TY - JOUR T1 - Hyperferritinemia Wins Again: Defining Macrophage Activation Syndrome in Pediatric Systemic Lupus Erythematosus JF - The Journal of Rheumatology JO - J Rheumatol SP - 1355 LP - 1357 DO - 10.3899/jrheum.210024 VL - 48 IS - 9 AU - Emily A. Smitherman AU - Randy Q. Cron Y1 - 2021/09/01 UR - http://www.jrheum.org/content/48/9/1355.abstract N2 - Macrophage activation syndrome (MAS) is a potentially life-threatening condition of hyperinflammation that can be secondary to an underlying chronic rheumatic condition, commonly systemic juvenile idiopathic arthritis (sJIA) but also childhood-onset systemic lupus erythematosus (cSLE). MAS is characterized by excessive activation of T lymphocytes and macrophages that lead to overproduction of cytokines and results in cytopenia, liver dysfunction, and coagulopathy1. It is critical to recognize MAS early in order to initiate the appropriate treatment quickly and prevent morbidity and mortality. However, in MAS secondary to rheumatic conditions, it can be difficult to distinguish MAS from active disease due to overlapping inflammatory features. Criteria to diagnose MAS in children with sJIA have been developed and initially validated2,3. Guidelines to diagnose MAS in children with SLE have been previously proposed though not further validated4. In the current issue of The Journal of Rheumatology, Gerstein and colleagues present novel criteria to discriminate MAS from active disease in patients with newly diagnosed cSLE, especially in those who are hospitalized, and compare the performance of their developed criteria to existing criteria5.In this report, the authors retrospectively reviewed hospitalizations of patients newly diagnosed with cSLE at a single center and divided patients into 2 cohorts from 2003–2007 and 2008–2013. They selected patients who were febrile, with no prior corticosteroid exposure, and with no evidence of infection. These criteria identified 34 patients in the 2003–2007 cohort and 41 patients in the 2008–2013 cohort. … Address correspondence to Dr. E.A. Smitherman, The Children’s Hospital, CPP N G10, 1600 7th Ave S, Birmingham, AL 35223-1711, USA. Email: Emily.Smitherman{at}peds.uab.edu. ER -