[Reversible and irreversible damage to hematopoiesis following unexpected whole body irradiation: markers in peripheral blood].

During the past decade worldwide experience concerning radiation accidents demonstrated that the medical diagnosis and therapy of radiation victims has to be reconsidered. This paper describes and analyzes the clinical relevance of one of the most simple diagnostic methods, namely daily monitoring of the characteristic blood cell changes. On the basis of these methods the physician is in the position to decide at an early stage-independently of the physical dose-whether reversible or irreversible damage of the hemopoiesis is present. This is of great importance because the expected clinical development and, thus, the therapy and prognosis are different. The different behaviour of the blood cells depends on their life span, cell kinetics, radiation sensitivity and pathophysiology. Reversible damage (category I-IV) can be recognized at the latest on the 5th-6th day after radiation exposure and, according to the degree, may require supportive therapy. Irreversible damage which can probably be repaired by stem cell transfusion (category V) can also be determined on the 5th to the 6th day after radiation exposure. Irreversible damage without any chance of survival (category VI) can already be diagnosed 24 hours after the radiation event. Reversible and irreversible damage to hemopoiesis with the typical blood cell changes is presented with reference to some patients exposed to ionizing radiation in the Marshall Islands 1954, in Oak Ridge 1958, in Chernobyl 1986, in Los Alamos II 1946 just as III 1958, and in Wood River Junction 1964.