Table 2. Main results of the eligible studies.

Study	Diagnosis	Specimen type	OPN variants	Cases			Controls			Unit	Detection method
				Mean	SD	N	Mean	SD	N
Shiratori B 2014	PTB	Plasma	NR	150.73	53.43	37	74.23	19.34	30	ng/mL	ELISA
Shiratori B 2017	PTB	Plasma	Full-length and cleaved OPN	59.46	37.70	36	40.05	27.72	19	ng/mL	ELISA
Inomata SI 2003	PTB	Plasma	Full-length OPN	433.0	259.0	47	170.0	65.9	25	ng/mL	ELISA
Zhang YT 2018	PTB	Serum	NR	657.5	315.6	48	170.3	114.2	53	ng/mL	ELISA
Wu TF 2017	Spinal tuberculosis	Serum	NR	538.94	258.41	51	143.12	78.31	63	ng/mL	ELISA
Ding YL 2017	PTB	Plasma	NR	563.2	123.4	20	40.2	11.2	20	ng/mL	ELISA
Hao XL 2016	Smear-negative PTB	Serum	NR	712.62	335.75	43	185.34	120.23	40	pg/mL	ELISA
Cui JX 2014	PTB	Serum	NR	588.42	271.67	80	169.12	97.43	100	ng/mL	ELISA
Guo SX 2013	PTB	Serum	NR	683.21	321.76	42	168.46	117.31	36	ng/mL	ELISA
Gan B 2009	TB	Plasma	NR	160.54	32.42	44	76.18	20.69	20	ng/mL	ELISA
Du H 2020	PTB	Serum	NR	564.52	126.51	50	40.26	11.72	20	ng/mL	ELISA
Wang Q 2019	PTB	Serum	NR	663.45	94.20	92	384.14	37.15	50	ng/mL	ELISA
Wu YX 2019	PTB	Serum	NR	663.9	282.6	90	356.4	130.2	90	pg/mL	ELISA
Feng PL 2017	PTB	Serum	NR	691.54	102.72	55	171.94	36.83	60	ng/mL	ELISA
Yuan Y 2016	PTB	Serum	NR	683.2	321.8	52	168.5	117.3	45	ng/mL	ELISA
Qiao YF 2013	PTB	Serum	NR	652.4	270.8	62	155.6	107.2	35	ng/mL	ELISA
Sun XX 2016	PTB	Serum	NR	652.31	264.74	84	152.93	113.26	80	ng/L	ELISA

PTB, pulmonary tuberculosis; TB, tuberculosis; SD, standard deviation; NR, not reported; ELISA, enzyme-linked immunosorbent assay.