Advances in our understanding of the pathogenesis of RA over the past two decades, particularly the identification of cytokines that promote synovial inflammation (e.g. TNF-α, IL-1 and IL-6), have led to treatment courses that affect the disease process itself, beyond alleviation of symptoms. In turn, emphasis has shifted to intervention early enough in the disease course to prevent the joint destruction that follows inflammation. Accordingly, in 2010 the ACR and the European League Against Rheumatism (EULAR) put forward revised classification criteria emphasizing RA characteristics that emerge early in the disease course, including ACPAs, a biomarker that predicts aggressive disease. These were in contrast with the 1987 ARA criteria, which distinguished established RA patients from those with other forms of arthritis, and identified patients with later disease. The categories of the 2010 ACR/EULAR criteria are grouped into four classifications, with point scores for each: joint symptoms; serology (including RF and/or ACPA); symptom duration, whether <6 weeks or >6 weeks; and acute-phase reactants (CRP and/or ESR). The criteria were developed in a three-phase process, beginning with an analysis of patient cohorts to determine what disease characteristics had persuaded clinicians to initiate MTX therapy, followed by consensus-based decisions and the creation of a scoring system that would predict which patients would go on to develop persistent and/or erosive disease.