Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement

The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.


Anti-Aquaporin-4 Antibodies Are Highly Specific for Neuromyelitis Optica and Show No Association with Sjgrens Syndrome and Other Autoimmune Diseases

Dellavance1,  Alessandra, Alvarenga2,  Rossana R., Rodrigues2,  Silvia H., Kok3,  Fernando, Souza2,  Alexandre W. S., Andrade2,  Luis Eduardo C.

Fleury Health and Medicine. São Paulo, Brazil
Universidade Federal de Sao Paulo, Sao Paulo, Brazil
Universidade de Sao Paulo, Sao Paulo, Brazil

Purpose:

Neuromyelitis optica (NMO; Devic's syndrome) is a severe CNS demyelinating syndrome characterized by optic neuritis (ON) and acute myelitis. Anti-aquaporin 4 antibodies have been recently reported as a biomarker for NMO with specificity over 90% in patients with optic-spinal syndrome and other demyelinating conditions. The specificity of anti-aquaporin 4 antibodies for NMO has not been tested against a wider spectrum of systemic autoimmune diseases but a recent report has suggested that patients with Sjögren's syndrome may present anti-aquaporin 4 antibodies. Therefore we set to screen anti-aquaporin 4 antibodies in a wide clinical spectrum of systemic and organ-specific autoimmune diseases, demyelinating neurological diseases and infectious diseases.

Method:

Serum was obtained from patients regularly followed at specialized outpatient clinics at Federal and State University of São Paulo, Brazil: 37 with NMO, 22 with other demyelinating conditions, 28 with primary Sjögren's syndrome, 32 with rheumatoid arthritis, 80 with systemic lupus erythematosus, 38 with systemic sclerosis, 40 with myasthenia gravis, 37 with primary biliary cirrhosis, 23 with hepatitis C virus, 12 with miscellaneous infectious disease (CMV, dengue, herpes simplex), and 200 samples from patients from the general outpatient clinic without any suspicion of neurological disease. IgG anti-aquaporin 4 antibodies were determined by indirect immunofluorescence on rat cerebellum at a screening dilution of 1/10 as previously established (Lennon VA et al, JEM 2005, 202:473). Slides were read by two blinded independent observers at ×200 and ×400 magnification.

Results:

The characteristic staining pattern of anti-aquaporin 4 antibodies was observed in 30 of 37 samples from patients with neuromyelitis optica (81% sensitivity) and in none of 549 samples not related to this disease (100% specificity). Detailed clinical data was available for 15 patients with documented primary Sjögren's syndrome and revealed neurologic involvement in 4 of them. Peripheral polyneuropathy occurred in two and cranial neuropathy in two other patients. No patient had central nervous system involvement. Cutaneous small vessel vasculitis was observed in two patients and in one of them it was associated with cryoglobulinemia.

Conclusion:

Anti-aquaporin 4 antibodies are highly specific for the diagnosis of NMO in the context of several autoimmune and infectious diseases. There was no association of anti-aquaporin 4 antibodies with neurological manifestations in Sjögren's syndrome.

To cite this abstract, please use the following information:
Dellavance, Alessandra, Alvarenga, Rossana R., Rodrigues, Silvia H., Kok, Fernando, Souza, Alexandre W. S., Andrade, Luis Eduardo C.; Anti-Aquaporin-4 Antibodies Are Highly Specific for Neuromyelitis Optica and Show No Association with Sjgrens Syndrome and Other Autoimmune Diseases [abstract]. Arthritis Rheum 2009;60 Suppl 10 :503
DOI: 10.1002/art.25585

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