title: Immune cell transcript modules reveal leukocyte heterogeneity in synovial biopsies of seronegative spondylarthropathy patients.
abstract: BACKGROUND
  The objective of this study was to identify leukocyte cell types found within the synovia of patients with seronegative spondylarthropathies (SpA), such as ankylosing spondylitis (AS), using transcription based analyses.
  
  
  METHODS
  Leukocyte transcriptional profiles obtained from the NCBI's gene expression omnibus and prediction analysis of microarrays (PAM) was used to identify 25-gene leukocyte metagenes. Subsequently, transcriptional profiles from murine and clinical models of AS and SpA were interrogated to characterize the local infiltration of leukocytes in SpA synovia.
  
  
  RESULTS
  Analysis of a proteoglycan-induced murine model of AS reveals infiltration of dendritic cells, CD4+ T cells, monocytes, and natural killer cells to the spine. In human SpA and AS patients, transcriptional analysis of synovial biopsies revealed local infiltration of dendritic cells and CD4+ T cells.
  
  
  CONCLUSIONS
  We identified leukocyte cell types that infiltrated the synovial of SpA patients. Our results imply a role for dendritic cells and CD4+ T cells in the local inflammation that underlies pathogenesis in patients with SpA.
authors.forename: Robin M
authors.initials: RM
authors.lastname: Hallett
authors.affiliation: Department of Graduate Education and Research, Canadian Memorial Chiropractic College, 6100 Leslie Street, Toronto, Ontario M2H 3J1, Canada. tchew@cmcc.ca.
authors.forename: Tracy
authors.initials: T
authors.lastname: Chew
mesh_terms: D000818:Animals; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D025242:Spondylarthropathies / Q000097:blood* / Q000276:immunology* / Q000473:pathology; D013582:Synovial Fluid / Q000276:immunology* / Q000378:metabolism