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Measurement of erythrocyte membrane mannoses to assess splenic function
Author(s) -
Cao Huan,
Mathur Abhinav,
Robertson Charlotte,
Antonopoulos Aristotelis,
Henderson Sadie,
Girard LouisPierre,
Wong Jin Hien,
Davie Adam,
Wright Sonja,
Brewin John,
Rees David C.,
Dell Anne,
Haslam Stuart M.,
Vickers Mark A.
Publication year - 2022
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/bjh.18164
Subject(s) - spleen , mononuclear phagocyte system , haemolysis , mannose , immunology , biology , phagocytosis , microbiology and biotechnology , mannan binding lectin , lectin , biochemistry
Summary Red blood cells (RBCs) lose plasma membrane in the spleen as they age, but the cells and molecules involved are yet to be identified. Sickle cell disease and infection by Plasmodium falciparum cause oxidative stress that induces aggregates of cross‐linked proteins with N‐linked high‐mannose glycans (HMGs). These glycans can be recognised by mannose‐binding lectins, including the mannose receptor (CD206), expressed on macrophages and specialised phagocytic endothelial cells in the spleen to mediate the extravascular haemolysis characteristic of these diseases. We postulated this system might also mediate removal of molecules and membrane in healthy individuals. Surface expression of HMGs on RBCs from patients who had previously undergone splenectomy was therefore assessed: high levels were indeed observable as large membrane aggregates. Glycomic analysis by mass spectrometry identified a mixture of Man 5‐9 GlcNAc 2 structures. HMG levels correlated well with manual pit counts ( r = 0.75–0.85). To assess further whether HMGs might act as a splenic reticuloendothelial function test, we measured levels on RBCs from patients with potential functional hyposplenism, some of whom exhibited high levels that may indicate risk of complications.