Transplant reaction reversed in patients.

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). 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.--N.S.