Retention in microsphilters of immature and mature GIEs. (A) Retention in microsphilters of stages II, III, IV, and V GIE from different P falciparum clonal lines (B10, H4, and 3D7GFP) in culture or directly collected from the blood of a hyposplenic patient treated for a malaria attack (clinic). Immature GIEs (stages II-IV) are retained by the microsphilters while mature GIEs (stage V) flow through. (B) Differential interference contrast images of paraformaldehyde-fixed GIEs as they flow through the microsphilters. Immature stages (left panel) keep a convex oval or round shape, unlike uninfected erythrocytes (white star), whereas a majority of mature GIEs are twisted and dumbbell-shaped (right panel). (C) Graphical representation for the proportion of GIEs showing a regular (dark gray) or twisted (light gray) shape in a population of immature (n = 100) and mature (n = 36) GIEs (χ² test, P = 1 × 10⁻⁹).