Background: Passenger lymphocyte syndrome (PLS) is a less known etiology of acute onset anemia following ABO-compatible (ABO-c) liver transplantation (LT). Available literature on PLS after pediatric LT is limited. Therefore, we evaluated the prevalence, clinical course, and risk factors of PLS in children following ABO-c LT.
Methods: A single-center retrospective review of all children who underwent LT between 2000 and 2017 was performed. PLS was defined as a drop-in hemoglobin >20 g/L within 30 days of LT, with positive direct antiglobulin test and 1 laboratory test confirming hemolysis. Chi square and student t tests compared variables between subjects with and without PLS.
Results: Amongst 333 pediatric LT performed, 51 children received an ABO-c graft. PLS was diagnosed in 7 (14%) subjects at a median of 10 days after LT. There were no significant differences in patient demographics, graft type, or immunosuppression between those who did and did not develop PLS. Recipient blood group A+ receiving a donor O+ graft was a risk factor for PLS (P = 0.015). All PLS subjects recovered with blood transfusions (median 2), and no additional interventions. Three subjects initially received recipient (instead of donor) blood group red cells.
Conclusions: We report a 14% prevalence of PLS following pediatric ABO-c LT. Recipient blood group A+ receiving a donor O+ graft is a risk factor for PLS. Recognition of PLS as a cause of early acute anemia in pediatric ABO-c LT enables timely transfusion with donor (rather than recipient) blood group red cells.