Association between IL-4 and IL-4R Polymorphisms and Periodontitis: A Meta-Analysis

Table 1

Characteristics of studies included in meta-analysis.

Study; (author, year)	Country	Ethnicity	Disease type	Source	Sample Size; case/control	Smoker %	Genotyping method	for HWE	NOS score
IL-4 -590C/T
Byung 2003 [7]	Korea	Asian	CP	HB	32/150	37.5	PCR	0.28	7
Scarel-Caminaga 2003a [24]	Brazil	Caucasian	CP	HB	50/37	0	PCR-RFLP	0.74	7
Scarel-Caminaga 2003b [24]	Brazil	Mixed	CP	HB	19/7	0	PCR-RFLP	0.43	7
Gonzales 2004a [15]	Europe	Caucasian	AgP	PB	30/33	NA	PCR-RFLP	0.18	7
Gonzales 2004b [15]	Japan	Asian	AgP	PB	30/31	NA	PCR-RFLP	0.09	7
Gonzales 2007 [6]	Germany	Caucasian	AgP	PB	58/51	12	PCR-RFLP	0.83	7
Kara 2007 [20]	Turkey	Caucasian	CP	PB	75/73	0	PCR-RFLP	0.48	7
Holla 2008 [17]	Czech	Caucasian	CP	PB	194/158	31.3	PCR-RFLP	0.53	7
Hooshmand 2008a [18]	Iran	Asian	CP	PB	26/56	0	PCR-RFLP	0.35	7
Hooshmand 2008b [18]	Iran	Asian	AgP	PB	27/56	0	PCR-RFLP	0.35	7
Anovazzi 2010 [11]	Brazil	Caucasian	CP	HB	125/125	15.2	PCR-RFLP	0.04	6
Atanasovska-Stojanovska 2011 [12]	Macedonia	Caucasian	CP	HB	92/286	0	PCR-RFLP	<0.05	6
Loo 2012 [22]	China	Asian	CP	PB	440/850	NA	PCR	<0.05	6
Chen 2012 [13]	China	Asian	CP	HB	198/128	NA	PCR	0.07	7
Liu 2015 [21]	China	Asian	CP	HB	104/106	27.9	PCR-RFLP	0.65	7
IL-4 -33C/T
Gonzales 2007 [6]	Germany	Caucasian	AgP	PB	58/51	12	PCR-RFLP	0.67	7
Holla 2008 [17]	Czech	Caucasian	CP	PB	194/158	31.3	PCR-RFLP	0.53	7
Anovazzi 2010 [11]	Brazil	Caucasian	CP	HB	125/125	15.2	PCR-RFLP	<0.05	6
Atanasovska-Stojanovska 2011 [12]	Macedonia	Caucasian	CP	HB	92/286	0	PCR-RFLP	<0.05	6
Jain 2013a [19]	India	Dravidian	CP	PB	63/101	NA	PCR	0.63	7
Jain 2013b [19]	India	Dravidian	AgP	PB	61/101	NA	PCR	0.63	7
Liu 2015 [21]	China	Asian	CP	HB	104/106	27.9	PCR-RFLP	0.65	7
Chen 2016 [14]	China	Asian	CP	HB	440/324	0	PCR	1.12	7
IL-4 -1099T/G
Chen 2012 [13]	China	Asian	CP	HB	278/324	NA	PCR	<0.05	6
Chen 2016 [14]	China	Asian	CP	HB	440/324	0	PCR	0.17	7
IL-4 70 bp repeat
Byung 2003 [7]	Korea	Asian	CP	HB	32/150	37.5	PCR	0.27	7
Gonzales 2004a [15]	Europe	Caucasian	AgP	PB	30/33	NA	PCR-RFLP	0.70	7
Gonzales 2004b [15]	Japan	Asian	AgP	PB	30/31	NA	PCR-RFLP	0.16	7
Kara 2007 [20]	Turkey	Caucasian	CP	PB	75/73	0	PCR-RFLP	0.36	7
Holla 2008 [17]	Czech	Caucasian	CP	PB	194/158	31.3	PCR-RFLP	0.53	7
Anovazzi 2010 [11]	Brazil	Caucasian	CP	HB	125/125	15.2	PCR	0.80	7
Grigorovich 2015a [16]	Russian	Caucasian	CP	PB	150/150	NA	PCR	0.80	7
Grigorovich 2015b [16]	Russian	Caucasian	AgP	PB	150/150	NA	PCR	0.80	7
IL-4R Q551R
Donati 2005a [10]	Swedish	Caucasian	CP	PB	60/39	50	PCR	0.44	7
Donati 2005b [10]	Swedish	Caucasian	CP	PB	30/34	0	PCR	0.32	7
Reichert 2011a [23]	Germany	Caucasian	CP	PB	68/89	25	PCR-SSP	0.52	7
Reichert 2011b [23]	Germany	Caucasian	AgP	PB	86/89	35.3	PCR-SSP	0.52	7

Mixed = Afro-Americans, Mulattos, and Asians. HB = hospital-based. PB = population-based. NA = not available.
Smoker % = smoker among patients %.