Expression of circulating p38 inhibited cutaneous squamous cell carcinoma-associated long non-coding RNA in rheumatoid arthritis: A descriptive study

Background & objectives Rheumatoid arthritis (RA) is a chronic inflammatory disease characterised by joint destruction. Long non-coding RNAs (lncRNAs) have emerged as key regulators in RA pathogenesis. This study explores the serum expression of p38-inhibited cutaneous squamous cell carcinoma-associated lncRNA (PICSAR lncRNA) as a potential non-invasive biomarker for RA. Methods PICSAR lncRNA expression was measured in serum samples from 36 individuals with RA and 20 healthy individuals using qRT-PCR over a 24 h time course. Correlation analyses with demographic and biochemical parameters, American College of Rheumatology (ACR) scores, and ROC analysis were conducted to evaluate the diagnostic potential of PICSAR lncRNA. Results We observed significant upregulation of PICSAR lncRNA in individuals with RA at 0 h (448.9±358.6, P=0.0059) and 6 h (202.0±121.2, P=0.0005) compared to healthy individuals, with stable levels maintained up to 24 h. The ROC analysis yielded a substantial AUC value of 0.74 for PICSAR lncRNA in individuals with RA. In females with RA, PICSAR lncRNA levels showed a positive correlation with ACR scores and a negative correlation with age. Interpretation & conclusions PICSAR lncRNA is implicated in RA pathogenesis and may serve as a potential non-invasive diagnostic biomarker for RA.