Equis ISSN 2398-2977

Serum amyloid A

Synonym(s): SAA

Contributor(s): Annalisa Barrelet, Stein Jacobsen

Introduction

  • Serum amyloid A is a major equine acute phase protein.
  • It is a highly sensitive, rapidly reacting inflammatory protein which has very low or undetectable levels in the plasma of healthy individuals and very high levels in plasma of individuals suffering from septic and aseptic inflammatory disease.
  • It is produced by hepatocytes and certain non-hepatic cell types under the influence of cytokines.
  • Cytokines are released from cells, especially monocytes and macrophages, activated by aseptic and septic stimuli during the acute phase response.
  • SAA is complexed to high density lipoprotein in plasma.
  • Synthesis rate is the only important determinant of the plasma concentration.
  • SAA has a short half-life and SAA concentrations start to decline shortly after synthesis has ceased.

Normal ranges

  • Most normal horses have immeasurable levels, quoted normal ranges obtained with different assays are <20 mg/l.
  • Levels may be slightly higher than basal in neonatal foals (up to 200 mg/l) and in post-parturient mares.
  • Otherwise, no consistent age or gender variation has been demonstrated.

Pathological changes

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Uses

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Limitations

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Test methodology

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Validity

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Labelle A L et al (2011) Effects of ophthalmic disease on concentrations of plasma fibrinogen and serum amyloid A in the horse. Equine Vet J 43 (4), 460-465 PubMed.
  • Jacobsen S & Kjelgaard-Hansen M (2008) Evaluation of a commercially available apparatus for measuring the acute phase protein serum amyloid A in horses. Vet Rec 163 (11), 327-330 PubMed.
  • Duggan V (2008) Serum amyloid A in the neonatal foal: the significance of peri-parturient events. Vet J 176 (3), 267-269 PubMed.
  • Jacobsen S & Andersen P H (2007) The acute phase protein serum amyloid A (SAA) as a marker of inflammation in horses. Equine Vet Educ 19 (1), 38-46.
  • Jacobsen S, Halling-Thomsen M & Nanni S (2006) Concentrations of serum amyloid A in serum and synovial fluid from healthy horses and horses with joint disease. Am J Vet Res 67, 1738-1742 PubMed.
  • Jacobsen S, Jensen J C, Frei S, Jensen A L & Thoefner M B (2005) Use of serum amyloid A and other acute phase reactants to monitor the inflammatory response after castration in horses: a field study. Equine Vet J 37, 552-556 PubMed.
  • Hulten C & Demmers S (2002) Serum amyloid A (SAA) as an aid in the management of infectious disease in the foal: comparison with total leucocyte count, neutrophil count and fibrinogen. Equine Vet J 34, 693-698 PubMed.
  • Stoneham S J, Palmer L, Cash R & Rossdale P D (2001) Measurement of serum amyloid A in the neonatal foal using a latex agglutination immunoturbidometric assay: determination of the normal range, variation with age and response to disease. Equine Vet J 33, 599-603 PubMed.
  • Hultén C, Sandgren B, Skioldebrand E et al (1999) The acute phase protein serum amyloid A (SAA) as an inflammatory marker in equine influenza virus infection. Acta Vet Scand 40, 323-333 PubMed.
  • Wada A, Yamada T & Kuboto N (1997) Measurement of serum amyloid A by commonly used automated analysers. Ann Clin Biochem 34, 569-574 PubMed.
  • Nunokawa Y, Fujinaga T, Taira T et al (1993) Evaluation of serum amyloid A protein as an acute-phase reactive protein in horses. J Vet Med Sci 55, 1011-1016 PubMed.
  • Chavatte P M, Pepys M B,  Roberts B et al (1992) Measurement of serum amyloid A protein (SAA) as an aid to differential diagnosis of infection in newborn foals. Equine Inf Dis VI, 33-38.
  • Pepys M B, Bajtz M I, Tennant G A et al (1989) Serum amyloid A protein (SAA) in horses; objective measurement of the acute phase response. Equine Vet J 21, 106-109 PubMed.


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