title: Relationship between clinical features and inflammation-related monocyte gene expression in bipolar disorder - towards a better understanding of psychoimmunological interactions.
abstract: OBJECTIVE
  Existing and previously published datasets were examined for associations between illness and treatment characteristics and monocyte pro-inflammatory gene expression in patients with bipolar disorder (BD). We hypothesized a priori that increased monocyte pro-inflammatory gene expression would be found more frequently in patients with a lifetime history of psychotic symptoms.
  
  
  METHODS
  Monocyte quantitative polymerase chain reaction and symptom data from 64 patients with BD were collected from three Dutch studies. Regression analyses were performed to analyze the various associations between pro-inflammatory gene expression and clinical features, from which feature-expression heat maps were drawn.
  
  
  RESULTS
  No associations were found between pro-inflammatory gene expression and lifetime psychotic symptoms, whereas a positive association was identified between subcluster 2 genes and manic symptoms. For several subcluster 1a genes, a negative association was found with age at onset. For most subcluster 2 genes, a positive association was found with the duration of illness. Current use of antidepressants and of anti-epileptic agents was associated with subcluster 2 gene expression, and current use of lithium and antipsychotic agents with subcluster 1a gene expression.
  
  
  CONCLUSIONS
  Our hypothesis that lifetime psychotic features would be associated with pro-inflammatory monocyte gene expression was not confirmed. In an explorative analysis we found: (i) a possible relationship between pro-inflammatory gene expression and manic symptomatology; (ii) a differential immune activation related to age at onset and duration of illness; and (iii) support for the concept of an immune suppressive action of some of the mood-regulating medications.
authors.affiliation: Department of Psychiatry, Leiden, The Netherlands.
authors.forename: Bartholomeus C M
authors.initials: BC
authors.lastname: Haarman
authors.forename: Rixt F
authors.initials: RF
authors.lastname: Riemersma-Van der Lek
authors.forename: Huibert
authors.initials: H
authors.lastname: Burger
authors.forename: Mina
authors.initials: M
authors.lastname: Netkova
authors.forename: Roosmarijn C
authors.initials: RC
authors.lastname: Drexhage
authors.forename: Florian
authors.initials: F
authors.lastname: Bootsman
authors.forename: Esther
authors.initials: E
authors.lastname: Mesman
authors.forename: Manon Hj
authors.initials: MH
authors.lastname: Hillegers
authors.forename: Anne T
authors.initials: AT
authors.lastname: Spijker
authors.forename: Erik
authors.initials: E
authors.lastname: Hoencamp
authors.forename: Hemmo A
authors.initials: HA
authors.lastname: Drexhage
authors.forename: Willem A
authors.initials: WA
authors.lastname: Nolen
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000276:immunology / Q000473:pathology*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents; D016207:Cytokines
keywords: bipolar disorder; gene expression; inflammation; monocyte; phenotype