Clinical significance of CD34(+) cell dose in long-term engraftment following autologous peripheral blood stem cell transplantation

The number of CD34(+) cells has been described as the best parameter for pr edicting the quality of engraftment in peripheral blood progenitor cell (PB PC) transplantation in the early post-transplant period. In this study we h ave determined the optimal number of CD34(+) cells in order to maintain eng raftment in the long term in a series of 100 patients receiving autologous PBPC transplantation. Based on our previous experience on the speed of earl y hematopoietic recovery, four subgroups of patients were established: pati ents infused less than 0.75 x 10(6)/kg CD34(+) (n = 9), 0.75 to 1.25 (n = 2 4), 1.25 to 2.0 (n = 37) and more than 2.0 (n = 30), These groups were desi gnated as low, intermediate-low, intermediate-high and high CD34 groups, re spectively. Transitory loss of neutrophil engraftment was observed in 67%, 30%, 16% and 6% of patients in the four mentioned CD34 groups respectively, with statistically significant differences between the different groups. S ignificant differences were also observed between the low CD34 group and th e rest of the groups as regards platelet and red blood cell transfusion req uirements, fever episodes, days of hospitalization and antibiotic requireme nts throughout the first year. Our results show that the dose of CD34(+) ce lls influences engraftment also in the late post-transplant period, and cor relates with transfusion and antibiotic requirements, fever episodes and da ys of hospitalization during the first year posttransplant.