The detection and role of circulating antibodies in rejection.

Purpose of Review: In this review, we first discuss the evolution and current controversies in antibody detection methodology for transplant candidates. Then, we summarize how immunologists and transplant clinicians integrate new evidence with their understanding of how recipient alloantibodies influence patient management and posttransplant outcomes.
Recent Findings: New advances in solid-phase assays have allowed a more accurate and discriminate appraisal of preformed antibodies. As a result, sensitized patients who are awaiting suitable heart donors can now be better risk-stratified and screened by virtual crossmatch. Yet, the progress in the field also brings to light some new contentious issues in need of further exploration and consideration. Some of these issues are explored in this review: are the new solid-phase assays too sensitive? What are the reasons for and the clinical implications of inconsistencies in results between the different techniques? Which antibodies from a growing list are clinically pertinent? What is the role of the virtual crossmatch? And how do antibodies impact posttransplant outcomes?
Summary: Serologic detection of preformed or de-novo donor anti-human leukocyte antigen (HLA) antibodies has been closely linked to allograft rejection and poor outcomes. Although welcome, new histocompatibility testing methods also pose new challenges in clinical decision-making. Increased interaction between the clinicians and the histocompatibility laboratory is paramount to better understand the significance of antibodies, to maximize safe donor organ use, and to improve the overall posttransplant outcomes.