Experimental Trypanosoma brucei infection in deer mice: splenic changes.

Forty deer mice (Peromyscus maniculatus) were infected with Trypanosoma brucei organisms and were killed 33 to 83 days after inoculation (average, 63). The outstanding lesion was infiltration of plasma cells in various tissues. These cells caused disruption of the periarteriolar lymphocytic sheaths and thickening of red pulp cords in the spleen. The lymph node was almost completely replaced by plasma cells. The spleen and lymph nodes also had marked hyperplasia of germinal centers and granulomatous-like proliferation of macrophages. The nervous system showed meningoencephalitis characterized by accumulations of plasma cells.