[Erythrocytemia and splenomegaly in an experimental Trypanosoma brucei gambiense infection in the mouse].

In accordance with observations reported in the litterature concerning experimental african trypanosomiasis, highly significant correlations were found between any pair of the following parameters: duration of infection, parasitaemia, spleen volume, number of erythrocytes, or between the sharp decrease of the number of erythrocytes and the combines effect of the increase of all other parameters. In subacute T. gambiense infections in mice, it was statistically demonstrated that, in the absence of variation in numbers of erythrocytes, any correlation between the increase of spleen volume and of parasitaemia is repealed. This result suggests the existence of a clear interaction, in the course of the infection, between the development of splenomegaly and the drop of erythrocytaemia. However, it is not clear which one, of the erythrophagocytic activity or the hypertrophy of the spleen is the cause of the other. The influence of splenectomy was studied, assuming that the anaemic syndrome was due to augmentation of the phagocytic activity. However, the suppression on that occasion of the erythrocytic and immunological activities of this important organ, did not produce any improvement in the course of the disease or a prolongation of the survival time of the infected animals. In rodents, the functions of production and of removal of erythrocytes are indeed performed by the same organ, so that no conclusions can be drawn from the splenectomy. We also wondered whether the sequestration and destruction of red cells sensitized by the parasitic antigen could not be extended to immature cells of the erythroblastic line present in the bone marrow (and also in the spleen, in rodents), if, as could be assumed, these cells are coated "in situ" by the soluble antigens actively concentrated by these major effector organs of the reticuloendothelial system.