Anti-aquaporin-4 antibody positivity in neuromyelitis optica is associated with lesion activity

Aims: To assess the demographic, clinical and spinal cord MRI characteristics of clinically definite neuromyelitis optica (NMO) patients for association with anti-aquaporin-4 (AQP4) antibody positivity in Chinese patients. Methods: We recruited 72 consecutive patients with NMO. The clinical assessments, sera and spinal MRI scans were obtained within 1 week after the onset of symptoms of acute myelitis. The statistical significance of potential differences in demographic, clinical and spinal MRI lesion characteristics between the two groups (anti-AQP4 antibody positive vs. negative) was determined using the two-sample t test or Fisher's exact test. Results: Forty-nine patients (49/72, 68.1%) were anti-AQP4 antibody positive and 23 patients (23/72, 31.9%) were anti-AQP4 antibody negative. The only characteristic that was significantly different between the groups was the presence of an enhancing spinal cord lesion (p < 0.001). Conclusion: We found a strong association between serum anti-AQP4 antibody positivity and lesional gadolinium enhancement in patients with clinically definite NMO. These findings support prior evidence that anti-AQP4 antibody could be pathogenic in NMO lesion development.