Background: Systemic juvenile idiopathic arthritis (sJIA) (Still’s disease) associated lung disease is a rare but severe complication of Still disease, characterized by pulmonary involvement with high morbidity and mortality rates. While the incidence of sJIA-LD has increased, its pathogenesis and risk factors remain poorly understood.

Objectives: This multicenter retrospective study aimed to evaluate the clinical, radiological, and laboratory features of patients with sJIA-LD, assess the impact of prior biologic treatments, and analyze treatment outcomes.

Methods: Data were collected from 18 patients diagnosed with sJIA-LD between 2007 and 2024 across five pediatric rheumatology clinics in Turkey. Clinical features, imaging findings, and treatment regimens before and after sJIA-LD diagnosis were analyzed. HLA-DRB1*15 typing was performed in a subset of patients.

Results: The median age of sJIA-LD diagnosis was 11.21 years, with a median disease duration of 2.76 years from sJIA diagnosis. MAS occurred in 88.9% of patients prior to the diagnosis of lung disease. Cough (100%), dyspnea (83.3%), and clubbing (50%) were the most common clinical manifestations. Ground-glass opacities were the most frequent imaging finding (66.6%). DRESS was observed in 11.1% of patients, with 27.7% experiencing adverse reactions to biologics. Treatment revision after sJIA-LD diagnosis occurred in 66.7% of patients, with JAK inhibitors demonstrating clinical stabilization or improvement in some cases. The overall survival rate was 94.4%, with one death due to fulminant MAS.

Conclusion: sJIA-LD is associated with high morbidity and systemic inflammation, particularly in patients with a history of MAS. Early recognition and comprehensive pulmonary assessment are critical for improving outcomes. Multidisciplinary approaches and further research are needed to refine management strategies and understand disease pathogenesis.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: None declared.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.