![]() ![]() Beta-interferon, a treatment promoted for MS, exacerbates NMOSD. ![]() Treatments for NMOSD include corticosteroids and plasmapheresis for acute attacks and mycophenolate mofetil, azathioprine, and rituximab for relapse prevention. Currently, in the AQP4-IgG era, 5 years after onset, approximately 30% of NMO patients will require a cane to walk and 10% will be wheelchair bound. More effective treatments combined with earlier and more accurate diagnosis has led to improved outcomes. NMOSD attacks are often severe resulting in a rapid accumulation of disability (blindness and paraplegia). NMOSD typically has a worse natural history than MS, with frequent and early relapses. Importantly, the prognosis and optimal treatments for the 2 diseases differ. Many patients with NMOSD are misdiagnosed as having MS. The clinical course is characterized by relapses of optic neuritis or transverse myelitis, or both. Symptoms and signs attributable to area postrema involvement include intractable hiccups, nausea and vomiting, and these may occur in isolation, herald the onset of NMO, or occur in association with the more classical optic neuritis or Longitudinally Extensive Transverse Myelitis (LETM).(5) Magnetic resonance imaging typically reveals large inflammatory spinal cord lesions involving 3 or more vertebral segments.ĭuring acute attacks, the cerebrospinal fluid contains inflammatory cells, but usually lacks evidence of intrathecal IgG synthesis. Circumventricular organs (CVO eg, area postrema) are preferentially involved. Results are calculated by comparing the median fluorescence response for SS-A/Ro and SS-B/La microspheres to a 4-point calibration curve.(Package insert: Bioplex 2200 ANA Screen.Neuromyelitis optica (NMO), sometimes called Devic disease or opticospinal multiple sclerosis (MS) is a severe, relapsing, autoimmune, inflammatory and demyelinating central nervous system disease that predominantly affects optic nerves and spinal cord.(1) The disorder is now recognized as a spectrum of autoimmunity (termed NMO spectrum disorders: NMOSD) targeting the astrocytic water channel aquaporin-4 (AQP4).(1,2) Brain lesions are observed in >60% of patients with NMOSD and approximately 10% will be MS-like.(3) Children tend to have greater brain involvement than adults and brain lesions are more symptomatic than is typical for adult patients.(4) Extensive cerebral white matter signal abnormalities are sometimes encountered, most commonly in children, and are sometimes associated with encephalopathy. ![]() A primary laser reveals the fluorescent signature of each microsphere to distinguish it from microspheres that are labeled with other antigens, and a secondary laser reveals the level of PE fluorescence associated with each microsphere. The microspheres are washed to remove unbound conjugate, and bound conjugate is detected by laser photometry. Phycoerythrin (PE)-conjugated antihuman IgG antibody is then added to detect IgG anti-SS-A/Ro or anti-SS-B/La bound to the microspheres. The microspheres are washed to remove extraneous serum proteins. SS-A/Ro antibodies, if present in diluted serum, bind to the SS-A/Ro antigens on the microspheres, and SS-B/La antibodies, if present, bind to the SS-B antigen on the microspheres. Recombinant SS-A/Ro 52 kD, affinity-purified SS-A/Ro 60 kD, and affinity-purified SS-B antigen are coupled covalently to polystyrene microspheres that are impregnated with fluorescent dyes to create a unique fluorescent signature. SSB antibodies are found primarily in patients with Sjogren syndrome or SLE, where they occur with frequencies of approximately 60% and 15%, respectively.(1,2) SSB antibodies occur only infrequently in the absence of SSA antibodies.įor more information see Connective Tissue Disease Cascade. SSB or La is composed of a 48-kDa protein combined with RNA species. SSA antibodies are associated with childhood SLE, neonatal SLE, and with congenital heart block in infants born to mothers with SLE.(1,2) SSA antibodies have also been reported to be associated with features of extraglandular inflammation in patients with SLE including vasculitis, purpura, cytopenias, and adenopathy. SSA antibodies occur in patients with several different connective tissue diseases including Sjogren syndrome, an autoimmune disease that involves primarily the salivary and lachrymal glands (up to 90% of cases) systemic lupus erythematosus (SLE) (40%-60% of cases) and rheumatoid arthritis. SSA or Ro is composed of protein antigens of 52 kDa and 60 kDa combined with cytoplasmic RNA species. Antibodies to ENA are common in patients with connective tissue diseases (systemic rheumatic diseases). Sjogren syndrome (SS)A (Ro), SSB (La), ribonucleoprotein (RNP), and Smith (Sm) proteins are autoantigens commonly referred to as extractable nuclear antigens (ENA). ![]()
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