Table 9. Cytokine concentrations and responses measured by a commercial MMIA.

Cytokine	Subject Group	Nil	Mitogen Response	ESAT-6+CFP-10+TB7.7 Response
IFN-γ	Patients	165	2,002	913
		(0 to 885)	(502 to 3,791)	(108 to 2,974)
	Controls	79	1,930	38
		(0 to 827)	(766 to 3,459)	(−8 to 190)
	p-value	0.184	0.908	<0.001
IL-2	Patients	10	332	286
		(0 to 35)	(30 to 1,081)	(37 to 1,553)
	Controls	6	590	2
		(0 to 63)	(160 to 1,340)	(−7 to 11)
	p-value	0.222	0.033	<0.001
IL-6	Patients	34	6,941	438
		(0 to 156)	(222 to 25,260)	(58 to 1,302)
	Controls	11	5,146	11
		(0 to 49)	(608 to 9,632)	(−2 to 46)
	p-value	0.202	0.817	<0.001
IL-8	Patients	199	17,810	2,682
		(40 to 819)	(227 to 90,979)	(135 to 21,942)
	Controls	247	9,182	170
		(41 to 635)	(2,093 to 29,080)	(−22 to 735)
	p-value	0.166	0.564	<0.001
IL-12	Patients	0	4	0
		(0 to 0)	(0 to 19)	(0 to 0)
	Controls	2	4	0
		(0 to 25)	(0 to 18)	(0 to 1)
	p-value	0.317	0.829	0.317
IP-10	Patients	3,807	26,252	39,065
		(143 to 25,641)	(6,786 to 58,752)	(2,530 to 158,425)
	Controls	589	25,663	21
		(149 to 1,275)	(5,687 to 62,714)	(−202 to 349)
	p-value	0.033	0.954	<0.001
MCP-1	Patients	2,879	20,372	13,729
		(39 to 12,764)	(4,842 to 44,202)	(−221 to 39,519)
	Controls	290	19,525	494
		(28 to 1,319)	(4,418 to 44,461)	(−72 to 1,899)
	p-value	0.024	0.908	<0.001
MIP-1β	Patients	373	47,076	8,245
		(60 to 1,389)	(20,657 to 75,448)	(773 to 24,204)
	Controls	180	46,596	64
		(59 to 415)	(20,537 to 75,511)	(0 to 198)
	p-value	0.021	0.817	<0.001
TNF-α	Patients	65	3,268	303
		(0 to 329)	(250 to 6,715)	(42 to 719)
	Controls	9	1,470	14
		(0 to 105)	(491 to 3,910)	(0 to 94)
	p-value	0.074	0.184	<0.001

Median background cytokine concentrations (Nil, pg/mL) and cytokine responses (pg/mL) to phytohemagglutinin (Mitogen Response) and to a combination of early secreted antigenic target-6, culture filtrate protein 10, and TB7.7 (ESAT-6+CFP-10+TB7.7 Response) are listed with ranges in parentheses. Cytokine concentrations were measured with a custom commercial multiplexed microsphere-based immunoassay (commercial MMIA) for patients with culture-confirmed tuberculosis (patients) and subjects at low risk for M. tuberculosis (Mtb) infection (controls). For values that were designated “out of range” by Bio-Plex Manager software, low values are reported as 0 and high values are reported as the observed value of the highest standard concentration multiplied by the dilution factor. Responses were calculated by subtracting the background cytokine concentration in plasma from blood incubated with saline (Nil) from the cytokine concentration in plasma from blood incubated with mitogen or Mtb antigen. N = 12 for patients and N = 12 for controls. P values were calculated by Mann-Whitney U Rank Sum test comparing cytokine concentrations or responses for patients versus controls. Significant differences (p<0.05) are indicated in bold type.