Assessing the potential of epigenetic targets as biomarkers in the diagnosis and treatment of rheumatoid arthritis

IntroductionAlthough there are gold-standard diagnostic guidelines and effective treatments to slow the disease progression of rheumatoid arthritis (RA), approximately 40% of patients still do not respond adequately to their initial treatment. The identification of specific and sensitive biomarkers for early and accurate diagnosis and response to treatment is a clinical priority and could reduce the time to effective therapy to mitigate the severity of tissue damage. Emerging studies show that epigenetic biomarkers play a role in RA-related pathways and are worthy targets that warrant further characterization.Areas coveredIn this review, the current significant literature around epigenetic studies of RA will be discussed, specifically, DNA methylation and histone modifications, being the most extensively studied. The pitfalls of biomarker studies in RA and how to potentially overcome barriers to their clinical application will be discussed.Expert opinionEpigenetic studies have shed light on mechanisms that mediate RA pathogenesis and potential roles as biomarkers of diagnosis and treatment response in conjunction with other biomarkers. Although these biomarkers are informative, limitations lie in their ease of use in clinical management and the requirement to ensure that the data are robust in large and diverse populations.