Ultraviolet-induced DNA-repair synthesis in lymphocytes from patients with chronic lymphatic leukemia.

Ultraviolet-induced DNA-repair synthesis was studied in peripheral lymphocytes from 10 patients with chronic lymphatic leukemia (CLL). An ultraviolet-dose curve was established for each patient and compared with curves for healthy individuals. The same level of DNA-repair synthesis was recorded in CLL and normal lymphocytes. This contrasts with a report from another laboratory. Evidence is presented of the necessity of inhibiting replicative DNA-synthesis with hydroxyurea in order to adequately estimate the DNA-repair synthesis.