title: The acute-phase mediator serum amyloid A is associated with symptoms of depression and fatigue.
abstract: OBJECTIVE
  Establish whether inflammatory biomarkers-serum amyloid A (SAA), C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α)-are related to key symptoms of depression, including anxiety and fatigue, in a cross-sectional, out-patient setting to identify biomarkers that reflect psychiatric symptomatology in a naturalistic, real-life population.
  
  
  METHODS
  We measured SAA, CRP, IL-6, and TNF-α in plasma samples from 89 adult psychiatric out-patients by multiplex, high-sensitivity electrochemiluminescent assays. Psychiatric symptoms were evaluated using the Hamilton Depression Rating Scale (HAMD-17), the Patient Health Questionnaire (PHQ-9), and the Center for Epidemiological Studies Depression Scale (CES-D).
  
  
  RESULTS
  Plasma SAA was most robustly associated with depressive symptoms across diagnostic boundaries in this cohort of out-patients. Elevated SAA was significantly associated with higher total scores on the HAMD-17 scale and correlated with multiple scale items that rated symptoms of fatigue and depressed mood, but not with anxiety-related items.
  
  
  CONCLUSIONS
  SAA might constitute a cross-diagnostic marker indicative of depressed mood and fatigue in a naturalistic patient setting. Because SAA activates Toll-like receptors 2 and 4, present on macrophages and glial cells, its association with depression severity could also implicate this inflammatory mediator in the pathogenesis of mood disorders.
authors.affiliation: Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA.
authors.forename: E Y
authors.identifier: http://orcid.org/0000-0002-1168-0078
authors.initials: EY
authors.lastname: Bryleva
authors.affiliation: Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA.|Division of Psychiatry and Behavioral Medicine, Michigan State University, Grand Rapids, MI, USA.|Department of Physiology, Michigan State University, East Lansing, MI, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Keaton
authors.affiliation: Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA.
authors.forename: J
authors.initials: J
authors.lastname: Grit
authors.affiliation: Bioinformatics and Biostatistics Core, Van Andel Research Institute, Grand Rapids, MI, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Madaj
authors.affiliation: Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sauro-Nagendra
authors.affiliation: Pine Rest Christian Mental Health Services, Grand Rapids, MI, USA.
authors.forename: L
authors.initials: L
authors.lastname: Smart
authors.affiliation: Pine Rest Christian Mental Health Services, Grand Rapids, MI, USA.
authors.forename: S
authors.initials: S
authors.lastname: Halstead
authors.affiliation: Division of Psychiatry and Behavioral Medicine, Michigan State University, Grand Rapids, MI, USA.|Pine Rest Christian Mental Health Services, Grand Rapids, MI, USA.
authors.forename: E
authors.initials: E
authors.lastname: Achtyes
authors.affiliation: Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA.|Pine Rest Christian Mental Health Services, Grand Rapids, MI, USA.
authors.forename: L
authors.initials: L
authors.lastname: Brundin
mesh_terms: D000328:Adult; D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D003430:Cross-Sectional Studies; D003863:Depression / Q000378:metabolism*; D005221:Fatigue / Q000378:metabolism*; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D000685:Serum Amyloid A Protein / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D055815:Young Adult
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; D000685:Serum Amyloid A Protein; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: C-reactive protein; biomarker; inflammation; interleukin-6; mood disorders