OBJECTIVE: To validate the Juvenile Spondyloarthritis Disease Activity Index (JSpADA), and modified versions thereof, in a North American cohort of patients with enthesitis-related arthritis (ERA).

METHODS: We utilized the Childhood Arthritis and Rheumatology Research Alliance Registry database ERA cohort to validate the JSpADA and its modifications (JSpADA6-no Schober, no C-reactive protein [CRP]/erythrocyte sedimentation rate [ESR]; JSpADA7-no Schober; and JSpADA7-no CRP/ESR) using the Outcome Measures in Rheumatology principles of face validity, discriminative validity, and responsiveness to change.

RESULTS: There were 51 subjects (64 visits) with complete JSpADA data with a mean age of 13.7 years and disease duration of 30.9 months. Subjects were predominantly White (84.3%), and 56.9% were male and 50% were HLA-B27 positive. The JSpADA showed high correlation with the clinical 10-joint Juvenile Arthritis Disease Activity Score (cJADAS10; = 0.81), moderate-to-high correlation with physician global assessment (PGA; = 0.69), and low-to-fair correlation with Childhood Health Assessment Questionnaire (CHAQ; = 0.22). The modifications of the JSpADA (JSpADA7-no Schober; JSpADA7-no CRP/ESR; and JSpADA6-no Schober, no CRP/ESR) performed similarly with high correlation with cJADAS10 ( = 0.81, 0.79, and 0.80, respectively), moderate-to-high correlation with PGA ( = 0.65, 0.67, 0.64, respectively), and low-to-fair correlation with CHAQ ( = 0.35, 0.34, 0.39, respectively). All modified versions of JSpADA had good responsiveness to change. All versions of JSpADA had excellent discriminative validity.

CONCLUSION: We propose the term for the modification of JSpADA with 6 elements (JSpADA6-no Schober, no CRP/ESR). This shorter disease activity index may improve implementation of JSpADA in both clinical practice and research trials.

<p><strong>OBJECTIVES: </strong>To evaluate the current practices in management of patients with juvenile spondyloarthritis (JSpA) who failed anti-tumour necrosis factor agents (anti-TNF).</p>

<p><strong>METHODS: </strong>An online survey was distributed to Childhood Arthritis and Rheumatology Research Alliance (CARRA) members of the JIA workgroup. Data collection included estimated number of JSpA patients who have failed anti-TNF therapy over two-year period, reasons for discontinuing anti-TNF therapy and other medications used afterward. The JSpA population was de ned as the following subtypes: enthesitis-related arthritis, psoriatic arthritis, undifferentiated spondyloarthritis, juvenile ankylosing spondylitis (AS) i.e. meeting modi ed NY criteria for AS before age 16, and reactive arthritis. Findings were summarised using descriptive statistics.</p>

<p><strong>RESULTS: </strong>The survey response rate was 36% (n= 60/169). The majority of participants were paediatric rheumatologists (93%). Many physicians have JSpA patients who failed anti-TNF therapy (63%). The most common reason for changing anti-TNF therapy was secondary non-response (72%). Sacroiliitis was the most important factor considered when assessing response to an anti-TNF agent and the most common reason for primary non-response (45%). When assessing anti-TNF failure for sacroiliitis, many (65%) felt imaging of the sacroiliac joints was the most important aspect in their decision making. The majority try a second anti-TNF agent after initial anti-TNF failure (87%) and switch to another medication class after 2 anti-TNF agents have failed (62%).</p>

<p><strong>CONCLUSIONS: </strong>More than half of paediatric rheumatologists surveyed have at least one JSpA patient who failed anti-TNF therapy. The majority failed because of secondary non-response. Sacroiliitis is an important but challenging aspect to manage for patients with JSpA.</p>

<p><strong>OBJECTIVE: </strong>Magnetic resonance imaging (MRI) is pivotal in the assessment of early sacroiliitis in children. We aimed to evaluate the agreement between local radiology reports and central imaging reviewers for active inflammation and structural damage at the sacroiliac joints (SIJs).</p>

<p><strong>METHODS: </strong>Eight hospitals each contributed up to 20 cases of consecutively imaged children and adolescents with juvenile idiopathic arthritis and suspected sacroiliitis. Studies were independently reviewed by 3 experienced musculoskeletal pediatric radiologists. Local assessments of global impression and lesions were coded from the local radiology reports by two study team members. Test properties of local reports were calculated using the central imaging team's majority as the reference standard.</p>

<p><strong>RESULTS: </strong>For 120 evaluable subjects, median age was 14 years, half of cases were male, and median disease duration at time of imaging was 0.8 years (IQR: 0-2). Sensitivity, 93.5% (95% CI: 78.6-99.2%), and specificity, 69.7% (95% CI: 59.0-79.0%), of local reports for inflammation were high and moderate, respectively, but positive predictive value (PPV) was low 51.8% (95% CI: 38.0-65.3%). Twenty-seven (23%) cases had active inflammation reported locally but rated normal centrally, nineteen (70%) with subsequent medication changes. Sensitivity of local reports detecting structural damage was low, 45.7% (95% CI: 28.8-63.4%), and specificity, 88.2% (95% CI: 79.4-94.2%), was high; PPV was low 61.5% (95% CI: 40.6-79.8%).</p>

<p><strong>CONCLUSION: </strong>Substantial variation exists in the interpretation of inflammatory and structural lesions at the SIJs in children. In order to reliably identify pathology, additional training in the MR appearance of the maturing SIJ is greatly needed.</p>