title: S100A9 is not essential for disease expression in an acute (K/BxN) or chronic (CIA) model of inflammatory arthritis.
abstract: OBJECTIVE
  S100A8 (calgranulin A, MRP8) and S100A9 (calgranulin B, MRP14) are calcium-binding proteins highly expressed by activated myeloid cells and thought to be involved in the pathogenesis of inflammatory diseases. Circulating levels of S100A8/S100A9 are elevated in both human and experimental models of autoimmune disease, including rheumatoid arthritis (RA).
  
  
  METHODS
  Mice deficient in S100A9 (S100A9 - /-) and wild-type controls were immunized using standard techniques for the K/BxN serum transfer or the collagen-induced arthritis (CIA) model.
  
  
  RESULTS
  S100A9 - /- animals, with defective expression of both S100A8 and S100A9 proteins, had similar arthritis and histopathology to that of wild-type controls in both mouse models.
  
  
  CONCLUSIONS
  S100A8 and S100A9 are not essential for disease expression in either the K/BxN serum transfer or the CIA model of inflammatory arthritis.
authors.affiliation: Thurston Arthritis Research Center, University of North Carolina School of Medicine, Division of Rheumatology, Allergy, and Immunology, Chapel Hill, NC 27599, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Rampersad
authors.forename: D
authors.initials: D
authors.lastname: Esserman
authors.forename: M W
authors.initials: MW
authors.lastname: McGinnis
authors.forename: D M
authors.initials: DM
authors.lastname: Lee
authors.forename: D D
authors.initials: DD
authors.lastname: Patel
authors.forename: T K
authors.initials: TK
authors.lastname: Tarrant
mesh_terms: D000208:Acute Disease; D000818:Animals; D001168:Arthritis / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D040502:Calgranulin B / Q000096:biosynthesis*; D002908:Chronic Disease; D004195:Disease Models, Animal; D018450:Disease Progression; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D011379:Prognosis; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D040502:Calgranulin B