RESUMO
Natural killer cytolitic activity, the basis of cancer immunotherapy that uses cytolytic cells, may be impaired in cancer. The aim of this work was to study in vitro the natural killer cytolitic activity and its response to the immunomodulators interleukin-2 interferon and phytohemagglutinin stimulated lymphocyte proliferation in a group of 9 patients with renal cell cancer and 6 with prostatic cancer. The results were compared with those of 20 normal volunteers. Twelve patients were operated and were studied twice 48 h and 14 days after surgery. Natural killer cytolitic activity was significantly lower in renal cell and prostatic cancer patients than controls (3.3 ñ 1.6, 4.9 ñ 2.2 and 20.6 ñ 3.7 per cent of specific lysis respectively). This activity was not modified in cancer patients by interleukin-2 50 Ul/ml or interferon 3000 Ul/ml and did not differ in the two postoperative pèriods. Phytohemagglutinin stimulated lymphocyte proliferation was also lower in cancer patients, compared to controls (stimulation index of 18 ñ 3 and 26.5 ñ 5 respectively). It is concluded that these patients have a low immunological level and this study is the first step towards an immunological characterization of cancer patients that are candidate to adoptive immunotherapy