CD34 cell dose in granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell grafts affects engraftment kinetics and development of extensive chronic graft-versus-host disease after human leukocyte antigen-identical sibling transplantation

A retrospective analysis of granulocyte colony-stimulating factor (G-CSF)-m obilized peripheral blood mononuclear cell (G-PBMC) products harvested from healthy donors indicates significant variability in both the absolute numb er and relative proportion of CD34, CD3, and CD14 cells obtained. This repo rt examined whether variations in the cellular composition of G-PBMC produc ts correlated with clinical outcomes after myeloablative allogeneic transpl antation. The numbers of CD34, CD3, and CD14 cells infused into 181 human l eukocyte antigen (HLA)-identical sibling recipients were analyzed with resp ect to tempo of engraftment, acute graft-versus-host-dis ease (GVHD), clini cal extensive chronic GVHD, overall survival, and disease relapse. Neither acute GVHD, overall survival, nor disease relapse was statistically signifi cantly associated with CD34, CD3, or CD14 cell doses or the CD14 to CD3 rat io. CD3 and CD14 cell doses and CD14 to CD3 ratios did not correlate with t he tempo of neutrophil and platelet engraftment. However, increasing CD34 c ell numbers were significantly associated with accelerated neutrophil (P = .03) and platelet (P = .01) engraftment. Higher doses of CD34 cells (> 8.0 x 10(6)/kg) were also associated with a significantly increased hazard of c linical extensive chronic GVHD (HR = 2.3, 95% confidence interval [CI] 1.4- 3.7, P = .001), but neither CD3 nor CD14 doses were statistically significa ntly associated with chronic GVHD. It was concluded that CD34 cell dose in G-PBMC grafts appears to affect both the engraftment kinetics and the devel opment of clinical extensive chronic GVHD in HLA-identical sibling recipien ts but without a demonstrable impact on survival, relapse, and acute GVHD. Given the morbidity associated with extensive chronic GVHD, efforts to furt her accelerate engraftment in HLA-matched sibling transplants by increasing CD34 cell number in G-PBMC products may be counterproductive. (Blood. 2001 ;98:3221-3227) (C) 2001 by The American Society of Hematology.