Spontaneous and therapeutic glycosidic accommodation of host and graft in ABO(H)-incompatible transplantation, a hypothesis.

In contrast to non-nucleated ABO(H) red cells, which when transfused to a blood group O(H) recipient undergo destruction within minutes, such hyperacute, humoral rejection occurs relatively rare in transplantations of highly nucleated, metabolically active solid organs, and it is extremely rare in liver transplantations (Adams 1991; Della-Guardia et al. 2008). Moreover, a case of transient, selective disappearance of preexisting donor-specific HLA-antibodies after an incompatible liver transplantation, without any rejection episodes, has been reported by Bastiani (2006), and according to Taner et al. (2014)<i> </i>such transient decrease of donor-specific HLA-antibodies is not uncommon after incompatible liver transplantation. In addition, an exponential fall in both anti-A/B reactive IgM and IgG titers were observed after ABO(H) incompatible bone marrow transplantation (Rowley et al. 2000; Lee et al. 2003).These phenomena most likely reflect a complex mechanism, in which pre-existing anti-graft-reactive immunoglobulins are adsorbed on complementary sites on the cell surfaces of the graft, but other than on the surfaces of metabolically weak red cells, appear transiently to be completed by graft-phenotype-specific protective glycosylation and reappear when the graft-intrinsic enzymatic power is exhausted.

与输注给O(H)血型受者后数分钟内即发生破坏的无核ABO(H)红细胞不同，这种超急性体液排斥反应在高核、代谢活跃的实体器官移植中相对少见，在肝移植中则极为罕见（Adams 1991；Della-Guardia et al. 2008）。此外，Bastiani（2006）曾报道1例不相容肝移植术后出现一过性、选择性的预先存在供者特异性HLA（人类白细胞抗原，Human Leukocyte Antigen）抗体消失，且未发生任何排斥反应发作的病例；而Taner等（2014）指出，不相容肝移植术后供者特异性HLA抗体的一过性下降并不少见。除此之外，ABO(H)不相容骨髓移植后，抗A/B反应性免疫球蛋白M（IgM）与免疫球蛋白G（IgG）滴度均出现指数级下降（Rowley et al. 2000; Lee et al. 2003）。上述现象大概率反映了一套复杂的机制：预先存在的抗移植物反应性免疫球蛋白会吸附于移植物细胞表面的互补位点，但与代谢活性较弱的红细胞表面不同，该过程会暂时通过移植物表型特异性的保护性糖基化作用完成，并在移植物内在酶活性耗尽时重新出现。