Malignant ovine theileriosis: serum concentrations of some inflammatory components and adenosine deaminase activity

Abstract

Theileria lestoquardi (hirci) is a tick-transmitted protozoan parasite that causes a malignant disease in sheep. The parasite invades ovine leukocytes and stimulates a variety of immune responses in the host. In order to evaluate serum adenosine deaminase activity and the status of some inflam- matory mediators, 34 fat-tailed Iranian sheep naturally infect- ed with T. lestoquardi were selected and divided into three subgroups according to their parasitemia rates ( 4 %). Fifteen non-infected sheep were sampled as controls. Blood samples were taken from jugular vein into EDTA- containing tubes for measuring haematological parameters and without anticoagulant for serum concentrations of inflam- matory cytokines (IL-1β, IL-6, IFN-γ and TNF-α) and aden- osine deaminase (ADA) activity. Remarkable decreases were seen in haematological parameters including red blood cells (RBCs), packed cell volume (PCV) and haemoglobin in in- fected sheep. In contrast, serum levels of the measured cyto- kines and also ADA activity were significantly increased in infected animals. However, with increase in the parasitemia rate, no significant increase or decrease was observed in the levels of cytokines and ADA activity. The results showed that the infection with T. lestoquardi promotes significant changes in major inflammatory components in infected sheep. These remarkable alterations could be triggered from earlier stage of infection.