Determination of the relationships between serum amyloid a, serum calprotectin and fecal calprotectin in healthy and infectious diarrheic calves and their diagnostic significances as inflammatory markers

In this study, serum amyloid A (SAA), serum calprotectin (SCalp) and fecal calprotectin (FCalp) levels were investigated in neonatal calves with infectious diarrhea. Study groups were divided into E. coli (n = 17), C. parvum (n = 11), C. Parvum + viral (mix) (n = 8), viral (n = 19) and control group (n = 15) according to etiological diagnoses and a total of 70 calves were included in this study. Body temperature, respiration and pulsation numbers, stool, sucking and mental status scores of calves were recorded on the day 0, when diarrhea was first detected, and on the 7th day, after treatment. On these days, blood and stool samples were also taken. WBC counts and serum GGT values were measured from blood samples. SAA, SCalp and FCalp levels were measured with commercial ELISA kits. All calves with diarrhea were successfully treated and there was no calf loss. Statistically significant improvements were detected on the 7th day in all clinical parameters. Serum GGT concentrations on day 0 did not show a statistically significant difference for the diarrheal and control groups, therefore it was concluded none of the calves showed sign of passive transfer failure in both groups. Mean SAA concentrations on day 0 were measured as 0.54 (0.16 - 2.18) ng/ml and 38.40 (8.28 - 83.96) ng/ml for the diarrhea and healthy group, respectively. There was a statistical difference between the measurement day (P <0.001). In the study presented, a statistically significant difference was obtained between the diarrheic (68.02 ng/ml) and control (24.05 ng / ml) groups in terms of SCalp levels on day 0 (P <0.001). In addition, the cut-off value of SCalp was found to be ≤70.969 ng/ml (Sens: 94%, Spec: 62.5, AUC: 0.842, P = 0.002) in the ROC analysis performed to determine the power to distinguish bacterial and viral diarrhea cases. FCalp levels on day 0 were 98.23 ng/ml and 87.91 ng/ml in the healthy and diarrheal groups, respectively. Statistical difference was obtained between the two groups (P = 0.01). According to ROC analysis, the cut-off concentration of FCalp was found to be > 91.804 ng/ml (AUC: 0.694, P = 0.0057). In addition, as a result of the logistic regression analysis, it was seen that FCalp was able to identify animals with diarrhea with 6.316 times (P = 0.009). The highest levels of SCalp and FCalp measured on day 0 were found in E. coli group. As a result, the importance of FCalp and SCalp in diagnosing the status of infective diarrhea for the first time in the veterinary literature is emphasized.