Hypomethylation of the Human OAS2 Gene in Blood Cells as a Potential Biomarker for Rheumatoid Arthritis: Findings from an Iranian Case-control Study.

BACKGROUND

Given the pivotal role of DNA methylation in the progression and severity of rheumatoid arthritis (RA), identifying a unique methylation pattern associated with the disease could support early detection, disease monitoring, and the development of personalized treatment plans. We aimed to explore the potential of OAS2 and OAS3 methylation levels in peripheral blood cells. These levels could be used to diagnose RA and predict patient outcomes.

METHODS

We collected 105 peripheral blood specimens from RA patients and 110 from healthy subjects. We then performed methylation analysis using the methylation-quantification of endonuclease-resistant DNA (MethyQESD) technique. Finally, we analyzed the data using appropriate nonparametric tests.

RESULTS

Our study revealed a significant decrease in OAS2 gene methylation in RA patients (P<0.001). The ROC curve analysis further underscored the potential of OAS2 DNA methylation (AUC=0.718, P<0.001) to effectively distinguish RA patients from healthy individuals. Although OAS2 methylation was generally reduced in RA patients compared to controls, RA patients with a positive family history exhibited higher methylation than those without (P=0.018). Moreover, increased OAS2 methylation was associated with reduced CRP levels (r=-0.317, P<0.001).

CONCLUSION

The methylation levels of OAS2 in peripheral blood cells show promise in distinguishing RA patients from healthy individuals. Furthermore, these levels show potential in identifying inflammation, a family history of RA, and other related disorders.