Donor selection for xenotransplantation: detection of Gal alpha 1-3Gal on different porcine organs

The expression of the major porcine xenoantigens (Gal alpha 1-3Gal) in diff erent tissues varies between species. The selection of suitable donors and the interpretation of studies which attempt to prevent hyperacute rejection are dependent on donor expression of Gal alpha 1-3Gal, Screening of large number of animals to find potential Gal alpha 1-3Gal negative donors requir es a robust tissue-based and practical method of assessing Gal alpha 1-3Gal expression. In this study, we have assessed the expression of Gal alpha 1- 3Gal in a variety of pig organs using anti Gal alpha 1-3Gal antibody. Biops ies of heart, kidney ear and tail were obtained from 20 outbred pigs, Biops ies were fixed in formalin and stained with a human anti Gal alpha 1-3Gal a ntibody obtained from pooled human AB serum passed down a Gal alpha 1-3Gal immunoadsorbent column. Tissue from all 4 organs from all 20 pigs expressed Gal alpha 1-3Gal. This study shows that detection of Gal alpha 1-3Gal on a n ear or tail biopsy is a simple but very reliable method for assessing Gal alpha 1-3Gal expression on the heart and kidney and facilitates donor sele ction for xenotransplantation.