Haematological and immunological response of calves to infection with Taenia saginata.

Abstract

Calves were infected with eggs ofTaenia saginata and the haematologic response and the antigen-induced responsiveness of their peripheral blood lymphocytes was followed. No changes were observed in the erythrocyte levels, but a leukocytosis developed. This was contributed to primarily by a lymphocytosis, but also by an eosinophilia. Antigen-induced lymphocyte blastogenesis measured the antigen-sensitive cell population in peripheral blood and this population showed a maximum increase at 11 and 32 days after infection, however, antigen-sensitive cells remained at above normal levels for the remaider of the infection. Ten weeks after infection 11 calves were treated with albendazole at 50 mg/kg. Inter alia this resulted in an 86% destruction of the metacestodes in the treated animals as compared to the placebo treated animals and four days after treatment there was a significant leukopaenia and lymphopaenia. Coincidently, there was an increase in the responsiveness of the peripheral blood lymphocytes to antigen. Upon challenge infection with 15,000 eggs the infected calves showed a marked secondary eosinophilia, but no change was apparent in the other blood elements. At this time there was a marked increase in the response of the peripheral blood lymphocytes to antigen. Two lightly infected calves showed a leukocytosis and a lymphocytosis beginning 31 days after infection. The calves did not demonstrate an eosinophilic response, nor did the transformation of their lymphocytes with antigen differ from that of the uninfected animals. However, upon challenge infection these calves showed a marked eosinophilia and an increase in the responsiveness of their lymphocytes to antigen.