A RETROSPECTIVE DUTCH STUDY COMPARING T-CELL DEPLETED ALLOGENEIC BLOOD STEM-CELL TRANSPLANTATION VS T-CELL DEPLETED ALLOGENEIC BONE-MARROW TRANSPLANTATION

Retrospectively, a cohort of 43 hematological patients receiving an al logeneic T cell-depleted (TCD)-PBSCT between 1994 and 1997, was compar ed to a cohort of 435 patients, who received an allogeneic TCD-BMT bet ween 1990 and 1996, Both cohorts were comparable with respect to diagn osis, risk status, age and ses, PB grafts contained four to five times more hematopoietic progenitor cells and T cells as compared to BM gra fts. T cell depletion was performed by either elutriation, CD34 select ion, E-rosetting, or Campath serotherapy. Conditioning was cyclophosph amide/TBI in the majority of patients of both cohorts. All patients re ceived cyclosporin A as GVHD prophylaxis until day 90 post-transplant. Engraftment was significantly faster in the PBPCT cohort with a media n time to neutrophil recovery (>0.5 x 10(9)/l) of 16 vs 21 days in the BMT cohort (P = 0.0009), Platelet recovery to 50 x 10(9)/l was 16 vs 34 days for the PB and BM cohort respectively (P < 0.0001). A median p ercentage of 76% of BMT patients recovered to 50 within 100 days post- BMT vs 91% of patients receiving a PB graft. The incidence of acute GV HD grades II, III and IV was similar in both cohorts. In contrast, the probability of developing chronic GVHD was 21% in the BM cohort vs 37 % in the PB cohort. Relapse incidence was reduced in the PB cohort (9 vs 29%), while treatment-related mortality was not different for both cohorts. These favorable results require confirmation by a prospective randomized trial, which is currently being performed by several Europ ean centers.