Sustained DMARD-free remission in rheumatoid arthritis - about concepts and moving towards practice.

Sustained DMARD-free remission (SDFR) is the best possible outcome in RA. It is characterized by sustained absence of clinical arthritis, which is accompanied by resolution of symptoms and restoration of normal physical functioning. Therefore it's the best proxy for cure in RA. The mechanisms underlying SDFR-development are yet unidentified. Hypothetically, there are two possible scenarios. The first hypothesis is based on the concept of regaining immune-tolerance, which implies that RA-patients are similar at diagnosis and that disease-processes during the disease-course shift into a favorable direction, resulting in regaining a state in which arthritis is persistently absent. This could imply that SDFR is theoretically achievable for all RA-patients. The alternative hypothesis is that RA-patients who achieve SDFR are intrinsically different from those who cannot. This would imply that DMARD-cessation could be restricted to a subgroup of RA-patients. Since the 1990s, DMARD-discontinuation and SDFR have been increasingly studied as long-term-outcome in RA. In this review, we describe hitherto results of clinical, genetic, serological, histological and imaging studies and looked for arguments for the first or second hypothesis in both auto-antibody-positive and auto-antibody-negative RA. In auto-antibody-negative RA, SDFR is presumably restricted to a subgroup of patients with high serological-markers of inflammation at diagnosis and a rapid and sustained decrease in inflammation after treatment-start. Identifying these RA-patients could be helpful in realizing personalized-medicine. In auto-antibody-positive RA, only few patients achieve SDFR and no definite conclusions can be drawn, but data could suggest that SDFR-patients might be a subgroup with relatively low inflammation from disease-presentation onwards.