Effects of washing on phytohemagglutinin responsiveness of lymphocytes from irradiated patients.

The peripheral lymphocytes from irradiated patients generally have a reduced capability to respond to phytohemagglutinin (PHA). Whether a relationship exists between PHA-responsiveness and chromosome aberration frequencies was examined by washing the lymphocytes with culture medium. The results indicate that the defect in lymphocyte activation in patients receiving radiation therapy was caused by some reversible changes in the lymphocyte membrane directly associated with radiation exposure rather than by a radiation induced suppressor substance secondarily acting on the lymphocyte membrane.