Significance of the Peripheral Blood CD34+ Cell Count by Stem-Kit in Peripheral Blood Stem Cell Collection

Kim, Kwang Jin; Cho, Duck; Kee, Seung Jung; Shin, Jong Hee; Suh, Soon Pal; Ryang, Dong Wook

Abstract

BACKGROUND: Peripheral blood stem cell transplantation (PBSCT) has been widely used as a substi-tute of bone marrow transplantation for the treatment of various solid tumors or hematologic malig-nancies. The success of PBSCT is correlated with peripheral blood CD34+ cell count per kilogram of the recipient body weight. Standardization of flow cytometric CD34+ cell enumeration was improved by the modified International Society of Hematotherapy and Gene Engineering (ISHAGE) protocol. The purpose of this study was to evaluate the peripheral parameters (WBCs, mononuclear cells, the CD 34+ cells) that may predict the total CD34+ cell count in the harvest product, using the Stem-Kit (Beck-man Coulter Inc., Fullerton, CA, USA).
METHODS
The study tested 88 PBSC harvests and peripheral blood (PB) on the day before collection from 26 patients. The CD34+ cells were analyzed using the Stem-Kit. The WBC and MNC count were measured by Coulter STKS (Beckman Coulter Inc.). The correlation and regression analysis between peripheral parameters (WBCs, MNCs, CD34+ cells) and the total CD34+ cell count in the harvest product were performed.
RESULTS
The CD34+ cell count per weight (kg) of 88 PBSC harvests was 1.59 +/- 2.61 (0.01 -17.35). The mean number of WBC, MNC, and CD34+ cell in PB prior to harvest were 10.57 +/- 8.36 (1.50 - 32.50) X 10(3)/micro L, 1.85 +/- 1.28 (0.39- 7.43) X 10(3)/micro L, and 17.21 +/- 33.19 (0.12-239.19)/micro L, respectively. With the CD34+ cells numbering under 3/micro L in peripheral blood (PB), we could not harvest more than 0.5 X 10(6) /kg PBSC. With the cells numbering 3-6/micro L (59%) and 10- 20/micro L (89%), however, we could harvest more than 0.5 X 10(6) /kg and 1.0 X 10(6) /kg, respectively. More than 2.0 X 10(6)/kg of PBSC was collected with 10-20/micro L (31%). The peripheral blood CD34+ cell count prior to harvest significantly correlated with the total CD34+ cell count in the harvest product (r=0.97, P<0.05).
CONCLUSIONS
Peripheral blood CD34+ cell enumeration using the Stem-Kit was an efficient predictor of when to harvest peripheral blood stem cells after mobilization therapy. We could not collected the CD34+ cell in harvest product of more than 0.5 X 10(6)/kg if the peripheral blood CD34+ cell count was less than 3/micro L.