Acute phase proteins as promising biomarkers: Perspectives and limitations for human and veterinary medicine

Abstract

Acute phase proteins (APPs) are highly conserved plasma proteins that are increasingly secreted by the liver in response to a variety of injuries, independently of their location and cause. APPs favor the systemic regulation of defense, coagulation, proteolysis, and tissue repair. Various APPs have been applied as general diagnostic parameters for a long time. Through proteomic techniques, more and more APPs have been discovered to be differentially altered. Since they are not consistently explainable by a stereotypic hepatic expression of sets of APPs, most of these results have unfortunately been neglected or attributed to the nonspecificity of the acute phase reaction. Moreover, it appears that various extrahepatic tissues are also able to express APPs. These extrahepatic APPs show focally specific roles in tissue homeostasis and repair and are released primarily into interstitial and distal fluids. Since these focal proteins might leak into the circulatory system, mixtures of hepatic and extrahepatic APP species can be expected in blood. Hence, a selective alteration of parts of APPs might be expected. There are several hints on multiple molecular forms and fragments of tissue-derived APPs. These differences offer the chance for multiple selective determinations. Thus, specific proteoforms might indeed serve as tissue-specific disease indicators.

Proteomic profiling of mdx-4cv serum reveals highly elevated levels of the inflammation-induced plasma marker haptoglobin in muscular dystrophy

“…This acute phase plasma protein is a tissue damage marker and is often increased in serum in relation to cellular degeneration and inflammation (75). Since there is an urgent need to establish new biomarker candidates of X-linked muscular dystrophy (76), the proteomic identification of elevated haptoglobin levels in dystrophinopathy is an encouraging result.…”

Microchip gel electrophoretic analysis of perchloric acid‐soluble serum proteins in systemic inflammatory disorders

“…Laboratory analysis is necessary for monitoring systemic inflammation, and it is of utmost importance to help clinical decision‐making, and for early recognition of complications . Conventional inflammatory parameters (WBC, hs‐CRP, and ORM) are tested widely in daily routine.…”

Breed and adaptive response modulate bovine peripheral blood cells’ transcriptome

“…In dairy cows milk urea reflects the catabolism of protein by the ruminant tissues and within the rumen by bacteria. The decrease of rumen ammonia may indicate that animals increase the protein synthesis during an adaptive response [113]. Indeed, high levels of APPs and at the same time high expression of gene products of several pathways were observed in APP+ animals.…”