How an ABO-incompatible graft may contribute to its survival by phenotype-specific glycosylation of the host. A hypothesis.

In contrast to non-nucleated ABO-incompatible red cells, which from a HLA-compatible donor are transfused to a blood group O(H) recipient and undergo immediate destruction, a nucleated, metabolic active tissue that from the same donor is transplanted to the same recipient may, taking into account the effect of all therapeutic measures, occasionally show extreme long survival times. It appears to be established that tissue transplants always maintain their original, phenotype-specific metabolic properties, and expanding the concept of “glycosidic exclusion”, a transplanted ABO-incompatible, metabolically active tissue potentially uses its phenotype-specific enzymatic equipment to contribute to a compatible environment by consistent glycosylation of complementary sites of the plasma proteins and the differentiating B-cell surfaces of a HLA-compatible recipient.