AUTOLOGOUS BLOOD PROGENITOR-CELL TRANSPLANTATION IN RELAPSED HODGKINS-DISEASE - THE ROLE OF HEMATOPOIETIC GROWTH-FACTORS

Thirty-seven patients with Hodgkin's disease in sensitive relapse were autografted using blood-derived haematopoietic progenitor cells. At t he time of transplantation 22 patients were in complete remission and 15 patients in partial remission. Twenty-six patients were male and 11 female, with a median age of 31 years (range 21-52). The pre-transpla nt conditioning therapy consisted of cyclophosphamide, BCNU and etopos ide (CBV). Five patients died of transplant-related complications and 11 patients relapsed after a median time of four months following auto grafting. For the remaining 21 patients the probability of event-free survival (EFS) was 45% at 68 months. Blood progenitor cell collection can be integrated into salvage therapy by administering haematopoietic growth factors (HGFs) to enhance the chemotherapy-induced progenitor cell rebound during leucocyte recovery. In a subgroup of 14 patients, seven received recombinant human granulocyte-macrophage colony stimula ting factor (rhGM-CSF) (250 mug/m2/day) by continuous intravenous infu sion following dexamethasone, BCNU, etoposide and melphalan (Dexa-BEAM ) as salvage therapy, while seven patients were treated without haemat opoietic growth factor (HGF) post-chemotherapy. The yield of total nuc leated cells (TNC) and granulocyte-macrophage colonies (CFU-GM) collec ted per leukapheresis was 2.2- and 2.4-fold higher respectively in the rhGM-CSF-treated patients. Following high-dose conditioning therapy, the seven patients autografted with rhGM-CSF-mobilised stem cells show ed a faster leucocyte recovery compared with the control group. Neutro phil recovery (> 1.0X10(9)/L) and platelet recovery (>20x10(9)/L) were also accelerated in the rhGM-CSF-treated group. Subsequently, in a gr oup of eight patients filgrastim (rhG-CSF) (5 mug/m2/day) was given by subcutaneous infusion 24 hours after salvage therapy to increase the chemotherapy-induced progenitor cell rebound for blood progenitor cell collection. Following the CBV regimen, all patients achieved complete engraftment after a median of 14 days for a white blood cell (WBC) co unt of 1.0X10(9)/L, 24 days for a polymorphonuclear (PMN) count of 1.0 x10(9)/L and 31 days for a platelet count of 20X10(9)/L. A significant correlation was noted between the number of CD34+ cells/kg transplant ed and platelet recovery (R = -0.90; p<0.002). The data demonstrate th at complete and sustained engraftment can be achieved following high-d ose conditioning therapy with filgrastim or rhGM-CSF-mobilised blood p rogenitor cells. No additional bone marrow support or HGF was given po st-transplantation. Prospective studies are required to compare filgra stim and GM-CSF with respect to their mobilising capacity and effect o n the different subpopulations of haematopoietic cells.