Prophylactic intracavitary treatment with interferon alpha increases interferon gamma production by peripheral blood mononuclear cells in patients with superficial transitional cell carcinoma of the bladder.

The immunomodulatory effect of prophylactic intravesical instillations of interferon alpha 2b (IFN-alpha-2b) on interferon gamma (IFN-gamma) and interleukin 4 (IL-4) production by peripheral blood mononuclear cells (PBMCs) from patients with superficial transitional cell carcinoma (STCC) of the bladder has been analysed. There were no significant differences in the production of IFN-gamma and IL-4 by PBMCs from untreated patients and healthy control subjects after 24 h of phytohaemagglutinin (PHA) stimulation. However, between 3 and 6 months after finishing the prophylactic intracavitary treatment with IFN-alpha-2b, PHA-stimulated PBMCs from patients with STCC of the bladder showed a significantly enhanced production of IFN-gamma and a significantly decreased production of IL-4. Both IFN-gamma and IL-4 returned to pretreatment levels 1 year after ending the treatment. In conclusion, prophylactic intravesical instillations of IFN-alpha-2b in patients with STCC of the bladder have an immunoregulatory effect on the production of IFN-gamma and IL-4 by PBMCs.