Meta-analysis for disease risk in different rheumatoid arthritis (RA) subgroups divided by the presence/absence of anti-CarP and anticyclic citrullinated peptide (anti-CCP) antibodies in subjects exposed to any HLA-DRB1 SE alleles compared with non-exposed subjects
| Group | Cohort | SE | OR* | 95% CI | p Value | |
|---|---|---|---|---|---|---|
| None N (%) | Any N (%) | |||||
| CarP-FCS | ||||||
| Controls | Leiden EAC | 674 (55.7) | 537 (44.3) | 1.0 | Ref. | – |
| Swedish EIRA | 635 (49.7) | 643 (50.3) | 1.0 | Ref. | – | |
| Meta-analysis | 1.0 | Ref. | – | |||
| CCP−/CarP-FCS− | Leiden EAC | 147 (52.5) | 133 (47.5) | 1.14 | 0.88 to 1.47 | 0.34 |
| Swedish EIRA | 286 (45.0) | 350 (55.0) | 1.22 | 1.01 to 1.49 | 0.043 | |
| Meta-analysis | 1.19 | 1.02 to 1.39 | 0.028 | |||
| CCP−/CarP-FCS+ | Leiden EAC | 29 (56.9) | 22 (43.1) | 0.95 | 0.54 to 1.68 | 0.87 |
| Swedish EIRA | 43 (50.6) | 42 (49.4) | 0.92 | 0.59 to 1.44 | 0.73 | |
| Meta-analysis | 0.93 | 0.66 to 1.32 | 0.69 | |||
| CCP+/CarP-FCS− | Leiden EAC | 20 (20.4) | 78 (79.6) | 4.90 | 2.96 to 8.10 | <0.001 |
| Swedish EIRA | 111 (17.7) | 515 (82.3) | 4.63 | 3.65 to 5.86 | <0.001 | |
| Meta-analysis | 4.68 | 3.78 to 5.80 | <0.001 | |||
| CCP+/CarP-FCS+ | Leiden EAC | 57 (20.4) | 222 (79.6) | 4.89 | 3.58 to 6.68 | <0.001 |
| Swedish EIRA | 78 (12.7) | 536 (87.3) | 6.99 | 5.37 to 9.10 | <0.001 | |
| Meta-analysis | 5.91 | 4.16 to 8.38 | <0.001 | |||
| CarP-Fib | ||||||
| Controls | Leiden EAC | 674 (55.7) | 537 (44.3) | 1.0 | Ref. | – |
| Swedish EIRA | 635 (49.7) | 643 (50.3) | 1.0 | Ref. | – | |
| Meta-analysis | 1.0 | Ref. | – | |||
| CCP−/CarP-Fib− | Leiden EAC | 168 (53.5) | 146 (46.5) | 1.09 | 0.85 to 1.40 | 0.49 |
| Swedish EIRA | 290 (46.0) | 340 (54.0) | 1.16 | 0.96 to 1.41 | 0.14 | |
| Meta-analysis | 1.13 | 0.97 to 1.32 | 0.11 | |||
| CCP−/CarP-Fib+ | Leiden EAC | 12 (41.4) | 17 (58.6) | 1.78 | 0.84 to 3.76 | 0.13 |
| Swedish EIRA | 39 (42.9) | 52 (57.1) | 1.35 | 0.87 to 2.08 | 0.18 | |
| Meta-analysis | 1.45 | 0.99 to 2.11 | 0.05 | |||
| CCP+/CarP-Fib− | Leiden EAC | 35 (26.7) | 96 (73.3) | 3.44 | 2.30 to 5.15 | <0.001 |
| Swedish EIRA | 90 (18.3) | 403 (81.7) | 4.50 | 3.48 to 5.82 | <0.001 | |
| Meta-analysis | 4.12 | 3.22 to 5.28 | <0.001 | |||
| CCP+/CarP-Fib+ | Leiden EAC | 44 (17.3) | 210 (82.7) | 5.99 | 4.25 to 8.45 | <0.001 |
| Swedish EIRA | 99 (13.3) | 648 (86.7) | 6.58 | 5.17 to 8.37 | <0.001 | |
| Meta-analysis | 6.38 | 5.24 to 7.77 | <0.001 | |||
Bold typeface indicates statistical significance.
*ORs in Sweden cohort adjusted for age, gender and residential areas.
EAC, Early Arthritis Clinic; EIRA, Epidemiological Investigation of Rheumatoid Arthritis; FCS, fetal calf serum; SE, shared epitope.