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Modification of red cell antigenic characteristics via covalent modification with branched poly (ethylene glycol) Srubiski, Aviva

Abstract

Background: Red Blood Cell (RBC) transfusions are associated with the risk of rejection and sensitization for the recipient. Covalent modification of human RBC using poly (ethylene glycol)) (PEG) is currently being investigated as a method to modify the antigenic characteristics of RBC in order to develop an antigenically silent RBC transfusion product. The focus of this study is to determine whether a branched PEG, 4PEGss [MW 10,000] can concurrently camouflage and stabilize the RBC membrane, giving the red cell higher osmotic resistance. Study Design and Methods: Human blood was collected from consenting donors into EDTA tubes. RBC were separated, counted, washed and incubated with 4PEGss stock solution for up to 120 minutes at room temperature (RT). Agglutination assays and flow cytometry were used to determine polymer-dependent antigen masking while scanning electron microscopy (SEM), erythrocyte sedimentation rate (ESR) assays, osmotic fragility assays, hemolysis measurements and generation of hemoglobin oxidation species were used to measure the impact of 4PEGss treatment on RBC function. Results: Agglutination assays and flow cytometry showed that 4PEGss treatment significantly camouflaged RhD and A and B antigens in a dose-dependent manner. However, SEM and ESR assays indicated 4PEGss treatment may cause cell aggregate formation. Osmotic fragility assays and hemolysis measurements showed a 4PEGss-mediated increase of hemolysis. Conclusions: At all concentrations investigated, 4PEGss modification yielded antigenically camouflaged (both ABO and RhD) yet less stable RBC compared to non-treated controls.

Item Metadata

Title
Modification of red cell antigenic characteristics via covalent modification with branched poly (ethylene glycol)
Creator
Srubiski, Aviva
Publisher
University of British Columbia
Date Issued
2006
Description
Background: Red Blood Cell (RBC) transfusions are associated with the risk of rejection and sensitization for the recipient. Covalent modification of human RBC using poly (ethylene glycol)) (PEG) is currently being investigated as a method to modify the antigenic characteristics of RBC in order to develop an antigenically silent RBC transfusion product. The focus of this study is to determine whether a branched PEG, 4PEGss [MW 10,000] can concurrently camouflage and stabilize the RBC membrane, giving the red cell higher osmotic resistance. Study Design and Methods: Human blood was collected from consenting donors into EDTA tubes. RBC were separated, counted, washed and incubated with 4PEGss stock solution for up to 120 minutes at room temperature (RT). Agglutination assays and flow cytometry were used to determine polymer-dependent antigen masking while scanning electron microscopy (SEM), erythrocyte sedimentation rate (ESR) assays, osmotic fragility assays, hemolysis measurements and generation of hemoglobin oxidation species were used to measure the impact of 4PEGss treatment on RBC function. Results: Agglutination assays and flow cytometry showed that 4PEGss treatment significantly camouflaged RhD and A and B antigens in a dose-dependent manner. However, SEM and ESR assays indicated 4PEGss treatment may cause cell aggregate formation. Osmotic fragility assays and hemolysis measurements showed a 4PEGss-mediated increase of hemolysis. Conclusions: At all concentrations investigated, 4PEGss modification yielded antigenically camouflaged (both ABO and RhD) yet less stable RBC compared to non-treated controls.
Genre
Thesis/Dissertation
Type
Text
Language
eng
Date Available
2011-03-12
Provider
Vancouver : University of British Columbia Library
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
DOI
10.14288/1.0101075
URI
http://hdl.handle.net/2429/32404
Degree
Master of Science - MSc
Program
Pathology
Affiliation
Medicine, Faculty of; Pathology and Laboratory Medicine, Department of
Degree Grantor
University of British Columbia
Campus
UBCV
Scholarly Level
Graduate
Aggregated Source Repository
DSpace

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For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.