Decreased TCGF activity in the culture medium of PHA stimulated peripheral mononuclear cells from patients with metastatic cancer.

Activities of T cell growth factor (TCGF) of conditioned media from PHA stimulated cultures of peripheral mononuclear cells (PHA-MNC-CM) were compared among patients with cancer, patients with non-malignant disease and normal persons. In nine out of 10 cases of cancer with metastasis (including extensive infiltration to surrounding tissues), the activities were much lower than normal persons, whereas in four out of five cases of cancer without metastasis, the activities were almost the same as those of normal persons. The low activities of PHA-MNC-CM from patients with metastatic cancer were not due to the older age of patients, nor did it seem to be attributed to the malnutritional state of patients. When we examined the activity using non-adherent MNC instead of the whole MNC, the activities in patients with metastatic cancer rose up to almost the normal levels. In normal persons the decline of the activities after 3 days of culture were not observed after the removal of adherent cells. Our data indicate that the adherent cells have a suppressive effect on TCGF production in both normal persons and cancer patients, but that the effect may be exaggerated in patients with metastatic cancer.