ALLOGENEIC BLOOD STEM-CELL TRANSPLANTATION FOR REFRACTORY LEUKEMIA AND LYMPHOMA - POTENTIAL ADVANTAGE OF BLOOD OVER MARROW ALLOGRAFTS

Peripheral blood stem cells (PBSCs) have been used rarely for allogene ic transplantation because of concerns regarding graft failure and gra ft-versus-host disease (GVHD). We evaluated the results of allogeneic PBSC transplantation (allo-PBSCT) in 9 patients with refractory leukem ia or lymphoma receiving myeloablative therapy followed by allo-PBSCT from an HLA-identical sibling donor. Three patients had relapsed 11 to 21 months after allogeneic bone marrow transplantation (allo-BMT) and underwent allo-PBSCT using the same donor. Six patients received PBSC s as their initial allogeneic transplant. Filgrastim-mobilized PBSCs w ere collected from the donors in 3 to 4 aphereses and cryopreserved. T he apheresis collections contained a median nucleated cell count of 16 .5 x 10(8)/kg (range, 10.8 to 28.7 x 10(8)), 10.7 x 10(6) CD34(+) cell s/kg (range, 7.5 to 22.5 x 10(6)), and 300.0 x 10(6) CD3(+) cells/kg ( range, 127.8 to 1,523.2 x 10(6)). The median recovery of CD34(+) proge nitor cells after freezing, thawing, and washing was 106.4% (range, 36 .7% to 132.0%). All patients received filgrastim posttransplant throug h engraftment, and cyclosporine and methylprednisolone were used for G VHD prophylaxis. Neutrophil recovery to greater than 0.5 x 10(9)/L and greater than 1.0 x 10(9)/L occurred at a median of 9 (range, 8 to 10) and 9 days (range, 8 to 11) posttransplant, respectively, which was s imilar to historical controls after allo-BMT and granulocyte colony-st imulating factor therapy. Platelets recovered to greater than 20 x 10( 9)/ L and greater than 50 x 10(9)/L at a median of 12 (range, 8 to 25) and 15 days (range, 11 to 59), respectively, which was significantly more rapid than for the controls (P<.01). Donor cell engraftment was d ocumented by cytogenetics, fluorescence in situ hybridization, and/or restriction fragment length polymorphisms with longest follow-up of 28 3+ days. Three patients developed grade 2 acute GVHD involving only th e skin. Three of five evaluable patients show limited chronic GVHD. Cr yopreserved, filgrastim-stimulated allogeneic PBSCs may be a suitable alternative to allogeneic marrow for transplantation with the advantag e of more rapid platelet recovery. Acute GVHD was minimal despite the infusion of 1 log more CD3 cells than with marrow allografts. Further studies are required to assess long-term risks of chronic GVHD. (C) 19 95 by The American Society of Hematology.