Table 4 Changes in levels of rheumatoid factor and anti‐cyclic citrullinated peptide antibodies assessed before and after 1 year of treatment according to the anti‐tumour necrosis factor agent used.
| Treatment | Level* | |||
|---|---|---|---|---|
| Baseline | 1 year | p Value | ||
| Anti‐CCP | Infliximab | 30.48 (14.08–73.21) | 30.25 (6.43–64.86) | 0.071 |
| Etanercept | 26.82 (3.7–87.72) | 28.98 (3.46–104.87) | 0.084 | |
| Adalimumab | 35.64 (2.23–75.02) | 36.78 (2.23–67.6) | 0.426 | |
| All | 31.18 (6.22–78.95) | 30.89 (4.56–66.25) | 0.589 | |
| RF (nephelometry) | Infliximab | 115 (43.3–290.3) | 65 (25.65–166.25) | <0.001 |
| Etanercept | 61 (17.67–367) | 54 (17.25–200) | 0.036 | |
| Adalimumab | 64 (15–259.75) | 30 (11.5–130.75) | 0.003 | |
| All | 90 (22.5–304.5) | 51.7 (17–163) | <0.001 | |
| IgM‐RF | Infliximab | 41.3 (17.07–117.05) | 30.9 (15.82–67.42) | <0.001 |
| Etanercept | 23.55 (7.25–86.25) | 22.35 (5.2–70.95) | 0.034 | |
| Adalimumab | 17.6 (6.67–84.97) | 11.7 (5.07–31.77) | 0.048 | |
| All | 29.9 (10.8–104.5) | 23.45 (9.15–64) | <0.001 | |
| IgA‐RF | Infliximab | 64.2 (22.1–179.4) | 41.8 (17.42–92.42) | <0.001 |
| Etanercept | 23.7 (6.45–109) | 22.7 (8.3–33.47) | 0.004 | |
| Adalimumab | 16.9 (8.8–33.47) | 12.3 (7.37–30.35) | 0.067 | |
| All | 30.1 (10.85–144.35) | 28.6 (9.45–83.5) | <0.001 | |
| IgG‐RF | Infliximab | 61.6 (28.87–156.8) | 42.6 (24.72–75.95) | <0.001 |
| Etanercept | 58.35 (33.35–181.1) | 53.5 (28.45–127.6) | 0.144 | |
| Adalimumab | 27.5 (12.5–76.1) | 20.5 (12.8–28.62) | 0.096 | |
| All | 48 (24.2–132.9) | 38.8 (19.7–86.3) | <0.001 | |
Anti‐CCP, anti‐cyclic citrullinated peptide antibodies; RF, rheumatoid arthritis.
*Median value (interquartile range).