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 repair was measured in bone marrow cells and peripheral lymphocytes of patients with refractory anemia with excess of blasts (RAEB). Bone marrow cells from RAEB, when exposed to a 2 J/m dose of UV, exhibited 50% lower incorporation of tritiated thymidine than those of control subjects. A similar finding was observed in the peripheral lymphocytes. These data suggest that bone marrow cells and peripheral lymphocytes from RAEB are deficient in repair of UV-induced lesions by DNA. Furthermore, this impaired DNA repair efficiency in RAEB was not related to the presence or absence of a karyotype abnormality.