Table 1.
Demographics of the healthy controls and the patients with rheumatoid arthritis (RA).
| Variables | Discovery Set (LC-MS/MS) |
Validation Set (MRM) |
||
|---|---|---|---|---|
| Healthy Controls (n = 20) |
RA Patients (n = 20) |
Healthy Controls (n = 43) |
RA Patients (n = 50) |
|
| Sex (Female/Male) | 14/6 | 14/6 | 25/18 | 39/11 |
| Age (Years) | 55.3 ± 3.9 | 59.2 ± 5.8 | 56.9 ± 4.7 | 59.9 ± 6.7 |
| RF (IU/mL) | - | 97.95 ± 81.1 | - | 79.5 ± 67.4 |
| RF-Positive, n | - | 16 | - | 40 |
| RF-Negative, n | - | 4 | - | 10 |
| ACPA (U/mL) | - | 161.2 ± 120.5 | - | 124.8 ± 112.6 |
| ACPA-Positive, n | - | 15 | - | 35 |
| ACPA-Negative, n | - | 5 | - | 15 |
| DAS28 | - | 3.3 ± 1.2 | - | 2.7 ± 1.2 |
| Low activity, n (DAS28 < 3.2) |
- | 12 | - | 37 |
| Moderate activity, n (3.2 ≤ DAS28 > 5.1) |
- | 6 | - | 9 |
| High activity, n (DAS28 > 5.1) |
- | 2 | - | 3 |
LC-MS/MS, Liquid chromatography–tandem mass spectrometry; MRM, multiple reaction monitoring; RF, rheumatoid factor; ACPA, anti-citrullinated protein antibodies; DAS28, Disease activity score in 28 joints.