PITTSBURGH — Transplant pioneer Thomas E. Starzl, 90, died Saturday at his Pittsburgh home, according to a friend, former colleague and the executor of his estate, John Fung, director of the University of Chicago Transplantation Institute.

“He worked right up to the end of his life,” Fung said Sunday. “He was working four-hour days in the same offices he had worked in for 30 years.”

Starzl, who performed the world’s first liver transplant, went on to achieve greater success after he joined the University of Pittsburgh School of Medicine in 1981 as a professor of surgery. He led the team of surgeons who performed Pittsburgh’s first liver transplant. The team performed 30 such transplants that year. It was the only liver transplant program in the country at the time.

Starzl retired from clinical and surgical service in 1991 but, until then, served as chief of transplantation services at Presbyterian University Hospital, Children’s Hospital of Pittsburgh and the Veterans Affairs Hospital in Pittsburgh. As the chief, he oversaw the largest and busiest transplant program in the world. He was director of the University of Pittsburgh Transplantation Institute, which was renamed the Thomas E. Starzl Transplantation Institute in 1996. Since that year,

By 1984, Starzl had built the largest transplant program in the world. “In 1991, we had done over 560 liver transplants that year,” Fung said.

Starzl and Fund researched immunosuppressant drugs and methods of suppressing organ rejection. They developed a drug that now is the most widely used immunosuppressant drug in transplantation around the world: FK506.

Doctors from around the world were regularly coming to Pittsburgh to train with Starzl, who willingly accepted them, , trained them, and then sent them back out into the world. Many became heads of their own transplant teams.

Starzl performed the world’s first liver transplant in Denver in 1963. That patient and the four who followed didn’t survive long. But four years later, using a mix to combat organ rejection, Starzl performed the first liver transplant on a patient who survived for a year.

Starzl performed about 175 liver transplants at the University of Colorado, with a success rate between 30 percent to 50 percent. He was chairman of surgery at the University of Colorado School of Medicine from 1972 until 1980, when he came to Pittsburgh.

The University of Pittsburgh and the University of California, Los Angeles, competed for Starzl when he was ready to leave Denver. He chose Pittsburgh, where the surgery department was headed by Henry Bahnson, who had been best man at Starzl’s first wedding.

Starzl and Pittsburgh achieved worldwide acclaim while the doctor worked at Presbyterian Hospital and the University of Pittsburgh. In 1996, the university’s transplant institute was renamed in his honor.

Starzl transformed the hospital into the busiest transplant center in the world. By Feb. 26, 2001, which was the 20th anniversary of Pittsburgh’s first liver transplant, the center’s team had transplanted more than 5,700 livers, 3,500 cadaveric kidneys, 1,000 lungs and 500 hearts.

In 1985, Presbyterian tightened controls over Starzl’s program after a series of articles in The Pittsburgh Press pointed to favoritism in the kidney transplant program, with foreigners being pushed to the top of waiting lists and paying more than Americans for the same operations. The team also accepted personal gifts and research grants from the foreign patients.

The U.S. Justice Department investigated those problems and in 1989 announced that no charges would be brought against Starzl.

In 1992, Starzl published an autobiography called “The Puzzle People,” which revealed that the celebrated surgeon hated doing surgery. His mother, a nurse whose death from breast cancer devastated her 21-year-old son, wanted Starzl to be a surgeon and he was determined to satisfy her wish. “But I had an intense fear of failing the patients who had placed their health or life in my hands,” he wrote. “It was as if I had trained all of my life to become a violin virtuoso, only to discover that I loathed giving concerts or even playing privately.”

Thomas Starzl was born March 11, 1926, in LeMars, Iowa, the son of newspaper editor and science fiction writer Rome Starzl and his Anna Laura Fitzgerald.

He attended Westminster College in Fulton, Missouri, where he earned his bachelor’s degree in biology. He went on to the Northwestern University Medical School in Chicago, where in 1950 he received a master’s degree in anatomy. In 1952, he earned both a doctoral degree in neurophysiology and a medical degree with distinction.

Following postgraduate work at Johns Hopkins Hospital in Baltimore, Starzl pursued his interest in surgery and research with a fellowship and residencies at Johns Hopkins, the University of Miami and the Veterans Administration Research Hospital in Chicago. He was a Markle Scholar in Medical Science, a distinguished honor bestowed annually to a small group of exceptionally promising young physicians in academic medicine. Starzl was on the faculty of Northwestern University from 1958 to 1961 and joined the University of Colorado School of Medicine as an associate professor in surgery in 1962. He was promoted to professor in 1964 and was chairman of the department of surgery from 1972 to 1980.

Starzl is survived by his wife of 36 years, Joy Starzl, of Pittsburgh; and a son, Timothy Starzl of Boulder, Colorado.