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.