Table 1.
Classification of HLA-DRB1 alleles and their role relative to onset of rheumatoid arthritis. Highlighted alleles constitute the most frequently reported alleles associated with rheumatoid arthritis. The risk of developing rheumatoid arthritis is among others associated with the presence of specific amino acids in the amino acid positions 70–74. Crucial is the RAA motif in positions 72–74, but the effect is modulated by the amino acids in positions 71 and 70 as well, where K in position 71 confers the highest risk, R an intermediate risk, and A and E a lower risk. Similarly, the amino acids Q and R in position 70 confer a higher risk than D. Bold alleles represent the most common alleles detected in individuals with rheumatoid arthritis.
| Sequence | SE Motif | Alleles | Relative Genotype Risk * | References |
|---|---|---|---|---|
| QKRAA | + | *04:01, *04:09, *04:13, *04:16, *04:19, *04:21,*14:21 | 5.9 | [32] |
| DKRAA | - | *13:03 | 5.9 | [32] |
| QRRAA | + | *01:01, *01:02, *01:05, *04:04, *04:05, *04:08, *04:10, *04:19, *14:02, 14:06, *14:09, *14:13, *14:17, *14:20 | 3.3 | [31,32] |
| RRRAA | + | *10:01 | 3.3 | [32] |
| QRRAE | - | *04:03, *04:06, *04:07, *04:11, *04:17, *04:20 | 1 | [33] |
| RRRAE | - | *09:01, *14:01, *14:04, *14:05, *14:07, *14:08, *14:10, *14:11, *14:14, *14:18 | 1 | [33] |
| QARAA | - | *13:09, *15:01 | 1 | [33] |
| QKRGR | - | *03:01, *04:22, *11:07 | 1 | [33] |
| DRRGQ | - | *07:01 | 1 | [33] |
| DRRAL | - | *08:01 | 1 | [32] |
| DRRAA | - | *04:15, *08:05, *11:01, *11:04, *11:05, *11:06, *11:09, *11:10, *11:12, *11:15, *11:18, *11:19, *11:22, *12:01, *13:05, *13:06, *13:07, *13:11, *13:12, *13:14, *13:21, *13:25, *14:22, *16:01, *16:05 | 1 | [31,32] |
| DERAA | - | *01:03, *04:02, *11:02, *11:03, *11:16, *11:20, *11:21, *13:01, *13:02, *13:04, *13:08, *13:15, *13:17, *13:19, *13:22, *13:23, *14:16, *15:01 | 1 | [31,32] |
* Relative to model proposed by Du Montcel et al. [33] when expressing two of the same HLA-DR1 alleles.