Ten who did not receive such therapy (median IGRA value, 0.42 IU/mL; range 0.35–10 IU/mL) repeated the IGRA test 1 to 6 months later, and 8 of them had negative results.

This observational study is limited by the small number of converters, but it highlights the challenges of interpreting serial IGRA test results. Variations in immunity or technical problems could ...