Natural killer cell activity in patients with prostatic carcinoma and its in vivo boosting with bacillus Calmette-Guérin.

In patients with prostatic carcinoma, natural killer (NK) cell activity was monitored in a chromium release assay. Cells from the human myeloid cell line K 562 and from a human prostatic cancer cell line (PC 3) were used as target cells. Additionally, in vitro stimulation with beta-interferon was done in each sample. NK activity in patients with localized prostatic cancer was increased as compared to age-matched controls. Patients with advanced disease showed reduced levels of NK activity. Furthermore, hormonally treated patients in relapse had significantly lower activity than patients in remission or with stable disease. Hormone therapy was without major influence on NK activity. BCG vaccination as an adjuvant immunotherapy was done in a small group of patients. Baseline NK activity and interferon-stimulated activity were enhanced by BCG in most cases.