Figure 5

Changes in spleen histology during Plasmodium falciparum infection. 5A-D: At d13 of infection (just before chloroquine treatment), the red pulp was further enlarged in relation to controls and d7 of infection and laden with haemozoin (A, asterisk). The follicles were also enlarged and limits between the red and white pulp were blurred (A, arrow). Phagocytes were heavily laden with pigment and strings of cells suggestive of plasmacytogenesis cords were observed near the T-cell zone (B). Follicles showed penetrating RBCs and limits between red and white pulp were blurred (C). Follicles were interspersed with cells of different morphology, showing phagocytes with malaria pigment, centroblasts and mainly small lymphocytes in the periphery (D). E, F: At d28 (15 days after start of chloroquine treatment), the red pulp phagocytes were heavily laden with malaria pigment (E, F). The distribution of haemozoin-containing phagocytes was better defined in relation to d13, with individual cells containing more compacted, less granulous pigment (E, F). The follicles were further enlarged in relation to d13, with large follicles touching each other with little red pulp in between (E) and showed mostly activated cells (F). All sections were stained with Lennert’s Giemsa.