Interpreting immune biomarkers after liver transplantation starts with the clinical question: An indication-first approach

Immune monitoring after liver transplantation is expanding rapidly, but the clinical significance of an abnormal result often remains uncertain, particularly in recipients with stable graft function. Donor-specific antibody testing, donor-derived cell-free DNA, histology, and emerging molecular assays measure different aspects of alloimmune activity or graft injury, and none should be interpreted independently of the clinical context. We propose an indication-first approach that shifts immune monitoring from post hoc interpretation of abnormal results toward prospective test selection, in which the clinical question, anticipated management consequence, competing causes of graft injury, longitudinal testing strategy, and next diagnostic step are defined before testing is ordered. This framework distinguishes targeted diagnostic testing from routine surveillance and research-based monitoring, while emphasizing concordance among biomarkers, liver-test trends, imaging, histology, adherence, and other potential causes of injury. Abnormal biomarkers should not, in isolation, prompt treatment or intensification of immunosuppression; the response should be proportional to the strength and consistency of the available evidence. Prospective evaluation is needed to determine whether an indication-first strategy reduces low-value testing and unnecessary downstream interventions while preserving timely recognition of clinically consequential alloimmune injury. As immune-monitoring technologies become increasingly sensitive, their value will depend not simply on what they can detect, but on whether each test is connected to a defined clinical decision.