Resolution of Inflammation Following Treatment of Ankylosing Spondylitis Is Associated with New Bone Formation

Abstract

Our study of AS spines documents that MRI findings predict new bone formation on radiograph. Demonstration of an increased likelihood of developing new bone following resolution of inflammation after anti-TNF therapy supports the theory that TNF-α acts as a brake on new bone formation. Because the number of new syndesmophytes was low, further study is necessary to make firm conclusions.

Magnetic Resonance Imaging of Vertebral Erosion in Spondyloarthritis

“…The presence of erosion may not tell us much about disease activity, but as we already know that the presence of a syndesmophyte is a predictor of damage progression 16 , and if erosion predicts syndesmophytosis, then spinal erosion could turn out to be an earlier predictor of the same outcome. It has been shown that resolution of inflammation with anti-TNF therapy may be associated with development of new syndesmophytes 17,18,19,20 , and so it may be reasonably expected that an accelerated osteoproliferative phase would include the disappearance of erosion, as suggested in this article. Whether this progresses to ankylosis remains to be seen.…”

Ankylosing Spondylitis – the changing role of imaging

“…Thus once inflammation improves on TNFα blocking treatment, the "brake" is released and repair and new bone formation can proceed [13]. This possible link with inflammation is supported by a recent study suggesting that syndesmophyte formation is more frequent in vertebral corners in which a previous inflammatory lesion has resolved [14]. A second study found that fatty vertebral corner lesions, thought to be a post-inflammatory finding, predate syndesmophyte formation in affected spinal units [15].…”

Analysis of Bone Samples from Patients with Spondyloarthritides—Identifying Causes of New Bone Formation in Axial Spondyloarthritis

“…16 ). Others reported that inflammatory lesions of the spine on MRI predict the development of new bone formation in AS 17,18 . A limitation of all MRI studies is that MRI, even if performed within short intervals, will not capture all inflammatory lesions between disease onset and occurrence of bone proliferative changes as detected by radiography.…”