Deficiency of NK activity of HNK-1+ cells after transplantation of fetal thymus and liver or haploidentical soybean agglutinin-treated marrow cells in two severe combined immunodeficiency patients.

Two severe combined-immunodeficiency patients successfully transplanted with fetal thymus and liver or haploidentical lectin-treated marrow cells lacked NK activity, with a normal number of HNK1+ cell-defined NK cells. The defect was not due to the inhibiting factor in patients' sera. Their NK cells bound to their targets, but did not lyse them in a single-cell agarose assay, and did not respond to alpha-IFN or IL-2. IL-2 did not stimulated the development of mature NK cells that bear M1 antigens from precursors that lack M1 antigens.