Time-Dependent Analysis of Sicca Symptoms and Anti-Ro/SSA and Anti-La/SSB Antibodies in Patients with AQP4-IgG-Positive Neuromyelitis Optica Spectrum Disorder

Time-Dependent Analysis of Sicca Symptoms and Anti-Ro/SSA and Anti-La/SSB Antibodies in Patients with AQP4-IgG-Positive Neuromyelitis Optica Spectrum Disorder

Tetsuya Akaishi,^1,2 Toshiyuki Takahashi,^1,3 Tatsuro Misu,¹ Kazuo Fujihara,⁴ Ichiro Nakashima⁵ and Masashi Aoki¹

¹Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
²Department of Education and Support for Regional Medicine, Tohoku University Hospital, Sendai, Miyagi, Japan
³Department of Neurology, National Hospital Organization Yonezawa National Hospital, Yonezawa, Yamagata, Japan
⁴Multiple Sclerosis Therapeutics, Fukushima Medical University, Fukushima, Fukushima, Japan
⁵Department of Neurology, Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, Japan

Anti-aquaporin-4 antibody (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD) and Sj<00F6>gren syndrome (SS) are likely comorbidities. However, the exact effects of age and disease duration on the positivity rates of serum anti-Ro/SSA and anti-La/SSB (anti-SSA/SSB) antibodies and the presence of sicca symptoms in patients with AQP4-IgG remain unknown. In the present study, we evaluated the data from patients with suspected NMOSD who had neurological episodes and tested for serum AQP4-IgG. Associations between the presence of serum AQP4-IgG and SS-related findings were evaluated. The presence of anti-SSA/SSB antibodies [odds ratio (OR), 7.34; 95% confidence interval (CI), 5.71-9.43; p < 0.0001] and that of sicca symptoms (OR, 2.08; 95% CI, 1.67-2.58; p < 0.0001) were both higher in patients with AQP4-IgG (n = 1,651) than in those without AQP4-IgG (n = 2,796). Meanwhile, neither age nor the elapsed time from neurological onset was linked to the prevalence of anti-SSA/SSB antibodies or sicca symptoms, and the prevalence rates of the SS-related factors were elevated since the onset of neurological episodes in those with AQP4-IgG. The frequency of sicca symptoms among those with anti-SSA/SSB antibodies was irrespective of AQP4-IgG (OR, 1.11; 95% CI, 0.67-1.85; p = 0.6892). The measured AQP4-IgG titers did not differ significantly according to the presence of anti-SSA/SSB antibodies (p = 0.2386; Mann-Whitney U test). In summary, age and duration of NMOSD were not the factors producing an elevated prevalence of anti-SSA/SSB antibodies and sicca symptoms in patients with AQP4-IgG, implying that the occurrence of comorbid SS is likely to temporarily precede or synchronize with the onset of AQP4-IgG-positive NMOSD.

Key words —— anti-aquaporin-4 antibodies (AQP4-IgG); anti-Ro/SSA and anti-La/SSB antibodies; neuromyelitis optica spectrum disorder (NMOSD); sicca symptoms; Sj<00F6>gren syndrome

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Tohoku J. Exp. Med., 2023 July, 260(3), 215-221.

Correspondence: Tetsuya Akaishi, Department of Neurology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.

e-mail: t-akaishi@med.tohoku.ac.jp