PHYSIOLOGICAL AND PATHOPHYSIOLOGICAL ASPECTS OF THE IMMUNE-SYSTEM CONTRIBUTING TO A BIOMATHEMATICAL MODEL OF LYMPHOCYTES

The effects of chronic low-dose irradiation on the immune system and t he lymphocytes are largely unknown, The uranium miners in the former G erman Democratic Republic (GDR) mere exposed mainly to a local low-dos e irradiation in the lung by radon and its progeny, but also to some w hole-body gamma irradiation, The local irradiation led to an increased rate of lung cancer and perhaps to some increase in extrapulmonary ne oplasms, But little is known about the effects on the lymphocytes circ ulating and recirculating to the lung, ris a prerequisite for the esta blishment of a biomathematical model to estimate lymphocyte fluxes, an d to assess the radiation effects on the lymphocytic (and stem cell) p opulations passing through the lung, it was necessary to establish the current knowledge with respect to the physiology and pathophysiology of the lymphocytic cell renewal systems, The data concerning lymphopoi esis and lymphocyte kinetics, which are important for the development of this model, are summarized. The distribution of lymphocytes between different compartments including the lung is taken into consideration , as well as the effects of acute and chronic irradiation on the immun e system, The extracorporeal irradiation of the blood (ECIB) may serve as a model of irradiation of blood in the lung, This review shows tha t many data necessary for development of a detailed biomathematical mo del are still missing, especially data concerning details on lymphocyt e production rates of their different subsets and regulatory mechanism s of the lymphocytic system.