Glossary
Serum amyloid A.
Direct answer
Serum amyloid A is an acute phase protein produced by the liver during inflammation, infection or tissue damage. In the horse the resting concentration is very low, and after a stimulus the level multiplies within hours. Once the stimulus is removed the concentration falls back just as quickly.
The wide gap between resting and reacting values makes serum amyloid A sensitive in horses: even a limited inflammation lifts the result clearly. Its short half-life also allows the course of an episode to be followed closely. A rise reports activity only, never its cause and never its location in the body.
Humans also produce serum amyloid A, but there it sits behind C-reactive protein, the reference marker of human medicine. This reversal of rank is the heart of the comparison: same protein, different role. Figures from horse and human are only comparable when the same assay method has been used.
Related content
Acute phase proteinC-reactive proteinAcute inflammationHalf-life
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