TABLE 2.

Summary of studies exploring the relationship between the levels of TNF-α and IS.

References	Case		Control		Sample size		Origin
	Mean	SD	Mean	SD	Case	Control
Bokhari et al. (2014)	64.00	68.80	1.00	2.10	131	47	Plasma
de Sousa Parreira et al. (2015)	7.70	6.44	9.20	9.00	93	134	Plasma
Billinger et al. (2017)	2.30	7.00	2.00	6.50	12	14	Plasma
Intiso et al. (2004)	30.10	12.50	29.00	13.90	41	40	Serum
Zaremba and Losy (2001b)	14.00	10.20	9.10	1.60	23	15	Serum
Domac et al. (2007)	44.32	16.92	16.70	5.50	70	22	Serum
Jefferis et al. (2009)	1.83	0.79	1.81	0.77	299	587	Serum
Cure et al. (2013)	75.60	25.00	65.90	9.10	54	50	Serum
Wytrykowska et al. (2016)	12.86	7.33	10.26	4.38	42	34	Serum
Shishkova et al. (2018)	1.29	1.00	1.14	1.57	196	119	Serum
Zhang W. et al. (2018)	3.88	2.30	2.53	1.55	182	40	Serum
Ma et al. (2020)	118.50	27.20	96.20	23.60	288	300	Serum
Zaremba and Losy (2001a)	9.10	5.80	6.60	0.50	23	15	Cerebrospinal fluid
Wytrykowska et al. (2016)	74.78	108.89	30.31	51.37	43	27	Gingival crevicular fluid