New Strategy For Fighting Transplant Complication
NEW YORK, Jul 20 (Reuters Health) -- Destroying a particular
type of immune cell in transplant recipients may reduce or even
eliminate graft versus host disease, a potentially life-threatening complication in bone marrow transplant patients.
The findings, from a study in mice, suggest a new way of
preventing the ailment, according to a report in the July 16th issue of Science.
In graft versus host disease, the donor's T lymphocyte immune
cells attack the recipient, causing skin reddening and swelling, loss of hair, and lesions of the joints and heart. Patients are also at risk for serious bacterial infections that can be fatal.
Treatment strategies are aimed at suppressing the T cells.
However, the T lymphocytes are initially triggered by
antigen-presenting cells (APC) -- scavenger cells that engulf
foreign particles, chew them up and display the foreign proteins to the T cells.
While it was not clear whether the donor's or recipient's APCs
set off graft versus host disease, the study findings suggest that the transplant recipient's APCs are to blame.
In a series of experiments, Dr. Warren D. Shlomchik of the
University of Pennsylvania School of Medicine in Philadelphia,
and colleagues found that recipient mice whose APC cells were
altered or eliminated tended to have less severe or delayed graft
versus host disease compared with other mice.
The results suggest that depleting a recipient's APC cells before
transplant should reduce the risk of graft versus host disease
without the need for long-term suppression of T lymphocytes, the
investigators conclude.
Such cells could possibly be destroyed by attaching toxins or
radioactive particles to antibodies that bind specifically to the
APC cells.
"Thus, strategies for preventing graft versus host disease could be developed that are based on inactivating host antigen-presenting cells," the authors explain. "Such strategies could expand the safety and application of allogeneic bone marrow transplantation in treatment of common genetic and neoplastic (malignant)diseases."
Science 1999;285:412-415.
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