title: Update on enthesitis-related arthritis.
abstract: This review provides a detailed update regarding the genetics, pathogenesis, disease phenotype evaluation, therapies and expected outcomes for children with enthesitis-related arthritis (ERA).
  
  
  
  Recent studies evaluated human leukocyte antigen (HLA)-B27 subtypes and non-major histocompatibility complex genes including toll like receptor 4, NLRP3, CXCR4 and PTPN12 in children with ERA. The microbiome and γδ-T cells have also been an area of active investigation. Several studies focus on the imaging phenotype of children with ERA, including the use of ultrasonography and MRI. MRI techniques studied in this population include dedicated MRI, whole-body MRI and diffusion-weighted imaging. Conventional and biologic disease-modifying agents continue to be the mainstay of therapy, though the past 2 years have witnessed several greatly needed randomized controlled trials to study the efficacy of these medications in ERA. Finally, long-term effectiveness studies of biologics in children with ERA have helped inform provider and patient expectations of disease response and prognosis.
  
  
  
  Further evaluation of the role of the microbiome and the interleukin 17/interleukin 23 axis, techniques to optimize evaluation of disease features, and efficacy and effectiveness of newer medications are greatly needed in this understudied population of children.
authors.affiliation: aDivision of Rheumatology, The Children's Hospital of PhiladelphiabDepartment of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Pennsylvania, Philadelphia, USA.
authors.forename: Pamela F
authors.initials: PF
authors.lastname: Weiss
mesh_terms: D000293:Adolescent; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001171:Arthritis, Juvenile / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000235:genetics / Q000276:immunology*; D001688:Biological Products / Q000627:therapeutic use; D002648:Child; D038524:Diffusion Magnetic Resonance Imaging; D000069196:Gastrointestinal Microbiome / Q000276:immunology*; D015796:HLA-B27 Antigen / Q000235:genetics; D006801:Humans; D056724:Immunity, Humoral / Q000276:immunology*; D008279:Magnetic Resonance Imaging; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein / Q000235:genetics; D010641:Phenotype; D011379:Prognosis; D054594:Protein Tyrosine Phosphatase, Non-Receptor Type 12 / Q000235:genetics; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D019718:Receptors, CXCR4 / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology*; D051197:Toll-Like Receptor 4 / Q000235:genetics; D014463:Ultrasonography
chemical_list: D018501:Antirheumatic Agents; D001688:Biological Products; C527276:CXCR4 protein, human; D015796:HLA-B27 Antigen; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C453881:NLRP3 protein, human; D016692:Receptors, Antigen, T-Cell, gamma-delta; D019718:Receptors, CXCR4; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; C516738:PTPN12 protein, human; D054594:Protein Tyrosine Phosphatase, Non-Receptor Type 12