Renal complications of intravesical bacillus Calmette-Guérin therapy

We report 3 patients who developed signs of systemic infection and renal insufficiency after intravesical bacillus Calmette-Guérin (BCG) instillations for a bladder cancer. Renal biopsy showed tubulo-interstitial nephritis with or without epithelioid granulomas in 2 cases, and mesangial glomerulonephritis in the last case. All patients had granulomatous hepatitis in association. It seems that hematogenous dissemination via a traumatic instillation of BCG and/or an immune-complex mechanism may have contributed to the renal damage, which was only partially reversible in 2 patients.