Physiological Markers for Radiation Illness

Abstract

Radiation illness is defined as the damage to the organ tissues due to the excessive exposure to ionizing radiation. The exposure to radiation interferes with the process of cell division. Markers can be classified into several categories and are measured with a variety of techniques. The most useful markers are those that are easily collected and immediately available, inexpensive, diagnostic and prognostic, and specific for a given disease These markers might be classified as predictive, prognostic, diagnostic, and dosimetric markers as regard their effects on normal tissues. Markers of physiological effects response to radiation: 1) Markers of Cell Death. 2) Markers of Hypoxia. 3) Cytokines and inflammatory mediators [these cytokines: TGF-β1, Interleukins (IL-1, IL-6, IL-10 and IL-8), intracellular adhesion molecule-1(ICAM-1), Pulmonary Surfactant Proteins, Krebs von den Lungen-6 (KL-6), Thrombomodulin, etc] 4)Polymorphonuclear leukocyte (PMN) and CD34+ markers 5). Other protein markers as Amylase, Flt3-ligand, Citrulline, Plasma oxysterol concentrations as physiological markers of MODS. 6) Gene expression and amplification in response to radiation and the status of microarray analysis. Other markers include: 1.Markers leading to radiation-related side effects including those that can be used to identify subjects at greater risk than normal toxicity, before exposure; 2.Markers useful for diagnosis, prognosis, biodosimetry, and therapy; 3.Physiological markers are important available markers for radiation effects on tissues; 4. Cytokines appear to play the role of both causative agent and marker; 5. The evidence has demonstrated a potential value of determining the early response of blood markers to ionizing radiation in predicting latent radiation toxicity, which may be used for planning individualized treatment regimens. The future of research on markers of radiation tolerance is increasingly important due to the growing number of cancer treatment survivors. Although no validated blood markers are currently available for daily practice, further research in this area has become important. Radiation illness is defined as the damage to the organ tissues due to the excessive exposure to ionizing radiation. The exposure to radiation interferes with the process of cell division(1). Radiation illness results from excessive exposure to ionizing radiation when humans (or other animals) are exposed to very large doses of ionizing radiation(2). Radiation exposure can occur as a single large exposure (acute), or a series of small exposure spread over time (chronic) (3). Poteintial markers of radiation illness: Over the past five decades, those interested in markers of radiation effect have focused primarily on tumor response. More recently, however, the view has broadened to include irradiated normal tissues—markers that predict unusual risk of side-effects, prognosticate during the prodromal and therapeutic phases, diagnose a particular toxicity as radiation-related, and, in the case of bioterror, allow for tissue-specific biodosimetry (4). Markers profiles will vary with tissue and time due to the complex nature and protracted course of radiation toxicity. Markers are needed at all stages of