title: A longitudinal analysis of serum cytokines in the Hartley guinea pig model of osteoarthritis.
abstract: OBJECTIVE
  To evaluate chosen serum cytokines and their association with osteoarthritis (OA) in the guinea pig.
  
  
  METHODS
  The levels of 18 cytokines were measured in Hartley guinea pig serum at time points ranging from 3 weeks to 18 months of age. These levels were then tested for any correlation with total histology, and a comprehensive evaluation of these statistics was conducted using data previously collected from OA-resistant Strain 13 guinea pigs.
  
  
  RESULTS
  After all cytokines demonstrating a significant association with weight or age were excluded, IL-6 (p=0.016) and G-CSF (p=0.024) were found to correlate positively with total histological score. Models involving each of these cytokines paired independently with weight explained 43-44% of the variance in total histology.
  
  
  CONCLUSIONS
  Only the age and weight-independent associations of IL-6 and G-CSF with histological OA were significant under the conditions imposed by the Holm step-down adjustment for multiple comparisons. Though the observed changes of these cytokine levels may be due to a correlation with age, it is highly unlikely given the significant difference between Hartley and Strain 13 age-matched cohorts.
authors.affiliation: Duke University Medical Center, Division of Rheumatology, Department of Medicine, Durham, NC 27710, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Huebner
authors.forename: D R
authors.initials: DR
authors.lastname: Seifer
authors.forename: V B
authors.initials: VB
authors.lastname: Kraus
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D016207:Cytokines / Q000097:blood*; D004195:Disease Models, Animal; D006168:Guinea Pigs; D010003:Osteoarthritis / Q000097:blood* / Q000473:pathology
chemical_list: D015415:Biomarkers; D016207:Cytokines