The Comparison of the Autologous Peripheral Blood Stem Cell Mobilization and Collection in Young and Elderly Patients
Authors: Birekul Ayse , Unal Ali , Unal Cagri mehmet , Esra Yildizhan , Sivgin Serdar , Esra Turak , Kaynar Leylagul , Eser Bulent , Cetin Mustafa , Ferhanoglu A. Burhan 
Published: October 2019

Abstract
Introduction:
Adequate hematopoietic stem cell mobilization and collection is essential for patients who are a candidate for autologous stem cell transplantation. In this study, we compared mobilization success rates, the amount of collected stem cells and the factors that could affect the procedure for patients younger and older than 60 years old.
Materials (or patients) and methods:
For this study, 112 patients who admitted to Erciyes University BMT Center for autologous stem cell transplantation were enrolled. Thirty-three of them (36%) were under 60 years called young group and 76 of them (%64) over 60 years called elderly group.Among the participants, 73 of them were multiple myeloma, 23 of them Non-Hodgkin's lymphoma, 17 of them Hodgkin's lymphoma. Between the groups we compared the amount of pre-apheresis white blood cell (WBC), platelets, peripheral CD34+ cells, value of collected CD34+ cells and mononuclear cells, mobilization failure and success rates and number of apheresis sessions.
Results:
The median values of pre-apheresis peripheral CD34+ cells were 8,72 /µl and platelets were 86 ×109/L in the young group; CD34+ cells were 8,95/µl and platelets were 86,5 ×109/L in the elderly group (p=0,918, p=0,899). The median values of collected CD34+ cells were 7,61×106/kg (2,52-46,62) and 7,60×106/kg (2,87-25,50) in under and over 60 years, respectively (p=0,800). Also the median values of total collected mononuclear cells (MNC) were 1,41×107/kg and 1,4 ×107/kg in young and elderly group (p=0,607). It was found as 1,89 days in the elderly group and 1,7 days in the young group when we compared their apheresis sessions (p=0,786). There was no statistical significance between two groups; despite the mobilization failure rates were 18 % and 6 % in patients older and younger than 60 years (p=0,087).
On the other hand, the number of multiple myeloma in the patients with applied autologous stem cell mobilization was higher in elderly patients than young ones (p=0,004) and we also demonstrated that the failure of mobilization were lower in patients with multiple myeloma than lymphoma patients (p=0,003). There was no significant difference between the amounts of pre-apheresis WBC, platelets and peripheral CD34+ cells in mobilization failure group and success group.Table.Total<60years>60yearsP valueNumber of patients (%)11237(33)75(67)AgeMean4165Pre-apheresisWBC (median)8.958.720.918PLT (median)8686.50,899CD34+ Cell (µl)8.728,950,918CollectedCD34+ Cell (×106/kg)7,617,600,800MNC (×107/kg)1,411,400,607Apheresis sessions (day)1,71.890,607Mobilization failure (%)2(6)13(18)0,087
Discussion:
We demonstrated that the amount of pre-apheresis peripheral or collected CD34+ cells and numbers of apheresis sessions are not significantly different in comparison of the young and elderly patients who are planned autologous stem cells transplantation. Mobilization failure rate was higher in lymphoma patients than myeloma patients. It was also found that mobilization failure rates were higher in elderly patients than young patients.

Disclosures
No relevant conflicts of interest to declare.