Early neutrophil engraftment following autologous BMT provides a functional predictor of long-term hematopoietic reconstitution

BACKGROUND: Previous studies have demonstrated that the number of CD34+ progenitor cells in the stem cell graft is highly predictive of the rapidity of short-term hematopoietic engraftment. The aim of this study was to identify factors that predict long-term hematopoietic reconstitution (LHR) following autologous BMT. STUDY DESIGN AND METHODS: To identify predictors of LHR, peripheral blood counts and marrow biopsies were evaluated at 1 year after transplant in 81 patients with B-cell non-Hodgkin's lymphoma (NHL) or chronic lymphocytic leukemia who underwent autologous BMT. Results were correlated with CD34+ cell dose, granulocyte-monocyte colony-forming units (CFU-GM) infused, and time to neutrophil engraftment (TNE). RESULTS: Total MNC dose, CD34+ cell dose, and CFU-GM infused were significantly associated with TNE (p = 0.011, p < 0.0001, and p = 0.078, respectively). Patients with chronic lymphocytic leukemia were more likely to have received a low CD34+ cell dose than patients with B-cell non-Hodgkin's lymphoma (p = 0.01). Among the four principal predictors, only TNE showed consistent significant correlation with WBC, absolute neutrophil, and platelet count at 1 year after transplant. Logistic regression model showed that TNE was a more sensitive predictor of LHR than either CD34+ cell dose or CFU-GM infused. CONCLUSION: TNE is an in vivo functional measure of LHR and is a more sensitive predictor of LHR at 1 year after BMT than either CD34+ cell dose or CFU-GM infused.