Macrophage activation syndrome complicating rheumatic diseases in adults: case-based review

Macrophage activation syndrome (MAS) is a life-threatening complication of rheumatologic diseases. Data regarding the clinical course, management and outcome of adults with MAS is limited. Therefore, we aimed to describe the clinical features, treatment and outcome of adult patients with MAS, and review the literature for previous cohorts. We retrospectively reviewed patients with MAS complicating rheumatologic diseases between the years 2007 and 2017. Through Pubmed, Medline and Scopus literature search we identified previous cases of adult patients with MAS. We identified 7 patients with MAS complicating rheumatologic diseases (5 females and 2 males). The median age of diagnosis was 32 (range 26-57) years. The median follow-up was 30 months (range 6.95-36.5) months. The underlying rheumatologic disease was adult onset Still's disease (AOSD) in 3 patients, systemic juvenile idiopathic arthritis (sJIA) in 2 patients, systemic lupus erythematosus (SLE) in 1 patient, and systemic vasculitis in 1 patient. Four patients developed MAS concurrently with the clinical development of the rheumatologic disease. All the patients were treated with systemic corticosteroids. Five patients were treated with cyclosporine A, one of which received combination therapy with anakinra, and one received tocilizumab. Two patients deceased during the hospitalization. We identified 92 patients from literature cohorts, 73 (79%) of them with AOSD. MAS developed concurrently with the underlying rheumatologic disease in 25 (27%) patients, and 30 (33%) patients deceased. Our cohort and previous cohorts demostrate that MAS often presents concurrently with the underlying rheumatologic disease and is associated with a high mortality rate. Further larger prospective studies are needed to determine the optimal management of MAS.