PBSC harvests individually optimized by using pre-collection CD34(+) values and on-line flow cytometric analysis of the mononuclear cell enrichment.

Background We have investigated how the amount of blood processed during collection of PBSC affects the yield of CD34 + cells. Methods We first established a method of significantly increasing the enrichment of mononuclear cells (MNC), CD34 + cells and granulocyte^macrophage progenitors (GM-CFU) by on-line flow cytometric (FCM) analysis of the leukocyte populations in the collect line. A total of 166 PBSC collections from 94 patients, were divided into five groups according to the blood volume processed: 15 L. Results When the yield of CD34 cells was compared between these groups, a positive correlation was seen (r=0.97) between the processed blood volume and the yield, expressed as a ratio between total number of CD34 + cells in the harvest and the CD34 + cell concentration in blood. This correlation can be used to estimate the volume that must be processed to exceed a specific target number of CD34 cells. The implications of these results on the need for one, two or more leukapheresis procedures in order to collect a sufficient amount of stem and progenitor cells for a given patient are discussed, in relation to clinical logistics and the benefits for the patients. Discussion PBSC harvests can be improved by individually-adjusted leukapheresis according to on-line FCM analysis and pre-harvest levels of CD34 + cells and the processed blood volume can be used to predict the CD34 + yield.