Living-donor liver transplantation at the University of Tokyo, 1996-2011: the impact of HLA matching and a positive crossmatch on long-term survival and tolerance.

OBJECTIVE

We analyzed a single center's experience during 16 years of living-donor liver transplantation (LDLT). The impacts of HLA mismatches and positive crossmatches on long term outcomes and tolerance were evaluated.

METHODS

This study was of primary LDLTs of consecutive patients from January 1996 to December 2011; re-transplants were not included. Long-term survival was compared by primary disease, number of HLA mismatches, and crossmatches. Demographics and complications after transplantation between pediatric recipients who achieved clinical operational tolerance and those who did not were compared.

RESULTS

One-year liver graft survival rates for adult and pediatric cases were 90.4% and 91.9%, respectively; the 5-year rates were 83.1% and 89.2%, respectively; the 10-year rates were 79.7% and 89.2%, respectively; and 15-year rates were 65.9% and 83.8%, respectively. For the grafts that survived more than one year, the 10-year rates for adult and pediatric cases were 88.2% and 97.0%, respectively. The 10-year rates for adult LDLT in 0 mismatches, 1-2 mismatches, 3-4 mismatches, and 5-6 mismatches were 79.2%, 86.8%, 77.4%, and 69.4%, respectively. Although the survival rates were not significantly different, the survival rates were lowest in LDLT recipients with 5-6 HLA mismatches. Ten-year liver graft survival rates for adult LDLT with negative T-cell crossmatch, and positive T-cell crossmatch were 80.0% and 71.1%, respectively. The 1-year liver graft survival rates for adult LDLT with negative B-cell crossmatch, and positive B-cell crossmatch were 90.6% and 88.2%, respectively. None of the factors--age of recipients and donors, primary disease, donor gender, relationship of donors to recipients, positive crossmatches, or number of HLA mismatches--was significantly different between COT and non-COT recipients, except for recipient gender (p = 0.01); in COT cases, there were more female recipients (88.9%) than male (11.1%). Post-transplant complications--acute rejection rate in one year post-transplant, biliary complications rate, and vascular complication rate--were not significantly different between COT and non-COT recipients.

CONCLUSIONS

High long-term survival was achieved by both adult and pediatric recipients. Even higher survival can be achieved by improving early graft loss. Further studies are necessary to determine the impact of HLA mismatches and positive crossmatches on long-term outcomes and tolerance.