Circulating Long Intergenic Non-Coding RNA LINC01538 as Potential Novel Biomarker for Acute Myocardial Infarction: Prospective Cohort Study

ABS TRACT Objective: Non-coding RNAs are the RNAs with no pro- tein coding function, long non-coding RNAs (LncRNAs) are the non-co-ding RNAs with more than 200 nucleotides. During the journey of discovering novel biomarkers for diagnosis of myocardial infarction (MI), the principle of studying the LncRNA as a potential would be al- ways attractive, as it needs easy sample collection, has high detection sensitivity and high myocardial tissue specificity. Our main objective was to investigate the potential of LINC01538 as a novel diagnostic biomarker for MI. Material and Methods: Quantitative real-time poly- merase chain reaction (RT-qPCR) was used to assess the expression of the serum LINC01538 in 50 ST Elevation MI (STEMI) patients and 48 controls. Results: The study showed a significant increase in serum level expression of LINC01538 in MI patients compared to controls [12 (6.6- 21.8) vs. 0.07 (0.01-0.2), p<0.001]. LINC01538 expression level in MI group was positively correlated with creatine kinase MB and high sen- sitive cardiac troponin I (hs-cTnI) (r=0.39, p=0.006 and r=0.22, p=0.007, respectively). Hs-cTnI found to have diagnostic value for MI with an area under curve (AUC) 0.917 [95% confidence interval (CI): 0.855-0.979, p<0.001] at an optimal cutoff point of 1.45 ng/L, 90% sensitivity and 91% specificity. However, LINC01538 showed the highest diagnostic value with an AUC 0.980 (95% CI: 0.942- 1, p<0.001) at an op- timal cut-off point of 1.76, 100% sensitivity and 98% specificity. Conclusion: Our findings have, for the first time, demonstrated that cir- culating LINC01538 are highly expressed in patients with MI, functioning as potential novel biomarker for diagnosis.