1475-2875-9-S2-O101475-2875 Oral presentation <p>A micro-bead device to explore <it>Plasmodium falciparum</it>-infected, spherocytic or aged red blood cells prone to mechanical retention by spleen endothelial slits</p> DeplaineGuillaume SafeukuiInnocent JeddiFakhri LacosteFrançois BrousseValentine PerrotSylvie BiliguiSylvestre GuillotteMicheline GuittonCorinne DokmakSafi AussilhouBéatrice SauvanetAlain CouvelardAnne PayeFrançois ThellierMarc MazierDominique MilonGeneviève MohandasNarla PuijalonMercereauOdile DavidHPeter BuffetAPierre

Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, Département de Parasitologie Mycologie, F- 75015 Paris, France

CNRS, URA2581, Paris, France

INSERM - UPMC (Paris 6 University) UMRs945, F-75013 Paris, France

Fond Ackermann, Fondation de France

Department of Pediatrics, Necker Hospital, AP-HP, F-75015 Paris, France

Department of Parasitology, Pitié Salpétrière Hospital, AP-HP, F-75013 Paris, France

Department of Haematology, Kremlin-Bicêtre Hospital, AP-HP, F-94270 Le Kremlin-Bicêtre, France

Department of Surgery, Beaujon Hospital, AP-HP, F-92110 Clichy, France

Department of Pathology, Beaujon Hospital, AP-HP, F-92110 Clichy, France

Department of Surgery, Saint-Antoine Hospital, AP-HP, F-75018 Paris, France

Institut Pasteur, mmunophysiologie et Parasitisme Intracellulaire, Département de Parasitologie Mycologie, F-75015 Paris, France

New York Blood Centre, New York, NY 10065, USA

 Malaria Journal <p>Parasite to Prevention: Advances in the understanding of malaria</p> Meeting abstracts - A single PDF containing all abstracts in this supplement is available here. http://www.biomedcentral.com/content/pdf/1475-2875-9-S2-info.pdf <p>Parasite to Prevention: Advances in the understanding of malaria</p> Edinburgh, UK 20-22 October 2010 1475-2875 2010 9 Suppl 2 O10 http://www.malariajournal.com/content/9/S2/O10 10.1186/1475-2875-9-S2-O10 20102010 2010Safeukui et al; licensee BioMed Central Ltd.This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Experimental tools to identify human red blood cells (RBC) prone to mechanical retention upstream from the spleen venous sinus inter-endothelial slits are currently suboptimal. We designed a micro-bead device mimicking the geometry of the human narrow and short inter-endothelial slits. Upon filtration through a mixture of 5-25 μm diameter micro-beads, Plasmodium falciparum-hosting RBC (Pf-RBC) were retained in a parasite developmental stage-dependent way, the retention rates of a subset of ring-RBC being similar in micro-beads and in isolated-perfused human spleens. We found that this retention might be linked principally to the reduced surface-area-to-volume ratio of Pf-RBC. Interestingly, other rigid RBC, such as heat-treated RBC, and RBC from hereditary spherocytosis patients were also retained in micro-beads without any hemolysis. Micro-beads allow (i) depletion of heterogeneous RBC population from its rigid-RBC subpopulation ii) characteriziation of distinct molecular signatures of rigid versus deformable RBC subpopulations. This simple method portends wide medical applications, such as improving the quality of stored RBC concentrates prior to transfusion.