Defective Ultraviolet-Induced DNA Repair in Bone Marrow Cells and Peripheral Lymphocytes of Patients with Refractory Anemia with Excess of Blasts

The extent of ultraviolet (UV) irradiation-induced DNA repairwas measured in bone marrow cells and peripheral lymphocytesof patients with refractory anemia with excess of blasts (RAEB).Bone marrow cells from RAEB, when exposed to a 2 J/m dose ofUV, exhibited 50% lower incorporation of tritiated thymidinethan those of control subjects. A similar finding was observedin the peripheral lymphocytes. These data suggest that bonemarrow cells and peripheral lymphocytes from RAEB are deficientin repair of UV-induced lesions by DNA. Furthermore, this impairedDNA repair efficiency in RAEB was not related to the presenceor absence of a karyotype abnormality.