Intravesical BCG therapy in bladder carcinoma. Effect on cytotoxicity, IL-2 production and phenotype of peripheral blood mononuclear cells.

The purpose of the study was to examine the effects of intravesical BCG treatment on the cytotoxicity, interleukin-2 (IL-2) production and distribution of the subsets of peripheral blood mononuclear cells (PBMC) in patients with carcinoma in situ of the bladder. Treatments were made in 6 patients during a conventional BCG treatment schedule. Four patients showed a complete response, one a partial response and one had a progressive disease after BCG treatment. Intravesical BCG did not induce significant changes in the cytotoxicity of PBMC. The distribution of NK-cells and T-cells also remained unchanged and so did the lectin induced production of IL-2. The results suggest that the effects of intravesical BCG on the immune system should be studied in lymphocytes isolated from the bladder.