Interferon-alpha 1 expression indicates the disease activity and response of patients with ankylosing spondylitis to anti-TNF-α treatment.

Objectives: This study aimed to investigate whether interferon-alpha 1 (IFNA1) is predictive of Ankylosing spondylitis (AS) progression and treatment response to Tumour necrosis factor inhibitors (TNFis).

Methods: Data of 50 AS patients receiving TNFi for 24 weeks were retrospectively analysed. AS patients who reached the Assessment of Spondyloarthritis International Society 40 response at the W24 were classified as responders to TNFi treatment; otherwise, they were classified as nonresponders. Human fibroblast-like synoviocytes (HFLS) isolated from AS patients (AS-HFLS) were used for in vitro validation.

Results: When the IFNA1 expression level was used to diagnose AS patients, an area under the curve of 0.895 was yielded (P < .001). Pearson correlation analysis showed negative correlations between IFNA1 expression, C-reactive protein (CRP) level, Bath AS Disease Activity Index scores, AS Disease Activity Score with CRP, and the production of inflammatory cytokines. An increased IFNA1 expression level was found to be associated with a better treatment response to TNFi. IFNA1 overexpression could protect HFLS against inflammatory response in the setting of AS.

Conclusions: Blood IFNA1 deficiency is correlated with inflammatory cytokine production and disease activity and is indicative of unsatisfied response to TNFi treatment in AS patients.