Résumé : The antitumorigenic effect of intravesical bacillus Calmette-Guerin (BCG) in superficial bladder cancer was reported to be initiated by the attachment of BCG to the bladder wall via fibronectin. The antigen 85 complex secreted in BCG culture filtrate binds specifically to fibronectin and is a powerful T cell stimulus. Therefore, we investigated the evolution and clinical significance of the cellular proliferative response and cytokine production during intravesical BCG therapy against this purified antigen 85 complex.