Diminished interleukin-2 activity production in cancer patients bearing solid tumors and its relationship with natural killer cells.

Interleukin-2 (IL-2) activity production by stimulated peripheral blood lymphocytes (PBL) from solid tumor bearing cancer patients was lower than in normal subjects. Natural-killer (NK) cell activity in the PBL of cancer patients was very significantly correlated to IL-2 activity production (P less than 0.001). These results might suggest a central role for IL-2 in the immune dysfunctions in cancer patients, and the possible use of IL-2 as an immunological response modifier in these patients.