Use of an interferon-gamma based assay to assess bladder cancer patients treated with intravesical BCG and exposed to tuberculosis

OBJECTIVE: Compare the QuantiFERON-TB Gold In-Tube (QFT) assay and the tuberculin skin test (TST) in bladder cancer patients receiving high dose BCG therapy (BCG patients). DESIGN AND METHODS: BCG patients and healthy visitors, both exposed to tuberculosis, were screened with a TST and QFT. RESULTS: QFT-TST correlation was excellent in visitors, but poor in BCG patients. BCG therapy predicted a positive TST (p<0.001) but not a positive QFT (p=0.35). DISCUSSION: The management of BCG patients was impacted, by measuring the QFT.