Table 3.

Biomarker levels and utility of individual biomarkers to distinguish between spinal TB and mechanical back pain.

	Spinal TB	Mechanical back pain	p-value	AUC	AUC	Sensitivity	Specificity
				(95% C.I.)	p-value	(95% C.I.)	(95% C.I.)
Fibrinogen	9120	1688	<0.001	0.99	<0.001	100.0	94.1
	[5729 – 16537]	[1217 – 2155]		(0.96 – 1.00)		(89.1 – 100.0)	(71.3 – 99.9)
CRP	384770	11310	<0.001	0.95	<0.001	88.5	94.1
	[133567 – 517455]	[6176 – 32819]		(0.87 – 1.00)		(69.8 – 97.6)	(71.3 – 99.9)
IFN-γ	27	0.00	<0.001	0.92	<0.001	92.3	94.1
	[16 – 49]	[0.00 – 0.00]		(0.83 – 1.00)		(74.9 – 99.1)	(71.3 – 99.9)
NCAM	368555	217416	<0.001	0.88	<0.001	76.9	88.2
	[301809 – 447342]	[189118 – 271548]		(0.78 – 0.98)		(56.4 – 91.0)	(63.6 – 98.5)
Ferritin	252060	105944	0.002	0.78	<0.001	69.2	82.4
	[164326 – 1.32e+6]	[50653 – 172244]		(0.64 – 0.92)		(48.2 – 85.7)	(56.6 – 96.2)
CCL1	10	6	0.01	0.74	<0.001	73.1	64.7
	[7 – 20]	[5 – 9]		(0.59 – 0.90)		(52.2 – 88.4)	(38.3 – 85.8)
IL-10	0.41	0.00	0.04	0.68	0.02	57.7	76.5
	[0.00 – 1.78]	[0.00 – 0.00]		(0.53 – 0.82)		(36.9 – 76.6)	(50.1 – 93.2)
GDF-15	1054	653	0.12	0.64	0.06	61.5	70.6
	[491 – 1396]	[416 – 853]		(0.48 – 0.81)		(40.6 – 79.8)	(44.0 – 89.7)
CXCL10	50	35	0.15	0.63	0.08	61.5	70.6
	[30 – 61]	[28 – 46]		(0.46 – 0.80)		(40.6 – 79.8)	(44.0 – 89.7)
VEGF-A	192	143	0.15	0.63	0.07	50.0	88.2
	[79 – 359]	[85 – 186]		(0.46 – 0.80)		(29.9 – 70.1)	(63.6 – 98.5)
CXCL9	1933	1575	0.20	0.62	0.10	57.7	88.2
	[1341 – 2949]	[1408 – 1736]		(0.44 – 0.79)		(36.9 – 76.6)	(63.6 – 98.5)
Factor D	3.71e+6	4.17e+6	0.20	0.62	0.10	58.8	65.4
	[3.11e+6 – 4.31e+6]	[3.59e+6 – 4.60e+6]		(0.44 – 0.79)		(32.9 – 81.6)	(44.3 – 82.8)
VCAM-1	1.05e+6	911522	0.22	0.61	0.11	53.8	70.6
	[759996 – 1.46e+6]	[780792 – 1.11e+6]		(0.44 – 0.79)		(33.4 – 73.4)	(44.0 – 89.7)
ApoAI	243608	271259	0.23	0.61	0.11	70.6	53.8
	[218886 – 277761]	[243145 – 308291]		(0.43 – 0.80)		(44.0 – 89.7)	(33.4 – 73.4)
MPO	481671	327798	0.30	0.60	0.15	57.7	70.6
	[254725 – 691086]	[249070 – 502977]		(0.43 – 0.77)		(36.9 – 76.6)	(44.0 – 89.7)
ICAM-1	424590	347445	0.30	0.60	0.15	57.7	70.6
	[307328 – 603615]	[241430 – 451406]		(0.41 – 0.78)		(36.9 – 76.6)	(44.0 – 89.7)
CXCL8	10	17	0.31	0.59	0.16	64.7	61.5
	[6 – 17]	[8 – 23]		(0.41 – 0.78)		(38.3 – 85.8)	(40.6 – 79.8)
OPG	940	1070	0.53	0.56	0.27	53.8	64.7
	[759 – 1258]	[870 – 1295]		(0.38 – 0.74)		(26.6 – 66.6)	(14.2 – 61.7)
CFH	484400	477628	0.89	0.51	0.45	52.9	61.5
	[463443 – 535822]	[460687 – 544841]		(0.33 – 0.70)		(23.0 – 72.2)	(20.2 – 59.4)

TB, tuberculosis; AUC, area under the receiver operator characteristic plot; 95% C.I., 95% confidence interval. Biomarkers are ordered from highest to lowest AUC. Data are expressed as median and interquartile range with between-group differences assessed using a Mann-Whitney U test. CRP, Fibrinogen, ApoA1 and CFH measured in ng/ml and other biomarkers are measured in pg/ml.