PARASITIC EFFECT BY Haemonchus contortus ON LEUKOCYTE OXIDATIVE METABOLISM

Abstract The immune response to hemoncosis can be modulated by the Th2 profile, and the main effector cells responsible are eosinophils responsible for a efficient elimination of the parasite, but when it is modulated by the Th1 profile, neutrophils are the main effector cells, responsible for a more deficient parasitic elimination, probabely, because in vitro tests have shown that the parasite depresses the oxidative metabolism of phagocytes. Thus, this study aimed to evaluate if the degree of parasitic infection observed by the amount of eggs per gram of feces (EPG) of Haemonchus contortus interferes in the leukogram, and if it impacts on leukocyte oxidative metabolism in sheep naturally affected by hemoncosis. 39 adult male sheep without alterations in the physical examination, except for mucosal collor, were separated into 4 groups according to parasitic infection 0-350 (n = 15), 400 to 1000 (n = 10), 1100. -2000 (n = 7) and 2100-4700 (n = 7). Significant positive correlation was observed between EPG and neutrophils (r=0.56P=0.0003) and significant negative correlation between EPG and eosinophils (r=-0,56,P = 0.0012) and EPG and leukocyte oxidative metabolism (P = 0.0001), allowing to conclude that there is a relationship between effector cells and the severity of parasitic infection in sheep naturally infected with hemoncose, and the high parasitic infection promotes decreased leukocyte oxidative metabolism.