Predictive value of TNF-α, IFN-γ, and IL-10 for tuberculosis among recently exposed contacts in the United States and Canada

Table 2 Median (IQR) Cytokine Responses in pg/ml Among Contacts By Outcome Group

Characteristic	Contact Outcome Group
Characteristic	Co-prevalent TB (n = 41)	Incident TB (n = 19)	Converter (n = 93)	TST+ (n = 502)	TST- (n = 617)_
TNF-α
Unstimulated	0	0	0	0	0
Unstimulated	(0–4)	(0–0)	(0–4)	(0–2)	(0–3)
PHA	8328	–	4204	4660	4737
PHA	(4664–9012)		(3612–4662)	(2854–6679)	(2921–8131)
M. tb culture filtrate protein	129^a	257^a	48	103^a	50
M. tb culture filtrate protein	(28–1326)	(67–2011)	(0–246)	(20–383)	(0–300)
IFN-γ
Unstimulated	0	0		0	0
Unstimulated	(0–4)	(0–0)	(0–1)	(0–4)	(0–1)
PHA	9988^a	1238^a	21,165	13,842	18,986
PHA	(151–15,690)	(0–14,256)	(4430–58,356)	(674–55,046)	(981–62,161)
M. tb culture filtrate protein	231^a	88	32	130^a	0
M. tb culture filtrate protein	(61–549)	(0–445)	(0–302)	(0–771)	(0–130)
IL-10
Unstimulated	0	0	0	0	0
Unstimulated	(0–2)	(0–0)	(0–1)	(0–1)	(0–1)
M. tb culture filtrate protein	8	14	6	7	6
M. tb culture filtrate protein	(0–139)	(3–88)	(1–19)	(1–30)	(0–28)

^aP < .05 vs. TST- group; ∅P < .05 comparing Incident TB vs. TST+ group; ∆ P < .05 comparing Co-prevalent TB vs. TST+ group
Definitions: PHA Phytohemagglutinin. TB Tuberculosis, TST Tuberculin skin test, TNF Tumor necrosis factor, IFN Interferon gamma; IL-10 = Interleukin 10; M. tb = Mycobacterium tuberculosis; Co-prevalent TB defined as TB diagnosis before or < 30 days after blood draw; Incident TB defined as TB diagnosis > 30 days after blood draw
Clarifications: PHA stimulation not performed for IL-10; the number of contacts included varies slightly from the numbers presented in the heading because 14 contacts were missing TNF culture filtrate protein results, 38 contacts were missing IFN culture filtrate protein results, and 23 contacts were missing IL10 culture filtrate protein results

ISSN: 1471-2334