T-cell depletion and manipulation in allogeneic hematopoietic cell transplantation

Graft-vs-host disease (GVHD) in allogeneic hematopoietic transplantation can be abrogated by T-cell depletion (TCD) of the graft. Researchers have sought the optimal TCD procedure, which would alter the activity, number, and/or subpopulation profile of T cells to acceptable levels, while retaining sufficient engraftment potential of the harvested hematopoietic stem cells. The techniques that have successfully survived the translation from research studies into practical clinical application may be analyzed by their effectiveness, efficiency, ease of application, and cost. The predominant techniques rely on either physical separation of the T cell (binding to erythrocytes, lectins, centrifugation) or reaction with monoclonal antibodies (immunomagnetic, panning, complement-mediated cytotoxicity, immunotoxins). Comparative trials between the various techniques are few, making comparisons difficult. However, all of the techniques, whatever their relative advantages and disadvantages, must meet the same challenges.