CR1 and malaria: We examined changes in surface expression of: glycophorin A (GPA), a sialoglycoprotein affecting RBC charge; CD47, an anti-phagocytic RBC marker; C3b deposition on RBC surfaces; CD35, complement receptor 1; CD55, a decay accelerating factor regulating complement on the cell surface; CD147; and sialic acid, all of which can reflect RBC age and overall membrane integrity and/or have been implicated in malaria merozoite invasion.