Serum Biochemical Parameters And Cytokine Profiles Associated With Animal African Trypanosomiasis In Naturally Infected Cattle In Ghana

ABSTRACT Animal African Trypanosomiasis (AAT) greatly affects livestock production in sub-Saharan Africa. In Ghana prevalence of AAT is estimated to range between 5 – 50%. Studies have reported serum biochemical aberrations and variability in cytokine profiles in animals during infection. However, information regarding the biochemical parameters and cytokine profiles associated with natural infections are limited. This study was therefore aimed at establishing the levels of serum biochemical parameters and cytokine profiles in naturally infected cattle over a period of six months in 40 individual cattle at 4 – 5 weeks intervals. Nested Internal Transcribed Spacer (ITS)-based PCR and sequencing were used to characterize trypanosome infection in cattle at two areas (Adidome and Accra) of different endemicities. Levels of serum biochemical parameters (Creatinine, Cholesterol, Alkaline phosphatase (ALP), Alanine aminotransferase (ALT), Total bilirubin and Total protein) and cytokines (IL-10, IL-4, IFN-γ, TNF-α and IL-12) were measured in serum samples collected and then compared between infected cattle and uninfected controls. The predominant trypanosome species detected in Accra (non-endemic) and Adidome (endemic) were Trypanosoma theileri and Trypanosoma vivax respectively. Serum biochemical parameters were similar between infected and uninfected cattle in Accra. Infected cattle at Adidome however had significantly higher levels of ALP (infected = 613.15U/L, uninfected = 342.5U/L, p = 0.02), Creatinine (infected = 101.90 µmol/L, uninfected = 77.75 µmol/L, p = 0.01), Total Protein (infected = 77.14 µmol/L, uninfected = 71.26 µmol/L, p = 0.01) and Total Bilirubin (infected = 2.45 µmol/L, uninfected = 1.96 µmol/L, p = 0.04) and significantly lower levels of cholesterol (infected = 2.45 mmol/L, uninfected = 3.15 mmol/L, p = 0.02) at specific time points. iv At basal levels and during infection, significantly higher pro-inflammatory/anti-inflammatory (Th1/Th2) cytokine ratios were observed in cattle at Adidome compared to Accra, indicating a shift towards Th1 immune response in Adidome. Levels of IL-10 and TNF-α were however significantly elevated in infected cattle in Accra, suggesting high anti-inflammatory cytokine response in Accra. These results generally demonstrate that cattle in the non-endemic area, which were predominantly infected with non-pathogenic trypanosome species, have different biochemical profiles and immune responses compared to cattle in the endemic area with predominantly pathogenic trypanosome species.