Several advances have been made in the understanding of the pathogenesis, as well as in the clinical evaluation and treatment, of early inflammatory
arthritis. The presence of
anti-citrullinated protein antibodies (
ACPAs) has emerged as a major new
biomarker for use in clinical practice. The presence of
ACPAs can be used to divide patients with early
arthritis into subsets that are phenotypically similar but have varying pathogenetic and prognostic features. Although the detection of
ACPAs is a major development in the diagnosis and prognosis of
rheumatoid arthritis (RA), prediction of the outcome of
arthritis at the individual level can still be much improved. For patients diagnosed with RA, and who have active
polyarthritis, treatment is not dependent on the assessment of prognostic factors, as these patients are best treated with combination
therapy; over 40% of these patients achieve remission with such treatment. In patients who present with
oligoarthritis, however, management should be based on the assessment of prognostic factors. The success of early treatment of inflammatory
arthritis and the recognition of a measurable preclinical phase of RA offer hope that treating the disease before it becomes clinically active might be possible.