The predictive value of an immature information (IMI) in the peripheral blood for determining the optimal time for peripheal blood stem cell collection

초록

Background: Because PBSC harvest by serial daily apheresis procedure is expensive and time consuming, it is crucial to reduce the number of apheresis procedures by determining the optimal time for collection. Recently, the automated hematology analyzer SE-9000(TM)(Japan) has begun to service an immature information (IMI) channel that is capable of identifying immature leukocytes. In this study, we evaluated the preapheresis hematologic parameters and IMI that may predict the PBSC yields. Methods: One hundred seventy six PBSc collections from 68 patients (median age:32 yrs, 46 patients with hematologic malignancy; 22 with solid tumor) were performed using large volume leukapheresis. The G-CSF following chemotherapy of only G-CSF were used to mobilize the PBSC. Results: With the use of linear regression analysis, preapheresis WBC an MNC counts were not correlated significantly with the CD34+ cell yield in harvest. However, the preapheresis CD34+ cells and IMI in peripheral blood correlated well with the number of harvested CD34+ cells (r=0.75, 0.55, respectively). Good correlation was presented between IMI and CD34+ cells in peripheral blood (r=0.83). Conclusions: The number of CD34+ cells and IMI can be a reliable predictor of the CD34+ cell yield in subsequent leukapheresis. In addition, IMI is utilized efficiently with ease and rapidity as compared to the CD34 assay which is both expensive and operator-dependent. Our result confirms the clinical usefulness of SE-9000(TM)'s ability to measure IMI potitive cells in monitoring PBSC mobilization.