Assessment of the in vitro radiosensitivity of human peripheral blood lymphocytes.

Abstract

The proliferative capacity of sensitive lymphocyte progenitor cells from 31 clinically normal adults was evaluated following in vitro X irradiation at 0-400 R. Radiation effects were studied using both whole blood and density gradient-separated mononuclear cells in the lymphocyte stimulation test (LST) and colony formation assay with six different mitogens/antigens. The sensitivities of the different methods are compared. Generally, assays using whole blood were capable of detecting radiation effects at lower dose levels than assays using gradient-separated cells. The colony formation assay was consistently more radiosensitive than the LST within mitogen/antigen groups. Dose-response curves were determined for the different test groups. Survival curves based upon the LST were characterized by a typical dose-response curve with a shoulder at low dose levels, followed by a single-exponential decrease. The number of colonies relative to dose generally followed a two-exponential curve that lacked a shoulder a...