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(H)-incompatible red cells, which undergo destruction within minutes, when transfused to a blood group O(H) recipient, such by predominantly anti-A/B-antibodies caused hyperacute rejection of a highly nucleated, metabolically active, solid organ, transplanted from the same donor to an HLA-compatible recipient of the same blood group, occurs relatively rare, and for obviously unknown reason is extremely rare for liver transplants. It appears that transplants always maintain their original, phenotype-specific metabolic properties, and expanding the concept of glycosidic exclusion, the phenotype determines simultaneous glycosylation of the cell surfaces and immunoglobulins. Thus, it may be assumed that a transplanted ABO-incompatible, metabolically active tissue may use its phenotype-specific enzymatic equipment to contribute to a compatible environment by consistent glycosylation of complementary sites of the plasma proteins and the B-cell surfaces of a HLA-compatible recipient.