cold hemoglobinuria. They showed that an antibody in this disease reacted in the cold with the patient's own erythrocytes. By definition, the Donath–Landsteiner antibody was an autoantibody. This revolutionary discovery flew in the face of “horror autotoxicus,” a principle that Paul Ehrlich had expounded after failing to find autoantibodies in . . .