Demethylation of CDKN2A in systemic lupus erythematosus and rheumatoid arthritis: a blood biomarker for diagnosis and assessment of disease activity

Introduction/objectives Considering the phenotypic and serological heterogeneity of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), significant challenges may intervene with the precise diagnosis. In this regard, numerous studies have shown that changes in DNA methylation levels can be used to distinguish between healthy individuals and those with SLE and RA, as well as to predict disease activity and prognosis. Methods In the current study, we evaluated quantitative methylation level of CDKN2A promoter in peripheral blood mononuclear cells (PBMCs) of SLE and RA patients, and healthy controls by methylation-quantification of endonuclease-resistant DNA (MethyQESD), a bisulfite conversion-independent method. Results Our findings revealed an excessive hypomethylation of CDKN2A in SLE and RA patients compared to healthy individuals ( P