Systemic immune response after intravesical instillation of bacille Calmette-Guerin rin (BCG) for superficial bladder cancer

The mechanism of anti-tumour activity by BCG is not known clearly. However, many studies suggest that immunological response is related to effectivene ss of intravesical instillation of BCG in the therapy for superficial bladd er carcinoma. Peripheral blood mononuclear cells (PBMC), urine and serum we re obtained from patients with superficial carcinoma at various times durin g the course of BCG instillation. Urine of patients showed increased levels of IL-1 beta, IL-2, IL-6, tumour necrosis factor-alpha (TNF-alpha), interf eron-gamma (IFN-gamma) and macrophage colony-stimulating factor (M-CSF) aft er BCG instillation. Levels of IL-2 and IFN-gamma in the serum also increas ed after BCG instillation, but IL-1b, IL-6, TNF-alpha and M-CSF were not de tectable. Maximal levels of IL-2 and IFN-g in the urine or serum were shown after the fourth instillation. BCG-induced killer cell activity in PBMC in creased significantly after the third BCG instillation. These results sugge st that BCG instillation involved not only local immunological efforts but also systemic immune responses. Tumour-free patients produced higher BCG-in duced killer cell activity than tumour recurrence patients. BCG-induced kil ler cell activity may be useful for monitoring the effectiveness of intrave sical BCG instillation.