Despite reports that associate donor specific antibody (DSA) with rejection after liver transplantation, grafts are still allocated according to blood group (ABO) but not human leukocyte antigen (HLA) compatibility, possibly due to the absence of an easily discernible clinical association between adverse recipient outcome and DSA. Re-transplantation provides a test environment where the presence of preformed DSA or other antibodies is prevalent and events (graft loss) more common so that the effect of these antibodies on outcome should be apparent. This is an observational study of routine clinical care to determine these effects on our own patients. The goal is to perfect donor-recipient matching to attain the best outcome. In addition, we may develop hypotheses and potential treatments that would be tested in further clinical trials

Despite reports that associate donor specific antibody (DSA) with rejection after liver transplantation, grafts are still allocated according to blood group (ABO) but not human leukocyte antigen (HLA) compatibility, possibly due to the absence of an easily discernible clinical association between adverse recipient outcome and DSA. Re-transplantation provides a test environment where the presence of preformed DSA or other antibodies is prevalent and events (graft loss) more common so that the effect of these antibodies on outcome should be apparent. This is an observational study of routine clinical care to determine these effects on our own patients.

In phase 1, we will examine the effect of antibodies specifically directed against the second donor in liver retransplantation. Other factors known to effect the outcome will be checked to allow for risk adjustment.

In phase 2, we will examine the role played by specific auto-antibodies such as angiotensin II receptor type 1 antibodies and endothelin-1 type A receptor antibodies on the outcome of liver retransplantation.

The goal of these observational study is to perfect donor-recipient matching to attain the best outcome. In addition, we may develop hypotheses and potential treatments that would be tested in further clinical trials.

Inclusion Criteria:

• Recipients of a second liver transplantation performed at LHSC

Exclusion Criteria:

• Recipients of ABO incompatible second liver transplantation
• Recipients of multiple organs

all patients who have undergone a repeat transplantation of the liver at LHSC.

Study mechanisms and de-identified subject level data will be shared with researchers who contact the principal investigator.

From publication until 5 years later

De-identified subject level data will be shared with researchers who contact the principal investigator, submit a research plan and sign an agreement. Approval by Western Research Ethics may be required depending on the request.