OBJECTIVETo evaluate the feasibility and safety of peripheral CD34+ cell mobilization in patients with severe autoimmune disease.

METHODSForty-two patients underwent a total of 46 mobilizations by the regimen of cyclophosphamide 2-3 g/m2+ recombinant human granulocyte colony stimulating factor (rhG-CSF) 5 microg x kg(-1) x d(-1). The positive selection of CD34+ cell was performed through the CliniMACS.

RESULTSIn 8.1 +/- 2. 3 days after administration of cyclophosphamide, the peripheral white blood cell and mononuclear cell (MNC) decreased to the lowest level. In 3.7 +/- 1.6 days after injection of rhG-CSF, the peripheral absolute MNC and CD34+ cell counts were 0.95 x 10(9)/L and 0.035 x 10(9)/L, respectively. After 2.4 +/- 0.6 times of leukapheresis, there gained 4.46 x 10(8)/kg of MNC and 5.26 x 10(6)/kg of CD34+, respectively. After mobilization, the underlying diseases were ameliorated more or less. In systemic lupus erythematosus (SLE) patients, SLE Disease Activity Index (SLEDAI) decreased from a median of 17 to 3 (P < 0.01). In rheumatic arthritis patients, an American College of Rheumatology criteria for 20% (ACR20) response was achieved in all five patients. Totally, 17.4% of patients whose absolute neutrophil count < 0.5 x 10(9)/L suffered infection, and 31.0% of patients had bone pain after the injection of rhG-CSF. Two patients suffered severe complications, one with acute renal failure and recovered by hemodialysis, the other died of thrombotic thrombocytopenic purpura. Failed mobilization occurred in three patients.

CONCLUSIONSSufficient CD34+ cells can be mobilized by low dose of cyclophosphamide and rhG-CSF. CD34+ cell mobilization for treatment of severe autoimmune disease not only is appropriate in both effectiveness and safety but ameliorates disease also.