Page 193 - Veterinary Immunology, 10th Edition

Acute-Phase Proteins
VetBooks.ir Under the influence of IL-1β, TNF-α, and especially IL-6,

hepatocytes synthesize new proteins. Because this increase is

associated with acute infections and inflammation, these newly
produced proteins are called acute-phase proteins (APPs). Type I
APPs are induced by IL-1 and TNF-α, while type II APPs are
induced by IL-6. These proteins are also synthesized in lymph

nodes, tonsils, and the spleen, as well as by blood leukocytes. The
increase in APPs begins about 90 minutes after injury or systemic
inflammation and subsides within 48 hours (Fig. 7.3). It may also
occur following prolonged stress such as road transportation or

confinement. About 30 acute-phase proteins have been recognized,
and many are important components of the innate immune system.
They include soluble PRRs, complement components, clotting
molecules, protease inhibitors, and iron-binding proteins. Different

species produce different acute-phase proteins (Fig. 7.4).

FIG. 7.3 The rise in C-reactive protein levels in six dogs following
anesthesia and surgery (red line) and in six dogs undergoing
anesthesia alone (blue line). (From Burton SA, Honor DJ, Mackenzie AL, et
al: C-reactive protein concentration in dogs with inflammatory leukograms, Am J Vet
Res 55:615, 1994.)

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