Spontaneous, drug-induced, and drug-free remission in peripheral and axial spondyloarthritis.

In spondyloarthritis (SpA), spontaneous remission is best described in reactive arthritis, a form of peripheral SpA. Prior SpA observational studies suggested that a significant percentage of patients reached spontaneous remission; however, these patients were followed up under older, broader European Spondyloarthropathy Study Group (ESSG) criteria or were not defined by specific criteria. In general, they were mixed populations of peripheral and axial disease, and the subsets were not differentiated when assessing end points such as remission. There are limited data on the natural history of axial SpA, in part because of the evolution of the criteria with the more recently developed Assessment of SpondyloArthritis International Society (ASAS) criteria, including the designation of non-radiographic axial SpA and peripheral SpA. Clinical trials have been conducted with various remission end points including withdrawal of therapy to determine remission maintenance. The following review addresses the potential for remission in axial and peripheral SpA based on the data from both observational studies and clinical trials.