[False-positive interferon-gamma test?].

M. tuberculosis specific interferon-gamma tests have been established lately as an important additional instrument in the diagnosis of the latent tuberculosis infection (LTBI). In several studies these tests had a higher specificity compared to the tuberculin skin test (TST). In this report we describe the case of a woman without increased risk for LTBI and with discordant results for the interferon-gamma tests QuantiFERON-TB Gold In-Tube and T-SPOT.TB and for the TST. The findings suggest repeated false-positive results of the QuantiFERON-TB Gold In-Tube test.