Ludwik Hirszfeld (August 51884 Warsaw – March 71954 Wroclaw) was a Polish microbiologist and a serologist. He is considered one of the co-discoverers of the inheritance of ABO blood type. He established a laboratory of experimental medicine at the State Institute of Hygiene in Poland shortly after World War I. In 1946, he published his autobiography, The Story of One Life.
Hirszfeld gradually found the working conditions at Heidelberg too confining and to familiarize himself with the entire field of hygiene and microbiology, in 1911 he accepted an assistantship at the Hygiene Institute of the University of Zurich, just after he had married. His wife, also a physician, became an assistant at the Zurich Children's Clinic under Emil Feer.
In 1914 Hirszfeld was made an academic lecturer on the basis of his work on anaphylaxis and anaphylatoxin and their relationships to coagulation; he was also named "Privatdozent." When World War I broke out Serbia was devastated by epidemics of typhus and bacillary dysentery. In 1915 Hirszfeld applied for duty there. He remained with the Serbian army until the end of the war, serving as serological and bacteriological adviser. At this time, in the hospital for contagious diseases in Thessaloniki he discovered the bacillus "Salmonella paratyphi" C, today called "Salmonella hirszfeldi."
After the end of the war Hirszfeld and his wife returned to Warsaw, where he established a Polish serum institute modeled after the Ehrlich Institute for Experimental Therapy in Frankfurt. He soon became deputy director and scientific head of the State Hygiene Institute in Warsaw and, in 1924, professor there. In 1931 he was named full professor at the University of Warsaw and served on many international boards. After the occupation of Poland by the German army Hirszfeld was dismissed as a "non-Aryan" from the Hygiene Institute but, through the protection of friends, managed to do further scientific work at home until February 1941; it was, however, almost impossible for him to publish.
On 20 February 1941 Hirszfeld was forced to move into the Warsaw ghetto with his wife and daughter. There he organized anti-epidemic measures and vaccination campaigns against typhus and typhoid, as well as conducting secret medical courses. In 1943 he and his family fled the ghetto and were able to survive underground through using false names and continually changing their hiding place; his daughter died of tuberculosis in the same year.
When a part of Poland was liberated in 1944, Hirszfeld immediately collaborated in the establishment of the University of Lublin and became prorector of the university. In 1945 he became director of the Institute for Medical Microbiology at Wrocław and dean of the medical faculty. He taught at the institute, now affiliated with the Polish Academy of Sciences and named after him, until his death.
Hirszfeld received many honors, including honorary doctorates from the universities of Prague (1950) and Zurich (1951). He wrote almost 400 works in German, French, English, and Polish, many in collaboration with other well-known scholars and not a few with his wife.
Hirszfeld and von Dungern were responsible for naming the blood groups A, B, AB, and O; previously they were known as groups I, II, III, and IV. He proposed the A and B designations for the agglutinins. In 1910-1911 Hirszfeld discovered the heritability of blood groups and with this discovery established serological paternity exclusion. During World War I he and his wife wrote works on sero-anthropology, which brought forth fundamental findings on the racial composition of recent and historical peoples. According to his so-called Pleiades theory of blood groups, the other groups probably developed from the archaic O group in the course of evolution.
Hirszfeld was the first to foresee the serological conflict between mother and child, which was confirmed by the discovery of the Rhesus factor. Upon this basis he developed, in the last years of his life, an "allergic" theory of miscarriage and recommended antihistamine therapy. Hirszfeld also investigated tumors and the serology of tuberculosis. His discovery of the infectious agent of paratyphoid C had far-reaching consequences for differential diagnosis.
In 1914, together with R. Klinger, Hirszfeld developed a serodiagnostic reaction test for syphilis, which did not, however, replace the Wasserman test introduced in 1906. His studies of goiter in Swiss endemic regions brought him into sharp disagreement with E. Bircher over the theory -- today widely confirmed -- that endemic Goitres are caused by iodine deficiency in water and food, in opposition to the hydrotelluric theory.