title: Aquaporin-4 positive neuromyelitis optica spectrum disorders secondary to thrombopenic purpura: A case report.
abstract: BACKGROUND
  Neuromyelitis optica spectrum disorders (NMOSD) is considered as an immune-mediated disorder in the central nervous system (CNS). Numerous autoimmune diseases are frequently complicated with NMOSD and distinct clinical characteristics are noted in NMOSD patients with other autoimmune diseases. However, to our best knowledge, co-occurrence of NMOSD and thrombopenic purpura is rarely identified.
  
  
  METHODS
  We presented a rare case of a 72-year-old female with 6-year history of thrombopenic purpura, and 1-month history of blurred vision as well as chest zonethesia. Anti-aquaporin-4 (AQP4) antibodies was positive in the serum of the patient.
  
  
  METHODS
  With the addition of laboratory findings, iconography findings and physical examination results, the diagnosis of NMOSD was established according to the most recent diagnostic criteria.
  
  
  RESULTS
  With the treatment of intravenous immunoglobulin (IVIg), the patient felt better at discharge without changing of expanded disability status scale (EDSS) score.
  
  
  CONCLUSIONS
  The case indicates that NMOSD could co-occur with thrombopenic purpura. The disturbance of immune system balance may explain this overlap. Further studies are warranted to reveal the mechanism and to explore whether patients with NMOSD with and without thrombopenic purpura have distinct clinical feature, drug responsiveness or prognosis.
authors.affiliation: aDepartment of Neurology, the First Hospital of Jilin University bDepartment of Ophthalmology, the Second Hospital of Jilin University, Changchun cCurrent address: Department of Life Sciences, the National Natural Science Foundation of China, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Gong
authors.forename: Mingqin
authors.initials: M
authors.lastname: Zhu
authors.forename: Chao
authors.initials: C
authors.lastname: Lu
authors.forename: Li
authors.initials: L
authors.lastname: Sun
authors.forename: Jiachun
authors.initials: J
authors.lastname: Feng
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000368:Aged; D051401:Aquaporin 4 / Q000276:immunology*; D005260:Female; D006801:Humans; D009471:Neuromyelitis Optica / Q000276:immunology*; D011696:Purpura, Thrombocytopenic / Q000150:complications*
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4