IgG donor-specific crossmatches are not associated with graft rejection or poor graft survival after liver transplantation. An assessment by cytotoxicity and flow cytometry.

Early studies in liver transplantation suggested that there was no association between graft outcome or rejection and the presence of alloantibodies before transplantation. More recent reports have suggested lower graft survival rates and a higher incidence of chronic rejection in patients with IgG warm-T crossmatches. In the present study, panel reactive antibody, direct crossmatch testing, and flow cytometry were used to detect preformed antibodies in sera from 158 consecutive adult recipients of first hepatic grafts. The relationship between preformed antidonor antibodies and liver allograft survival and rejection was determined. Twenty-six (17%) patients were panel reactive antibody (PRA)-positive before transplantation, 22 (15%) had positive donor-specific crossmatches, and 14 (9%) were positive by IgG-specific flow cytometry. Cumulative survival distribution and multivariate analysis failed to reveal any significant associations between overall graft survival and antibody status. Graft survival in patients with PRA-positive sera was 81% compared with 77% for those with PRA-negative sera, 68% for those with positive donor-specific crossmatches compared with 80% for those who were donor-specific crossmatch negative, and 79% for those who were antibody positive by flow cytometric analysis compared with 78% for those who were antibody negative. Subgroup analysis also failed to reveal any significant associations. In addition, Cox proportional hazards regression analysis failed to reveal a relationship between acute or chronic graft rejection with the presence or absence of preformed antibodies, irrespective of immunoglobulin class, cell type (T or non-T), specificity, or technique used for antibody detection. In conclusion, there appears to be no association between either donor-specific or "third-party" alloreactive IgG or IgM antibodies and liver transplant survival or rejection. These data do not indicate a need for prospective crossmatching of liver transplant recipients.