CD34+ cell dose and CD33- subsets: collection and engraftment kinetics in autologous peripheral blood stem cells transplantation

Abstract

BACKGROUND AND OBJECTIVE: We analyzed the factors that affected the number and quality of peripheral blood stem cells (PBSC) collected for transplant in order to establish a minimum threshold for rapid hematopoietic recovery. DESIGN AND METHODS: From January 1995 to November 1996, a consecutive series of 67 patients, with hematologic and solid tumors underwent autologous PBSC transplantation. Collection of PBSC was performed after mobilization with granulocyte-colony stimulating factor (G-CSF) or with chemotherapy (CT) plus G-CSF. We calculated the factors that influenced PBSC collection, the kinetics of granulocyte and platelet recovery and the threshold value of CD34+ cells for a rapid recovery. The data were analyzed by means of multivariate Cox regression model and the receiver operating characteristic (ROC) methodology. RESULTS: Our results showed that mobilization with chemotherapy plus G-CSF was associated with a higher yield of PBSC in comparison with mobilization with G-CSF alone. Disease status, fewer cycles of conventional prior chemotherapy and absence of prior radiation therapy also influenced the yield of PBSC. The number of CD34+ cells, CD34+CD33- cell subsets, the mobilization schedule, and the conditioning regimen correlated significantly with time to hematopoietic recovery. In the multivariate analysis only the CD34+CD33- cell content and the total number of CD34+ were related with rapid neutrophil and platelet recovery, respectively. Use of G-CSF after transplant significantly shortened the neutrophil recovery time only in patients transplanted with suboptimal dose of PBSC. INTERPRETATION AND CONCLUSIONS: These data suggest the utility of quantitation of CD34+ cells subsets to predict quick engraftment.