INTRACAVITARY PROPHYLACTIC TREATMENT WITH INTERFERON-ALPHA-2B OF PATIENTS WITH SUPERFICIAL BLADDER-CANCER IS ASSOCIATED WITH A SYSTEMIC T-CELL ACTIVATION

The activation and proliferation of peripheral blood mononuclear cells (PBMNCs) are complex processes involving several surface molecules, c ell secretion and response to cytokines. This paper investigates the i mmunomodulatory effect of prophylactic treatment with interferon alpha 2b (IFN-alpha(2b)) upon the blastogenic response of PBMNCs from patie nts with superficial transitional cell carcinoma (STCC) of the bladder to mitogenic signals that interact with surface molecules [phytohaema gglutinin, PHA and anti-CD3 monoclonal antibodies, (MABs)]. PBMNCs fro m the patients were studied prior to the transurethral resection (TUR) of the tumour, during the second month of prophylactic intravesical i nstillation of IFN-alpha(2b) amd 3 and 6 months after finishing the in stillation treatment. The [H-3]thymidine uptake of PBMNCs from 17 pati ents with STCC of the bladder after 5 days of PHA and anti-CD3 MAb sti mulus was found to be significantly lower than that of healthy control s (P > 0.05). The addition of interleukin 2 (IL-2) to the culture medi um did not correct this defective proliferative response to PHA and th e anti-CD3 MAb. There were no significant differences between IL-2 pro duction in PBMNCs from STCC patients after stimulation with PHA and in PBMNCs from healthy controls (P > 0.05). Patients without evidence of recurrence showed a significantly enhanced proliferative response in PBMNC to PHA and anti-CD3 MAb after intravesical prophylactic treatmen t with interferon-alpha(2b) in the follow-up examinations 3 and 6 mont hs after treatment (P < 0.01). However, three patients had evidence of tumour recurrence, and they showed no enhancement of the PBMNC prolif erative response to these mitogens in the same examinations. In conclu sion, the prophylactic intracavitary treatment of STCC with IFN-alpha( 2b) may induce a systemic immunomodulatory effect which is associated to the clinical evolution of the disease.