Investigation of the relationship between serum selenium level and peripheral circulating CD4+ and CD8+ T lymphocytes in calves with neonatal diarrhea

In this study, it was aimed to determine the relationship between serum selenium level and circulating CD4+ and CD8+ T lymphocytes in calves with neonatal diarrhea. The study was carried out on a total of 50 calves of different breeds in the neonatal period (1-28 days old). Calves were grouped as Rotavirus (n=10), Cryptosporidium parvum (C.parvum) (n=10), Coronavirus (n=5), Rotavirus+C.parvum (n=5) and Control (n=20) groups. 8 ml blood samples were taken from vena jugularis into tubes without anticoagulant and 3 ml in EDTA blood collection tubes from animals in all groups, in accordance with the technique. After the blood samples taken into tubes without anticoagulant coagulated, they were centrifuged at 5000 g at +4oC for 10 minutes in a refrigerated centrifuge, and serum samples were extracted. Serum selenium levels were analyzed by inductively coupled plasma-mass spectrophotometer (ICP-MS). In the determination of cell surface antigens, EDTA containing anticoagulant blood samples were analyzed in a Flow Cytometry device to determine CD4+ and CD8+T lymphocyte levels. There was no statistically significant difference between the serum selenium levels of the study groups (p>0.261). In terms of CD4+T lymphocyte levels, the Rotavirus+ C.parvum group was found to be statistically significantly higher than the coronavirus group (p<0.002). In terms of CD8+T lymphocyte level, it was determined that the coronavirus group was statistically higher than the control group (p<0.001). In intragroup comparisons of CD8+T lymphocyte levels, coronavirus group compared to rotavirus group (p<0.004); Coronavirus group compared to C. parvum group (p<0.010); It was determined that the coronavirus group was statistically significantly higher than the C.parvum +Rotavirus group (p<0.023). A negative correlation was found between selenium and CD4+T lymphocytes (r=-0.339, p=0.016). In conclusion, according to the data obtained from this study, it was revealed that there are differences in the immune response of CD4+ and CD8+ T lymphocytes depending on the type of etiological factor. Keywords: CD4+, CD8+, Calf diarrhea, Selenium, Flow cytometry