The work by Dr. Ellen Vitetta, director of the Cancer Immunobiology Center, and Dr. Robert Collins, director of the UT Southwestern Hematopoietic Cell Transplant Program, is part of research at UT Southwestern designed to identify the problem cells in a bone-marrow transplant and eliminate them before the transplant is carried out.

The latest findings will appear in the Feb. 4 issue of the Proceedings of the National Academy of Sciences and online at the journal's Web site.

In a bone-marrow transplant, the patient is treated with very high doses of chemotherapy, with or without radiation, to destroy cancer cells. This process also destroys the bone marrow, which is replaced with healthy marrow cells obtained either from the patient beforehand (autologous) or from a healthy donor (allogenic). Once transplanted, the donated bone-marrow cells multiply and repopulate the patient's blood cells.

Allogenic stem cell transplants are preferred for many hematologic malignancies or inherited disorders. But while this type of transplant often has an anti-leukemic effect, the risk is graft-versus-host disease (GVHD), where the donated immune system (the graft) begins to attack the recipient's body (the host).

If the graft T cells (lymphocytes) are depleted prior to transplant, GVHD is eliminated. However, there is no anti-leukemic effect, and the patients are at-risk for infection.

"Graft-versus-host disease when T cells are not eliminated and infections when they are causes significant morbidity and mortality in patients," said Vitetta, the study's senior author.

To combat this problem, Vitetta and Collins are developing and refining an in-vitro procedure to activate the donor T cells responsible for causing GVHD. These activate
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Contact: Scott Maier
scott.maier@utsouthwestern.edu
214-648-3404
UT Southwestern Medical Center
4-Feb-2003