In symptomatic patients with suspected axial spondyloarthritis (axSpA) in whom baseline magnetic resonance imaging (MRI) scanning is normal, a repeat MRI scan approximately 12 weeks later may be beneficial for diagnosis in men who are HLA-B27 positive, but not in women who are HLA-B27 positive or in those who are HLA-B27 negative, according to the results of a United Kingdom cohort study published in The Journal of Rheumatology.
Investigators sought to examine the natural history of MRI-determined bone marrow edema over a 12-week period in persons with suspected axSpA. A total of 109 MRI scans were performed on 30 participants who met Assessment of Spondyloarthritis International Society (ASAS) inflammatory back pain criteria. MRI was done at baseline and at 4, 8, and 12 weeks.
There were 29 participants who completed the study. All patients exhibited ≥1 SpA clinical feature and 86% (25 of 29) of participants had ≥2 SpA clinical features. Nonradiographic axSpA was diagnosed in 79% of participants, and 21% had mechanical back pain.
When ASAS classification criteria were applied, 26% of participants met the imaging arm, 39% met the clinical arm, and 35% met both arms. Overall, 59% of participants met the ASAS clinical criteria for axSpA prior to MRI scanning. A further 38% met ASAS imaging arm classification criteria throughout the study, and an additional 10% had a positive MRI of the spine with normal sacroiliac joint involvement.
In 14% of participants, axSpA changed from MRI negative to MRI positive (all HLA-B27-positive; odds ratio, 2.74). Overall, axSpA in 43% of men who were HLA-B27 positive and 12.5% of women who were HLA-B27 positive changed from MRI negative to MRI positive. No patients with HLA-B27-negative axSpA had a change.
The investigators concluded that repeat MRI scans within a 12-week period should be considered in men with HLA-B27-positive disease. “These results are highly relevant to aid in clinical decision making and to add to the body of evidence on MRI use in axSpA diagnosis,” they wrote.
Sengupta R, Marzo-Ortega H, McGonagle D, Wadeley A, Bennett AN; on behalf of the British Society for Spondyloarthritis. Short-term repeat magnetic resonance imaging scans in suspected early axial spondyloarthritis are clinically relevant only in HLA-B27-positive male subjects [published online December 1, 2017]. J Rheumatol. doi:10.3899/jrheum.170171