Serum Amyloid A Concentrations of Healthy and Clinically Diseased Japanese Black Breeding Cattle—Preliminary Measurements for Determining the Cut-Off Concentrations

Abstract

The present study aimed to compare serum amyloid A (SAA) concentrations of Japanese Black (JB) breeding cows in both clinically normal and diseased cows diagnosed by veterinarians using modified latex agglutination turbidimetric immunoassay (LATIA) to determine the cut-off values for healthy and diseased JB cows. For the comparison, a total of 289 serum samples of healthy cows without any clinical symptoms intended for the metabolic profile test and 66 serums from diseased cows clinically diagnosed by veterinarians were measured for the SAA concentrations. A significant difference (p-value = 6.68 × 10−29) was observed in the mean SAA concentrations between the healthy (2.8 ± 3.2 mg/L) and diseased (54.8 ± 76.8 mg/L) groups, and the median concentrations of the healthy and diseased groups were 1.5 mg/L and 31.2 mg/L, respectively. Finally, the cut-off SAA concentrations at each probability were 2.9 mg/L (p = 0.05), 5.7 mg/L (p = 0.1), 13.7 mg/L (p = 0.5), and 21.8 mg/L (p = 0.9), respectively, and 6.5 mg/L (p = 0.122) based on evaluation performed using the receiver operating characteristic curve. The results indicated that, with the practical application of the obtained cut-off value, the measurement of SAA concentrations for JB breeding cows with LATIA could be potentially beneficial in the early evaluation of inflammatory diseases in JB breeding cows and possibly useful in the prevention of not only metabolic diseases but also non-nutritional diseases during the perinatal period of JB breeding cows.

Usefulness of Measuring Serum Amyloid A Concentration in Japanese Black Cattle in Clinical Practice

“…Although the standard range of SAA concentration in Japanese Black cattle is unknown, it decreased significantly from the second to the fifth day of illness and then recovered. In contrast, the SAA concentration of case 2 was 65.7 mg/L on the second day of illness, which was significantly higher than the cut-off value (6.5 mg/L) previously reported by the authors [ 26 ]. The SAA concentration further increased to 366.5 mg/L on the eighth day of illness and was discontinued on the fourteenth day.…”

“…The SAA cut-off value for Japanese Black steers is unknown. However, according to the cut-off value (6.5 mg/L) for Japanese Black cattle previously reported by the authors [ 26 ], the SAA concentration increased due to dehorning but recovered to a value within the reference range by day 7 after dehorning. The SAA concentration peaks on the second day after surgery and returns to normal within 7−14 days in horses [ 13 ].…”

“…Continuous measurement of the SAA concentration is effective in horses [ 13 ] and cats [ 9 ]. In addition, as previously reported by the authors, a diagnosis cannot be made based on the results of a single measurement of SAA in clinical settings; therefore, it is necessary to measure the SAA concentration multiple times during the course of the illness [ 26 ]. Based on the results of this study, the SAA concentration must decrease rapidly from the viewpoint of prognostic prediction in Japanese Black cattle, and it is considered beneficial for clinical veterinarians to record the changes in the SAA concentration during a single course of medical treatment.…”

“…Although there have been several reports on the measurement of SAA concentrations in dairy cows [ 23 , 24 ] and Japanese Black suckling calves [ 25 ], no reports have been published on the SAA concentrations in Japanese Black breeding cattle. We recently reported a cut-off value of SAA (6.5 mg/L) for Japanese Black cattle for the first time [ 26 ]; therefore, as an additional verification, the usefulness of measuring the SAA concentrations in Japanese Black cattle using the cut-off value in clinical practice was evaluated.…”

Performance of an automated immunoturbidimetric assay for bovine serum amyloid A

“…A new multispecies automated SAA assay (VETSAA, Eiken Chemicals Co, Ltd., Tokyo, Japan) has become available. The assay has previously been validated in horses, 5 dogs, 6 and cats, 7 and it has been used in experimental studies in cattle 8–10 . Besides a single short report examining plasma samples in cows with mastitis, 11 little information regarding performance characteristics for measuring SAA in clinical bovine serum has been reported.…”