High one-month liver graft failure rates in flow cytometry crossmatch-positive recipients.

In a retrospective study of 84 primary cadaver donor orthotopic liver transplants (OLTs), we investigated the damaging effect of preformed donor-specific antibodies by a standard T-cell warm crossmatch test (TWXM) and a more sensitive flow cytometry crossmatch test (FCXM). The incidence of a positive crossmatch was 12% (10/84) by TWXM and 24% (20/84) by FCXM, respectively. The incidence of 1-month graft failure was 30% (3/10) for patients with a positive TWXM, compared with 23% (17/74) for a negative TWXM. The deleterious effect was more pronounced when the patients were examined by FCXM. Nine of 20 (45%) FCXM-positive recipients lost their grafts within 1 month (p = 0.01) and 8 of those 9 failures occurred within 2 weeks posttransplant. A comparison of graft survival rates at 6 months demonstrated that FCXM-positive patients had a 25% lower survival rate (p = 0.01) than those with a negative FCXM. The positive rate of FCXM was 4 times higher in sensitized patients (PRA 11-100). However, 9 patients in the non-sensitized group (PRA 0-10) had a positive FCXM, and 5 of 9 patients had graft failure within 1 month, suggesting that even a low level of antibodies or non-complement fixing antibodies may have a very damaging effect. This study shows that preformed donor-specific antibodies do have a deleterious effect on allografts. Although the effect is not necessarily expressed as hyperacute rejection, the antibody response is capable of damaging the allografted organs within 1 month. Consideration should be given to crossmatching OLT patients in order to avoid transplantation over a positive crossmatch.