Systemic juvenile idiopathic arthritis and macrophage activation syndrome: update on pathogenesis and treatment

Curr Opin Rheumatol. 2018 Sep;30(5):514-520. doi: 10.1097/BOR.0000000000000526.


Purpose of review: The past decade has seen substantial progress in defining the cause and pathogenesis of the chronic childhood arthropathy systemic juvenile idiopathic arthritis (SJIA) and its related complication macrophage activation syndrome (MAS). The purpose of this review is to describe and synthesize advances in this field, particularly since 2016, with the potential to transform clinical practice.

Recent findings: Newly developed MAS classification criteria have been further studied and validated in other diseases and populations, as well as a recently proposed score to distinguish MAS from familial hemophagocytic lymphohistiocytosis. There has also been substantial progress toward understanding the genetic underpinnings of SJIA and MAS, both through targeted study of specific genes and the results of a large genome-wide association study. The immunopathogenesis of SJIA has been further elucidated through several studies regarding the proinflammatory cytokines interleukin-18, interferon (IFN)γ, and how their interplay impacts emergence of MAS. Finally, big data studies integrating genomic information with immunophenotypes have potential to provide novel insights into disease mechanisms in SJIA.

Summary: Collectively, these research advances have significant implications regarding the classification and diagnosis of SJIA and MAS, and support a next generation of biologic treatments including kinase inhibitors and targeted interleukin-18 or IFNγ blockade.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Arthritis, Juvenile / drug therapy
  • Arthritis, Juvenile / genetics*
  • Arthritis, Juvenile / immunology
  • Biological Factors / therapeutic use
  • Child
  • Cytokines / immunology
  • Genetic Predisposition to Disease
  • Genome-Wide Association Study
  • Humans
  • Interleukin-18 / immunology
  • Macrophage Activation Syndrome / drug therapy
  • Macrophage Activation Syndrome / genetics*
  • Macrophage Activation Syndrome / immunology


  • Biological Factors
  • Cytokines
  • IL18 protein, human
  • Interleukin-18