Early Signals of the Transition From Immune Quiescence to Activation in the Liver Allograft Microenvironment and in the Circulation

Inclusion criteria

• Participant and parent or guardian must be able to understand and provide informed assent and consent, respectively
• Recipient of a living or deceased donor Liver transplant (LTx) at <7 years of age
• > 3 years but <7 years after LTx at the time of study enrollment
• Stable liver tests defined as baseline serum alanine aminotransferase (ALT) level < 30 IU/l and gamma-glutamyl transferase (GGT) level < 50 IU/l (based on the average of the 3 most recent values prior to screening; all must be within 1 year of screening; 2 must be within 6 months of screening)
• No Acute rejection (AR) or chronic rejection within 12 months of enrollment
• Tacrolimus monotherapy for > 6 months with baseline 12-hour trough levels <8 ng/mL (based on the average of 3 values prior to screening; all must be within 1 year of screening; 2 must be within 6 months of screening)
• Participants of childbearing potential must have a negative pregnancy test upon study entry

Exclusion criteria

• Liver transplant (LTx) for autoimmune disease, including autoimmune hepatitis or primary sclerosing cholangitis
• LTx for hepatitis B or hepatitis C
• Recipient of any other organ transplant or liver re-transplant, except for patients who have a repeat LTx within 30 days of first LTx who are eligible for enrollment
• >=50 percent dose increase in tacrolimus within 12 months of enrollment
• Discontinued a second Immunosuppression (IS) agent within 12 months of enrollment
• Systemic illness requiring chronic or recurrent use of IS for which there is a risk of reactivation if tacrolimus is reduced
• Use of medication to treat systemic conditions which in the judgement of the investigator could influence results of the study
• Active or chronic infection requiring treatment
• Inability or unwillingness to comply with the study protocol
• Use of investigational drug within 4 weeks (or 5 half-lives of investigational drug, whichever is longer) of enrollment
• Has any condition that, in the opinion of the investigator, will interfere with safe participation in the trial