Linear dose response of acrocentric chromosome associations to gamma irradiation in human lymphocytes

Purpose The frequency of acrocentric chromosome associations (ACA) was studied to determine the possible dose-response relationship of gamma irradiation in human lymphocytes. Methods Peripheral blood collected from three healthy donors was irradiated with 0, 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, and 5 Gy of gamma radiation. Chromosomal preparations were made after 48 h of culture as per standard guidelines. The experiment was repeated three times, with a different donor each time. Results The ACA frequency in irradiated lymphocytes increased with radiation dose. The D-G type of association was most prominent and showed a significant dose-dependent increase in frequency. The dose response of ACA frequency to radiation was found to be linear: ACA frequency = 0.2923 (+/- 0.0276) + 0.1846 (+/- 0.0307) x D (correlation coefficient r = 0.9442). As expected, dicentric chromosome (DC) frequencies followed the linear quadratic fit model, with DC frequency = 0.0015 (+/- 0.0013) + 0.0220 (+/- 0.0059) x D + 0.0215 (+/- 0.0018) x D(boolean AND)2 (correlation coefficient r = 0.9982). A correlation curve was prepared for ACA frequency versus DC frequency, resulting in the regression equation y = 1.130x + 0.4051 (R-2 = 0.7408; p = 0.0014). Conclusion Our results showed an increase in ACA frequency in irradiated lymphocytes with an increase in radiation dose; thus, ACA may serve as a candidate cytogenetic biomarker for radiation biodosimetry.

Automated summary

By studying the frequency of acrocentric chromosome associations (ACA) in human lymphocytes exposed to gamma radiation, we found that the frequency of ACA increased with radiation dose. We also observed a correlation between ACA frequency and dicentric chromosome (DC) frequency, indicating that ACA may serve as a potential cytogenetic biomarker for radiation biodosimetry.