Change in Panel Reactive Antibodies in Patients Bridged to Lung Transplantation with Extracorporeal Membrane Oxygenation.

Extracorporeal membrane oxygen (ECMO) is increasingly used as a bridge to lung transplantation. Although other mechanical circulatory support devices have been associated with a transfusion-independent increase in calculated panel reactive antibodies (CPRA), it is unknown whether ECMO is a sensitizing exposure. In this single center retrospective cohort study of lung transplant candidates between 5/1/2015-6/30/2021, antibodies against human leukocyte antigens (HLA-Ab) were evaluated at the time of ECMO initiation and weekly thereafter. Multivariate logistic regression was used to evaluate associations between CPRA increase and ECMO exposure adjusting for a history of any packed red blood cell (PRBC) transfusion and female gender. Sixty-two candidates were placed on ECMO as a bridge to transplant. Of these, 39 (62.9%) either had available HLA-Ab screens from pre- and post-ECMO initiation or multiple HLA-Ab screens post-ECMO. Of the 250 non-ECMO exposed recipients, 224 (89.6%) had multiple pre-transplant screens and served as the comparison cohort. Nine (23.1%) ECMO bridged recipients had an increase in CPRA, compared to 16 (7.1%) of non-ECMO exposed recipients (Fisher's exact p=0.005). Among those with increased CPRA, the median increase was 6% in ECMO bridge patients and 9% in non-ECMO exposed patients. After adjusting for covariates, however, ECMO bridge was not an independent risk factor for increased CPRA (OR=1.85, 95% CI 0.58-5.95, p=0.30). A history of PRBC transfusion trended toward an association with increased CPRA (OR=2.93, 95% CI 0.98-8.78, p=0.06). Pre-lung transplant ECMO was not independently associated with an increase in CPRA when adjusting for PRBC transfusion, although the study was underpowered for small or moderate effect sizes. Where clinically appropriate, PRBC transfusions should be limited in these patients. [ABSTRACT FROM AUTHOR]