Assessment of Oxidative Stress in Clinical Bovine Leukosis and Asymptomatic Seropositive Cattle

Introduction: Bovine leukemia virus (BLV), a retrovirus, causes enzootic bovine leukosis, a chronic infectious disease in cattle worldwide. BLV establishes persistent infection by integrating proviral DNA into the host genome, targeting B-lymphocytes. Beyond its oncogenic potential, BLV infection is linked to immune dysfunction, reduced productivity, and poses a major challenge in bovine health management. Oxidative stress is associated with the pathogenesis of many infectious diseases, but its role in clinical and subclinical BLV infection has not been sufficiently described.

Methods: We investigated oxidative stress parameters in 30 BLV seropositive cattle: 15 asymptomatic seropositive and 15 with clinical bovine leukosis. Blood was collected from the jugular vein, and serum was stored at -70°C. Total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels were measured using commercial ZellBio (Germany) kits. Statistical comparisons were performed between asymptomatic seropositive and clinically affected groups.

Results: SOD activity differed significantly between groups (P = 0.0001), with higher levels in asymptomatic seropositive cattle. TAC was also higher in asymptomatic seropositive cattle. MDA and GPx were higher in clinically affected animals, though not statistically significant (P > 0.05).

Conclusions: BLV infection correlates with host oxidative status, particularly antioxidant defense mechanisms. Altered SOD activity suggests a potential role in early intracellular antioxidant responses to BLV infection in cattle. Oxidative stress dynamics may offer new avenues to understand BLV pathogenesis from a One Health perspective.