Comparison of demographic, clinical and histopathological features, triggers, treatments and outcome between patients classified as MAS or non-MAS, by the expert panel*
| N | Patients classified as MAS (n=70) | N | Patients classified as non-MAS (n=33) | p Value | |
|---|---|---|---|---|---|
| Demographic characteristics | |||||
| Sex | 70 | 33 | 0.81 | ||
| Female | 42 (60.0) | 19 (57.6) | |||
| Male | 28 (40.0) | 14 (42.4) | |||
| Age at onset of MAS, median (IQR), years | 69 | 10.5 (4.4–14.6) | 32 | 7.6 (4.1–11.6) | 0.01 |
| Duration of systemic JIA at MAS onset, median (IQR), years | 69 | 0.9 (0.1–2.4) | 31 | 1.5 (0.1–4.1) | 0.31 |
| Clinical manifestations at onset of MAS | |||||
| Fever | 69 | 68 (98.5) | 33 | 28 (84.9) | 0.01† |
| Hepatomegaly | 67 | 50 (74.6) | 33 | 16 (48.5) | 0.01 |
| Splenomegaly | 65 | 37 (56.9) | 33 | 16 (48.5) | 0.43 |
| Lymphadenopathy | 65 | 36 (55.4) | 32 | 8 (25.0) | 0.005 |
| Active arthritis | 69 | 42 (60.9) | 33 | 17 (51.5) | 0.37 |
| Central nervous system involvement | 65 | 31 (47.7) | 33 | 8 (24.2) | 0.02 |
| Haemorrhagic manifestations | 67 | 26 (38.8) | 33 | 4 (12.1) | 0.006 |
| Heart, lung or kidney failure | 69 | 13 (18.8) | 33 | 1 (3.0) | 0.03 |
| Triggers | 0.49‡ | ||||
| Active disease | 58 | 28 (48.3) | 27 | 14 (51.8) | – |
| Infection | 58 | 23 (39.6) | 27 | 7 (25.9) | – |
| Treatment toxicity | 58 | 1 (1.7) | 27 | 3 (11.1) | – |
| Other | 58 | 3 (5.2) | 27 | 2 (7.4) | – |
| Unknown | 58 | 3 (5.2) | 27 | 2 (7.4) | – |
| Histopathological features | |||||
| Bone marrow aspiration and/or biopsy of l ymphnode and/or liver | 69 | 54 (78.3) | 33 | 16 (48.5) | 0.002 |
| Haemophagocytosis on bone marrow aspiration and/or biopsy of lymphnode and/or liver | 54 | 31 (57.4) | 16 | 11 (68.7) | 0.42 |
| Therapeutic interventions | |||||
| Any corticosteroids | 69 | 68 (98.5) | 33 | 33 (100.0) | 1.0 |
| Cyclosporine | 69 | 47 (68.1) | 33 | 24 (72.7) | 0.64 |
| Intravenous immunoglobulin | 68 | 27 (39.7) | 33 | 10 (30.3) | 0.36 |
| Biological medications† | 68 | 17 (25.0) | 33 | 9 (27.3) | 0.81 |
| Etoposide | 67 | 10 (14.9) | 33 | 4 (12.1) | 1.0 |
| Other immunosuppressants | 66 | 5 (7.6) | 32 | 3 (9.1) | 0.71 |
| Plasma exchange | 67 | 6 (9.0) | 33 | 2 (6.1) | 1.0 |
| Outcome | |||||
| ICU admission | 58 | 26 (44.8) | 29 | 5 (17.2) | 0.01 |
| Death | 69 | 7 (10.1) | 33 | 0 (0.0) | 0.01 |
*Except where indicated otherwise, data are the number (%).
†Administered biological medications included anakinra, tocilizumab, canakinumab, etanercept, abatacept, rituximab, alentuzumab.
‡The statistical comparison was made on the ensemble of triggering factors.
ICU, intensive care unit; JIA, juvenile idiopathic arthritis; MAS, macrophage activation syndrome.