Yasin, Shima

Objective To develop and validate classification criteria for pediatric chronic nonbacterial osteomyelitis (CNO) jointly supported by EULAR and the American College of Rheumatology (ACR). Methods This international initiative had 4 phases: (1) candidate items were proposed in a survey of pediatric rheumatologists, (2) criteria definition and reduction by Delphi and nominal group technique exercises, (3) criteria weighting using multicriteria decision analysis, and (4) refinement of weights and threshold score in a development cohort of 441 patients and validation in another cohort of 514 patients. Results The new EULAR/ACR classification criteria for CNO require typical radiographic or magnetic resonance imaging findings and bone pain as an obligatory entry criterion and exclusion criteria of malignancy, infection, vitamin C deficiency, and hypophosphatasia, followed by additive weighted criteria in 5 clinical (site of bone lesions, pattern of bone lesions, age at onset, coexisting conditions, fever) and 4 pathology/laboratory domains (bone biopsy findings if done, anemia, C‐reactive protein level, and erythrocyte sedimentation rate). A total score ≥55 is required for classification as CNO. The new criteria had a sensitivity of 82% and specificity of 98% in the validation cohort. Conclusion These new classification criteria for pediatric CNO developed with international input reflect current views about CNO, have high specificity and good sensitivity, and provide a key foundation for future CNO research.

Objective Systemic juvenile idiopathic arthritis–associated lung disease (SJIA‐LD) is a life‐threatening disease complication. Key questions remain regarding clinical course and optimal treatment approaches. The objectives of the study were to detail management strategies after SJIA‐LD detection, characterize overall disease courses, and measure long‐term outcomes. Methods This was a prospective cohort study. Clinical data were abstracted from the electronic medical record, including current clinical status and changes since diagnosis. Serum biomarkers were determined and correlated with presence of LD. Results We enrolled 41 patients with SJIA‐LD, 85% with at least one episode of macrophage activation syndrome and 41% with adverse reactions to a biologic. Although 93% of patients were alive at last follow‐up (median 2.9 years), 37% progressed to requiring chronic oxygen or other ventilator support, and 65% of patients had abnormal overnight oximetry studies, which changed over time. Eighty‐four percent of patients carried the HLA‐DRB1*15 haplotype, significantly more than patients without LD. Patients with SJIA‐LD also showed markedly elevated serum interleukin‐18 (IL‐18), variable C‐X‐C motif chemokine ligand 9 (CXCL9), and significantly elevated matrix metalloproteinase 7. Treatment strategies showed variable use of anti–IL‐1/6 biologics and addition of other immunomodulatory treatments and lung‐directed therapies. We found a broad range of current clinical status independent of time from diagnosis or continued biologic treatment. Multidomain measures of change showed imaging features were the least likely to improve with time. Conclusion Patients with SJIA‐LD had highly varied courses, with lower mortality than previously reported but frequent hypoxia and requirement for respiratory support. Treatment strategies were highly varied, highlighting an urgent need for focused clinical trials.