Art-iRBC retention and processing. (A-B) Aspect and quantification of brown dots on Giemsa-stained sections showing that they correspond to dead parasite remnants. Brown dots colocalized with red blood cells (intraerythrocytic dead parasite remnants; Dii, α) or not (extraerythrocytic dead parasite remnants). Extraerythrocytic dead parasite remnants could be further classified as extracellular (Dii, β), intracellular in cord cells (Dii, γ)or intracellular in sinus wall cells (Dii, δ). Most extraerythrocytic dead parasite remnants colocalized with cord cells (A,Dii). (B) Mean number of brown dots per × 400 field on Giemsa-stained section as box plots for 4 different spleens in which different parasite loads had been introduced. (Ci-ii) Aspect and localization of Art-iRBCs and extraerythrocytic dead parasite remnants at a cellular scale, analyzed either by Giemsa-staining (Ci) or by immunohistochemistry (Cii). Fragmented Art-iRBCs colocalized with cord cells/macrophages (Ci-ii, row c). (D) Microcirculatory structures of the spleen were identified on Giemsa-stained sections (Di) allowing differential counting of intraerythrocytic and extraerythrocytic dead parasite remnants (Dii) on × 400 fields. To adjust for circulatory space on each field, dead parasite remnants numbers are expressed as mean (and standard error of the mean) for 100 RBCs in each zone (Diii). For statistical analysis, see “Art-iRBC retention and processing are zone dependent.”