Ex vivo hematopoiesis is increasingly used for clinical applications.
Models of ex vivo hematopoiesis are required to better understand the
complex dynamics and to optimize hematopoietic culture processes. A ge
neral mathematical modeling framework is developed which uses traditio
nal chemical engineering metaphors to describe the complex hematopoiet
ic dynamics. Tanks and tubular reactors are used to describe the (pseu
do-) stochastic and deterministic elements of hematopoiesis, respectiv
ely. Cells at any point in the differentiation process can belong to e
ither an immobilized, inert phase (quiescent cells) or a mobile, activ
e phase (cycling cells). The model describes five processes: (1) flow
(differentiation), (2) autocatalytic formation (growth),(3) degradatio
n (death), (4) phase transition from immobilized to mobile phase (quie
scent to cycling transition), and (5) phase transition from mobile to
immobilized phase (cycling to quiescent transition). The modeling fram
ework is illustrated with an example concerning the effect of TGF-beta
1 on erythropoiesis. (C) 1998 Published by Elsevier Science Ltd. All
rights reserved.