Aquaporin 4 Antibodies in the Cerebrospinal Fluid Are Helpful in Diagnosing Chinese Patients with Neuromyelitis Optica

Objective: It was the aim of this study to compare the diagnostic efficiency of anti-aquaporin 4 (AQP4) antibody detection between serum and cerebrospinal fluid (CSF) samples in Chinese patients with central nervous system demyelinating diseases. Methods: Anti-AQP4 antibodies were detected by a cell-based assay. We calculated the sensitivity, specificity and coherence in 118 patients with neuromyelitis optica (NMO, n = 39), multiple sclerosis (n = 34), longitudinally extensive transverse myelitis (LETM, n = 22), optic neuritis (ON, n = 6), opticospinal multiple sclerosis (n = 8) and acute partial transverse myelitis (n = 9). Results: Forty-four serum samples (33.8%) were positive for anti-AQP4 antibodies. Anti-AQP4 antibody seropositivity was 76.9, 59.1 and 16.7% in patients with NMO, LETM and ON, respectively. Sixty-five CSF samples (50%) were positive for anti-AQP4 antibodies. Anti-AQP4 antibody positivity was 87.1, 81.8, 83.3, 62.5 and 11.8% in patients with NMO, LETM, ON, opticospinal multiple sclerosis and multiple sclerosis, respectively. The kappa value of the coherence test was 0.585 (p < 0.0001) between the two types of samples. The antibody positivity rate was significantly different between the two body fluids (p = 0.0008, McNemar test). The sensitivity and specificity were 74.3 and 100% in serum, 85.7 and 88.2% in CSF, and 94.3 and 88.2% for serum and CSF combined, respectively. Conclusion: The sensitivity of antiAQP4 antibodies in the CSF was higher than that in the serum, and their combined use is helpful in diagnosing Chinese patients with NMO. Copyright (C) 2012 S. Karger AG, Basel