Immunohistochemical study of gastric cancer tissue using monoclonal antibodies.

Mononuclear cells in gastric cancer lesions of 42 patients were immunohistologically classified into functional subpopulations using various antibodies such as OKT3, OKT4, OKT6, OKT8, OKT9, OKT10, OKIal, OKM1, OKM5, OKB7, Leu7, Leu8, Leu11b, DRC1, anti-IL-2 receptor, anti-S-100 protein antibody and anti-lisozyme antibody. Most of these cells, which were T-cells, NK/K cells and IL-2 receptor positive cells in the early stage, were clearly greator in number when compared with the control group, but their numbers decreased as the disease stage progressed. In the histologically poorly differentiated type, there were fewer T-cells (mainly OKT4 positive cells). and in the scirrhous type, fewer NK/K cells were observed. On the other hand, in the higher grade of lymphocyte infiltration around cancer lesions, an increase in the number of NK/K cells and lymphfollicles with DRC1 positive cells was noted. When immunomodulator (OK-432) was locally injected into the tumor endoscopically, cells with IL-2 receptors, NK/K cells, dendritic reticulum cells and anti-S-100 protein antibody positive cells remarkedly increased. This study indicated that the endoscopic injection of immunomodulators into gastric cancer might activate immunologically important cells which have anti-tumor effects. The method should be tried in the clinical field.