Mathematical modeling of precursor hematopoietic stem cell mobilization and apheresis

Abstract

Hematopoietic stem cells (HSC) travel from bone marrow to peripheral blood and vice versa. We believe that this travel process is crucial for the cells to maintain their stem characteristics and for allowing the homogeneous distribution of the cells in the bone marrow. A mathematical model was developed to describe the mechanism proposed, where stem cells leave the bone marrow upon differentiation to the peripheral blood, and subsequently return to the bone marrow. The experimental data used in this work was obtained from the process of apheresis, where stem cells (CD34+) are collected from peripheral blood. Experimental data from 14 healthy volunteers was used to estimate parameters required for the model and determine ranges for all the variables that characterize the apheresis process. The model describes the apheresis process and provides an estimate for the net transport rate of the cell from the bone marrow. This is the initial theoretical step for characterizing the mobilization process and determining the feasibility and conditions required to experimentally test the proposed mechanism, in order to improve the stem cell collection process and provide new insights for HSC ex vivo amplification.