Table 6. The frequency distribution of HLA-DRB1*04 subtypes among DRB1*04 positive and ACPA-positive or ACPA-negative RA patients by ethnic group.
| Malay€ | Chinese¥ | Indian§ | ||||||||||
| Cases (n,%) | Controls (n,%) | OR, 95% CI | P value | Cases (n,%) | Controls (n,%) | OR, 95% CI | P value | Cases (n,%) | Controls (n,%) | OR, 95% CI | P value | |
| DRB1*0401 | ||||||||||||
| ACPA-positive | 3 (3.1) | - | 3 (3.1) | - | 21 (30.4) | - | ||||||
| ACPA-negative | 0 (0) | 2 (2.2) | 1 (7.7) | 2 (8.0) | 4 (15.4) | 12 (22.2) | ||||||
| DRB1*0402 | ||||||||||||
| ACPA-positive | 1 (1.0) | - | 0 (0) | - | 1 (1.0) | - | ||||||
| ACPA-negative | 0 (0) | 2 (2.2) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | ||||||
| DRB1*0403 | ||||||||||||
| ACPA-positive | 8 (8.2) | - | 0.27, 0.11–0.65 | 0.0023 | 6 (9.5) | - | 0.27, 0.08–0.89 | 0.0253 | 26 (37.7) | - | 0.45, 0.22–0.93 | 0.0294 |
| ACPA-negative | 6 (24) | 22 (24.4) | 4 (3.1) | 7 (28.0) | 13 (50.0) | 31 (57.4) | ||||||
| DRB1*0404 | ||||||||||||
| ACPA-positive | 1 (1.0) | - | 6 (9.5) | - | 0 (0) | - | ||||||
| ACPA-negative | 2 (8.0) | 7 (7.8) | 1 (7.7) | 1(4.0) | 5 (19.2) | 1(1.9) | 12.6, 1.39–114.5 | 0.0208 | ||||
| DRB1*0405 | ||||||||||||
| ACPA-positive | 81 (82.7) | - | 5.59, 2.91–10.76 | 7×10−8 | 46 (73.0) | - | 03.83, 1.45–10.09 | 0.051 | 9 (13.0) | - | ||
| ACPA-negative | 10 (40.0) | 46 (51.0) | 4 (30.8) | 10 (40.0) | 2 (7.7) | 4 (7.4) | ||||||
| DRB1*0406 | ||||||||||||
| ACPA-positive | 2 (2.0) | - | 0.15, 0.03–0.72 | 0.0162 | 6 (9.5) | - | 0.15, 0.03–0.72 | 0.0162 | 0 (0) | - | 0.15, 0.03–0.72 | 0.0162 |
| ACPA-negative | 1 (4.0) | 11 (12.2) | 3 (23.1) | 4 (16.0) | 1 (3.8) | 1 (1.9) | ||||||
| DRB1*0407 | ||||||||||||
| ACPA-positive | 0 (0) | - | 0 (0) | - | 1 (1.4) | - | ||||||
| ACPA-negative | 0 (0) | 0 (0) | 0 (0) | 1 (4.0) | 0 (0) | 0 (0) | ||||||
| DRB1*0408 | ||||||||||||
| ACPA-positive | 0 (0) | - | 0 (0) | - | 5 (7.2) | - | ||||||
| ACPA-negative | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 2 (3.7) | ||||||
| DRB1*0410 | ||||||||||||
| ACPA-positive | 2 (2.0) | - | 0 (0) | - | 6 (8.7) | - | ||||||
| ACPA-negative | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 1 (3.8) | 3 (5.6) | ||||||
| DRB1*0401/*0404/*0405/*0408/*0410 | ||||||||||||
| ACPA-positive | 87 (88.8) | - | 1.94, 2.36–10.73 | 1×10−5 | 52 (81.3) | - | 13.72, 4.51–41.72 | 3×10−7 | 41 (59.4) | - | 2.13, 1.03–4.4 | 0.0397 |
| ACPA-negative | 18 (72.0) | 55 (61.1) | 1.64, 0.62–4.32 | 0.3171 | 6 (46.2) | 13 (52.0) | 2.71, 0.65–11.29 | 0.1663 | 12 (46.2) | 22 (40.7) | 1.25, 0.49–3.20 | 0.6464 |
€,¥,§The frequency of DRB1 genotypes in ACPA subgroups was calculated as the number of ACPA-positive or ACPA-negative rheumatoid arthritis(RA) cases for a specific DRB1 allele (DRB1*04 +)divided by the total number of cases within that ACPA subgroup (Malay :98 DRB1*04+/ACPA-positive cases, 25 DRB1*04+/ACPA-negative cases; Chinese: 64 DRB1*04+/ACPA-positive cases, 13 DRB1*04+/ACPA-negative cases; Indian: 69 DRB1*04+/ACPA-positive cases, 26 DRB1*04+/ACPA-negative cases).