Lymphocyte responsiveness to phytohemagglutinin (PHA) and serum inhibitory effect in patients with gastric cancer.

The in vitro lymphocyte response to PHA was determined in patients with gastric cancer in various stages prior to the surgical treatment. The lymphocyte responsiveness in the presence of homologous pooled AB serum in patients of stages II, III and IV were markedly reduced as compared with that in healthy controls (stages II, III; p less than 0.05, stage IV; p less than 0.01). Inhibition of normal lymphocyte responsiveness to PHA by serum from patients in stages III and IV were statistically significant only in the advanced stage. It was concluded that the suppression of the immune response in the early stage of gastric cancer was mainly due to the impairment of lymphocyte itself, which advanced with the progress of the stage and was modified by the serum inhibitory effect in advanced stages. In patients with advanced cancer, the higher was the lymphocyte responsiveness to PHA and PWM prior to the initial treatment, the more effective was the immunotherapy. This shows that the indication of the immunotherapy in patients with advanced cancer could be initiated. Furthermore, the correlation between the lymphocyte responsiveness to PHA and the clinical results of immunotherapy was discussed.