Second, imaging findings, such as bone marrow edema on magnetic resonance imaging (MRI) of the pelvis, can be seen in asymptomatic, healthy individuals. In one study of 187 individuals aged 45 and younger, bone marrow edema and fat infiltration was seen on the MRI in 7% of healthy patients and 14% of patients, respectively. This study examined 75 patients with ankylosing spondylitis, 27 with pre-radiographic inflammatory back pain, 26 with nonspecific back pain and 59 healthy controls.3
Third, interpretation of imaging study results may vary among radiologists. Efforts to use data-driven definitions for active and structural lesions of the sacroiliac joints as evaluated by MRI are ongoing.
Pathogenesis: Dr. Deodhar noted that genetics, gut microbiome dysbiosis and entheseal trauma and inflammation likely all play a role in axSpA pathogenesis. The association between ankylosing spondylitis and HLA-B27 positivity has long been recognized. Work by Dr. Deodhar et al. has helped clarify how ankylosing spondylitis patients with this finding may differ from those who are negative for HLA-B27. Example: HLA-B27 negative ankylosing spondylitis is more prevalent in non-white patients. Those with non-radiographic axSpA experience a longer diagnostic delay and have a higher frequency of peripheral arthritis, dactylitis, psoriasis and inflammatory bowel disease. They also have less frequent radiographic sacroiliitis and less symmetry of syndesmophytes as compared with their HLA-B27 positive counterparts.4
Management Recommendations
With respect to evidence-based guidelines for the management of patients with axSpA, a number of international societies have written recommendations. But reconciling discrepancies between these documents can be challenging. Dr. Deodhar highlighted points of agreement among these international guidelines.
Overall, these points include managing ankylosing spondylitis and non-radiographic axSpA in a similar manner. It also entails individualizing treatment based on patient-specific signs and symptoms, extra-articular manifestations and co-morbidities. Non-pharmacologic interventions include physical therapy, exercise, smoking cessation and management of psychosocial factors. For treatments, non-steroidal anti-inflammatory drugs (NSAIDs) should be used as first-line interventions, and long-term systemic corticosteroids are discouraged. The first-line biologic agent should be a tumor necrosis factor-alpha (TNF-α) inhibitor or interleukin (IL) 17 inhibitor. In general, Janus kinase (JAK) inhibitors should be used after failure of a TNF-α inhibitor.5,6
Patient Care
Dr. Deodhar concluded by discussing how rheumatologists can optimize quality of care in axSpA. One way is to individualize the treatment of the condition. Dr. Deodhar speculates that, in the future, this approach may include personalized medicine practices based on genetics, pharmacokinetics and other factors. He advises clinicians to routinely collect patient-reported outcomes and take these outcomes seriously when using a treat-to-target approach with patients. Focus on enhancing the multidisciplinary care of patients and the evaluation of potentially modifiable drivers of health-related quality of life. Also, it’s reasonable to explore tapering biologics with patients when it is appropriate to do so, but clinicians should avoid abruptly stopping medication completely.
