Dynamics of Serum Amyloid A and Haptoglobin After Experimentally Induced Inflammation in Caspian Horses (Equus ferus caballus)

Introduction: The Caspian horse (Equus ferus caballus), one of the rarest and oldest horse breeds worldwide, is native to northern Iran. Although it is not listed on the International Union for Conservation of Nature (IUCN) endangered species list, the breed is endangered due to its small population and limited distribution. Health monitoring of this breed is crucial, particularly using biomarkers such as acute phase proteins (APPs) to detect inflammation and subclinical stress. This study aimed to evaluate changes in serum levels of total protein (TP), albumin (Alb), serum amyloid A (SAA), and haptoglobin (Hp) following experimentally induced inflammation in Caspian horses. A randomized controlled trial was conducted on healthy, purebred Caspian horses from the Khojir Research Center, Tehran, Iran. Materials & Methods: Thirty ۱۰-year-old male Caspian horses were randomly assigned to a treatment group (subcutaneous turpentine injection, n=۱۵) or a control group (saline injection, n=۱۵). Inflammation was induced using ۵ mL of turpentine, and blood samples were collected at baseline (۱ h before injection) and at multiple time points up to ۱۴۴ h post-injection. Serum TP and Alb were measured by spectrophotometry using commercial kits, while SAA and Hp were quantified via ELISA. Statistical analysis was performed using t-tests, with significance level set at P<۰.۰۵. Results: TP concentrations were significantly lower in the treatment group compared to control at ۴۸ and ۷۲ h post-injection (P<۰.۰۵). Alb concentrations were significantly reduced in the treatment group from ۴ to ۷۲ h post-injection (P<۰.۰۵). Hp concentrations were significantly elevated in the treatment group at ۷۲ and ۱۴۴ h post-injection (P<۰.۰۵), while SAA concentrations were significantly increased from ۱۶ to ۱۴۴ h post-injection (P<۰.۰۵). Among the biomarkers, SAA showed the most rapid and pronounced response to inflammation, highlighting its reliability for early detection of the acute phase response in Caspian horses. Hp also increased significantly, though with a delayed onset. Conclusion: In contrast, while TP and Alb showed statistically significant changes, their values remained within reference intervals, suggesting limited diagnostic utility for these markers in this breed.

کلیدواژه ها:

Acute phase response ، Caspian horse ، inflammation ، Serum amyloid A (SAA) ، Haptoglobin (Hp)