Evaluation of group A1B erythrocytes converted to type as group O: studies of markers of function and compatibility.
BACKGROUND
Enzymatic conversion of blood group A1B red blood cells (RBC) to group O RBC (ECO) was achieved by combined treatment with α-galactosidase and α-N-acetylgalactosaminidase. The aim of this study was to evaluate the function and safety of these A1B-ECO RBC in vitro.


METHODS
A 20% packed volume of A1B RBC was treated with enzymes in 250 mM glycine buffer, pH 6.8. The efficiency of the conversion of A and B antigen was evaluated by traditional typing in test tubes, gel column agglutination technology and fluorescence-activated cell sorting (FACS) analysis. The physiological and metabolic parameters of native and ECO RBC were compared, including osmotic fragility, erythrocyte deformation index, levels of 2,3-diphosphoglycerate, ATP, methaemoglobin, free Na(+), and free K(+). The morphology of native and ECO RBC was observed by scanning electron microscopy. Residual α-galactosidase or α-N-acetylgalactosaminidase in A1B-ECO RBC was detected by double-antibody sandwich ELISA method. Manual cross-matching was applied to ensure blood compatibility.


RESULTS
The RBC agglutination tests and FACS results showed that A1B RBC were efficiently converted to O RBC. Functional analysis suggested that the conversion process had little impact on the physiological and metabolic parameters of the RBC. The residual amounts of either α-galactosidase or α-N-acetylgalactosaminidase in the A1B-ECO RBC were less than 10 ng/mL of packed RBC. About 18% of group B and 55% of group O sera reacted with the A1B-ECO RBC in a sensitive gel column cross-matching test.


CONCLUSIONS
The conversion process does not appear to affect the morphological, physiological or metabolic parameters of A1B-ECO RBC. However, the A1B-ECO RBC still reacted with some antigens. More research on group O and B sera, which may partly reflect the complexity of group A1 the safety of A1B-ECO RBC is necessary before the application of these RBC in clinical transfusion.
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Hong-Wei
HW
Gao
Department of Transfusion, Affiliated Hospital of Academy of Military Medical Sciences, Beijing, China.
Hai-Long
HL
Zhuo
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Xue
X
Zhang
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Shou-Ping
SP
Ji
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Ying-Xia
YX
Tan
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Su-Bo
SB
Li
Beijing Red Cross Blood Center, Beijing, China.
Yan-Jun
YJ
Jia
Shaanxi Blood Center, Xi'an, China.
Hua
H
Xu
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Qing-Fa
QF
Wu
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Zhi-Min
ZM
Yun
Department of Transfusion, Affiliated Hospital of Academy of Military Medical Sciences, Beijing, China.
Qun
Q
Luo
Department of Blood Biochemistry and Molecular Biology, Beijing Institute of Transfusion Medicine, Beijing, China.
Feng
F
Gong
D000017:ABO Blood-Group System / Q000737:chemistry*; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D004912:Erythrocytes / Q000737:chemistry*; D006801:Humans; D008297:Male
D000017:ABO Blood-Group System