Regulation of platelet production: The normal response to perturbation andcyclical platelet disease

An age-structured model for the regulation of platelet production is develo ped, and compared with both normal and pathological platelet production. We consider the role of thrombopoietin (TPO) in this process, how TPO affects the transition between megakaryocytes of various ploidy classes, and their individual contributions to platelet production. After the estimation of t he relevant parameters of the model from both in vivo and in vitro data, we use the model to numerically reproduce the normal human response to a bolu s injection of TPO. We further show that our model reproduces the dynamic c haracteristics of autoimmune cyclical thromobocytopenia if the rate of plat elet destruction in the circulation is elevated to more than twice the norm al value. (C) 2000 Academic Press.