RT Journal Article SR Electronic T1 Hyperferritinemia Wins Again: Defining Macrophage Activation Syndrome in Pediatric Systemic Lupus Erythematosus JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 1355 OP 1357 DO 10.3899/jrheum.210024 VO 48 IS 9 A1 Smitherman, Emily A. A1 Cron, Randy Q. YR 2021 UL http://www.jrheum.org/content/48/9/1355.abstract AB