Trypanosoma brucei: attenuation by cortcosteroids of the anemia of infected mice

BALBc/J mice infected with pleomorphic stabilate of Trypanosoma brucei develop a severe anemia. The anemia is initially normoblastic and normocytic but becomes macrocytic due to brisk and sustained reticulocytosis. Red blood cells from uninfected animals are destroyed when transfused into infected animals. Neither extensive intravascular hemolysis nor red cell agglutinins were detected in infected animals, but spherocytes were common in the peripheral circulation. Treatment of mice with either dexamethasone or hydrocortisone greatly retarded the development of the anemia. Comparison of the course of infection in these treated mice to that in normal mice suggests that these corticosteroids attenuate the anemia through their immunosuppressive action.