[Macrophage activation syndrome associated with systemic juvenile idiopathic arthritis]

To describe the characteristics of macrophage activation syndrome associated with juvenile idiopathic arthritis.

This is a retrospective study involving 462 patients with juvenile idiopathic arthritis. Seven (1.5%) of those patients suffered from systemic onset juvenile idiopathic arthritis and developed macrophage activation syndrome. The median age of the juvenile idiopathic arthritis onset was 3 years and 10 months and the median duration of juvenile idiopathic arthritis before macrophage activation syndrome was 8 years and 4 months. All of them presented with fever, jaundice, hepatosplenomegaly, bleeding, pancytopenia, abnormal liver function tests and abnormal coagulation profile. Three cases presented associated infections and one patient developed macrophage activation syndrome two weeks after the administration of sulfasalazine. Three patients died and the macrophage hemophagocytosis was present in five. The treatment of macrophage activation syndrome included pulse therapy with methylprednisolone in all of them, cyclosporine A in three, plasma exchange in two and intravenous immunoglobulin in two.

Macrophage activation syndrome is a complication of the systemic onset juvenile idiopathic arthritis with a high morbidity and mortality rate.