PReS-FINAL-2141: Clinical features, therapeutic interventions and outcome of 362 patients with macrophage activation syndrome enrolled in a multinational survey

Introduction

A multinational collaborative effort aimed to develop a new set of criteria for macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (sjia) is ongoing. The data-collection phase of the project has been recently completed

Objectives

To describe the demographic, clinical, laboratory, and histopathologic features, therapeutic interventionsand outcome of 362 children with MAS collected in the study

Methods

Patient data were collected retrospectively in a web-based database, developed and handled at the coordinating centre (Istituto G. Gaslini, Genoa, Italy)

Results

362 patients with sjia-associated MAS were entered in the study website by 95 investigators (78.2% paediatric rheumatologists, 21.8% paediatric hemato-oncologists) from 33 countries. 208 patients (57.5%) were females. Median age at onset of sjia was 5.3 years (IQR 2.7-10.1 years) and median disease duration at onset of MAS was 3.5 months (IQR 0.1-2.6 years); MAS occurred at onset of sjia in 77 patients (22.2%). The most frequently observed clinical features were fever (96%), liver enlargement (70%) and spleen enlargement (58%); CNS involvement was reported in 122 patients (35%) and haemorrhagic manifestations in 71 patients (20%). The main laboratory abnormalities were: hyperferritinemia, increased D-dimer and liver enzymes, falling platelet count, hypertriglyceridemia and increased LDH. The most frequently reported trigger of MAS was sjia flare (53.8%), followed by infections (37.8%) and medication toxicity (4.3%). Hyperferritinemia, increased liver enzymes, LDH, triglycerides and D-dimer and falling platelet count were the sole laboratory parameters that showed a percentage change greater than 50% between pre-MAS visit and onset of MAS. Hemophagocytosis was seen in 2/3 of patients who underwent bone marrow aspirate. Therapeutic interventions included corticosteroids (97.7%), cyclosporine (61.2%), Iv Ig (36.3%), biologic medications (15.2%), etoposide (11.8%), other immunosuppressants (7.1%) and plasma exchange (4.1%). ICU admission was required in 34.9% of patients; the mortality rate was 8.1%

Conclusion

Fever and hepatosplenomegaly were the most frequently reported clinical features. Hyperferritinemia, increased liver enzymes, LDH, triglycerides and D-dimer and falling platelet count were the most frequently observed laboratory abnormalities. These laboratory parameters also showed the greatest change between pre-MAS visit and onset of MAS. Bone marrow aspirate exhibited hemophagocytosis in 2/3 of instances. Corticosteroids and cyclosporine were the most frequently used medications.

Disclosure of interest

None declared.