Jean Dausset, the French immunologist and specialist in blood disorders, was best known for his discoveries about the human immune system that considerably increased the chances of success in organ and blood-marrow transplants. The results of his research enable surgeons to verify the compatibility of the donor and the recipient in transplant operations.

He was awarded the Nobel Prize in Physiology or Medicine in 1980, sharing it with the American geneticist George Davis Snell and the American-Venezuelan immunologist Baruj Benacerraf.

The trio won the prize for their research “concerning genetically determined structures on the cell surface that regulate immunological reactions”, work that demonstrated why some people are better able to ward off infection that others.

Their work also showed why some people are at risk of suffering from autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, autoimmune hepatitis and lupus erythematosus. Autoimmune diseases are caused by an overactive immune response of the body to tissues and substances that are normally in the body; the body, in effect, attacks its own cells.

Dausset’s discoveries greatly increased our understanding of the human immune system. His major contribution was to show that a person’s immune response is determined by molecules, called human leukocyte antigens (HLA).

HLA antigens are a complex family of genetically inherited proteins found on the surface of cells throughout the body. They stimulate the production of antibodies to fight disease by helping the immune system to tell the difference between the body’s healthy cells and invading ones.

Dausset’s research enabled surgeons to classify (or type) cells to find out whether a patient’s body would accept or reject tissue from some other person who was donating an organ. Tissue typing is widely used for transplanting organs, such as liver, heart and so on.

It was an essential step forward for transplant surgery. Before it was available, transplants were often followed by organ rejection; the life expectancy of patients was then significantly reduced.

Dausset showed, by experimenting with skin grafts, that compatibility of antigens considerably increased the probability of the graft’s survival. In other words, tissue transplants were much more likely to be successful when both donor and recipient shared the same HLA types. He and his colleagues were also able to show that their results were valid for all ethnic and racial groups.

Jean Baptiste Gabriel Joachim Dausset was born in 1916 in Toulouse, southwest France, and spent his early childhood in Biarritz. His father, Henri Dausset, was an army physician who pioneered rheumatology.

When Jean was 11 his family moved to Paris and he continued his education at the Lycée Michelet, where he obtained his baccalaureate in mathematics. He then enrolled in the medical school of the University of Paris.

His studies were interrupted in 1939 when the Second World War began and he was mobilised into the French Army. When France fell in 1940 he went to North Africa and joined the Free French Forces, serving in the Medical Corps.