Systemic lupus erythematosus (SLE) and Sjogren’s syndrome are sometimes associated with various neurological syndromes, such as seizures and encephalopathy, but also myelitis and optic neuritis. In this context, the neurological syndromes have historically been regarded and treated as manifestations of the rheumatologic diseases.
An alternative view is that they represent coexistence of an autoimmune central nervous system (CNS) disease alongside a rheumatologic or other systemic autoimmune disease, said Brian Weinshenker, MD, Professor of Neurology and Consultant at the Mayo Clinic in Rochester, MN.
During the Monday session Lessons from Neuromyelitis Optica, Dr. Weinshenker will discuss immune-mediated CNS diseases, how they overlap with rheumatic disease, and the controversy surrounding whether they are manifestations of rheumatic disease or separate entities that may occur at higher frequency in those with underlying rheumatic disease. The session will be held from 1:00 – 2:00 pm in the Thomas Murphy Ballroom 1 & 2, Building B of the Georgia World Congress Center.
“Neuromyelitis optica is an inflammatory relapsing disease of the central nervous system that has been recognized for more than a century, over which time there had been considerable debate about whether it was a form of multiple sclerosis, which also frequently causes relapsing optic neuritis and myelitis,” Dr. Weinshenker said. “In the late 1990s, diagnostic criteria were developed that allowed its distinction from multiple sclerosis on clinical and radiologic grounds and, in 2004, a team of investigators at Mayo Clinic discovered a unique biomarker by indirect immunofluorescence that was specific for neuromyelitis optica.”
By 2005, Dr. Weinshenker said the antigenic target of the antibody was discovered and shown to be aquaporin-4 (AQP4). Subsequently, he said, facilitated by discovery of aquaporin-4-IgG, a highly specific biomarker, clinicians began to appreciate that the spectrum of neuromyelitis optica was far more diverse than previously recognized.
“Many patients with what had been diagnosed as idiopathic transverse myelitis and idiopathic optic neuritis, and who would not have satisfied criteria for neuromyelitis optica, were seropositive for aquaporin-4 autoantibodies,” Dr. Weinshenker said. “Recently revised international criteria now recognize those patients and others as having ‘neuromyelitis optica spectrum disorders (NMOSD),’ the umbrella term that is now used for these conditions.”
Lupus myelitis is a diagnosis often made by rheumatologists and neurologists, Dr. Weinshenker said, implying that SLE itself causes transverse myelitis.
“In most instances, patients who have transverse myelitis or optic neuritis in the setting of comorbid systemic lupus erythematosus are seropositive for aquaporin-4 autoantibodies, whereas patients without these neurological manifestations who have systemic lupus or Sjogren’s syndrome are hardly ever seropositive,” Dr. Weinshenker said. “Thus, a contemporary view suggests that the rheumatologic disorder and neuromyelitis optica spectrum disorders are co-associated, as opposed to the rheumatologic disorder being directly causal.”
For clinicians, he said, recognition of and testing for AQP4-IgG in the face of syndromes compatible with neuromyelitis optica spectrum disorders may facilitate a specific diagnosis and encourage them to make the appropriate referrals and treatment decisions.
“It is important to distinguish between a disease causing two different syndromes from two different syndromes being statistically co-associated,” Dr. Weinshenker said. “While treatments for neuromyelitis optica spectrum disorders overlap with those of many other autoimmune serological disorders, failure to make a diagnosis in this context may deprive the patient of benefit from new treatments for neuromyelitis optica spectrum disorders for which there is class 1 evidence for efficacy.”