A positive crossmatch in liver transplantation--no effect or inappropriate analysis? A prospective study

Controversy over the relationship of preformed lymphocytotoxic antibodies and liver graft outcome remains. Because graft loss associated with preformed lymphocytotoxic antibodies probably occurs early after transplant, analysis of long-term survival is of questionable value. We therefore prospectively analyzed the effect on short- and long-term graft survival of the presence of lymphocytotoxic alloantibody in 207 primary adult liver allograft recipients.

Pretransplant serum was tested for donor-specific lymphocytotoxic antibodies and panel-reactive antibodies (PRA) using donor splenic lymphocytes and lymphocytes obtained for routine tissue typing.

A positive crossmatch was detected in 24 recipients (11.5%): T-cell positive in 11 recipients and B-cell positive in 13 recipients. PRA were detected in 68 of 179 recipients tested (37.4%). High T-cell PRA (>55%) was detected in 17 recipients, and high B-cell PRA was detected in 20 recipients. Low PRA (<15%) against T cells was detected in 19 recipients and against B cells in 24 recipients. Graft failures occurred in 5 of 24 (21%) crossmatch-positive recipients and in 7 of 172 (4%) crossmatch-negative recipients. Graft survival was significantly lower in crossmatch-positive recipients at 1 month after transplant (chi-square=10.3, P=0.00133) but not at 3 months or 1 year. Causes of early graft loss were associated with immunological mechanisms, whereas later losses were due to nonimmunological mechanisms.

Early graft loss may be increased in those recipients who are crossmatch positive. However, the logistical problems and consequences associated with allocation probably outweigh the benefits of prospective crossmatching.