Article Title:  Neuromyelitis Optica and Non–Organ-Specific Autoimmunity
Authors:  Sean J. Pittock, MD; Vanda A. Lennon, MD, PhD; Jerome de Seze, MD; Patrick Vermersch, MD; Henry A. Homburger, MD; Dean M. Wingerchuk, MD; Claudia F. Lucchinetti, MD; He´lène Ze´phir, MD; Kevin Moder, MD; Brian G. Weinshenker, MD

Institutions: Mayo Clinic Rochester, MN, Mayo Clinic Arizona, Centre Hospitalier Regionale Universitaire de Lille, France

Background

Neuromyelitis optica (NMO) is a condition causing either or both attacks of optic neuritis or transverse myelitis.  The acute attacks of myelitis occurring in patients with NMO are associated with MRI lesions in the spinal cord that are 3 vertebral bodies in length or longer (longitudinally extensive transverse myelitis or LETM).  At Mayo Clinic, we recently discovered that NMO patients usually have antibodies in their blood that react with a protein called aquaporin-4, and this is now a specific test for NMO (NMO-IgG).   Patients with systemic lupus erythematosus (SLE) or Sjogren’s disease occasionally develop myelitis or optic neuritis.  It is also the case that patients with myelitis and optic neuritis may be found to have autoantibodies in their blood and occasionally will develop clinical symptoms suggestive of SLE or Sjogren’s disease after they are diagnosed with myelitis or optic neuritis.  In these circumstances, they are usually diagnosed as having a complication of their SLE or Sjogren’s syndrome.  We suspected, however, that this may represent coexistence between neuromyelitis optica (NMO) and SLE or Sjogren’s, rather than SLE or Sjogren’s being the cause of the myelitis and optic neuritis.

Methods

We evaluated 153 US patients with NMO-type illnesses, either with both optic neuritis and myelitis or with transverse myelitis and positive test results for NMO-IgG.  We also evaluated 14 French patients with NMO-type illnesses occurring in patients with systemic lupus or Sjogren’s and 4 with NMO-type illness without systemic lupus or Sjogren’s.  Control patients from both the US and France included patients with SLE or Sjogren’s without NMO symptoms.   These patients were tested for NMO-IgG. 

Results and Conclusions

1. No patient without NMO symptoms, including all the patients with SLE or Sjogren’s was seropositive for NMO-IgG.  This indicates that the NMO-IgG test is specific for NMO and is not falsely positive in SLE or Sjogren’s patients.

2. About half of patients with NMO-type illnesses and SLE or Sjogren’s were seropositive for NMO-IgG, and this was no different than those with NMO without these conditions.  This suggests that optic neuritis and myelitis occurring in the context of SLE or Sjogren’s is likely due to coexisting NMO.

3. Almost half of patients with NMO in the US had antibodies that could be associated with SLE, and about 15% antibodies associated with Sjogren’s disease; rarely did these patients have clinical symptoms of SLE or Sjogren’s.  Thus, although patients with NMO frequently have autoantibodies that are found in SLE or Sjogren’s, they do not commonly develop symptoms of these conditions.

4. Other autoimmune diseases occurred in approximately 20% of patients, the most common of which is autoimmune thyroid disease.

Practical Implications

1. If patients develop transverse myelitis (LETM) or optic neuritis and if they have a positive blood test consistent with SLE or Sjogren’s disease, they likely have NMO as well as SLE or Sjogren’s.  The LETM or ON are not likely a direct complication of SLE or Sjogren’s.  There is at least a 50% chance that NMO-IgG will be positive and confirm the diagnosis of NMO.  The chances that they will develop symptoms of SLE or Sjogren’s is low, but still increased over the risk in the general population.  Treatments directed at NMO are most appropriate in that circumstance.

2. Patients with NMO may develop other autoimmune disease more frequently than patients with MS, and should be monitored for these conditions.

The full text of this article may be read at the following link:
http://archneur.ama-assn.org/cgi/reprint/65/1/78.pdf?ijkey=pmBXnBsal3QNcQk&keytype=finite

Arch Neurol. 2008;65(1):78-83. ©2008 American Medical Association.