BACKGROUND: In children, it is very important to decide the optimum time to collect the peripheral blood stem cell (PBSC). So, we analyzed several predictive parameters for the yield of PBSC mobilization. METHODS: We analyzed data from 19 patients who
underwent 31 stem cell mobilization episodes and 44 leukapheresis procedures, retrospectively. In this study, CD34+ cells, total white blood cells (WBC), and monocyte counts in peripheral blood (PB) on the harvest day were used for analyses. Increment
of WBC and monocyte count from nadir to harvest day, and [increment of WBC count from nadir to harvest day (deltaWBC)]/[duration from nadir to harvest day (deltaT)], [increment of monocyte count from nadir to harvest day (delta MONO)]/[deltaT] were also
analyzed as predictive parameters for the yield of progenitor cell mobilization. RESULTS: Linear regression analysis revealed a strong correlation between CD34+ cell value in PB on the harvest day and the number of CD34+ cells collected (R=0.72,
P=0.001). WBC counts in PB on the harvest day, and increment of WBC count did not correlate with collected CD34+ cells. The yield of PBSC mobilization showed significant correlation with monocyte counts on the harvest day (R=0.314, P=0.038), deltaMONO
(R=0.302, P=0.046), deltaWBC/deltaT (R=0.417, P=0.005) and deltaMONO/deltaT (R=0.342, P=0.023). CONCLUSION: results suggested that the PBSC yield in pediatric patients could be predicted from the measurement of circulating CD34+ cell concentration on
the day of collection, which was consistent with previous data. In this study, we found other several predictive parameters for the yield of peripheral blood stem cell mobilization. Measurement of pre-apheresis peripheral blood CD34+ cell, monocyte
counts, the increment of monocyte counts, deltaWBC/deltaT, and deltaMONO/deltaT might be particularly useful in determining the optimum time to start PBSC collection in pediatric patients.