Autologous transplantation:: the viable transplanted CD34+ cell dose measured post-thaw does not predict engraftment kinetics better than the total CD34+ cell dose measured pre-freeze in patients that receive more than 2 x 106 CD34+ cells/kg

Background The aim of the study was to investigate whether the number of viable CD34(+) cells in cryopreserved PBPC autografts is a better predictor of engraftment than the total CD34(+) cell number determined before freezing. Methods A total of 119 patients was treated with autotransplantation for various malignant disorders during the period 1996 - 2002. All patients were reinfused with at least 2 x 10(6)/kg total CD34(+) cells analyzed before programmed freezing in 10% DMSO. The total CD34(+) cell number determined before freezing was compared with the number of viable cells determined after cryopreservation for 51 of these patients. The number of viable cells was determined by a flow cytometric analysis including triple staining with anti-CD34, anti-CD45 and the viability marker 7-actinomycin D (7-AAD). Results Simple linear regression analyses showed that both the total transplanted CD34(+) cell dose measured before freezing and the viable CD34(+) cell dose determined after cryopreservation were significantly correlated with neutrophil and platelet engraftment. In a multiple regression model the prediction of engraftment was not improved when the transplanted viable CD34(+) cell dose was included as a variable in addition to the total CD34(+) cell dose measured immediately after collection. Discussion Routine estimation of viable CD34(+) cells after cryopreservation of PBPC autografts is not necessary as long as the total CD34(+) cell dose is determined before freezing and the patients are reinfused with at least 2 x 10(6) cells/kg body weight.