Session Type: Abstract Submissions (ACR)
Background/Purpose: It is well known that rapidly progressive interstitial lung disease (RP-ILD) in patients with dermatomyositis (DM) is associated with poor outcome. Previous findings suggested that interferon alfa (IFNα), interferon beta (IFNβ) and interleukin-18 (IL-18) might play an important role in the pathogenesis of DM (including the DM subtype clinically amyopathic dermatomyositis, CADM) and RP-ILD. The aim of this study was to determine whether levels of IFNα, IFNβ, IL-18 and other cytokines were associated with disease activity in CADM and RP-ILD.
Methods: Serum samples and clinical data were collected from 28 patients diagnosed as having DM with or without RP-ILD (14 with RP-ILD, 9 with chronic ILD and 5 without ILD), 4 other connective tissue diseases (CTD) and 4 normal healthy controls (NHC). Serum IFNα, IFNβ, IL-18 and other proinflammatory cytokines were quantified by commercially-available enzyme-linked immunosorbent assay (ELISA) kits over the disease course and related to disease activity.
Results: IFNα was detected in 7 of 28 (25%) DM serum samples before treatment. All 7 patients who had high IFNα concentration were diagnosed as CADM and RP-ILD. IFNα decreaced significantly and was no longer detectable after treatment which reduced symptoms (33.8 pg/ml vs. 0.0 pg/ml, P=0.019). In contrast, no IFNα was detected in any sera from DM without RP-ILD, other CTD or NHC. Sera from 14 of 28 (50%) patients with DM had high IFNβ in contrast to only 1 of 8 (13%) with other CTD and NHC. Nine of 14 (64%) sera with IFNβ before treatment were from CADM with RP-ILD patients. As with IFNα, IFNβ levels of 7 CADM and RP-ILD patients who responded to therapy and survived decreased significantly after improvement of pulmonary symptoms (108.9 pg/ml vs. 38.3 pg/ml, P=0.027). IL-18 was detected in all sera from DM with or without RP-ILD as well as other CTD and NHC before treatment. Serum IL-18 levels in CADM with RP-ILD, as well as in DM without RP-ILD, decreased significantly, parelleling symptom improvement (70.2 pg/ml vs. 25.0 pg/ml, P=0.017). Serum IL-17A, IL-23 and BAFF were not detected in any DM patient or NHC.
Conclusion: These results suggest that serum IFNα, IFNβ and IL-18 levels might be involved in the pathogenesis of RP-ILD and CADM, and might represent a useful biomarker of disease activity.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/serum-interferon-%ce%b1-%ce%b2-and-interleukin-18-are-associated-with-disease-activity-of-rapidly-progressive-interstitial-lung-disease-in-patients-with-clinical-amyopathic-dermatomyositis/