In response to this problem, researchers at the Stanford University School of Medicine have developed a technique that can virtually eliminate this life-threatening complication, known as graft-versus-host disease, without compromising the transplanted cells' effectiveness against cancer.
The therapy entails adjusting the patient's level of a specific type of immune cell, the regulatory T cells, before the transplant is done. The method was first developed in mice by Samuel Strober, MD, professor of medicine (immunology and rheumatology), who has been studying these types of cells for more than 25 years. Robert Lowsky, MD, assistant professor of medicine (bone marrow transplantation), has adapted this strategy for humans along with Strober, and will present the results of tests Dec. 6 at the annual American Society of Hematology meeting in San Diego.
In two clinical trials funded by the National Institutes of Health, Lowsky, Strober and other colleagues found that only one of the 37 patients who received the treatment developed graft-versus-host disease. "You would have expected something in the order of 30 to 60 percent incidence of severe graft-versus-host disease in these patients, according to conventional methods," said Strober.
Studies of the new method found there was no increase in the rate of infections in the treated patients. The studies also found that the majority of patients who were in partial remission went into complete remission, and those who were in complete remission didn't relapse.
"It looks like there is a potent anti-tumor effect from our method despite the incidence of graft-versus-host disease being dramatically lowered," said Lowsky.
Also at the conference, Strober will conduct a