Ultrastructural study on the interaction of beta-thalassemic-erythrocytes and Plasmodium falciparum

beta-thalassemic erythrocytes and normal red blood cells were experimentally infected in vitro with Plasmodium falciparum cultured for 4 days and studied by means of transmission electron microscopy. Conspicuous alterations of the parasites appear in the advanced stage of schizogony leading to the fact that only a small amount of malaria pigment is formed, which in general is not crystalline, but always enclosed in extremely large vacuoles. Furthermore some of the developing merozoites reveal features of cellular degeneration, thus these merozoites lost their ability to invade new erythrocytes. Despite these findings alterations of the host cells are induced by the parasites, which, however, are comparable to those found in infected normal red blood cells, e.g. knobs appeared on the surface of the erythrocytes and membrane-bounded clefts became apparent in the cytoplasm of the host cell.