title: CD34 positive selection as prophylaxis against graft versus host disease in allogeneic peripheral blood stem cell transplantation.
abstract: We report our experience of CD34 positive selection as a means of graft T-cell depletion (TCD) in 14 consecutive HLA-identical Peripheral blood stem cells (PBSC) allografts as prophylaxis against graft versus host disease (GVHDp). CD34 positive selection was performed by immunomagnetic separation achieving a median CD34 and T-cell dose of 4.17 (range 1.4-8.50) x 10(6)/kg and 1.89 (range 0.92-13.18) x 10(4)/kg, respectively, in the graft. This represents 4-log depletion of T-cells. The median time to achieve a neutrophil count of 0.5 x 10(9)/l was 15 days and to achieve a platelet count of 50 x 10(9)/l was 20 days. Only four patients developed acute GVHD at a median of 41 days but this was exclusively mild grade I cutaneous disease and settled with oral steroids. Four patients, all of whom had AML, relapsed or progressed after transplant at a median of 161 (range 109-311) days. One of these had been transplanted in early relapse (9% blasts) whilst another was in second remission. The remaining 10 patients are alive and well. The median progression free survival for the whole population is 69% at 686 days. We conclude that CD34 positive selection by immunomagnetic separation in HLA-identical PBSC allografting achieves significant TCD with clinically trivial acute GVHD, prompt engraftment and an acceptable disease relapse risk.
authors.affiliation: Jose Carreras Bone Marrow Transplant Unit, Royal Liverpool University Hospital, Prescot Street, Liverpool, L7 8XP, UK. nbutt@liv.ac.uk
authors.forename: Nauman M
authors.initials: NM
authors.lastname: Butt
authors.forename: Noreen
authors.initials: N
authors.lastname: McGinnity
authors.forename: Richard E
authors.initials: RE
authors.lastname: Clark
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34 / Q000032:analysis*; D003520:Cyclophosphamide / Q000008:administration & dosage; D016572:Cyclosporine / Q000627:therapeutic use; D005260:Female; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000209:etiology / Q000517:prevention & control*; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D018189:Immunomagnetic Separation; D016130:Immunophenotyping; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D002955:Leucovorin / Q000627:therapeutic use; D007951:Leukemia, Myeloid / Q000628:therapy; D008212:Lymphocyte Depletion / Q000379:methods*; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D036102:Peripheral Blood Stem Cell Transplantation / Q000009:adverse effects*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019172:Transplantation Conditioning; D014184:Transplantation, Homologous / Q000009:adverse effects; D014916:Whole-Body Irradiation
chemical_list: D018952:Antigens, CD34; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D003520:Cyclophosphamide; D002955:Leucovorin; D008727:Methotrexate