In addition, Dr. Reveille discussed the 2019 Update of the American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network Recommendations for the Treatment of Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis. Dr. Reveille noted that the recommendations for treatment of ankylosing spondylitis and nr-axSpA are quite similar in this update.
Tumor necrosis factor inhibitor (TNFi) therapy is recommended over secukinumab or ixekizumab as the first biologic to be used, but either of the latter two medications is recommended over the use of a second TNFi in patients with primary nonresponse to the first TNFi. Co-administration of low-dose methotrexate with TNFi is not recommended, and sulfasalazine is recommended only for persistent peripheral arthritis when TNFi therapy is contraindicated.
With regard to patients with unclear disease activity, MRI of the spine or pelvis can be used to aid in assessment, but routine monitoring of radiographic changes with serial spine radiographs is not recommended in the 2019 guideline.8
Disease Progression
On this note, discussion of the best way to monitor disease activity in axial spondyloarthritis has been ongoing. In an editorial reflecting on the 2019 guideline, Michelena and Marzo-Ortega explain there are limitations in using MRI for disease monitoring in light of the limited knowledge on correlation between MRI lesions and treatment response and the uncertainty regarding the clinical significance of subclinical inflammatory changes on MRI. The authors also write that no therapies have yet been proved to be disease modifiers in axial spondyloarthritis and that data are limited regarding the potential effects from NSAIDs, TNFi’s and interleukin-17 inhibitors on slowing structural damage.9
Clinicians and patients alike also wonder what percentage of patients with nr-axSpA are likely to progress to radiographic axial spondyloarthritis over time. In a recent review on this subject, the authors note that most studies report 10–40% of patients with nr-axSpA progress to radiographic axial spondyloarthritis over a period of 2–10 years.6
Dr. Reveille noted in his lecture that male sex and elevated CRP are among the best predictors of radiographic progression. For this reason, Dr. Reveille advocates for repeat imaging of the sacroiliac joints when following patients over time, and this may include MRI studies when they can be covered by the patient’s insurance.
Studies in Radiology journals have noted that MRI can show new bone formation in the sacroiliac joints and peri-discal new bone formation in the spine.7 The proper use of such imaging for screening and monitoring disease may prove useful in the clinical care of patients.