AQP4 and systemic lupus erythematosus: These autoimmune diseases include thyroid disease, myasthenia gravis,[8] celiac disease,[9] systemic lupus erythematosis (SLE), and Sjögren's syndrome.[10] If typical optic neuritis and myelitis occur in a patient with SLE or Sjögren's, it is important to look for NMO IgG/AQP-4 antibody as, the co-occurrence of the two disorders can occur and is more likely than SLE or Sjögren syndrome causing myelitis.[10] Non-organ-specific autoantibodies are common in NMO: ANA is seen in 40%, SSA in 16%, and neuronal or muscle acetylcholine receptor antibodies in 38.5%.[11]