Anti-thyroid antibodies and thyroid function in neuromyelitis optica spectrum disorders

Abstract

Background: Neuromyelitis optica spectrum disorders (NMOSD) are complicated neuroautoimmune disorders which can coexist with other organ-specific autoimmune disorders. The most frequently specific organ is the thyroid. The aim of this study is to evaluate the thyroid function of NMOSD patients and detect the difference between anti-thyroid antibodies (ATAbs) seropositive and seronegative NMOSD patients.

Methods: 88 patients diagnosed with NMOSD were enrolled and their thyroid functions were evaluated. They were divided into two groups by ATAbs abnormalities. In addition, demographic characteristics, clinical symptoms and MRI scan results of brain and spinal cord were assessed.

Results: Anti-thyroid peroxidase antibodies (TPOAbs) and anti-thyroglobulin antibodies (TGAbs) seropositivities were detected more frequently in patients with NMOSDs when compared with healthy controls (37.5% vs 14.9%, P=0.01, Diff22.6%, 95CI[9.0%, 34.9%]; 31.8% vs 16.2%, P=0.022, Diff15.6%, 95CI[2.27%, 27.9%]). In NMOSD patients, the Expanded disability status scale score (EDSS) score was significantly higher in ATAbs seropositive group than that in ATAbs seronegative group (median 6.5 vs 3.75, P=0.012). However, there is no significant difference for demographic characteristics and other clinical symptoms. Moreover, NMOSD patients with ATAbs abnormalities had more brain and cervical cord lesions when compared with ATAbs negative NMOSD patients (83.8% vs 61.4%, P=0.029, Diff22.4%, 95CI[0.9%, 40.9%]; 93.9% vs 59.6%, P=0.001, Diff34.3%, 95CI[13.6%, 50.4%]).

Conclusions: NMOSD patients have a higher frequency of ATAbs abnormalities. ATAbs may be associated with disability status, brain abnormalities and cervical cord lesions.

Keywords: Anti-thyroid antibodies; Expanded disability status scale (EDSS) score; Magnetic resonance imaging (MRI); Neuromyelitis optica spectrum disorder (NMOSD).