Gene variation appears to reduce risk of serious complication after bone marrow transplant

Thursday, December 4th 2003, 12:00 am
By: News On 6

A common genetic variation appears to reduce the risk of a serious complication after a bone marrow transplant, new research shows.

People who had the gene variation were half as likely as other patients to develop severe graft-versus-host disease or die from the transplant, according to a study of 993 bone marrow recipients in Seattle.

The researchers said testing for the genetic variation could help determine treatment options for patients who are considering the risky procedure and could help their doctors adjust their medication afterward.

``People have assumed for a long time that genetic differences between patients will affect outcome of cancer therapy. This is clear, clinical evidence that supports that hypothesis,'' said one of the researchers, Dr. John A. Hansen of the Fred Hutchinson Cancer Research Center and the University of Washington.

The findings are reported in Thursday's New England Journal of Medicine.

Bone marrow transplants are used in the treatment of some types of cancer to restore blood stem cells that are destroyed by high doses of chemotherapy or radiation. But sometimes the donor's cells attack the recipient's body, resulting in graft-versus-host disease. First signs of the disease include a rash on the palms or soles. It can also attack the gut and liver, causing nausea, vomiting and jaundice.

The research found that a specific type of the interleukin-10 gene, found in a quarter of North Americans, protects patients against severe acute graft-versus-host disease and dying from the transplant. The three-year death rate from the transplant was 13 percent in those with the favorable gene type and as high as 26 percent in those without the variation.

Nine percent of the patients with the gene variation developed the disease in the three months after the transplant, compared with 21 percent of patients without it. The gene variant didn't protect against chronic graft-versus-host disease, which develops later.

The donors in the study were matched siblings of the patients; Hansen said they are now looking to see if the gene variation has the same benefit in non-related donor transplants. He said some studies have suggested the gene variation may also protect against rejection of other transplants, including heart and kidney.

The researchers said the finding may explain why Japanese patients have a lower rate of graft-versus-host disease, since about 67 percent of Japanese have the gene variation.

Drs. Kenneth R. Cooke and James L.M. Ferrara of the University of Michigan Comprehensive Cancer Center wrote in an accompanying commentary that they believe the findings support the use of genetic testing now for prospective transplant patients.

``The time has come were we should begin to do that,'' Cooke said.

But Hansen advised being selective in using the tests until more research is done.