Case of MOG-IgG-associated disease with ankylosing spondylitis: A rare coexistence.

Myelin oligodendrocyte glycoprotein-associated disease (MOGAD) is an inflammatory neurological disease. It progresses with attacks by affecting the optic nerves and spinal cord. Bilateral or recurrent optic neuritis are the most common findings in adult patients. Its association with systemic autoimmune disorders such as Sjögren syndrome, antiphospholipid syndrome, autoimmune thyroiditis, and celiac disease is rare. The first and only case of MOGAD in a patient with ankylosing spondylitis with a history of anti-tumor necrosis factor-alpha (anti-TNF-α) use was reported. Herein, we present the coexistence of MOGAD in a patient with AS who did not have a history of anti-TNF-α therapy.