Evolution in the Understanding of Pediatric-Onset Axial Spondyloarthritis.

Abstract

Over the last decade, there has been substantial evolution of the concept of axial spondyloarthritis (SpA) with the recognition of the group of patients with nonradiographic SpA in adults. Axial SpA is a chronic inflammatory rheumatic disease that primarily affects the axial skeleton but frequently the patients also demonstrate peripheral arthritis and enthesitis (1). In the United States, the estimated prevalence of axial SpA is 0.9-1.4% (2,3) In the current concept, axial SpA in adults includes both those with radiographic evidence of structural damage of the sacroiliac (SI) joints or lumbar spine (Ankylosing Spondylitis, AS) and patients without radiographic damage of the SI joints or spine (nonradiographic SpA). The Assessment of Spondyloarthritis International Society (ASIS) developed classification criteria for nonradiographic SpA for use in adults that require either MRI imaging evidence of SI inflammation or the presence of HLA-B27 plus clinical features (4). Recently, treatment guidelines for both AS and nonradiographic SpA in adults have been developed. In 2015, a collaborative between the American College of Rheumatology, the Spondylitis Association of America and the Spondyloarthritis Research and Treatment Network, published treatment guidelines for both the AS and nonradiographic axial SpA groups. It is recommended, for both groups, to use NSAIDs and also anti-tumor necrosis factor (anti-TNF) inhibitors for active arthritis that fails to respond to NSAIDs .