title: Neuromyelitis optica immunoglobulin G in Chinese patients detected by immunofluorescence assay on a monkey brain substrate.
abstract: BACKGROUND
  Serum neuromyelitis optica immunoglobulin G (NMO-IgG) is used as a biomarker to differentiate between neuromyelitis optica (NMO) and multiple sclerosis (MS). However, the original assay is expensive and complex and shows low sensitivity. Here, we investigated the potential of NMO-IgG detection using an indirect immunofluorescence (IIF) assay on monkey brains.
  
  
  METHODS
  NMO-IgG seroprevalence was determined in 168 samples by an IIF assay on a monkey brain substrate. The data were compared with those from a standard mouse brain IIF assay using McNemar and kappa tests.
  
  
  RESULTS
  Thirty-one of 50 (62%) NMO patients, 7 of 18 (38.9%) longitudinally extensive transverse myelitis patients, 6 of 57 (10.5%) MS patients, and 5 of 10 (50%) optic neuritis patients were seropositive for NMO-IgG. None of the acute partial transverse myelitis patients (n = 3) or healthy controls (n = 20) was positive. Thus, the sensitivity of the test was 62% for the patients with clinically definite NMO. The specificity was 89.5%, considering the 57 MS patients as the control group. The modified IIF assay on monkey brains and the standard IIF assay based on mouse brains were not significantly different (McNemar test; p = 1.000). The two assays were concordant in 39 seropositive samples and 100 seronegative samples (kappa test; kappa = 0.592, p < 0.0001).
  
  
  CONCLUSIONS
  Although the modified IIF monkey brain assay was no better than the standard mouse brain IIF assay, we affirmed that NMO-IgG is a sensitive and specific biomarker to differentiate between NMO and MS.
authors: Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University,Guangzhou, PR China.
authors: Youming
authors: Y
authors: Long
authors: Xueqiang
authors: X
authors: Hu
authors: Fuhua
authors: F
authors: Peng
authors: Zhengqi
authors: Z
authors: Lu
authors: Yuge
authors: Y
authors: Wang
authors: Yu
authors: Y
authors: Yang
authors: Wei
authors: W
authors: Qiu
mesh_terms: D000818:Animals; D051401:Aquaporin 4 / Q000378:metabolism; D044466:Asian People; D001921:Brain / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D000882:Haplorhini; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D051379:Mice; D008810:Mice, Inbred C57BL; D009471:Neuromyelitis Optica / Q000276:immunology*
chemical_list: D051401:Aquaporin 4; D007074:Immunoglobulin G