In vitro comparison of two methods of T cell depletion associated with different rates of graft failure after allogeneic marrow transplantation.

Clinical trials in another center have shown a substantially lower risk of graft failure associated with T cell depletion by treatment of donor marrow with the use of an antibody against CD6 compared to depletion with a mixture of eight antibodies previously used for clinical trials in our center. In order to evaluate mechanisms possibly responsible for this difference, we compared lymphoid cell surface phenotypes and in vitro functions in marrow cells treated by complement-mediated lysis with anti-T12 (CD6) or with the eight antibody mixture