Assessment of Serum Concentrations of IL-4, IL-6, and TNF-α in Cattle Infected with Trypanosomiasis

Abstract

Background and aim: Bovine Trypanosomiasis, caused by Trypanosoma spp., is an economically important parasitic disease that adversely affects cattle health and productivity in tropical and subtropical regions. The host cytokine response is a key determinant of disease progression and severity. This study aimed to evaluate the serum levels of IL-4, IL-6, and TNF-α in naturally infected cattle and determine their association with bovine Trypanosomiasis in Diyala Province, Iraq.

 Materials and Methods: A total of 550 cattle were screened for Trypanosoma spp. infection by microscopic examination, and 43 animals were identified as infected. Serum samples from 40 infected cattle were analyzed for IL-4, IL-6, and TNF-α using enzyme-linked immunosorbent assay (ELISA). Cytokine prevalence and serum concentrations were statistically analyzed, with significance set at p < 0.001.

Results: The prevalence of Trypanosoma spp. infection was 7.8% (43/550). Positive cytokine expression was detected in 70.0% of cattle for IL-4, 87.5% for IL-6, and 82.5% for TNF-α. Serum concentrations of all three cytokines were significantly higher in infected cattle than in non-infected controls (p < 0.001), indicating a strong association between cytokine response and infection.

Conclusions: Serum levels of IL-4, IL-6, and TNF-α were significantly elevated in cattle with bovine Trypanosomiasis, indicating their important role in the host immune response. IL-6 showed the strongest diagnostic potential, while TNF-α and IL-4 reflected inflammatory and immune regulatory responses. These cytokines may serve as useful biomarkers for disease diagnosis and monitoring.