Karl Landsteiner made blood transfusion safe

Person: Karl Landsteiner
Lived: 1868–1943
Field: Pathology
From: Austrian-American

The story

Before 1900, transfusing blood from one person to another was a gamble that very often ended in disaster, and no one knew why. As early as 1875 the physiologist Landois had reported that animal blood given to humans clumped and broke apart in the blood vessels, but human-to-human transfusions also failed unpredictably, causing shock, jaundice and death.

Karl Landsteiner, a Vienna-born physician from a Jewish family, was then an assistant in the pathological anatomy department of the University of Vienna, a busy researcher who in ten years there published 75 papers and performed thousands of autopsies. In 1900 he noticed that when the blood of two people was mixed, the red cells sometimes clumped together. The next year he showed that this happened when red cells met the blood serum of certain other people.

In 1901 he explained what he had seen: people have different types of red blood cells, in other words different blood groups. He identified three groups, A, B and a third he called C, now known as O, and by 1909 he had set out the familiar classification into A, B, AB and O. Transfusions between people of the same group did not destroy the red cells, while mixing different groups did. Landsteiner also suggested that the clumping reaction explained the shock and jaundice seen after earlier failed transfusions.

His work was slow to gain attention, but its practical value became clear. In 1907 Reuben Ottenberg performed the first successful transfusion based on Landsteiner's findings at Mount Sinai Hospital in New York. Doctors could now test and match blood before giving it, turning transfusion into a routine and reliable treatment and later making blood banks possible.

Landsteiner received the Nobel Prize in Physiology or Medicine in 1930 for his discovery of human blood groups. He kept working after the prize: in New York, with Philip Levine, he found the M, N and P groups, and with Alexander Wiener he identified the Rhesus factor, another key to safe transfusion. Earlier, with Erwin Popper, he had shown that polio is caused by a virus. Today knowledge of blood groups underpins not only transfusion but also organ transplantation and care in pregnancy.