Incidence, Clinical Characteristics and Risk Factors for Poor Mobilization of Hematopoietic Stem Cells in a Colombian Bone Marrow Transplantation Unit: A Retrospective Cohort Study
Authors: Cuervo-Sierra Jorge , Velasquez Quintero German Andres , Tobon Tobon Luz Maridier , giraldo Gomez deisy Johana , marin Montoya jurany Andrea , Castro Quintero Luisa Fernanda , Mesa Giraldo Maira Alejandra , jaramillo Alvarez juan Felipe , Rodriguez Rojas Hector Alexander , Flores-Jimenez Juan Antonio 
Published: December 2023

Background: mobilized peripheral hematopoietic stem cells (PHSC) are the main cell source for autologous bone marrow transplantation. Failure to mobilize an appropriate number of PHSC can jeopardize autologous bone marrow transplantation procedure.

Objective: our aim was to describe the clinical and demographics characteristics, the incidence of mobilization failure and the prevalence of risks factors for poor mobilization in patients in whom PHSC mobilization were attempted for autologous bone marrow transplantation between January 1st 2017 and 31 December 2022. A univariate and multivariate analysis (binary logistic regression) were done to determinate the association between risk factors and mobilization failure.

Results: 129 patients were included , the patients median age was 54 years. Indications for autologous bone marrow transplantation were multiple myeloma in 50,4 %, lymphoma in 46,5 % and systemic sclerosis in 2,3 % of patients respectively. Mobilization was attempted with Filgrastim in 71,1 %, Filgrastim plus Plerixafor in 26,6 % and chemotherapy (Cyclophosphamide) plus Filgrastim in 2,3 % of patients respectively. Mobilization failure occurred in 9,3 % of patients (12 patients) occurring in 11 % of patients who received Filgrastim, in 5,6 % who received Filgrastim plus Plerixafor and in none of patients who received chemotherapy plus Filgrastim. No difference in mobilization failure was found between patients who received Filgrastim monotherapy versus those who received Filgrastim plus Plerixafor ( χ 2 p=0,388, relative risk: 1,8, confidence interval 95% 0,43 - 8,1). Patients who received Filgrastim plus Plerixafor had been treated more frequently (four of more cycles of Lenalidomide) compared with patients who received Filgrastim alone (63,3 % versus 18,7 %, χ 2 p &lt; 0,001, RR=4,01, CI 95 %; 2,32-6,87).The median age of patients was superior in patients who received Filgrastim plus Plerixafor compared with those who received Filgrastim (58 vs 51 years, U Mann Whitney p = 0,02). The median number of treatment lines tended to be superior in patients receiving Filgrastim plus Plerixafor compared to those receiving Filgrastim (2 lines versus 1 line of therapy, U Mann Withney p= 0,054).

Patients who had been treated with intensive chemotherapy regimens like DHAP, ESHAP or Hyper CVAD (p=0,004, RR: 4,3, CI 1,5-12,3)) and patients older than 60 years (p=0,018, RR: 3,4 (1,2-9,85)) were significant more prone to mobilization failure in bivariate and multivariate analysis.

Conclusion: mobilization failure occurred in 9,3 % of patients , Filgrastim monotherapy was more frequently used, no difference in mobilization failure was found between those who received Filgrastim versus Filgrastim plus Plerixafor, history of treatment with more than 4 cycles of lenalidomide and older age were more frequently in patients who received Filgrastim plus Plerixafor. History of a treatment intensive chemotherapy regimen and being older than 60 years were consistently associated with mobilization failure in univariate and multivariate analysis.