Relationship between HLA-DR gene polymorphisms and outcomes of hepatitis B viral infections: A meta-analysis

Table 1 Main characteristics of case-control studies included in this systematic review and meta-analysis

No.	Study	Yr	Language	Ethnicity	Genotyping	Spontaneously recovered control		Chronic hepatitis B case		NOS score
						n	Characteristics	n	Characteristics
1	Thursz et al[32]	1995	English	Gambia	PCR-RFLP	413	218 children; 195 adults	225	185 children; 40 adults	7
2	Hohler et al[16]	1997	English	Caucasian	PCR-SSP	24	NA	70	Outpatients	7
3	Ahn et al[18]	2000	English	Korean	PCR-SSP	243	156 males, mean age: 41 yr	83	53 males, mean age: 35 yr	8
4	Chen et al[42]	2002	Chinese	Chinese Han	PCR-SSP	56	43 males, mean age: 47.6 yr	30	22 males, mean age: 38.7 yr	7
5	Akcam et al[33]	2002	English	Iran	PCR-SSP	30	20 males, mean age: 35.9 yr	30	7 males, mean age: 31.0 yr	7
6	Jiang et al[21]	2003	English	Chinese Han	PCR-SSP	30	24 males, mean age: 33.2 yr	52	43 males, mean age: 33.46 yr	7
7	Meng et al[20]	2003	English	Chinese Han	PCR-SSP	56	22 males, mean age: 38.7 yr	30	43 males, mean age: 47.6 yr	7
8	Wu et al[19]	2004	English	Chinese Han	SSOPH	324	169 males, mean age: 39.1 yr	98	66 males, mean age: 50.9 yr	8
9	Wu et al[19]	2004	English	Taiwanese aborigines	SSOPH	229	90 males, mean age: 52.1 yr	138	60 males, mean age: 45.7 yr	8
10	Lu et al[43]	2006	Chinese	Chinese Han	PCR-SSP	148	70 males, mean age: 37.75 yr	417	289 males; 207 CHB, 212ASC ASC	6
11	Zhang et al[34]	2006	English	Chinese Han	PCR-SSP	32	20 males, mean age: 38.4 yr	61	40 males, mean age: 38.4 yr	7
14	Yang et al[35]	2007	English	Chinese Han	PCR-SSP	108	Age and sex matched	108	90 males, 58 LC, 24 HCC	7
15	Song et al[44]	2007	Chinese	Chinese Han	PCR-SSP	102	63 males, mean age: 33.9 yr	276	168 males, 77 LC, 106 ASC	5
14	Zhu et al[36]	2007	English	Chinese Han	PCR-SSP	133	63 males, mean age: 37 yr	151	120 males, mean age: 40 yr	7
15	Hwang et al[37]	2007	English	Korean	PCR-SSP	438	286 man, mean age: 39 yr	198	148 males, 76 LC, 28 HCC	7
16	Kummee et al[38]	2007	English	Thai	PCR-SSP	100	48 males, mean age: 51.0 yr	150	80 males, mean age: 30.9 yr	8
17	Cho et al[39]	2008	English	Korean	PCR-SSP	80	60 males, mean age: 47.9 yr	384	283 males, mean age: 41.0 yr	8
18	Remezani et al[40]	2008	English	Iran	PCR-SSP	30	17 males, mean age: 32.2 yr	33	20 males, mean age: 38 yr	8
19	Albayrak et al[41]	2011	English	Turkish	PCR-SSP	30	15 males, mean age: 33.9 yr	75	48 males, mean age: 33.0 yr	8

NA: Relative data were not available in original studies; PCR-RFLP: Polymerase chain reaction-restriction fragment length polymorphism; PCR-SSP: Polymerase chain reaction sequence specific primers; PCR-SSO: Polymerase chain reaction sequence specific oligonucleotide probe; SSOPH: Sequence-specific oligonucleotide probe hybridization: CHB: Chronic hepatitis B; LC: Liver cirrhosis; HCC: Hepatocellular carcinoma; ASC: Asymptomatic hepatitis B virus carriers; NOS: Newcastle-Ottawa Scale.