Faster engraftment of peripheral blood progenitor cells compared to bone marrow from unrelated donors

Twenty-six patients received peripheral blood progenitor cells (PBPC) from unrelated donors at five European Centres. Twenty-five donors were HLA-A, -B and -DR identical and one had a one antigen mismatch. PBPC were mobilised by treatment with G-CSF for 4-5 days. Eleven patients receiving PBPC were compared to 11 patients receiving unrelated bone marrow with comparable prognostic factors. The median mononuclear cell count, the CD3+ cells and the CD56+ cells were seven to 10 times higher in PBPC, compared to bone marrow (P < 0.001). The median CD34+ cell content was 6.1 x 10(6)/kg recipient weight with PBPC, compared to 4.3 with bone marrow (NS). Time from transplantation to neutrophils >0.5 x 10(9)/l was a median of 11 (range 6-21) days using PBPC vs 15 (10-22) days after transplantation of bone marrow (P = 0.03). Transfusions and time to discharge did not differ between the two groups. All 26 patients receiving PBPC engrafted. Acute GVHD grades II-IV was seen in 8/26 (31%) and chronic GVHD in 8/18 (44%). Overall, 13/26 (50%) of the patients are alive and well with a median follow-up of 9 (2-35) months.