Technical Report No. 8-92
Dose survival of G0 lymphocytes irradiated in vitro: A test for a possible population bias in the cohort of atomic-bomb survivors exposed to high doses
Nakamura N, Sposto R, Akiyama MEditor’s note: A publication based on this report was published in Radiat Res 134:316-22, 1993.
Summary
An in-vitro colony assay was employed for X-ray dose-survival studies of peripheral-blood lymphocytes from 117 Adult Health Study participants with Dosimetry System 1986 doses <0.005 Gy and from 84 participants with doses of greater than or equal to 1.5 Gy. The mean (coefficient of variation [CV]) D10 values (the X-ray dose required to kill 90% of cells) for these two groups were 3.40 Gy (7.5%) and 3.34 Gy (7.8%), respectively. No statistically significant differences in their distributions were detected. In addition, neither sex nor age affected the in-vitro radiosensitivity of lymphocytes for either group or for all subjects combined. Therefore it was concluded that, as far as the G0-lymphocyte colony assay is concerned, there is no evidence for preferential loss of individuals with higher cellular radiosensitivity among the high-dose atomic bomb survivors. However, it should be noted that the interindividual variations in cellular radiosensitivity were not large compared with the experimental variations. Consequently, the above-mentioned results should be considered due to the small heterogeneity of lymphocyte radiosensitivity among the survivors.
An in-vitro colony assay was employed for X-ray dose-survival studies of peripheral-blood lymphocytes from 117 Adult Health Study participants with Dosimetry System 1986 doses <0.005 Gy and from 84 participants with doses of greater than or equal to 1.5 Gy. The mean (coefficient of variation [CV]) D10 values (the X-ray dose required to kill 90% of cells) for these two groups were 3.40 Gy (7.5%) and 3.34 Gy (7.8%), respectively. No statistically significant differences in their distributions were detected. In addition, neither sex nor age affected the in-vitro radiosensitivity of lymphocytes for either group or for all subjects combined. Therefore it was concluded that, as far as the G0-lymphocyte colony assay is concerned, there is no evidence for preferential loss of individuals with higher cellular radiosensitivity among the high-dose atomic bomb survivors. However, it should be noted that the interindividual variations in cellular radiosensitivity were not large compared with the experimental variations. Consequently, the above-mentioned results should be considered due to the small heterogeneity of lymphocyte radiosensitivity among the survivors.