Hisao Sako

Effect of fetal thymic extract on maturation of precursor lymphocytes from cancer patients with various stages

Abstract Thymus humoral factor seems to have an ability of differentiating the precursor T cells (PTC) into cells bearing T-cell (thymus-dependent lymphocyte) characteristics. Human fetal thymic extract (hFTE) was examined for in vitro effect on the concanavalin A (Con A) responsiveness of peripheral blood lymphocytes in 28 patients with uterine cervical cancer and 9 healthy volunteers. The result was expressed as percentage increase of Con A response of the hFTE-treated group to that of the nontreated group. The effect of hFTE was found to be pronounced in patients in Stages 0 and I, in spite of the small difference in T-cell count in unit volume of peripheral blood. Meanwhile, the effect of hFTE was no longer observed in patients with advanced cancer (Stages III and IV). The present study has suggested that some of PTC, which are prevented from differentiating into mature T cells in vivo due to presumably depressed thymic hormone production, accumulates in peripheral blood of patients with early cancer. And it was also suggested that decrease of both PTC and T-cell count in patients with advanced cancer is due to general immunodeficiency.

IMMUNOSUPPRESSIVE EFFECT OF SERUM IN PATIENTS WITH OVARIAN CARCINOMA

Cell-mediated immune response was measured in 23 patients with ovarian cystadenocarcinoma, 38 patients with benign ovarian tumor, and 44 healthy volunteers. The method used two indexes: the lymphocyte response per unit volume of peripheral blood to phytohemaggluttnin (PHA) and the immunosuppressive effect of serum on the response of normal lymphocytes to PHA stimulation. The lymphocyte response per 50 μl peripheral blood did not differ significantly between patients with ovarian cancer and healthy volunteers. The serum effect, in contrast, differed significantly between malignant and benign ovarian tumors, and was found to increase significantly even when the cancer masses were as small as about 5 X 5 X 5 cm in size, ie, in FIGO Stage 1. It is our belief that the measurement of the serum effect in patients with any ovarian tumor enables the early detection of ovarian cancer.