Between the shells: a review of acute-phase proteins in turtles

Acute-phase proteins (APPs) are used in veterinary science for diagnosing disease, identifying acute and subclinical inflammatory processes, monitoring disease progression, assessing patient response to treatment, and as a general health screening tool. In turtles, the utility of APPs, such as albumin, haptoglobin, fibrinogen, and myeloid-related protein (MRP)-126, as inflammatory markers has been investigated in a small number of studies. Serum or plasma protein electrophoresis, immunoassays, and biochemistry assays are most commonly employed to study such APPs, with mass spectrometry-based proteomics emerging as an important tool. Protein electrophoresis RIs have been established for a few turtle species. However, very few commercial assays are available for measuring specific APPs in turtles, with even fewer reported validated assays. Turtles have significant inter- and intraspecies biological variation; consequently, RIs of protein electrophoresis and specific APP assays for individual species should be established according to guidelines and referenced to determine if sex, age, reproductive status, and health status influence the results. For small populations of animals, particularly those of high conservation value, subject-based RIs are recommended if population-based RIs are not feasible. Further studies, especially biomarker identification, assay development, and validation, are required to increase the tools for disease diagnosis and monitoring of this taxon and contribute to the healthcare and conservation of many endangered turtle species.