The diagnostic ability of serum Fe concentrations as a marker of inflammation in horses

Abstract The present study investigated whether serum Fe concentrations may be used as an inexpensive and simple inflammatory marker in clinical practice as an alternative to existing acute phase proteins (APPs). The control group included 42 healthy adult horses and 20 healthy yearlings. Forty-two horses were enrolled in the inflammatory disease group. Plasma serum amyloid A (SAA) concentrations were significantly higher in the inflammatory disease group than in the control group. When the cut-off value for plasma SAA concentrations was set at > 99.45 µg/dL by a ROC analysis, AUC was 0.960 and sensitivity and specificity were 83.8 and 98.4%, respectively, reconfirming that SAA is an inflammatory marker that diagnoses inflammatory disease with a high probability. In addition, serum Fe concentrations were significantly lower in the inflammatory disease group than in the control group, with AUC = 0.842, indicating a high diagnostic ability. These results suggest that the diagnostic ability of serum Fe concentrations is similar to that of existing APPs and, thus, may be widely applied as an inexpensive inflammatory marker that is easy to measure.