Time to discard old concepts once and for all
Children with enthesitis-related arthritis often have a high burden of disease and could benefit from medications currently approved for adults with spondyloarthritis, according to a review published in Arthritis Care & Research.
Dr. Pamela F. Weiss
“Enthesitis-related arthritis (ERA) was the JIA [juvenile idiopathic arthritis] category applied to children with spondyloarthritis (SpA), recognizing enthesitis as a defining characteristic,” wrote Pamela F. Weiss, MD, of Children’s Hospital of Philadelphia, and colleagues.
The ERA criteria include “arthritis plus enthesitis; or arthritis or enthesitis plus at least two of the following: sacroiliac tenderness or inflammatory back pain, HLA-B27 positivity, first-degree relative with HLA-B27–associated disease, acute anterior uveitis, and arthritis in a male older than 6 years,” the review authors noted.
“None of the [Food and Drug Administration]–approved therapies for peripheral SpA or nonradiographic axial SpA” have been studied or approved for use in children with ERA, but data support biologic similarity to SpA in adults; notably, studies of the HLA-B27 allele have identified it as a risk factor for both SpA and ERA, they said.
Common factors in adult and childhood conditions
“The principal commonalities of children with ERA and axial arthritis, and adults with nonradiographic axial SpA, include enthesitis, arthritis, inflammatory back pain, anterior uveitis, HLA-B27 positivity, and family history of HLA-B27–associated disease,” the review authors wrote.
The first-line treatment for both ERA with axial arthritis and nonradiographic axial SpA is NSAIDs, followed by tumor necrosis factor (TNF) inhibitors if needed, they said. However, conventional disease-modifying antirheumatic drugs (cDMARDs) may be used in cases of peripheral disease affecting five or more joints. Studies of treatment response show similarities between ERA in children and SpA in adults, the authors added, with nearly half of adults with axial disease unable to achieve remission and approximately one-third of children with ERA failing to respond to therapy.
Clinical trials could improve options and outcomes for those with ERA who need advanced therapy and such trials should evaluate response of axial and peripheral disease separately, the review authors emphasized. For example, “Eligibility criteria for children with ERA and axial features could include the presence of some of the following disease features: active inflammatory sacroiliitis based on typical MRI changes according to ASAS/OMERACT [Assessment of SpondyloArthritis international Society/Outcome Measures in Rheumatology Clinical Trials] criteria; elevated CRP [C-reactive protein]; and inadequate response or intolerance to NSAIDs,” they noted. “Considering the similarities between adult spondyloarthritis and ERA in terms of etiology, genetics, pathogenesis, and clinical manifestations, it is evident that medications approved for axial or peripheral SpA should be studied in children with ERA involving axial or peripheral joints, respectively, with the intent to achieve labeling for use in children,” they concluded.
New data highlight ERA disease burden
The need for additional therapies for ERA patients gained more support from a recent study in which a majority of children with ERA or juvenile psoriatic arthritis (jPsA) used biologics, but those with sacroiliitis in particular showed a significant disease burden despite high biologic use.