TABLE 3.

Numbers of tested cattle and agreement between the PPD-B-stimulated IL-8 test and TST or IGRA^a

PPD-B-stimulated IL-8 test result	No. of cattle with the indicated result by:
	TST			IGRA
	Positive	Negative	Total	Positive	Negative	Total
Positive	113	2	115	113	2	115
Negative	13	116	129	7	122	129
Total	126	118	244	120	124	244

^aCattle from four different farms were tested. The cutoff value for the PPD-B-stimulated IL-8 test was set at 43.05 ng/ml. If the concentration of PPD-B-stimulated IL-8 was ≥43.05 ng/ml, the animal was considered infected with M. bovis. If the concentration of PPD-B-stimulated IL-8 was <43.05 ng/ml, the animal was considered bTB free. κ values were as follows: for the PPD-B-stimulated IL-8 test and TST, κ was 0.877; for the PPD-B-stimulated IL-8 test and IGRA, κ was 0.926. The relative sensitivities of the PPD-B-stimulated IL-8 test compared to the results of TST and IGRA were 90% and 94%, respectively. The relative specificities of the PPD-B-stimulated IL-8 test compared to the results of TST and IGRA were both 98%.