OBJECTIVETo explore the feasibility of a new protocol for acute graft versus host disease (aGVHD) prophylaxis in haploidentical bone marrow transplantation.

METHODSThirty-eight high-risk leukemia patients underwent haploidentical G-CSF primed bone marrow transplantation without ex-vivo T cell depletion, the donors were given G-CSF 250 microg/d for 7 days prior to marrow harvest. All patients received a same chemo-radiation conditioning regimen, including cytarabin, cyclophosphamide and total body irradiation (TBI). GVHD prophylaxis regimen consisted of ATG, CsA, MTX, Mycophenolate mofetil (MMF) and anti-CD(25) monoclonal antibody (MoAb).

RESULTSAll patients achieved engraftment of a median of 19 and 22 days for neutrophil and platelet, respectively. Cytogenetic analysis showed 100% donor hematopoietic cells in all recipients after transplantation. One of the twenty patients (5%) experienced grades II - IV acute GVHD. The recovery of CD(3)(+)CD(8)(+) T cells, CD(19)(+) cells and CD(56)(+) cells after transplantation was within 3 approximately 12 months. Of the 20 patients, 16 were alive with minimal and limited chronic GVHD and karnofsky score over 90% in a median follow-up of 9 months. Disease free survival (DFS) rates was (80 +/- 9)%.

CONCLUSIONG-CSF priming marrow graft along with sequential immunosuppressants, especially the addition of anti-CD(25) MoAb for aGVHD prophylaxis could achieve excellent engraftment, proper immune reconstitution and very low incidence of grade II - IV GVHD. The new protocol is effective and feasible in preventing severe acute GVHD and improving DFS.