Table 2.
HLA–DRB1 and PTPN22 genotypes in the entire IP cohort and in the RA, RF+, and anti-CCP+ subgroups*
| HLA–DRB1 and PTPN22 groups | No. (%) of entire IP cohort (n = 1,022) | No. (%) of RA subgroup (met ACR criteria by the tenth year) (n = 751) | No. (%) of IP cohort RF+ at baseline (n = 275) | No. (%) of IP cohort anti-CCP+ at baseline (n = 204) |
|---|---|---|---|---|
| 0 copies of SE alleles | 416 (40.7) | 288 (38.3) | 81 (29.5) | 40 (19.6) |
| 1 copy of SE alleles | 460 (45.0) | 349 (46.5) | 133 (48.4) | 108 (52.9) |
| HLA–DRB1*01 | 167 (16.3) | 119 (15.8) | 43 (15.6) | 28 (13.7) |
| HLA–DRB1*04 | 281 (27.5) | 220 (29.3) | 87 (31.6) | 76 (37.3) |
| HLA–DRB1*10 | 12 (1.2) | 10 (1.3) | 3 (1.1) | 4 (2.0) |
| 2 copies of SE alleles | 146 (14.3) | 114 (15.2) | 61 (22.2) | 56 (27.5) |
| HLA–DRB1*01/*01 | 15 (1.5) | 11 (1.5) | 2 (0.7) | 0 |
| HLA–DRB1*01/*04 | 59 (5.8) | 43 (5.7) | 23 (8.4) | 18 (8.8) |
| HLA–DRB1*0101/*0401 | 36 (3.5) | 24 (3.2) | 13 (4.7) | 11 (5.4) |
| HLA–DRB1*0101/*0404 | 12 (1.2) | 10 (1.3) | 5 (1.8) | 4 (2.0) |
| HLA–DRB1*01/*10 | 3 (0.3) | 3 (0.4) | 0 | 0 |
| HLA–DRB1*04/*04 | 63 (6.2) | 52 (6.9) | 34 (12.4) | 37 (18.1) |
| HLA–DRB1*0401/*0401 | 16 (1.6) | 14 (1.9) | 7 (2.5) | 7 (3.4) |
| HLA–DRB1*0401/*0404 | 33 (3.2) | 26 (3.5) | 22 (8.0) | 22 (10.8) |
| HLA–DRB1*04/*10 | 6 (0.6) | 5 (0.7) | 2 (0.7) | 1 (0.5) |
| PTPN22*1858T allele | ||||
| Negative | 608 (77.1) | 435 (77.5) | 138 (73.8) | 121 (72.5) |
| Positive | 181 (22.9) | 126 (22.5) | 49 (26.2) | 46 (27.5) |
*
Common genotype combinations are shown below the broad subtype combinations. IP = inflammatory polyarthritis; RA = rheumatoid arthritis; RF = rheumatoid factor; anti-CCP = anti–cyclic citrullinated peptide; ACR = American College of Rheumatology; SE = shared epitope.