title: Diagnostic utility of NMO/AQP4-IgG in evaluating CNS inflammatory disease in Thai patients.
abstract: Epidemiological studies in Thailand have reported that inflammatory demyelinating diseases (IDDs) commonly affect the optic nerve and spinal cord. We investigated the diagnostic utility of aquaporin (AQP)-4-IgG testing in 31 consecutive patients evaluated for CNS IDDs in 3 academic Thai hospital neurology clinics between February 2008 and January 2009. Patients were classified into 3 clinical diagnostic groups: Neuromyelitis optica (NMO, n=10) multiple sclerosis (MS, n=5) and unclassified IDD (n=16). All sera were tested blindly by cell binding (Euroimmun) assay (CBA). Sera were also tested by indirect immunofluorescence assay (IFA) and ELISA (RSR/Kronus). After initial screening by CBA, AQP4-IgG was detected in 6 NMO patients (60%); 3 of the 4 seronegative cases were receiving immunosuppressants. AQP4-IgG was detected in 13 unclassified IDD cases (81%), but in no MS cases. Cell binding assay and ELISA were more sensitive than IFA (p=0.0004). The 81% seropositivity rate in "unclassified" patients suggests that AQP4 autoimmunity accounts for a significant proportion of Thai CNS inflammatory demyelinating disease, especially those with optic neuritis or transverse myelitis, with or without abnormal brain MRI, in whom a specific diagnosis or clear-cut treatment approach is unclear.
authors: Department of Neurology, Prasat Neurological Institute, Bangkok, Thailand. apiwattanakul.metha@gmail.com
authors: Metha
authors: M
authors: Apiwattanakul
authors: Thanin
authors: T
authors: Asawavichienjinda
authors: Teeratorn
authors: T
authors: Pulkes
authors: Tasanee
authors: T
authors: Tantirittisak
authors: Thiravat
authors: T
authors: Hemachudha
authors: Erika S
authors: ES
authors: Horta
authors: Sarah M
authors: SM
authors: Jenkins
authors: Sean J
authors: SJ
authors: Pittock
mesh_terms: D000328:Adult; D051401:Aquaporin 4 / Q000097:blood; D044466:Asian People / Q000706:statistics & numerical data*; D001323:Autoantibodies / Q000097:blood; D020278:Demyelinating Autoimmune Diseases, CNS / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood / Q000175:diagnosis; D009471:Neuromyelitis Optica / Q000097:blood / Q000175:diagnosis; D011237:Predictive Value of Tests
chemical_list: D051401:Aquaporin 4; D001323:Autoantibodies; D007074:Immunoglobulin G