Table 2. Results of QuantiFERON-TB Gold In-Tube and T-SPOT.TB tests in initial evaluation of LTBI in patients with rheumatic diseases scheduled for TNF-α antagonist therapy.

	QFT-GIT
T-SPOT.TB	Positive	Negative	Indeterminate a	Total
Positive	41	28	1 b	70
Negative	4	74	2	80
Indeterminate a	-	6	-	6
Total	45	108	3	156

LTBI, latent tuberculosis infection; TNF, tumor necrosis factor; QFT-GIT, QuantiFERON-TB Gold In-Tube.

^aAll QFT-GIT indeterminate results occurred due to failure to generate an IFN-γ response to mitogens, and all T-SPOT.TB indeterminate results were due to excessive response of negative controls.

^bOne QFT-GIT-indeterminate patient with a 10 mm tuberculin skin test result received TB medication.