title: Association of thalamic serotonin transporter and interleukin-10 in bipolar I disorder: a SPECT study.
abstract: OBJECTIVE
  The serotonin hypothesis plays a critical role in the etiology of bipolar disorder (BD). Although many studies have demonstrated reciprocal relationships between serotonin metabolism and immune-inflammatory pathways that occur in depression, studies linking serotonergic function and cytokines are still limited concerning BD. The aim of this study was to investigate the interaction of brain serotonin transporter (SERT) and cytokines in BD.
  
  
  METHODS
  Twenty patients with euthymic BD and 20 age- and sex-matched healthy controls (HC) were recruited. Single photon emission computed tomography with the radiotracer (123) I-ADAM was used for the SERT imaging. The specific uptake ratio, which represents SERT availability, was the primary measured outcome. Cytokines included the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and the anti-inflammatory cytokine interleukin-10 (IL-10). Cytokine concentration was measured using an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  SERT availability was significantly lower in the midbrain and caudate of patients with BD compared with HC, but not in the thalamus and putamen. IL-10 was significantly higher, whereas TNF-α was not different in euthymic patients with BD compared with HC. There was a significant association of SERT availability and IL-10 in the thalamus, but not in the midbrain, caudate, or putamen.
  
  
  CONCLUSIONS
  Our results demonstrate the interaction of SERT availability and IL-10 in euthymic BD. This result may further explain the role of SERT and cytokines in the etiology of BD.
authors.affiliation: Department of Psychiatry, Taipei Veterans General Hospital and National Yang Ming University, Taipei, Taiwan.
authors.forename: Ju-Wei
authors.initials: JW
authors.lastname: Hsu
authors.forename: Jiing-Feng
authors.initials: JF
authors.lastname: Lirng
authors.forename: Shyh-Jen
authors.initials: SJ
authors.lastname: Wang
authors.forename: Chun-Lung
authors.initials: CL
authors.lastname: Lin
authors.forename: Kai-Chun
authors.initials: KC
authors.lastname: Yang
authors.forename: Mei-Hsiu
authors.initials: MH
authors.lastname: Liao
authors.forename: Yuan-Hwa
authors.initials: YH
authors.lastname: Chou
mesh_terms: D051722:ADAM Proteins; D000328:Adult; D001714:Bipolar Disorder / Q000000981:diagnostic imaging* / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000097:blood*; D007457:Iodine Radioisotopes; D008279:Magnetic Resonance Imaging; D008297:Male; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D007457:Iodine Radioisotopes; D050486:Serotonin Plasma Membrane Transport Proteins; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D051722:ADAM Proteins
keywords: 123I-ADAM; bipolar disorder; interleukin 10; serotonin transporter; tumor necrosis factor (TNF)-α