Immunomodulation in vitro. The predictive value of in vitro testing of lung cancer patients' lymphocyte responsiveness to stimulation by Thymex L. A preliminary report.

Eleven lung cancer patients were selected for combined radio and immunotherapy with a thymic agent-Thymex L. The selection criteria included the pre-therapy testing of patients' immunocompetence and the responsiveness of their lymphocytes to the in vitro addition of Thymex L: only patients with a significant degree of immunodepression, whose depressed cellular immunity parameters (the number of total and active T cells and their mitogen-induced lymphoproliferative response) were significantly increased upon this agent's action in vitro, entered the study. The results of the pre-therapy in vitro stimulation correlated with those obtained after completion of radioimmunotherapy: the administration of Thymex L along with radiotherapy seances prevented iatrogenic deterioration of initial depression of general immunocompetence and enabled to overcome it to a certain degree. This indicates that pre-therapy in vitro testing has a true predictive value. However, the initial immune disturbances were not normalized by immunotherapy; the post-therapy testing of the patients' lymphocytes to the addition of Thymex L in vitro showed that these cells possessed a residual potential to respond by a significant increase of the active T cell number and proliferative capacity, suggesting that immunotherapy could be prolonged in order to potentiate cellular immunity in immunodepressed lung cancer patients.