Intravesical Bacille Calmette-Guerin (BCG) Eradicates Bacteriuria in Antibiotic-Naïve Bladder Tumor Patients

Abstract

Intravesical Mycobacterium bovis bacille Calmette-Guerin (BCG) is standard therapy for high grade noninvasive bladder cancer. BCG induces a robust immune response in the bladder, characterized by cytokine production, inflammation, and recruitment of immune cells [1]. Neoplastic cells slough in the urine as they are destroyed, leaving denuded mucosa in responding patients. Invading uropathogens trigger similar cellular responses that cause rapid shedding of infected bladder epithelial cells into the urine, known as exfoliation [2]. Bacteria can evade exfoliation by invading deeper epithelial cells and establish a reservoir for urinary tract infection [3]. Although contraindicated in acute cystitis, we have shown that BCG is safe and effective in patients with asymptomatic bacteriuria [4]. We hypothesized that the immune response to BCG may augment innate immune defenses to eradicate bacteriuria.