Table I.
Clinical characteristics of the study population in the validation phase.
| Index | RA | Health control | SLE |
|---|---|---|---|
| Sex (male/female) | 4/38 | 5/39 | 5/40 |
| Age (years) | 56.47±12.07 | 54.57±14.27 | 53±9.87 |
| Duration (years) | 15.10±10.67 | N/A | N/A |
| TNF-α (ng/l) | 14.96±6.14 | N/A | N/A |
| IL-6 (pg/ml) | 21.21±19.17 | N/A | N/A |
| C3 (g/l) | 1.07±0.20 | N/A | N/A |
| C4 (g/l) | 0.21±0.07 | N/A | N/A |
| RA-IgG (IU/ml) | 201.103±91.77 | N/A | N/A |
| RA-IgM (IU/ml) | 289.58±166.40 | N/A | N/A |
| RA-IgA (IU/ml) | 327.21±112.02 | N/A | N/A |
| IgA (g/l) | 4.59±3.88 | N/A | N/A |
| IgG (g/l) | 14.01±4.84 | N/A | N/A |
| IgM (g/l) | 2.02±0.71 | N/A | N/A |
| IgE (g/l) | 37.515±19.49 | N/A | N/A |
| RF (IU/ml) | 530.827±378.19 | N/A | N/A |
| Anti-CCP (U/ml) | 477.97±207.23 | N/A | N/A |
| TJC | 13.96±8.05 | N/A | N/A |
| SJC | 10.12±6.72 | N/A | N/A |
| ESR (mm/h) | 68.08±27.91 | N/A | N/A |
| CRP (mg/l) | 51.27±29.36 | N/A | N/A |
| DAS28 score | 5.59±1.39 | N/A | N/A |
| SLEDAI | N/A | N/A | 9.64±4.66 |
RA, rheumatoid arthritis; SLE, systemic lupus erythematosus; RF, rheumatoid factors; anti-CCP, anti-cyclic citrullinated peptide; TJC, tender joint counts; SJC, swollen joint counts; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; DAS28, disease activity score 28; SLEDAI, systemic lupus erythematosus disease activity index; 0–4 score (essentially inactive group), 5–9 score (mild activity group) and score >10 (moderate to severe activity group).