Second transplantation with CD34+ bone marrow cells selected from a two-loci HLA-mismatched sibling for a patient with chronic myeloid leukaemia

A 43-year-old man with chronic myeloid leukaemia underwent a second transplant with CD34⁺ bone marrow cells selected from his two-loci HLA-mismatched sibling after rejection of the first graft from an HLA-matched unrelated donor. By immunomagnetic positive selection, CD34⁺ marrow cells at 0.95×10⁶/kg with 97% purity and CD3⁺ T lymphocytes at 1.3×10⁴/kg were collected and transplanted. Engraftment was confirmed to be of CD34⁺ cell-donor origin. The patient developed only grade I acute graft-versus-host disease (GVHD) and no chronic GVHD to date. These observations suggest that allogeneic CD34⁺ bone marrow cells are capable of reconstituting haemopoiesis and that CD34⁺ selection could be applicable to T-cell depletion.