Wednesday June 2, 6:21 pm Eastern Time
Release at 5 p.m. (2100 GMT)
By Leslie Gevirtz
BOSTON, June 2 (Reuters) - A new technique in bone marrow transplants holds the promise of treatment for a variety of immune disorders including arthritis, diabetes and multiple sclerosis, Thursday's New England Journal of Medicine said.
The technique allowed researchers to devise a way to make the T cells in the donated marrow "tolerant" of the recipients tissue.
The experimental technique "is really about all sorts of immune regulation," the study's lead author, Dr. Eva Guinan, said in an interview from her office at the Dana-Farber Cancer Institute in Boston.
"It's definitely about heart and kidney and liver transplants and it may very well be about rheumatoid arthritis, and multiple sclerosis and diabetes and other things that are dependent on immune recognition," she said.
The study involved 12 cancer patients, ranging in age from 6 months to 26 years old, who had failed to respond to chemotherapy, radiation therapy, and earlier bone marrow transplants.
Bone marrow transplants have become standard treatment for patients who are born with diseases of the blood, who have their bone marrow fail or who have cancers such as leukemia that originate in the bone marrow. These patients "really didn't have any other treatment option," said Guinan's co-author Dr. Lee Nadler.
The new technique involved paralyzing specific T cells. T cells are the immune system cells that fight infection, stand guard against cancer and attack foreign tissue. One of the main complications of conventional bone marrow transplants is graft-versus-host disease, a potentially fatal condition in which T cells in donated bone marrow launch an attack against recipients' tissue.
It was the first time the method, which has been known to work in laboratory experiments for the past three-to-five years, was used in humans.
"What we're doing with the new technique is to punch a hole in the immune system - to paralyze the specific T cells responsible for tissue rejection, but to leave intact those that fight infection and guard against cancer," Nadler said.
The method involves removing some white blood cells from a a patient and then treating the cells with chemotherapy and radiation to kill off their immune system. Bone marrow is then taken from a parent or sibling. The marrow and white blood cells are combined along with a chemical, CTLA-4-Ig, made by the Cambridge, Mass., biotech company Repligen Corp., and incubated for 36 hours, Guinan explained. The concoction is then transferred to the patient.
Seven of the 12 patients died after the procedure, but none of the deaths was due to tissue rejection. Five of the 12 were alive and in remission from 4.5 to 29 months after transplantation.
The method, which Dr. Baruj Benacerraf, winner of the 1980 Nobel Prize
in Medicine called "a pioneer work," significantly extends the option
of transplants to nearly everyone with a partially matched donor such as
a blood relative.
Guinan said the study was continuing and that further research will be needed "to really prove the concept."