Effects of PSK on Interleukin‐2 Production by Peripheral Lymphocytes of Patients with Advanced Ovarian Carcinoma during Chemotherapy

The effects of PSK on OKT 4/OKT 8 cell ratio, interleukin‐2 (IL‐2) production and expression of IL‐2 receptor were examined in peripheral blood lymphocytes (PBL) from patients with advanced ovarian cancer during the course of chemotherapy. Preoperative levels of OKT 4/OKT 8 cell ratio and IL‐2 production in PBL from patients with advanced ovarian cancer were significantly lower than those in cases of benign ovarian tumor. However, the expression of IL‐2 receptor did not show any significant difference between ovarian cancer and benign ovarian tumor patients. When a combination chemotherapy of cisplatin, adriamycin and cyclophosphamide was given, the OKT 4/OKT 8 cell ratio was significantly increased with a significant decrease of the absolute number of the OKT 8 cell subset, while the expression of IL‐2 receptor and the absolute number of the OKT 4 cell subset remained unchanged. In contrast, the IL‐2 production was markedly depressed after the first course of chemotherapy. When PSK was combined with combination chemotherapy, the degree of inhibition of IL‐2 production was reduced (though the effect was not statistically significant). If treatment with PSK was initiated after completion of combination chemotherapy, in addition to a significant elevation of OKT 4/OKT 8 cell ratio the depressed IL‐2 production was restored to benign control levels. On the other hand, the expression of IL‐2 receptor remained unchanged even if PSK was given after completion of chemotherapy.