Treatment of high-risk acute myelogenous leukaemia by myeloablative chemoradiotherapy followed by co-infusion of T cell-depleted haematopoietic stem cells and culture-expanded marrow mesenchymal stem cells from a related donor with one fully mismatched human leucocyte antigen haplotype.

A 20-year-old woman with high-risk acute myelogenous leukaemia was transplanted with granulocyte colony stimulating factor (G-CSF)-mobilized peripheral blood CD34+ haematopoietic stem cells and bone-marrow-derived mesenchymal stem cells (MSC) from her human leucocyte antigen haplotype-mismatched father after myeloablative conditioning therapy. The patient engrafted rapidly and had no acute or chronic graft-versus-host disease. Since transplantation, the patient has shown an enduring trilineage haematological complete response without any evidence of leukaemia relapse at 31 months. We suggest that MSC can be used effectively for genetically haploidentical haematopoietic stem cell transplantation for acute leukaemia.