Table 1

MAS in relation to lung disease

MAS before lung disease*†MAS at or during lung disease‡P value
Total MAS15 (33%)§Total MAS36 (78%)<0.0001
 Overt15 Overt240.059
 Subclinical only0 Subclinical only120.016
At sJIA onset12 (26%)First MAS episode20 (43%)
>1 episode6 (13%)
  • *MAS definitions were per Ravelli et al.11

  • †Before lung disease: up to 6 months before diagnosis of lung disease, because true onset of lung disease is not known.

  • ‡At or during lung disease: from 6 months before diagnosis of lung disease and thereafter.

  • §n=46 patients with sJIA, parenchymal lung disease and exposure to IL-1/IL-6 inhibition.

  • IL, interleukin; MAS, macrophage activation syndrome; sJIA, systemic juvenile idiopathic arthritis.