Table 1

Demographic, clinical, laboratory and histopathological features of AOSD and sJIA patients with MAS*

FeatureMAS in sJIA†
(n=362)
MAS in AOSD‡
(n=60)
Females208 (57.5)18 (30.0)
Median (IQR) age at onset of MAS, years8.1 (4.0–13.2)29.0 (22.0–37.0)
Fever341/355 (96.1)60/60 (100.0)
Splenomegaly201/347 (57.9)50/60 (83.3)
Active arthritis230/354 (65.0)19/60 (31.6)
Central nervous system disease122/349 (35.0)1/60 (1.7)
Haemorrhagic manifestations71/348 (20.4)1/60 (1.7)
Median (IQR) laboratory parameters
 Platelet count, x109/L144 (86–269)90 (60–144)
 Lactate dehydrogenase, units/L1203 (666–2345)1024 (599–2145)
 Triglycerides, mg/dL234 (151–318)208 (161–335)
 Fibrinogen, mg/dL267 (152–437)151 (104–219)
 Ferritin, ng/mL5353 (1500–13 040)1500 (1500–1500)§
Bone marrow haemophagocytosis149/249 (59.8)39/60 (65.0)
Death28/347 (8.1)13/60 (21.7)
  • *Data are number positive/number with information available (%), unless otherwise indicated.

  • †Adapted from Davì et al, Arthritis Rheumatol 2014;66:2871–80.

  • ‡Adapted from Wang et al, Ann Rheum Dis 2019, in press.

  • §The upper limit of ferritin detection was 1500 ng/mL.

  • AOSD, adult onset Still disease; MAS, macrophage activation syndrome; sJIA, systemic juvenile idiopathic arthritis.