Table 1.

Studies on specificity of interferon gamma assays in healthy BCG-vaccinated individuals

	No.	TST +ve	IGRA +ve	Specificity of IGRA (%)
Lalvani[30]*	36	ND	1	97
Pathan[32]*	28	ND	0	100
Chapman[31]*	33	ND	0	100
Brock[33]**	22	ND	0	100
Mori[27]**	216	113	4	98
Ravn[34]**	39	ND	0	100
Kang[28]**	99	51	4	96
Kobashi[29]**	37	18	0	100

ND – Not done,

^*T SPOT- TB Assay,

^**Quantiferon - TB Gold assay