title: Longitudinally extensive transverse myelitis immune-mediated in aquaporin-4 antibody negative patients: Disease heterogeneity.
abstract: BACKGROUND
  Longitudinally extensive transverse myelitis (LETM) is a frequent manifestation of neuromyelitis optica spectrum disorder (NMOSD). However, it can also occur in other immune-mediated diseases of the central nervous system (CNS). Positive aquoporin-4 antibodies (AQP4-ab) predict higher relapse rate after LETM.
  
  
  OBJECTIVE
  To assess clinical and brain/spinal cord magnetic resonance imaging (MRI) features of LETM immune-mediated at onset and to compare AQP4-ab negative (N-LETM) with AQP4-ab positive (P-LETM) patients.
  
  
  METHODS
  Thirty LETM patients remitted for consideration of inflammatory CNS diseases were included. Demographics, clinical, serological, disability and neuroimaging features at onset we reviewed retrospectively and divided into two groups according to serological status. AQP4-ab were tested using indirect immunofluorescence.
  
  
  RESULTS
  Twenty-one patients were N-LETM. We did not find significant differences between both groups as regards gender, age at onset, dysfunction (motor, sensory, bladder/bowel) or disability. However, recurrences (p=0.04) of myelitis and number of relapses (p=0.03) were associated to P-LETM. N-LETM was associated with normal brain MRI (p=0.04) at onset. AQP4-ab positive were only observed in NMOSD patients. N-LETM (24%) and P-LETM (56%) patients had relapses of optic neuritis (ON) during the follow-up.
  
  
  CONCLUSIONS
  LETM at onset is a heterogeneous syndrome with similar clinical and neuroimaging features between both groups. N-LETM displayed a lower relapse rate of myelitis and ON.
authors.affiliation: Department of Neurology, Hospital Carlos G. Durand, Buenos Aires, Argentina. Electronic address: junior.carnero@hotmail.com.
authors.forename: Edgar
authors.initials: E
authors.lastname: Carnero Contentti
authors.affiliation: Department of Neurology, Hospital Carlos G. Durand, Buenos Aires, Argentina.
authors.forename: Javier Pablo
authors.initials: JP
authors.lastname: Hryb
authors.affiliation: Department of Neurology, Hospital Carlos G. Durand, Buenos Aires, Argentina.
authors.forename: Sergio
authors.initials: S
authors.lastname: Morales
authors.affiliation: Department of Neurology, Hospital Carlos G. Durand, Buenos Aires, Argentina.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Gomez
authors.affiliation: Department of Immunology and Histocompatibility, Hospital Carlos G. Durand, Buenos Aires, Argentina.
authors.forename: Edson
authors.initials: E
authors.lastname: Chiganer
authors.affiliation: Department of Neurology, Hospital Carlos G. Durand, Buenos Aires, Argentina.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Di Pace
authors.affiliation: Department of Immunology and Histocompatibility, Hospital Carlos G. Durand, Buenos Aires, Argentina.
authors.forename: Carmen
authors.initials: C
authors.lastname: Lessa
authors.affiliation: Department of Neurology, Hospital Carlos G. Durand, Buenos Aires, Argentina.
authors.forename: Mónica
authors.initials: M
authors.lastname: Perassolo
mesh_terms: D000328:Adult; D051401:Aquaporin 4 / Q000276:immunology; D001323:Autoantibodies / Q000097:blood; D001921:Brain / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009188:Myelitis, Transverse / Q000000981:diagnostic imaging / Q000209:etiology / Q000276:immunology* / Q000628:therapy; D009471:Neuromyelitis Optica / Q000150:complications / Q000000981:diagnostic imaging / Q000276:immunology* / Q000628:therapy; D012008:Recurrence; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4; D001323:Autoantibodies
keywords: Aquaporin-4 antibodies; Longitudinally extensive transverse myelitis; Multiple sclerosis; Neuromyelitis optica spectrum disorders