RT Journal Article SR Electronic T1 Characterising the challenges of managing difficult red blood cell alloantibodies in liver transplant recipients JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP jcp-2024-209399 DO 10.1136/jcp-2024-209399 A1 Chornenkyy, Yevgen A1 Fink, Margaret Catherine A1 Felicelli, Christopher A1 Stowell, Sean R A1 Ramsey, Glenn Eugene A1 Yang, Guang-Yu YR 2024 UL http://jcp.bmj.com/content/early/2024/05/14/jcp-2024-209399.abstract AB Aims Formation of red blood cell alloantibodies (RBCAs) complicates transfusion support in liver transplantation (LT). Difficult RBCAs (DAs, >3 antibodies or antibodies for which <25% donors are antigen negative) further challenge care. This study characterises DA outcomes relative to non-difficult RBCAs (NDAs).Methods Single-centre, retrospective analysis of LT patients (2002–2021). RBCAs were defined as clinically significant antibodies. DAs were compared with NDAs.Results 89 patients had clinically significant RBCAs (DA=50, NDA=39). More DAs were anti-Jka, anti-M; fewer were anti-E, anti-K (all p<0.05). DA patients often had multiple antibodies (44% vs 12.8% NDA, p=0.0022). Probability of finding antigen-negative blood was lower for DAs (17.4% vs 68.1% NDA, p<0.0001) as was RBCs received (9.4 vs 14.7 units in NDA, p=0.0036). Although survival was similar, patients with DAs had more adverse reactions (8% vs 0%, p=0.128). Some antibodies appeared to occur with specific liver diseases (such as primary sclerosing cholangitis, alcoholic steatohepatitis and recurrent disease); however, due to low sample size, definitive conclusions cannot be made.Conclusions DA LT recipients contain >1 RBCA, have a lower probability of finding antigen negative blood and may experience more adverse transfusion event (ATE). Despite this, the incidence of ATEs was still quite low.All data relevant to the study are included in the article or uploaded as supplementary information.