Efficacy of Janus kinase inhibitors in the treatment of acute exacerbations of rheumatoid arthritis-associated interstitial lung disease: a retrospective observational case series.

Background: Acute exacerbation of rheumatoid arthritis-associated interstitial lung disease (AE-RA-ILD) is a life-threatening condition for which no standard therapy has been established. Although Janus kinase (JAK) inhibitors are effective for treating rheumatoid arthritis (RA) and have shown potential benefit in chronic RA-ILD, evidence supporting their use in AE-RA-ILD remains extremely limited. Methods: This retrospective observational study included consecutive patients hospitalized for AE-RA-ILD who received JAK inhibitors alongside systemic glucocorticoids between January and December 2024. Clinical characteristics, laboratory data, treatment regimens, and outcomes were extracted from medical records. High-resolution computed tomography images were quantitatively evaluated at three time points-before acute exacerbation (AE), at exacerbation onset, and after treatment-using a standardized computed tomography (CT) scoring system. Results: Six patients with AE-RA-ILD were included. In five of the six cases, the JAK inhibitor was discontinued due to an adverse event prior to AE onset, with a median interval of 9 days between discontinuation and AE onset. Upadacitinib was administered to four patients, and baricitinib to two patients. Three patients received methylprednisolone pulse therapy. Respiratory status improved in all patients, as indicated by increases in the PaO Conclusion: In this retrospective case series, adjunctive treatment with JAK inhibitors was associated with improvements in respiratory status and radiological findings in patients with AE-RA-ILD. These findings suggest that JAK inhibitors may represent a promising therapeutic option for this severe condition and support the need for further investigation in larger, prospective studies.