Therapeutic challenges in patients with multiple sclerosis and ankylosing spondylitis: A case series

Multiple Sclerosis (MS) is a chronic immune-mediated disease affecting >2 million people worldwide. Coexistence with other autoimmune disorders, such as systemic lupus erythematosus (SLE), has been reported. However, reports of MS patients concurrently diagnosed with ankylosing spondylitis (AS) are rare, likely due to their differing immunogenic pathways. Management of patients with both MS and AS presents a clinical challenge, particularly due to the contraindication of TNF-α inhibitors (TNFi) in MS.

We present three patients with coexisting MS and AS. We characterize this population as well as provide an updated review of the literature detailing case reports with clinical information about patients diagnosed with both diseases, focusing on therapeutic challenges.

Among the 18 total cases from case reports of MS patients with AS (15 published and 3 from this study), where clinical details are available, relapsing remitting MS was the most common MS subtype, and typical presentations included sensory deficits, spastic paraparesis, and optic neuritis. CSF oligoclonal bands were positive in 11 of the 13 cases where lumbar puncture results were reported. TNFi were used in eight patients for AS and were discontinued in all eight due to concern for demyelination. Diagnosis of MS in these patients happened after the TNFi treatment. In contrast, secukinumab, an IL-17A inhibitor, was well tolerated and effective in controlling AS symptoms without worsening MS in the five reported patients who received it. One of our cases illustrates the potential for secukinumab to be used alongside modern MS therapies such as dimethyl fumarate and ocrelizumab. Another case also highlights the complexity of treatment planning in the context of pregnancy.

Patients with concurrent MS and AS may have a specific clinical and laboratory profile. In instances where one disease process is more active than the other, a single immunotherapy agent targeting that condition may be favored, whereas using dual immunosuppression can be reserved for those with both highly active MS and AS.