Table 5. Evaluation of quantitative levels of anti-PGL-Tb1 and anti-ESAT-6/CFP10 antibodies (medians) in individuals with varying risk of latent tuberculosis infection stratified by the center of enrolment.

Antigen	Center		High risk controls
			Hospitalized non-ATB Patients		Heath Care Workers			Healthy Family Contacts			Cured TB Patients
		N	OD median (IQR)	N	OD median (IQR)		N	OD median (IQR)		N	OD median (IQR)
PGL-Tb1	Hinduja	40	0.078 (0.057–0.157)	38	0.064 (0.052–0.093)		0	NA		0	NA
	AIIMS	2	0.104 (0.067–0.140)	34	0.064 (0.051–0.088)		0	NA		0	NA
	Safdarjung	1	0.171	0	NA		0	NA		0	NA
	JALMA	30	0.076 (0.049–0.106)	0	NA		48	0.083 (0.045–0.118)		0	NA
	TRC	0	NA	49	0.095* (0.053–0.173)		56	0.098* (0.063–0.187)		90	0.112 (0.080–0.203)
ESAT-6/CFP10	Hinduja	42	0.074 (0.055–0.124)	38	0.046 (0.038–0.070)		0	NA		29	NA
	AIIMS	2	1.419 (0.056–2.781)	34	0.054 (0.042–0.078)		0	NA		5	NA
	Safdarjung	1	0.070	0	NA		0	NA		0	NA
	JALMA	30	0.030* (0.025–0.061)	0	NA		48	0.044 (0.028–0.060)		0	NA
	TRC	0	NA	49	0.055 (0.040–0.109)		56	0.064* (0.048–0.084)		90	0.076 (0.052–0.120)
Low risk controls
			Blood donors (BD)			Healthy Community Adults (HCA)
		N	OD median (IQR)	N		OD median (IQR)			p value BD versus HCA		p value BD from Hinduja vs BD from other sites
PGL-Tb1	Hinduja	199	0.065 (0.049–0.090)	100		0.067 (0.046–0.100)			0.9000		NA
	AIIMS	200	0.051 (0.035–0.076)	0		NA			NA		0.0003
	NIMS	60	0.039 (0.020–0.056)	0		NA			NA		<0.0001
ESAT-6/CFP10	Hinduja	199	0.057 (0.042–0.081)	100		0.059 (0.043–0.080)			0.0737		NA
	AIIMS	200	0.042 (0.029–0.053)	0		NA			NA		<0.0001
	NIMS	69	0.027 (0.018–0.041)	0		NA			NA		<0.0001

Footnotes: N =  number of serum tested; NA: not applicable because no individual has been recruited at that center;* p<0.01.