Clinical characteristics of patients with systemic JIA with or without macrophage activation syndrome (MAS).
| Characteristics | Systemic JIA with MAS (n = 33) | Systemic JIA without MAS (n = 48) | p |
|---|---|---|---|
| Male, n (%) | 16 (48.5) | 24 (50.0) | 0.54 |
| Age at systemic JIA onset, yrs, mean | 4.8 | 4.7 | 0.92 |
| Observation period, mo, mean | 97.8 | 102.2 | 0.43 |
| Time interval between JIA onset and MAS development, mo, mean | 24.8 | — | — |
JIA: juvenile idiopathic arthritis.