title: Effect of in vitro x-irradiation on human peripheral blood T and B lymphocytes.
abstract: The effect of in vitro irradiation with increasing in logarythmic progress X-ray doses on lymphocyte viability and on T and B lymphocyte populations was studied in normal adults, patients with myasthenia gravis and in patients undergoing long-term steroid therapy. Decrease in numbers of lymphocytes carrying T or B lymphocyte surface markers was higher than viable cell loss. The decrease showed no linear correlation with X-ray doses applied, which might reflect the existence of radioresistant T and B lymphocytes. A higher so called early radiosensitivity of B lymphocytes was demonstrated. In patients with myasthenia gravis early radioresistance of T lymphocytes was detected. In patients undergoing long-term steroid therapy, an increase in numbers of cells lacking markers of any of lymphocyte populations was found in parallel with a decrease in T lymphocyte number which, in these patients, showed a higher radiosensitivity.
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D009157:Myasthenia Gravis / Q000097:blood; D013256:Steroids / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000528:radiation effects*; D013997:Time Factors; D014965:X-Rays
chemical_list: D013256:Steroids