Ab0891 Long Non-Coding Rna (H19) in Axial Spondylarthritis Patients: Insights Into Diagnostic Potential and Disease Parameters

Background: Axial Spondylarthritis (axSpA) is a complex chronic inflammatory disorder with an incompletely understood genetic basis. Epigenetic modifications, including lncRNA H19, are being investigated to unravel the unidentified components of the genetic dilemma. Objectives: This study aimed to investigate the role of lncRNA H19 in axSpA patients and its correlation with various disease activity parameters, functional status, and spinal radiographic scores. Methods: This is an observational case-control study conducted on forty patients fulfilling the ASAS criteria for axSpA. Forty healthy were included as controls. Relative quantification of lncRNA H19 expression in peripheral blood mononuclear cells of axSpA patients and controls was done by using real-time reverse transcription polymerase chain reaction. HLA-B27 testing was done for all axSpA patients. Different disease parameters were assessed ASDAS-CRP, BASDAI, BASFI and BASMI. Imaging included plain radiography of sacroiliac joints for all axSpA, and MRI was done for those with grade 0 or 1 modified New York criteria. Plain x-ray of cervical and lumbosacral spine (anteroposterior and lateral view) was done to calculate the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Results: LncRNA H19 expression was significantly higher in axSpA patients compared to healthy controls p<0.001 (Table 1). Twenty axSpA were classified as radiographic (r-axSpA) and twenty as non -radiographic axSpA (nr-axSpA). There was no significant difference between both groups regarding the expression of lncRNA H19. According to the HLA-B27 status, there was no statistically significant difference in the relative expression of lncRNA H19 between HLA-B27 positive and negative patients. Also, there no significant difference in the relative expression of lncRNA H19 between active and inactive axSpA assessed by BASDAI. No statistical difference was detected between axSpA patients on biological treatment and those who are biological-naïve. There was no significant statistical correlation observed between the lncRNA H19 and the acute phase reactants ESR and CRP. Similarly, there was no significant statistical correlation between lncRNA H19 and the disease parameters BASDAI, BASFI, ASDAS-CRP, BASMI and mSASSS spinal radiographic score. By plotting the receiver operating characteristic (ROC) curve to evaluate the performance of lncRNA H19 relative expression as a predictive marker for detecting patients with axSpA, revealing a cut-off value of ≥ 2.44, with a sensitivity of 52.5%, specificity of 97%, and negative predictive value (NPV) of 67.8%. Conclusion: The significantly higher expression of lncRNA H19 in axSpA patients than healthy controls may suggest a potential role in identifying axSpA patients. This was emphasized by the finding of a specificity of 97% which may provide a value of lncRNA H19 in the early diagnosis of axSpA, particularly those not fulfilling the ASAS classification criteria. This study paves the way for further research on lncRNA in asymptomatic first-degree relatives of SpA also in fibromyalgia patients frequently misdiagnosed as axSpA. The absence of correlation of lncRNA H19 and different disease parameters need to be evaluated in larger cohort studies. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.