title: Clinical and Immunologic Investigations in Patients With Stiff-Person Spectrum Disorder.
abstract: Symptoms of stiff-person syndrome (SPS), stiff-limb syndrome (SLS), or progressive encephalomyelitis with rigidity, myoclonus, or other symptoms (SPS-plus) can occur with several autoantibodies, but the relative frequency of each antibody, syndrome specificity, and prognostic implications are unclear.
  
  
  
  To report the clinical and immunologic findings of a large cohort of patients with stiff-person spectrum disorder (SPSD), including SPS, SLS, and SPS-plus.
  
  
  
  This study retrospectively examined a case series (January 1, 1998, through December 31, 2014) of immunologic investigations performed in a neuroimmunology referral center. The study included 121 patients with clinical features of SPSD. Data analysis was performed from July 1, 2015, through November 1, 2015.
  
  
  
  Analysis of clinical-immunologic associations, including autoantibodies to 8 proteins expressed in inhibitory synapses.
  
  
  
  The median age of the patients was 51 years (interquartile range, 40-61 years), and 75 (62.0%) were female. Fifty (41.3%) had SPS, 37 (30.6%) had SPS-plus, 24 (19.8%) had SLS, and 10 (8.3%) had SPS or SLS overlapping with ataxia, epilepsy, or encephalitis. Fifty-two patients (43.0%) had glutamic acid decarboxylase (GAD65) antibodies (2 with γ-aminobutyric acid-A [GABA-A] receptor antibodies), 24 (19.8%) had α1-subunit of the glycine receptor (GlyR) antibodies (2 with GAD65 antibodies), 5 (4.1%) had other antibodies, and 40 (33.1%) tested negative for antibodies. None had gephyrin or glycine transporter antibodies. Among the main immunologic groups (GAD65 antibodies, GlyR antibodies, and antibody negative), those with GAD65 antibodies were more likely to be female (45 [86.5%] of 52, 8 [36.4%] of 22, and 18 [45.0%] of 40, respectively; P < .001), have systemic autoimmunity (34 [65.4%] of 52, 7 [31.8%] of 22, and 13 [32.5%] of 40, respectively; P = .004), and have longer delays in being tested for antibodies (median, 3 vs 0.5 and 1 year; P < .001). Patients with GAD65 antibodies were more likely to develop SPS (27 [51.9%] of 52) or overlapping syndromes (8 [15.4%] of 52) than patients with GlyR antibodies (5 [22.7%] and 0 [0%] of 22, respectively), who more often developed SPS-plus (12 [54.5%] of 22 vs 7 [13.5%] in those with GAD65 antibodies); antibody-negative patients had an intermediate syndrome distribution. In multivariable analysis, symptom severity (P = .001) and immunologic group (P = .01) were independently associated with outcome. Compared with patients with GlyR antibodies, those with GAD65 antibodies (odds ratio, 11.1, 95% CI, 2.3-53.7; P = .003) had worse outcome. Patients without antibodies had similar outcome than patients with GlyR antibodies (odds ratio, 4.2, 95% CI, 0.9-20.0; P = .07).
  
  
  
  In SPSD, symptom severity and presence and type of antibodies are predictors of outcome.
authors.affiliation: Department of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain2Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Martinez-Hernandez
authors.affiliation: Department of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain2Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
authors.forename: Helena
authors.initials: H
authors.lastname: Ariño
authors.affiliation: Departments of Neurology, Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Andrew
authors.initials: A
authors.lastname: McKeon
authors.affiliation: Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Iizuka
authors.affiliation: Department of Neurology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: Titulaer
authors.affiliation: Neurology Division, Hospital das Clinicas, São Paulo University, São Paulo, Brazil.
authors.forename: Mateus M
authors.initials: MM
authors.lastname: Simabukuro
authors.affiliation: Department of Neurology, University of Pennsylvania, Philadelphia.
authors.forename: Eric
authors.initials: E
authors.lastname: Lancaster
authors.affiliation: Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Petit-Pedrol
authors.affiliation: Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Planagumà
authors.affiliation: Department of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Blanco
authors.affiliation: Department of Pharmacology, UCL School of Pharmacy, London, England.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Harvey
authors.affiliation: Department of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain2Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Saiz
authors.affiliation: Department of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain2Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Graus
authors.affiliation: Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain7Department of Neurology, University of Pennsylvania, Philadelphia9Institució Catalana de Recerca i Estudis Avançats (ICREA), Catalonia, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Dalmau
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood* / Q000134:cerebrospinal fluid*; D015551:Autoimmunity; D015331:Cohort Studies; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018009:Receptors, Glycine / Q000276:immunology*; D012720:Severity of Illness Index; D016750:Stiff-Person Syndrome / Q000097:blood / Q000134:cerebrospinal fluid / Q000276:immunology
chemical_list: D001323:Autoantibodies; D018009:Receptors, Glycine; D005968:Glutamate Decarboxylase