Evaluating Gamma-H۲AX Expression as a Biomarker of DNA Damage after X-ray in Angiography Patients

Objective: Coronary heart disease (CHD) is one of the most common diseases. Coronary angiography (CAG) is an important apparatus used to diagnose and treat this disease. Since angiography is performed through exposure to ionizing radiation, it can cause harmful effects induced by double-stranded breaks in DNA which is potentially life-threatening damage. The aim of the present study is to investigate phosphorylation of Histone H۲AX in the location of double-stranded breaks in peripheral blood lymphocytes as an indication of biological effects of radiation on angiography. Materials and Methods: This method is based on the phosphorylation measurement of Histone (gamma-H۲AX or γ-H۲AX) levels on serine ۱۳۹ after the formation of DNA double-strand break. ۵ cc of blood samples from ۲۴ patients undergoing angiography were taken pre- and post-radiation. Blood lymphocytes were extracted, fixed and stained with specific γ-H۲AX antibodies. Finally, the percentage of phosphorylation of Histone H۲AX as an indicator of double-strand break was measured by a cytometry technique. Results: An increase was observed in all patients’ percentage of phosphorylated Histone H۲AX (double-stranded breaks DNA) after radiation (۲۰.۱۵ ± ۱۴.۱۸) compared to pre-exposure time (۱.۵۲ ± ۰.۳۴). Also, the mean of DNA double-strand break is shown in a linear correlation with DAP. Discussion: Although induction of DNA double-strand breaks was associated with the radiation dose in patients, the effect of individual factors such as radio-sensitivity and regenerative capacity should not be ignored. In the future, if we are able to measure DNA damage response in every angiography patient, we will use it as a biomarker for the patient dose; this will promote public health. Conclusion: Using flow cytometers readings done automatically is possible to detect γ-H۲AX in the number of blood cells, therefore, the use of this technique could play a significant role in monitoring patients.