Radiation-induced immune changes in patients with cancer of the cervix.

Immunological methods were used to estimate the therapeutic effect of irradiation and its influence on the immune capacity of patients with cervical cancer. Patients were examined during and following radiotherapy by means of lymphocyte counts, lymphocytic response to phytohaemagglutinin (PHA), and the depressive effect of their sera on the response of normal lymphocytes PHA stimulation. Lymphocyte counts and lymphocyte responses during radiotherapy were depressed to 20 to 50 per cent and 10 to 33 per cent respectively of the values found before treatment. Lymphopenia and depressed T-cell function persisted for years in many patients. The highest values for both lymphocyte counts and reactivities were found in those patients who had unexpectedly good responses to radiotherapy. The immunodepressive effect of patients' sera on normal lymphocyte reactivity decreased and disappeared during therapy and was not present in previously treated patients showing a good prognosis, whereas it showed no change or even increased during therapy in patients with a poor prognosis. The results suggest that not only does immune capacity influence the effect of radiation and the prognosis of the patient, but also that study of the serum-depressive effect could give important information about both the dosage and therapeutic effects of irradiation.