Reduction of arthritic symptoms by low dose radiation therapy (LD-RT) is associated with an anti-inflammatory phenotype

Purpose: The aim of this paper was to provide an integrative mechanistic appraisal to account for consistent observations of protective effects of ionizing radiation on the occurrence/ progression of arthritis in multiple animal models. Materials and methods: A critical analysis of the biomedical literature was undertaken to assess mechanisms by which low doses of ionizing radiation prevent and/or reduce the occurrence of experimental-induced arthritis in animal models. Results: Detailed mechanistic-related research indicates that low doses of ionizing radiation induce a highly integrated multiple pathway process that results in the formation of a generalized anti-inflammatory phenotype which can both prevent the occurrence of arthritic changes and/or reverse such effects. Conclusions: The manifestation of the anti-inflammatory features occurred within the context of highly consistent hormetic (i.e., biphasic dose) responses across studies, biological models and mechanisms. The reduction of multiple bioindicators of experimentally-induced arthritis by exposure to low doses of ionizing radiation was associated with the occurrence of a generalized anti-inflammatory phenotype. (authors)