It is mandatory, after protein identification, to validate candidate markers in a larger amount of samples for biomarker discovery. The most used methods for validation of new markers are enzymatic or immunoassay-based commercial kits. However, relatively few kits are available for farm animals. Selected reaction monitoring (SRM), a targeted quantitative proteomic technique, may be used as an alternative to commercial kits for the measurement and validation of target proteins. Acute phase proteins (APPs) are widely recognized inflammation and infection biomarkers (Eckersall, 2010) and there is recent evidence that they can be also considered as welfare markers (Giannetto et al., 2011). During an acute stress situation, the levels of some interleukins (IL-1β, IL-6 and TNF-α) are increased (Elenkov and Chrousos, 2002) and consequently the concentration of the APPs varies dramatically. In pigs the most important APPs include haptoglobin (Hp), C-reactive protein (CRP), the inter-α-inhibitor-heavy chain 4 (ITIH4, also called Pig major acute phase protein, or Pig-MAP), serum amyloid A (SAA) and apolipoprotein A-I (Apo A-I), but also other proteins are well known to mark the acute phase response, as albumin, transferrin (Heegaard et al., 2011) and fetuin A (Brown et al., 1992).
Proceedings of the 4th Management Committee Meeting and 3rd Meeting of Working Groups 1, 2 & 3 of Cost Action Fa1002, 2013, p. 217-220