Long noncoding RNA intersectin 1-2 gradually declines during adalimumab treatment, and its reduction correlates with treatment efficacy in patients with ankylosing spondylitis

Previous studies show that long noncoding RNA intersectin 1-2 (lnc-ITSN1-2) promotes the inflammation process and serves as a potential biomarker in autoimmune diseases, except for ankylosing spondylitis (AS). Therefore, this study aimed to explore the correlation of baseline lnc-ITSN1-2 expression with disease risk and activity of AS, and to investigate its longitudinal change with treatment response to a tumour necrosis factor alpha (TNFα) inhibitor in patients with AS. In total, 63 patients with AS receiving 12-week adalimumab treatment were included and their baseline clinical features were collected. Lnc-ITSN1-2 expression in peripheral blood mononuclear cells (PBMC) of patients with AS was detected by reverse transcription quantitative polymerase chain reaction. Meanwhile, Assessment in Spondyloarthritis International Society (ASAS) 40 response was evaluated at week 2 (W2), W4, W8, and W12. According to the ASAS40 response status at W12, patients with AS were classified into responders and non-responders. PBMC lnc-ITSN1-2 expression was also determined in healthy controls (N = 60). Lnc-ITSN1-2 expression was elevated in patients with AS compared to controls (P < 0.001). Baseline lnc-ITSN1-2 expression was positively associated with C-reaction protein (CRP) (P = 0.021), interleukin (IL)-1β (P = 0.020), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score (P = 0.040), and Ankylosing Spondylitis Disease Activity score with C-reactive protein (ASDAS(CRP)) (P = 0.045) in patients with AS. Furthermore, lnc-ITSN1-2 expression declined during the treatment with adalimumab (P < 0.001). Notably, this reduction was more obvious in responders than non-responders. In conclusion, declined lnc-ITSN1-2 expression during the TNFα inhibitor treatment correlates with good treatment efficacy in patients with AS, suggesting its clinical value for AS management.