Persistent subclinical inflammation among A-bomb survivors

Abstract

Purpose : To investigate the associations between inflammation tests and radiation dose in A-bomb survivors. Subjects and methods : Subjects were A-bomb survivors who underwent inflammation tests of leukocyte counts, neutrophil counts, erythrocyte sedimentation rate, corrected erythrocyte sedimentation rate, α -1 globulin, α -2 globulin and sialic acid between 1988 and 1992. Associations with radiation dose (DS86) were analyzed by regression analysis and heterogeneity among inflammatory diseases, anaemia at examination, or history of cancer was also tested. Results : The associations with radiation dose were statistically significant for leukocyte counts (71.0mm -3 Gy -1, p =0.015), erythrocyte sedimentation rate (1.58mm h -1 Gy -1, p =0.0001), corrected erythrocyte sedimentation rate (1.14 mm h -1 Gy -1, p =0.0001), α -1 globulin (0.0057 g dl -1 Gy -1, p =0.0001), α -2 globulin (0.0128 g dl -1 Gy -1, p =0.0001), and sialic acid (1.2711 mg dl -1 Gy -1, p =0.0001) but not for neutrophil counts (29.9mm -3 Gy -1, p =0.17). Heterogeneity was not statistically significant. Among inflammatory diseases, associations were the strongest for chronic thyroiditis and chronic liver diseases. Conclusions : This study suggests statistically significant association between inflammation in A-bomb survivors and radiation dose of during 1988-1992. The association might contribute, as an epigenetic and/or bystander effect, to development of several radiation-induced disorders.