[Immunohistochemical study of spleens in gastric cancer]

Immunohistochemical study was performed on the spleens of the stomach cancers using various monoclonal antibodies against mononuclear cells. The subjects consisted of 4 cases in stage I, 3 cases in stage II, 9 cases in stage III and 15 cases in stage IV. Five spleens of patients died of cerebrovascular disorders were used as a control. For 6 among these cancer cases, PSK was injected endoscopically into the tumor 10 days before operation. The results showed that: 1) OKT3+, OKT4+ and OKT8+ positive cells decreased in the marginal area of follicles with the progression of the stage of stomach cancer. 2) OKM1 and OKT10 positive cells increased in the marginal area of follicles and the red pulp of spleens which were in the latter stage of the stomach cancer. 3) OKIa1+ and OKB7+ positive cells decreased in the follicles in the later stage. 4) Leu7+, Leu11b+, OKT9+ and IL2 receptor+ cells apparently did not change in spite of the progression of the stage of stomach cancer. 5) OKT6+ positive cells were hardly noted in the spleen. 6) In PSK injected group, OKT4+, OKT8+ and OKB7+ cells tended to increase, while IL2 receptor+ cells and OKM1+ cells were definitely observed to increase. In conclusion, the spleen of the stomach cancer in the advanced stages exhibited the decrease of the T-cell system such as OKT3+, OKT4+ and OKT8+ cells and it is believed that the immune response was lowered through T-cell system as the stage advances. At the same time, the fact of a similar decrease in the B-cell system of OKB7+ seems to suggest a lowered state of antibody productivity. On the other hand, the increase of OKM1+ and OKT10+ cells in the advanced stage is considered to be a state of activation in the reticuloendothelial system. In the PSK injected cases, the increase of OKT4+, OKT8+ and IL2 receptor+ cells was observed. This was suggested that intratumorous injection of PSK was able to enhance the antitumor activity through the spleen by the activation of the T-cell system and reticuloendothelial system.