Selected biochemical and oxidative stress parameters and ceruloplasmin as acute phase protein associated with bovine leukaemia virus infection in dairy cows

The aim of this study was to determine the ceruloplasmin (Cp) and vitamin C concentrations, the total antioxidant status (TAS), and selected biochemical parameters in dairy cows spontaneously infected with bovine leukaemia virus (BLV). Of the 27 cows included in the study, 18 animals were seropositive for enzootic bovine leukosis (EBL), whereas nine cows were seronegative and were used as controls. The serum aspartate aminotransferase (AST) (P = 0.003) and Cp concentrations (P = 0.03) decreased (65.17 ± 5.03 and 7.70 ± 0.72 respectively) in BLV-infected cows, as compared to healthy animals (100.67 ± 11.50 and 10.40 ± 0.70 respectively). A slight insignificant increase in alkaline phosphatase activity and unchanged levels of alanine aminotransferase, lactate dehydrogenase, calcium, magnesium, and TAS were demonstrated in EBL cows. As the TAS and vitamin C levels remained unchanged in EBL cows, it may be suggested that ruminants may compensate for the impaired oxidative/antioxidative balance. The results obtained also indicate that BLV may suppress AST and Cp synthesis or secretion in the liver through an unknown mechanism. The mechanism of action of BLV in hepatocytes, especially on AST and Cp, requires further investigation to elucidate the immune suppression caused by oncogenic retroviruses.