Baseline clinical features comparison between patients with and without MAS during the followup. Values are n (%) or mean ± SD unless otherwise specified.
| Characteristics | Without MAS | Developing MAS | p* |
|---|---|---|---|
| Women (men), n | 41 (61) | 1 (4) | 0.367 |
| Age, yrs | 44.2 ± 15.7 | 57.0 ± 18.4 | 0.080 |
| Clinical features | |||
| Fever | 102 (100) | 5 (100) | – |
| Arthritis | 91 (89.2) | 3 (60) | 0.051 |
| Myalgia | 59 (57.8) | 5 (100) | 0.060 |
| Rash | 78 (76.5) | 3 (60) | 0.402 |
| Splenomegaly | 69 (67.6) | 5 (100) | 0.126 |
| Liver involvement | 57 (55.9) | 4 (80) | 0.288 |
| Lymphadenopathy | 48 (47.1) | 5 (100) | 0.021 |
| Sore throat | 55 (53.9) | 5 (100) | 0.043 |
| Lung involvement | 11 (10.8) | 2 (40) | 0.051 |
| Pericarditis | 16 (15.7) | 2 (40) | 0.156 |
| Pleurisy | 14 (13.7) | 1 (20) | 0.693 |
| Abdominal pain | 13 (12.7) | 3 (60) | 0.004 |
| Weight loss | 2 (1.9) | 0 | 0.569 |
| Systemic score, median (IQR) | 5 (4–7) | 8 (7–9.5) | 0.003 |
| Comorbidities | 30 (30.6) | 2 (40) | 0.299 |
| Laboratory markers | |||
| Leukocytosis > 15,000/mm3 | 48 (47.1) | 1 (20) | 0.236 |
| Serum ferritin, ng/ml, median (IQR) | 1090 (623.0–2000.0) | 4453 (1515.0–8441.0) | 0.013 |
| ESR, mm/h | 69.2 ± 25.5 | 75.4 ± 34.8 | 0.602 |
| CRP, mg/l, median (IQR) | 90 (20.0–110.0) | 120 (40.0–180.0) | 0.082 |
| Therapeutic strategies | |||
| Low-dose steroid monotherapy | 7 (6.9) | 0 | 0.545 |
| High-dose steroid monotherapy | 39 (38.2) | 2 (40) | 0.937 |
| Combination therapy, steroids + sDMARD | 28 (27.4) | 1 (20) | 0.714 |
| Combination therapy, steroids + biologics ± sDMARD | 28 (27.4) | 2 (40) | 0.542 |
↵* Statistical significance was expressed by p value < 0.005. Values in bold face indicate statistically significant results. MAS: macrophage activation syndrome; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; sDMARD: synthetic disease-modifying antirheumatic drugs; IQR: interquartile range.