Serum levels of interleukin-2 in cancer patients: preliminary considerations.

In order to investigate the production of interleukin-2 (IL-2) in human neoplasms, we determined IL-2 and soluble IL-2 receptors (sIL-2R) in serum from 18 patients with lymphoma and 28 patients with solid tumors, with (15 cases) or without (13 cases) metastases. As controls, 58 healthy subjects were evaluated. Low levels of IL-2 were not observed in patients with lymphoma or limited solid tumor but abnormally low concentrations of IL-2 were seen in 4/15 metastatic solid tumors, associated with abnormally high values of sIL-2R. This preliminary study confirms in vivo the reduced IL-2 production in metastatic solid neoplasms, previously documented in vitro.