Predictive factors for long-term engraftment of autologous blood stem cells

Data from 170 consecutive patients aged 19-66 years (median age 46 years) who underwent unmanipulated autologous blood stem cell transplant (ASCT) were analyzed to determine if total CD34⁺ cells/kg infused, CD34⁺ subsets (CD34⁺41⁺, CD34⁺90⁺, CD34⁺33^-, CD34⁺38-D, CD34⁺38^-DR^-), peripheral blood CD34⁺ cell (PBCD34⁺) count on first apheresis day, or various clinical factors were associated with low blood counts 6 months post ASCT. Thirty-four patients were excluded from analysis either because of death (n = 17) or reinduction chemotherapy prior to 6 months post ASCT (n = 13), or because of lack of follow-up data (n =4). Of the remaining 136 patients, 46% had low WBC (<4 × 10⁹/I), 41% low platelets (<150 × 10⁹/I), and 34% low hemoglobin (<120 g/l) at a median of 6 months following ASCT. By Spearman's rank correlation, both the total CD34⁺ cell dose/kg and the PBCD34⁺ count correlated with 6 month blood counts better than any subset of CD34⁺ cells or any clinical factor. The PBCD34⁺ count was overall a stronger predictor of 6 month blood counts than was the total CD34⁺ cells/kg infused. Both factors retained their significance in multivariate analysis, controlling for clinical factors. In conclusion, subsets of CD34⁺ cells and clinical factors are inferior to the total CD34⁺ cell dose/kg and PBCD34⁺ count in predicting 6 month blood counts following ASCT.