The detection of cellular antigens and biologic substances critical for investigations of the immunobiology of graft acceptance and rejection and the mechanism of action of immunosuppressive drugs. Without the information acquired through immunophenotypic analysis during the past decade, many of the basic mysteries of transplantation would not have been answered, and the present clinical success of organ transplantation would not have been achieved. Clinical applications of flow cytometry in solid organ transplantation include pretransplant cross- matching, HLA antibody screening, and post-transplantation antibody monitoring.In bone marrow transplantation, the enumeration of CD34+hematopoietic stem cells in the peripheral blood or bone marrow graft correlates with engraftment success and the length of hematopoietic recovery following stem cell transplantation.Other applications of flow cytometry in bone marrow transplantation include pre-transplantation determinations of the efficacy of ex vivo T-cell graft depletion, and post-transplantation evaluation of immune recovery, graft rejection, graft-versus host disease, and the graft-versus-leukemia effect.(15.)
