Transplant reaction reversed in patients

From Orlando, Fla., at a meeting of the American Society of Hematology

Patients with leukemia get a fighting chance when they receive a transplant of bone marrow cells from a healthy donor. Unfortunately, immune cells from these new arrivals can run amok in the recipient, creating a life-threatening complication called graft-versus-host disease (GVHD).

Last year, scientists in Sweden trying a new approach to reverse severe GVHD in 16 patients reported some early success (SN: 12/24/05, p. 417: Available to subscribers at Rare marrow cells tackle deadly immune reaction). They gave patients an additional transplant, using only adult mesenchymal stem cells from the marrow. These cells typically become bone, muscle, or other connective tissues but also can develop into a wide variety of other cells.

The researchers now report that 52 people who had severe GVHD after a previous bone marrow transplant have undergone the novel procedure.

Twenty-two of these patients remain alive, half in remarkably good health, says physician Katarina Le Blanc of the Karolinska University Hospital Huddinge in Stockholm. Some have survived more than 3 1/2 years.

“All these patients would have died, and quickly,” Le Blanc says. In some patients, the transplanted mesenchymal cells appeared to have immunosuppressive and possibly anti-inflammatory effects that shut down GVHD. There is also evidence that they aided the healing of damaged organs, she says.