Abstract | BACKGROUND: METHODS AND FINDINGS: Based on these observations we cloned human water channel AQP4, expressed the protein in a eukaryotic transcription/translation system, and employed the recombinant AQP4 to establish a new radioimmunoprecipitation assay (RIPA). Indeed, application of this RIPA showed that antibodies against AQP4 exist in the majority of patients with NMO (n = 37; 21 positive) as well as in patients with isolated longitudinally extensive transverse myelitis (n = 6; six positive), corresponding to a sensitivity of 62.8% and a specificity of 98.3%. By contrast, AQP4 antibodies were virtually absent in 291 other participants, which included patients with MS (n = 144; four positive), patients with other inflammatory and noninflammatory neurological diseases (n = 73; one positive), patients with systemic autoimmune diseases (n = 45; 0 positive), and healthy participants (n = 29; 0 positive). CONCLUSIONS: In the largest series reported so far to our knowledge, we quantified AQP4 antibodies in patients with NMO versus various other diseases, and showed that the aquaporin 4 water channel is a target antigen in a majority of patients with NMO. The newly developed assay represents a highly specific, observer-independent, and easily reproducible detection method facilitating clinically relevant discrimination between NMO, MS, and other inflammatory diseases.
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Authors | Friedemann Paul, Sven Jarius, Orhan Aktas, Martin Bluthner, Oliver Bauer, Heribert Appelhans, Diego Franciotta, Roberto Bergamaschi, Edward Littleton, Jacqueline Palace, Hans-Peter Seelig, Reinhard Hohlfeld, Angela Vincent, Frauke Zipp |
Journal | PLoS medicine
(PLoS Med)
Vol. 4
Issue 4
Pg. e133
(Apr 2007)
ISSN: 1549-1676 [Electronic] United States |
PMID | 17439296
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Aquaporin 4
- Autoantibodies
- Recombinant Proteins
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Topics |
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Aquaporin 4
(immunology)
- Autoantibodies
(blood)
- Child
- Diagnosis, Differential
- Female
- Humans
- Male
- Middle Aged
- Multiple Sclerosis
(diagnosis)
- Neuromyelitis Optica
(diagnosis, immunology)
- Radioimmunoprecipitation Assay
- Recombinant Proteins
- Sensitivity and Specificity
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