Karl Langsteiner: he gets an A+ for his work on blood types

Born 1868 Died 1943

Karl Landsteiner was born Jewish and later converted to Catholicism. He was an immunologist and histologist. Being an immunologist means he worked on understanding how the body fights diseases with antibodies; working with another scientist, he discovered the virus that causes polio. 

As a histologist, Landsteiner studied blood and he discovered the four major blood types: A, B, AB, O, and the Rh factor, positive and negative. Before Landsteiner’s discoveries, people who needed blood were often given whatever kind of blood a doctor had on hand- even sheep’s blood. The blood often clotted in their veins, killing them.

Recognizing the major types of blood and the Rh factor, and giving people blood that matched their own, saved millions of lives.  Landsteiner won the 1920 Nobel Prize in Physiology or Medicine for his discovery, but at first, nobody paid much attention to it. Doctors still gave patients mis-matched (A+ to a B+ patient) and the blood clots caused by that often killed the patient.

Before Landsteiner’s discovery of blood types, there was no way to know if you would survive a transfusion. Maybe. Maybe not.

That sheep’s blood smelled spoiled, perhaps?

People often receive transfusions of blood during surgery or after an accident. Karl Landsteiner’s discovery of blood types made these transfusions safe. Now we know our blood types as something rather trivial, just a bit of interesting information. 

But Landsteiner learned that matching the right blood types could save a life in a crisis — something most of us have never really thought about.