The relationship between clinical stage, natural killer activity and related immunological parameters in adenocarcinoma of the prostate.

Several immunological in vitro tests were performed on peripheral blood mononuclear cells of patients with adenocarcinoma of the prostate, stages A, B, C, D. The cytotoxicity of effector natural killer cells towards K-562 targets decreased with increasing disease spread, while their percentage was not significantly changed. The proportion of CD4 (helper/inducer) cells tended to fall with tumor advance, but the proportion of CD8 (suppressor/cytotoxic) cells remained almost constant. Secretion of interleukin-2 from peripheral blood mononuclear cells was diminished with disease progression. Pretreatment of a patient's lymphocytes with cimetidine (antagonist of H-2-bearing suppressor T cells) or indomethacin (inhibitor of prostaglandin synthesis) enhanced natural killer activity. Our data point to the existence of aberrant immune functions in early stages of carcinoma of the prostate and to aggravation of these immune abnormalities in advanced disease.