[Novel criteria for assessing red blood cell viability in blood banks].
In light of recent results on the mechanism of programmed cell death of human red blood cells (RBC), the aim of the present study was to solve the enigma of the rapid clearance of transfused RBCs.


METHODS
We describe new criteria of RBC viability founded on the use of flow cytometry. They were applied, in association with the classical ones: ATP and hemolysis measurements, to RBCs stored in SAGM medium for 42 days.


CONCLUSIONS
Application of an original method of flow cytometric quantitation of in vitro erythrophagocytosis showed that an important proportion of stored RBCs were phagocytized although the following classical signals for phagocytosis were absent, i.e.: desialylation, phosphatidylserine exposure in the outer leaflet of the RBC membrane, loss of CD47 receptor, an antiphagocytosis signal. In addition, ATP was still present and hemolysis was very low. This enigma was solved by the use of scanning electron microscopy, which showed the disappearance of discocytes and the presence of an important proportion of spheroechinocytes, which are the phagocytable forms of RBCs. The mechanism of this dramatic morphological transformation remains to be elucidated.
Mitrofan-Oprea
L
L
Université des sciences et technologies de Lille 1, unité de glycobiologie structurale et fonctionnelle, UMR CNRS/USTL no 8576, cité scientifique, 59655, Villeneuve-d'Ascq cedex, France.
Palii
C
C
Tissier
J-P
JP
Héron
A
A
Verpoort
T
T
Behague
M
M
Smagghe
E
E
Schooneman
F
F
Huart
J-J
JJ
Goudaliez
F
F
Montreuil
J
J
Bratosin
D
D
D017209:Apoptosis; D001771:Blood Banks / Q000592:standards*; D002470:Cell Survival; D004910:Erythrocyte Membrane / Q000502:physiology; D017707:Erythrocyte Transfusion / Q000592:standards*; D004912:Erythrocytes / Q000166:cytology* / Q000502:physiology; D005434:Flow Cytometry; D005602:France; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D010587:Phagocytosis
D006454:Hemoglobins