antibodies. HLA-DRB1 gene have more strong correlation with disease development. Susceptibility to and outcome for rheumatoid arthritis (RA) may associate with particular HLA-DR alleles, but these alleles vary among ethnic groups and geographic areas. MicroRNAs MicroRNAs are a factor in the development of that type of disease. MicroRNAs usually operate as a negative regulator of the expression of target proteins and their increased concentration after biologic treatment (bDMARDs) or after anti-rheumatic drugs. Level of miRNA before and after anti-TNFa/DMRADs combination therapy are potential novel biomarkers for predicting and monitoring outcome. For instance, some of them were found significantly upregulated by anti-TNFa/DMRADs combination therapy. For example, miRNA-16-5p, miRNA-23-3p, miRNA125b-5p, miRNA-126-3p, miRNA-146a-5p, miRNA-223-3p. Curious fact is that only responder patients showed an increase in those miRNAs after therapy, and paralleled the reduction of TNFα, interleukin (IL)-6, IL-17, rheumatoid factor (RF), and C-reactive protein (CRP). Monitoring progression Many tools can be used to monitor remission in rheumatoid arthritis. DAS28: Disease Activity Score of 28 joints () is widely used as an indicator of RA disease activity and response to treatment. Joints included are (bilaterally): proximal interphalangeal joints (10 joints), metacarpophalangeal joints (10), wrists (2), elbows (2), shoulders (2) and knees (2). When looking at these joints, both the number of joints with tenderness upon touching (TEN28) and swelling (SW28) are counted. The erythrocyte sedimentation rate (ESR) is measured and the affected person makes a subjective assessment (SA) of disease activity during the preceding 7 days on a scale between 0 and 100, where 0 is "no activity" and 100 is "highest activity possible". With these parameters, DAS28 is calculated as: From this, the disease activity of the affected person can be classified as follows: It is not always a reliable indicator of treatment effect. One major limitation is that low-grade synovitis may be missed. Other: Other tools to monitor remission in rheumatoid arthritis are: ACR-EULAR Provisional Definition of Remission of Rheumatoid arthritis, Simplified Disease Activity Index and Clinical Disease Activity Index. Some scores do not require input from a healthcare professional and allow self-monitoring by the person, like HAQ-DI. Prevention There is no known prevention for the condition other than the reduction of risk factors. Supplementation Evidence suggests that increasing vitamin D levels to the range of 40–60 ng/mL could reduce the risk of rheumatoid arthritis. Management There is no cure for RA, but treatments can improve symptoms and slow the progress of