DNA repair deficiency in lymphocytes from patients with actinic keratosis.

DNA repair activity was measured in peripheral blood lymphocytes from 18 patients with Actinic Keratosis and 18 age-matched control subjects, by comparing the incorporation of 3H-thymidine into cells after irradiation with ultraviolet light with that into unirradiated cells. The incorporation was followed autoradiographically or by measuring acid insoluble radioactivity in cells labelled in the presence of hydroxyurea. The repair activity in lymphocytes from Actinic keratosis patients was only 47.1 percent (+/- 6.5%) of that in cells from the control subjects.