Prediction of engraftment after peripheral blood stem cell transplantation by CD34-positive cells in grafts

total of 91 peripheral blood stem cell collections were performed in 26 children with various malignant tumors and peripheral blood stem cell transplantations (PBSCT) were performed in 15 of the children. There was a positive correlation between logarithm of total CD34⁺ cells/kg and logarithm of colony-forming unit-granulocyte macrophage (CFU-GM)/kg (r = 0.86). The time elapsed until the white blood cells (WBC) exceeded 1000/μL was related to both CFU-GM (r = 0.67) and CD34⁺ cell count (r = 0.60). The number of days elapsed until platelet count exceeded 5 times 10⁴/μL was not related to the logarithm of CFU-GM count/10⁵ per kg transfused (r = 0.47), but was related to the logarithm of CD34⁺ cell counts/10⁶ per kg transfused (r = 0.73). The number of days elapsed until the reticulocytes exceeded 5 times 10⁴/μL was not related to the logarithm of CFU-GM count/10⁵ per kg (r = 0.52), but was related to the logarithm of CD34⁺ cell counts/10⁶ per kg transfused (r = 0.91). Although CD34⁺ cell counts correlated with the number of CFU-GM, bone marrow regeneration rates in three lineages were predicted more accurately by the number of CD34⁺ cells transfused than by the number of CFU-GM. These results suggest that measurement of the CD34⁺ cell count may be useful in predicting bone marrow regeneration rate after PBSCT.