Identification of transfused blood cells in children with severe combined immunodeficiency syndrome by analysis of multiple cell lineages using restriction fragment length polymorphisms.

Four children with severe combined immunodeficiency syndrome (SCID) had evidence of circulating transfused cells detected by restriction fragment length polymorphism (RFLP). In two cases, the source of transfused cells was a single, unirradiated red cell transfusion and the patients developed severe graft-versus-host disease (GVHD). In another instance, engraftment of bone marrow cells, mononuclear cells, and neutrophils was noted 9 weeks following the infusion of 111indium-labeled maternal leukocytes for localization of infection. The patient also developed severe GVHD as a consequence of engraftment of functionally active maternal cells and rejected a paternal T cell-depleted marrow infused at a time when circulating maternal cells were present. In the fourth case, RFLP analysis was performed 2 h following completion of a leukocyte transfusion that had been irradiated with 3000 cGy prior to infusion. Third party mononuclear cells and neutrophils were transiently detected. The third party cells were of no clinical significance. The use of a limited panel of highly informative DNA probes allowed us to identify the affected circulating cell populations and source of foreign leukocytes in children with SCID without requiring a pretransfusion peripheral blood, bone marrow, or fibroblast sample.