Clinical features and sera anti-aquaporin 4 antibody positivity in patients with demyelinating disorders of the central nervous system from Tianjin, China

Abstract

Aims: To investigate the clinical characteristics and sera anti-aquaporin 4 (AQP4) antibody positivity in patients with inflammatory demyelinating disorders (IDDs) of the central nervous system (CNS) in Tianjin, China.

Methods: We retrospectively evaluated 234 patients with IDDs including neuromyelitis optica (NMO), recurrent optic neuritis (rON), longitudinally extensive transverse myelitis (LETM), clinically isolated syndrome (CIS), and multiple sclerosis (MS) groups. Sera from 217 patients were determined for AQP4-Ab. The clinical characteristics and sera anti-AQP4 positivity were compared.

Results: The IDDS comprised 63 MS, 51 NMO, 56 LETM, 10 rON, and 54 CIS. Compared with MS, NMO had a higher frequency of occurrence in women, intractable hiccup and nausea (IHN), medullospinal lesion, longitudinally extensive spinal cord lesions (LESCL) and bilateral ON, disease onset at a later age, and worsening residual disability. AQP4-Ab-positive rates were 84.1% and 69% in NMO and NMO spectrum disorders (NMOSD), respectively, whereas it was undetectable in all of the MS sera samples.

Conclusions: We comprehensively contrast the distinct clinical features of MS, NMO, and NMOSD in our center. A sensitive AQP4-Ab assay is necessary for the early diagnosis of NMOSD in our patients. Neither medullospinal lesion nor IHN is unique in NMO.

Keywords: Anti-aquaporin 4 antibody; Chinese; Clinical features; Multiple sclerosis; Neuromyelitis optica.

Figure 1

Anti‐AQP4 antibody binds to aquaporin 4 (AQP4). AQP4‐expressing cells were incubated with serum detected, followed by goat antiserum specific for IgG. The colocalization of the surface‐expressed AQP4 (green) and the anti‐IgG antibody (red) indicates that the antibodies are against AQP4. (Original magnification × 200).

Figure 2

MRI features in patients with intractable hiccup and nausea (IHN). (A and C) The T2‐hyperintense lesion (arrow) was limited in the medullospinal area and spared the medullary floor of the fourth ventricle or area postrema (AP) in the MS patient with IHN. (B and D) The T2‐hyperintense lesion (arrows) in the upper cervical cord rostrally extended to the fourth ventricle and AP in the patient with NMO.