title: Low T3 syndrome in neuromyelitis optica spectrum disorder: Associations with disease activity and disability.
abstract: BACKGROUND
  Neuromyelitis optica (NMO) sometimes coexists with serological marker-positive, non-organ-specific autoimmune disorders. We evaluated the prevalence of thyroid dysfunction and anti-thyroid antibodies in patients with NMO spectrum disorder (NMOSD) and investigated the associations between thyroid dysfunction/autoimmunity and clinical features of NMOSD.
  
  
  METHODS
  Forty-nine NMOSD patients with anti-aquaporin-4 antibody and 392 age- and sex-matched healthy controls were included. We measured the levels of thyroid hormones and anti-thyroid antibodies.
  
  
  RESULTS
  The prevalence of clinical hypothyroidism, subclinical hyperthyroidism, and low T3 syndrome were higher in patients with NMOSD (4.1%, 12.2%, and 20.4%, respectively) compared with healthy controls (0.3%, 2.8%, and 0.5%, respectively; p=0.034, p=0.001, and p<0.001, respectively). However, anti-thyroperoxidase antibody (anti-TPO)-positivity did not significantly differ between NMOSD patients (20.4%) and controls (11.5%). Low T3 syndrome was more prevalent among patients during an attack (N=10/19, 52.6%) than those in remission (N=1/30, 3.3%). In addition, patients with low T 3 syndrome had significantly higher EDSS scores at the last visits as well as at sampling compared to those without low T3 syndrome. T3 levels were inversely correlated with EDSS score at the last visit after adjustment for age, sex, disease duration, clinical status (attack vs. remission), oral prednisolone use, iv methylprednisolone use, other immunosuppressive agents use, and the location of lesion (ρ=-0.416, p=0.010).
  
  
  CONCLUSIONS
  Our study suggests that thyroid dysfunction is frequent in patients with NMOSD; particularly, serum T3 levels may be a useful indicator of disease activity and disability in NMOSD.
authors: Department of Neurology, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Republic of Korea.
authors: Eun Bin
authors: EB
authors: Cho
authors: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea. Electronic address: juhongm@gmail.com.
authors: Ju-Hong
authors: JH
authors: Min
authors: Department of Neurology, The Catholic University of Korea, College of Medicine, Bucheon St. Mary's Hospital, Bucheon, Republic of Korea.
authors: Hye-Jin
authors: HJ
authors: Cho
authors: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea.
authors: Jin Myoung
authors: JM
authors: Seok
authors: Department of Neurology, Chungbuk National University Hospital, Cheongju, Republic of Korea.
authors: Hye Lim
authors: HL
authors: Lee
authors: Center for Health Promotion, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors: Hee Young
authors: HY
authors: Shin
authors: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea.
authors: Kwang-Ho
authors: KH
authors: Lee
authors: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea. Electronic address: bjkim@skku.edu.
authors: Byoung Joon
authors: BJ
authors: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051401:Aquaporin 4 / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D015415:Biomarkers / Q000097:blood; D017252:CD3 Complex / Q000097:blood; D004185:Disability Evaluation; D005067:Euthyroid Sick Syndromes / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D015995:Prevalence; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000187:drug effects / Q000503:physiopathology; D013963:Thyroid Hormones / Q000097:blood; D055815:Young Adult
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4; D001323:Autoantibodies; D015415:Biomarkers; D017252:CD3 Complex; D013963:Thyroid Hormones
keywords: Anti-thyroid antibodies; Autoimmune thyroid disease; Low T3 syndrome; Neuromyelitis optica spectrum disorder