Early indicators of response to accidental radiation exposure and the relevance for clinical management strategies.
In the development of clinical strategies to manage radiation accident casualties, the medical doctor in charge should be encouraged to use a "decision tree" to establish by a "sequential diagnosis procedure". This should be done within the first few days after exposure to determine whether or not a spontaneous recovery of hemopoietic function can be expected. With the assistance of a computer simulation model it appears possible to relate certain granulocyte response patterns to the extend and quality of damage caused in the hematopoietic stem cell pool. The determination of this damage is of great importance because it quantifies the strain inflicted upon the hemopoietic system by radiation exposure. It must be remembered that some stem cells are intact or are able to repair the damage completely. These stem cells serve as the ultimate source of hemopoietic recovery. The other stem cells that are left with the restricted hematopoietic potential are the source for the so called abortive recovery. On this basis it must be recognized that the day-to-day detailed analysis of documentation of blood cell changes for the first 5-10 days after exposure is of critical importance in order to be able to answer the question whether a spontaneous hemopoietic recovery can be expected or not. If the stem cell pool is sufficiently damaged (less than 6-8 in 10,000 stem cells) then one can expect a particular constellation of blood cells around day 5-7 characterized by severe granulocytopenia, severe lymphopenia and beginning thrombocytopenia. This blood cell response pattern is indicative of an irreversible stem cell damage. In this case, a transplantation of stem cells may well be life saving if done using the criteria developed for the treatment of severe aplastic anemia by bone marrow transplantation including an appropriate conditioning regimen for immune suppression.
Weinsheimer
W
W
Department for Occupational and Social Medicine, University of Ulm.
Szepesi
T
T
Fliedner
T M
TM
D000059:Accidents; D001853:Bone Marrow / Q000528:radiation effects; D003198:Computer Simulation; D003663:Decision Trees; D006098:Granulocytes / Q000528:radiation effects; D006801:Humans; D007958:Leukocyte Count; D008954:Models, Biological; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000097:blood / Q000175:diagnosis / Q000628:therapy*; D013997:Time Factors