ABSTRACT
In the present work, the total leucocytes count of infested mice with ticks Hyalomma dromedarii infected with nematodes showed significant increase than infested group with ticks only. The infested group of mice with ticks and infested mice with ticks and nematodes showed a markedly significant drop in the eryhrocytes count. The results showed a highly significant decrease in Hb concentration, and HCT percentage for mice infessted with ticks and a marked increase with ticks infested with nematodes. The results showed a significant decrease in level of IgG of mice infested with ticks, while in infected mice with ticks and nematodes, the IgG level increased to control level which might indicated that nematodes penetrate ticks that were feeding on mice through the thinner cuticle of engorging females. Differences in cytokines responses were observed between tick-infested and non-infested mice. Proinflammatory Th1 T lym-phocyte cytokines were suppressed and TH2 cytokines were enhanced for infestation with H. dromedarii. The date indicated a polarization of immune response towards Th2 lymphocytes.