Levels of Circulating DNA in Blood Serum and DNA Damage in Leukocytes of Healthy Donors of Different Genders and Ages

We studied the levels of extracellular nuclear and mitochondrial DNA of blood serum and DNA damage in leukocytes of healthy donors of different sex and age groups. The baseline levels of DNA damage in leukocytes and serum DNA levels were shown to vary greatly among different donors. The baseline level of DNA damage in leukocytes was not associated with the presence of chronic deceases or an occupational health risk for elderly donors. It was found that extracellular DNA concentrations were generally higher in men than in women. There is a tendency towards an increase in the relative mitochondrial DNA copy number determined by ΔCt in women but not in men: the relative mtDNA copy number in elderly individuals varies significantly in both sexes, possibly due to age-related physiological changes. It is necessary to consider the gender and age of patients when using an indicator such as the level of extracellular DNA of blood serum for diagnosis and monitoring.