The Coexisting Neuromyelitis Optica Spectrum Disorder and Systemic Lupus Erythematosus: A Therapeutic Challenge.

Neuromyelitis Optica (NMO), or Devic's disease, is an immune-mediated, usually relapsing, central nervous system (CNS) demyelination disorder associated with optic neuritis and transverse myelitis. It is characterised by the presence of longitudinally extensive transverse myelitis (LETM) and antibodies against water channel aquaporin-4 (AQP4-immunoglobulin G [IgG]). The term NMO spectrum disorder (NMOSD) includes patients with limited forms of NMO who are at risk of recurrence. Often patients with NMO or NMOSD have an associated systemic autoimmune disease, most commonly systemic lupus erythematosus (SLE) or Sjogren syndrome (SS) or a related profile of non-organ-specific autoantibodies. The intriguing aspect of coexisting NMOSD and SLE is whether they are independent diseases that can coexist with each other or the serological findings specific to both diseases in a patient is a non-specific finding of no prognostic or therapeutic concern. We have presented two cases of NMOSD coexisting with SLE and based upon the existing evidence in the literature we present that the two conditions are independent of each other, and, at times, it can throw a therapeutic challenge to any clinician.