Jean-Baptiste-Gabriel-Joachim Dausset was 93

Jean-Baptiste-Gabriel-Joachim Dausset (October 19, 1916 - June 6, 2009) was a French immunologist.

He was born in Toulouse, France. He received the Nobel Prize in Physiology or Medicine in 1980 along with Baruj Benacerraf and George Davis Snell for their discovery and characterisation of the genes making the major histocompatibility complex. With his Nobel Prize and a grant from the French Television, Dausset was able in 1984 to create the Human Polymorphism Study Center (CEPH), which soon after became Foundation Jean Dausset-CEPH.

Dr. Jean Dausset, a French immunologist who shared the Nobel Prize in Medicine in 1980 for discoveries about the human immune system that vastly improved the odds of success in organ transplants, died in Mallorca, Spain, on June 6. He was 92.

His death was announced by the Foundation Jean Dausset-CEPH, a research institute he founded in Paris.

Dr. Dausset, who specialized in blood diseases, shared the Nobel for Physiology or Medicine with two researchers working in the United States, Dr. Baruj Benacerraf and Dr. George D. Snell, for work done over several decades. The Karolinska Institute in Sweden, which awards the prize, said their research showed why some people were better able to defend themselves against infection than others, and why certain people were at risk for autoimmune diseases like rheumatoid arthritis or lupus.

Dr. Dausset’s findings transformed the understanding of the human immune system, Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, said in a telephone interview on Monday. His main achievement was demonstrating that molecules on the surface of cells, now called HLA antigens, determine an individual’s immune response. These antigens, which are genetically coded by a particular location on one chromosome, determine the body’s response to foreign tissue, for example. They set off the production of disease-fighting antibodies and help the immune system distinguish between the body’s own cells and invaders.

The research made it possible for transplant surgeons to “type” cells to determine whether a body would accept or reject tissue from a donor. Since then, such tissue typing has been used widely for heart, liver and other transplants.

In addition to demonstrating the existence of these antigens in people, Dr. Dausset “elucidated the genetic factors regulating their formation,” the Karolinska Institute said.

Working with Dr. Felix T. Rapaport, Dr. Dausset carried out a series of experimental skin grafts that provided evidence that incompatibility of antigens worked against the graft’s survival.

Subsequently, to find out if the genetic factors were valid for all humans and not just particular groups, Dr. Dausset and his colleagues went to far-flung places to obtain blood samples from people of 54 racial and ethnic groups. They found that the genetic laws controlling the antigens were valid for all groups.

Jean Baptiste Gabriel Joachim Dausset was born in Toulouse, France, on Oct. 19, 1916, the son of a prominent physician. He earned a bachelor’s degree at the Lycée Michelet in Paris and enrolled in medical school at the University of Paris in the late 1930s. With World War II looming, he was drafted into the military before he could complete his studies. After France fell to the German invasion in 1940, he made his way to North Africa and joined the Free French forces.

Before leaving, he gave his identity papers to a Jewish colleague at the Pasteur Institute, to help the man avoid persecution by the Nazis.

In North Africa, he performed blood transfusions and developed an interest in transfusion reactions that helped lead to his later work. He participated in the liberation of France in 1944 and left the military in 1945 as a second lieutenant.

He earned his medical degree and completed his internship and residency at hospitals in Paris before being appointed director of laboratories at the National Blood Transfusion Center in 1946, a post he held until 1963.

He married Rosita López in 1963 and the couple had two children, Henri and Irene.

Dr. Dausset held a number of teaching and research posts, including chief biologist for the Paris General Hospital System; chairman of the immunology department at the University of Paris, where he taught for many years; professor at the Collège de France; and director of research at the French National Institute of Health and Medical Research.

He was author or co-author of books including “Histocompatibility” (1976) and “Immunology” (1980). He was elected to the Academy of Science and the Academy of Medicine in France.

In 1984, Dr. Dausset started a laboratory, later a genome research center, the Center for the Study of Human Polymorphism, which coordinated the first international collaboration to map the human genome. In 1993 it became the Foundation Jean Dausset-CEPH, a nonprofit institute. He retired as president of the foundation in 2003.