Table 4 Patient characteristics of the three classes stratified by rheumatoid factor and anti-cyclic citrullinated peptide antibodies
Low/low class (n = 53) | Middle class (n = 183) | High/high class (n = 71) | p Value | |
|---|---|---|---|---|
RF, IU/ml | 11 (5, 30) | 87 (50, 139) | 384 (248, 604) | < 0.0001 |
Anti-CCP, U/ml | 7 (2, 22) | ≥ 100 (38, ≥ 100) | ≥ 100 (≥ 100, ≥ 100) | < 0.0001 |
Female sex | 89% | 83% | 76% | 0.1766a |
Age, years | 46.4 (13.0) | 49.3 (12.1) | 53.0 (10.3) | 0.0093 |
BMI | 22.2 (4.2) | 22.0 (3.3) | 22.8 (3.9) | 0.3774 |
Disease duration | 7.3 (6.9) | 7.9 (7.2) | 8.6 (8.7) | 0.8541 |
NSAID use | 89% | 87% | 90% | 0.8299a |
Glucocorticoid use | 66% | 70% | 65% | 0.6263a |
DMARD (other than MTX) use | 32% | 31% | 31% | 0.9793a |
MTX dose, mg/week | 7.6 (1.7) | 7.9 (1.8) | 7.7 (1.7) | 0.5264 |
Duration of MTX use | 2.7 (2.6) | 2.7 (2.8) | 2.6 (2.8) | 0.9885 |
Comorbidity | 77% | 74% | 87% | 0.0810a |
DAS28-CRP | 5.54 (4.92, 6.42) | 5.39 (4.89, 6.01) | 5.74 (5.12, 6.37) | 0.0251 |
Total modified Sharp score | 36.0 (8.0, 56.8) | 36.5 (12.0, 74.1) | 31.5 (13.0, 57.0) | 0.4305 |
HAQ | 1.21 (0.68) | 1.11 (0.63) | 1.38 (0.67) | 0.0132 |
MMP-3, ng/ml | 262 (132, 561) | 207 (105, 420) | 196 (101, 352) | 0.2372 |
IL-6, pg/ml | 26.5 (12.3, 56.5) | 28.5 (12.4, 70.2) | 33.6 (15.1, 61.8) | 0.6163 |
TNF, pg/ml | 0.73 (< 0.55, 1.09) | 0.91 (< 0.55, 1.23) | 1.15 (0.72, 1.82) | 0.0002 |
Low/intermediate/highb | 38%/55%/8% | 29%/63%/8% | 20%/51%/30% | 0.0007 |