Assessment of brain injury in cattle with Theileria annulata: Neuron-specific biomarkers, inflammation, oxidative stress and apoptosis

This study aimed to investigate selected brain-specific biomarkers in cattle with tropical theileriosis caused by Theileria annulata (T. annulata) and to evaluate their diagnostic and prognostic significance. The study group consisted of 25 cattle naturally infected with T. annulata, while the control group consisted of 10 healthy cattle. Animals with T. annulata were classified according to hematocrit (HCT) value as severe anemia group 1 (n:12) with HCT ≤12 and moderate anemia group 2 (n:13) with HCT between 13 and 24. Histopathological and immunohistochemical examinations of the brain tissue were performed in 10 nonsurvivor cattle. Serum calcium-binding protein B (S100B), glial fibrillary acidic protein (GFAP), tau protein and ubiquitin C-terminal hydrolase-1 (UCHL-1) concentrations in brain injury were measured using bovine-specific ELISA kits. S100B, GFAP, and Tau concentrations of cattle in the T. annulata group were found to be significantly higher than the control group (P<0.001). Brain specific biomarkers showed significant correlations with erythrocyte count, HCT and bilirubin. The presence of brain damage was confirmed by histopathological and immunohistochemical techniques. The results of ROC analysis showed that S100B with AUC value of 0.88 and GFAP with an AUC value of 0.82 were significant prognostic indicators. Additionally, S100B, GFAP and Tau showed significant diagnostic performance with an AUC value of 0.88, 0.92 and 0.86, respectively. In conclusion, brain-specific biomarkers can be used as diagnostic and prognostic markers in the assessment of brain damage in cattle naturally infected with T. annulata.