title: Combined screening for serum anti-nuclear and anti-aquaporin-4 antibodies improves diagnostic accuracy for distinguishing neuromyelitis optica from multiple sclerosis.
abstract: OBJECTIVE
  Neuromyelitis optica spectrum disorders (NMOSDs) and multiple sclerosis (MS) are distinct clinical entities but are poorly distinguished by serum markers, including serum anti-aquaporin-4 (AQP4-Ab). We examined if testing for serum anti-nuclear antibodies (ANAs) and AQP4-Ab improved diagnostic sensitivity for NMOSDs.
  
  
  METHODS
  Chinese patients with NMOSDs (n = 74) or MS (n = 49) were screened for serum ANAs (all patients) and AQP4-Ab (58/74 NMOSDs and 45/49 MS patients). The NMOSDs group included patients with neuromyelitis optica (NMO; n = 53), recurrent longitudinally extensive transverse myelitis (rLETM; n = 20), and recurrent optic neuritis (n = 1).
  
  
  RESULTS
  The seroprevalence rate for ANAs was significantly higher in the NMOSDs group than the MS group (45.9 vs. 2%; p < 0.01). Similarly, AQP4-Ab seroprevalence was higher in NMOSDs than MS (56.9 vs. 4.4%; p < 0.01). Sensitivities and specificities for diagnosing NMOSDs were 51.7 and 97.8% using ANAs, 56.9 and 95.6% using AQP4-Ab, and 74.1 and 93.3% using both assays.
  
  
  CONCLUSIONS
  Patients with NMO or rLETM had higher ANA seroprevalence than MS patients. Combined detection of both ANAs and AQP4-Ab improves the sensitivity of NMOSDs diagnosis without compromising specificity.
authors.affiliation: Department of The General Hospital of the Chinese People's Liberation Army, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wu
authors.forename: Dehui
authors.initials: D
authors.lastname: Huang
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Weiping
authors.initials: W
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D000974:Antibodies, Antinuclear / Q000097:blood*; D051401:Aquaporin 4 / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000276:immunology*; D009471:Neuromyelitis Optica / Q000175:diagnosis / Q000276:immunology*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000906:Antibodies; D000974:Antibodies, Antinuclear; D051401:Aquaporin 4; D015415:Biomarkers