Table 4.
Characteristics of two endotypes of RA cases with different autoantibody isotype patterns prior to RA diagnosis
| Characteristic | Early endotype (n = 116) | Late endotype (n = 98) | p-value |
|---|---|---|---|
| Duration of clinical follow-up available post-RA diagnosis, in years, mean (SD) | 7.4 (3.8) | 6.3 (3.20 | 0.03 |
| Age, mean years (SD) | 37.5 (8.5) | 36.2 (7.2) | 0.24 |
| Female Gender, % | 55 | 39 | 0.02 |
| Ever Smoke, % | 32 | 32 | 0.97 |
| Current smoker, % | 19 | 14 | 0.36 |
| X-ray Erosions, %1 | 47 | 41 | 0.33 |
| Lung Disease, % | 15 | 4 | 0.01 |
| Dry Eyes Mouth, % | 32 | 19 | 0.04 |
| Self-reported first-degree relative with RA, %2 | 18 | 14 | 0.29 |
| Body Mass Index | 0.75 | ||
| Normal, % | 21 | 22 | |
| Overweight, % | 47 | 46 | |
| Obese, % | 33 | 32 | |
| Medications, ever use % | |||
| Corticosteroids | 81 | 77 | 0.42 |
| Methotrexate | 91 | 83 | 0.06 |
| Leflunomide | 16 | 8 | 0.07 |
| Anti-TNF inhibitors | 81 | 64 | 0.01 |
| Rituximab | 7 | 8 | 0.73 |
| RA nodules | 8 | 7 | 0.86 |
| Mean # of Antibodies Positive post-diagnosis | 2.9 (1.7) | 1.6 (1.6) | <0.01 |
| Time of post-RA diagnosis serum sample for autoantibody testing, in years, mean (SD) | 1.4 (0.9) | 1.1 (0.9) | 0.05 |
1.
Erosions were assessed by chart review of all available follow-up data from the RA cases; there was no significant difference in numbers of subjects who had radiographs performed, or timing of radiographs, between endotypes.
2.
First-degree relative defined as parent, sibling or child with RA.