[A clinical study of immunological status in patients with gastric cancer: with special reference to T-cell subsets, interleukin-2 in the lymphocytes of peripheral blood].

Peripheral blood lymphocytes of 63 patients with gastric cancer were studied by using different monoclonal antibodies and flow cytometry. Used monoclonal antibodies were OKT3 (total T cell), OKT4 (helper/inducer), OKT8 (suppressor/cytotoxic), Leu 7 and Leu 11 (NK/K cell). Interleukin-2 was measured by tritium-labelled thymidine CTLL assay on the supernatant of peripheral blood lymphocytes after 24 hours stimulation with phytohemagglutinin. Interleukin-2 receptor was also studied by using monoclonal antibody (for Tac antigen) and flow cytometry. The results were as follows: among peripheral blood lymphocytes; 1. the number of OKT3, OKT4 cells and the percentage of OKT4 cells decreased significantly with more advanced stage of cancer. 2. production of interleukin-2 also decreased with the progression of the cancer. 3. decreases in the OKT4/OKT8 ratio were found with cancer progression. 4. the percentage and the number of OKT8 cells increased. 5. the percentage and the number of Leu 11 cells and the number of Leu 7 cells were increased significantly in the stage III (moderately advanced cancer). These results suggested that the activated helper T cells decreased, the induction capability of cytotoxic T cells decreased and the suppressor T cells increased with the progression of cancer. Quantitative and qualitative change in T-cell subsets in advanced stage may be one factor responsible for immunosuppression.