DISCUSSION
In our study, Lewis incompatibility did not
result in increased graft loss. Six-month graft
survival in our 17 definite or probable Lewisincompatible
grafts was 56%, compared to
58% in our program's overall experience.29
Liver transplants are also relatively more tolerant
of ABO and HLA mismatching than
renal grafts. Although ABO compatibility is
sought whenever possible, a number of successful
ABO-incompatible liver transplants
have been performed in our program.29 Also,
hepatic grafts are performed without regard
for HLA matching or lymphocytotoxicity
crossmatching. 31 In contrast, renal transplants
frequently undergo hyperacute rejection in
ABO incompatibility, are adversely affected
by HLA mismatching and incompatibility,
and in some series have had reduced survival
when Lewis incompatibility is present. Our
findings with the Lewis blood group system in
liver transplantation are consistent with the
generally greater tolerance of the transplanted
liver for other tissue incompatibilities.
We have also shown that the liver is generally
not the source of RBC Lewis glycolipids.
In 12 of 13 definite or probable Lewis-incompatible
liver transplants, the recipient retained
his or her original RBC Lewis phenotype. All
recipients were Le( a - b -) except for two
Le(a+b-) patients who received Le(a-b+)
livers. The single apparent RBC phenotype
switch was in a patient with Wilson's disease
who appeared to be Le(a-b-) preoperatively,
but Le(a- b+) postoperatively. In retrospect
in this patient, we cannot rule out the
possibility of preoperative weakened RBC
Lewis expression, which has been observed in
the settings of pregnancy, alcoholic cirrhos