Removal of cell membrane α-gal(1–3)β-galGlcNac epitopes (called α-gal) by chemical and enzymatic methods and chemical masking of other xenoantigens was performed to examine the impact on porcine erythrocyte (PRBC) antigenicity for xenotransfusion.

PRBCs were subjected to removal of membrane α-gal with α-galactosidase, covalent attachment of cyanuric acid-linked methoxypolyethylene glycol (PEGylation), or both. PRBC integrity was assessed by light and electron microscopy, osmotic fragility, and determination of p50. Effects of treatment were measured by hemagglutination, complement fixation, flow cytometric assay of IgG/M binding, cross-match testing to human sera and 51Cr red cell survival in mice.

PEGylation reduced hemagglutination titers moderately, although α-galactosidase treatment reduced hemagglutination titers to levels similar to negative controls. Combination of the treatments was most effective, by the reduction of binding of human IgM by 61% compared with controls. RBC morphology, stability, and p50 were maintained. Cross-match tests between PRBCs and human sera demonstrated increased compatibility.