Reliability of a Fully Automated Interpretation of γ -H2AX Foci in Lymphocytes of Moderately Trained Subjects under Resting Conditions

Background. analysis of γ-h2ax foci is a promising approach to evaluate exercise-induced dna damage. however,baseline levels and day-to-day variability of γ-h2ax foci have not been investigated in healthy subjects at rest. methods. blood was taken from eight moderately trained healthy males (29 ± 3 yrs,1.84 ± 0.03 m,and 85 ± 6 kg) at two separate days (m1/m2) after 24-hour exercise cessation. number of γ-h2ax foci per 100 lymphocytes (n),number of foci per affected lymphocyte (nal),percentage of affected lymphocytes (pal),and diameter (d) of γ-h2ax foci were analyzed (mean ± sd). differences between m1 and m2 were analyzed using paired t-tests (0.05). day-to-day variability was evaluated by calculating the coefficients of variation (cv%),bias,and limits of agreement (loa). results. there were no statistically significant differences between m1 (n: 7.6 ± 4.4,nal: 1.2 ± 0.2,pal: 5.9 ± 2.6%,and d: 0.63 ± 0.07) and m2 (n: 8.4 ± 4.6,nal: 1.3 ± 0.1,pal: 6.9 ± 4.2%,and d: 0.66 ± 0.06). cv was calculated to be 98.5% (n),88.9% (pal),11.3% (nal),and 8.0% (d). bias (loa) was 0.75 (-15.2/13.7),-0.02 (-0.36/0.33),-1.0 (-11.9/9.9),and -0.04 (-0.16/0.09),respectively. conclusions. background level in healthy subjects is approximately 0.07 to 0.09 γ-h2ax foci/cell. nal and d are reliable measures. © 2014 juliane heydenreich et al.