Novel Biomarkers May Help Predict the Susceptibility of a Population to Rheumatoid Arthritis

Genetics (i.e., mutations) are considered to be the main factor predisposing to the etiology of rheumatoid arthritis (RA), but they account for only a few changes in RA disease risk, and in contrast to genetics, the environment may have an important impact on epigenetic properties associated with disease etiology. Recently, in a study published in the journal Scientific Reports entitled "Epigenome association study for DNA methylation biomarkers in buccal and monocyte cells for female rheumatoid arthritis", scientists from Washington State University found through the study that cells from cheek wipes may reveal biomarkers of rheumatoid arthritis, which may help develop a new method to help diagnose and start the treatment of patients before the disease occurs.

In the study, the researchers found a group of apparent mutations in the cells of women with rheumatoid arthritis, which may be different from patients without joint-destructive autoimmune diseases; apparent mutations are molecular factors and processes around DNA, which regulate the activity of the genome, regardless of DNA sequence. This study finds or is expected to help develop novel therapies for the treatment of rheumatoid arthritis.

Researcher Michael Skinner said that if these patients can be found ten years in advance before the disease occurs, it may open up the entire field of research in preventive medicine that we previously could not obtain. Rheumatoid arthritis affects the health of about 200,000 people in the United States each year, with a higher incidence in women than in men; although current drug therapies have very limited efficacy in many patients who have developed the disease, some studies have shown that therapies started in the early stages of the disease may lead to links in patients' disease symptoms. Identifying novel biomarkers may allow patients to start treatment earlier before the initial signs begin.

In the article, the researchers used wipes to collect oral and cheek cells from two groups of women, one with 26 Caucasian women from Spokane City and the other with 23 African women from Los Angeles; in each group, approximately half of the participants had rheumatoid arthritis, while the other half served as controls. Although some samples come from the cheek, oral cells allow researchers to analyze the epigenome. The researchers found epigenetic changes in regions called DNA methylation in two groups of participants with rheumatoid arthritis. The aim of this study was to see whether there were some differences between ethnic groups, because African women had shown some signs of increased incidence of rheumatoid arthritis; however, although the researchers observed some differences, they found that there was a large overlap in epigenetic mutations in women with rheumatoid arthritis between the two ethnic groups, which means that the biomarkers they identified may be signals indicating the disease.

Surprisingly, the researchers also found that most of the consistent DNA methylation sites in patients with the disease may be related to genes previously involved in the pathogenesis of rheumatoid arthritis; these findings may increase the evidence that the disease may be a systemic disease, and this also means that it is not only found in immune system cells involved in the development of rheumatoid arthritis, but also present in many different cells throughout the body. In addition, the researchers tested immune-related monocyte types in blood samples from some women, but oral cells also showed apparent mutations, suggesting that researchers may be expected to develop a relatively diagnostic cheek wipe test technique to screen for this disease.

In summary, the results of this study suggest that biomarkers of rheumatoid arthritis with epigenetic mutations in DNA methylation may be unique to specific cell types, and researchers have observed similar findings in two populations with different ethnic backgrounds; and epigenetic diagnosis of rheumatoid arthritis susceptibility seems feasible, which may help improve the clinical management of patients and allow researchers to develop feasible preventive strategies or measures.