Table 1. Characteristics of studies in the meta-analysis.
| First author | Year | Ethnicity | Country | Genotyping method | Type of control | P for HWE | Cases/Controls | No. of cases | Allele frequencies of cases, n, (%) | No. of controls | Allele frequencies of controls, n, (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IL-18 -137 (rs187238) | GG | GC | CC | G | C | GG | GC | CC | G | C | |||||||
| Migita12 | 2009 | Asian | Japan | LM-PCR | Healthy | 0.531 | 47/63 | 43 | 3 | 1 | 89 (94.7) | 5 (5.3) | 52 | 10 | 1 | 114 (90.5) | 12 (9.5) |
| Kim13 | 2009 | Asian | South Korea | Taqman | CHB | 0.031 | 56/558 | 37 | 17 | 2 | 91 (81.3) | 21 (18.7) | 434 | 122 | 2 | 990 (88.7) | 126 (11.3) |
| Chen14 | 2012 | Asian | China | PCR-SSP | Healthy | 0.183 | 228/300 | 159 | 59 | 10 | 377 (82.7) | 79 (17.3) | 173 | 115 | 12 | 461 (76.8) | 139 (23.2) |
| Teixeira15 | 2013 | Mixed | Brazil | PCR-SSP | Healthy | 0.952 | 112/202 | 57 | 48 | 7 | 162 (72.3) | 62 (27.7) | 100 | 84 | 18 | 284 (70.3) | 120 (29.7) |
| Karra16 | 2015 | Asian | India | PCR-SSP | Healthy | 0.320 | 271/280 | 123 | 134 | 14 | 380 (70.2) | 162 (29.8) | 159 | 108 | 13 | 426 (76.0) | 134 (24.0) |
| Bao17 | 2015 | Asian | China | PCR-RFLP | Healthy | 0.548 | 153/165 | 122 | 28 | 3 | 272 (88.9) | 34 (11.1) | 106 | 54 | 5 | 266 (80.6) | 64 (19.4) |
| Zhang18 | 2016 | Asian | China | PCR-LDR | Healthy | 0.110 | 109/127 | 82 | 25 | 2 | 189 (86.7) | 29 (13.3) | 99 | 24 | 4 | 222 (87.4) | 32 (12.6) |
| Lau19 | 2016 | Asian | Taiwan, China | Taqman | Healthy | 0.370 | 342/559 | 266 | 73 | 3 | 605 (88.5) | 79 (11.5) | 476 | 78 | 5 | 1030 (92.1) | 88 (7.9) |
| IL18 -607 (rs1946518) | AA | AC | CC | A | C | AA | AC | CC | A | C | |||||||
| Migita12 | 2009 | Asian | Japan | LM-PCR | Healthy | 0.777 | 47/63 | 13 | 26 | 8 | 52 (55.3) | 42 (44.7) | 20 | 30 | 13 | 70 (55.6) | 56 (44.4) |
| Chen14 | 2012 | Asian | China | PCR-SSP | Healthy | 0.429 | 228/300 | 47 | 126 | 55 | 220 (48.2) | 236 (51.8) | 83 | 156 | 61 | 322 (53.7) | 278 (46.3) |
| Teixeira15 | 2013 | Mixed | Brazil | PCR-SSP | Healthy | 0.005 | 112/202 | 18 | 56 | 38 | 92 (41.1) | 132 (58.9) | 12 | 105 | 85 | 129 (31.9) | 275 (68.1) |
| Karra16 | 2015 | Asian | India | PCR-SSP | Healthy | 0.120 | 271/280 | 70 | 152 | 49 | 292 (53.8) | 250 (46.2) | 102 | 144 | 34 | 348 (62.1) | 212 (37.8) |
| Bao17 | 2015 | Asian | China | PCR-RFLP | Healthy | 0.322 | 153/165 | 37 | 73 | 43 | 147 (48.0) | 159 (52.0) | 41 | 76 | 48 | 158 (47.9) | 172 (52.1) |
| Zhang18 | 2016 | Asian | China | PCR-LDR | Healthy | 0.542 | 109/127 | 32 | 55 | 22 | 119 (54.6) | 99 (45.4) | 23 | 66 | 38 | 112 (44.1) | 142 (55.9) |
| Lau19 | 2016 | Asian | Taiwan, China | Taqman | Healthy | 0.777 | 342/559 | 88 | 167 | 87 | 343 (50.1) | 341 (49.9) | 148 | 276 | 135 | 572 (51.2) | 546 (48.8) |
IL18, interleukin-18; LM, ligation-mediated; PCR, polymerase chain reaction; SSP, sequence-specific primer; RFLP, restriction fragment length polymorphism; LDR, ligase detection reaction; CHB, chronically infected with hepatitis B virus; HWE, Hardy-Weinberg equilibrium.