Passenger Lymphocyte Syndrome due to Anti-Jkᵃ in a liver transplant

Background: We present a case of passenger lymphocyte syndrome (PLS) due to anti-Jkᵃ identified in a 66-year-old male who underwent liver transplantation for end-stage liver disease. The initial graft failed intra-operatively, due to graft non-viability, and re-transplantation was performed two days later. A post-operative positive antibody screen prompted hematopathology review.

Methods: Antibody screening was performed via gel card methodology using the indirect antiglobulin test with group O reagent red cells selected to express clinically significant antigens. Following a positive screen, an extended antibody identification panel was employed using reagent red cells with defined antigen phenotypes. Direct antiglobulin test (DAT) and eluate studies were undertaken to assess in vivo coating and confirm antibody specificity.

Results: One day following the second liver transplant, the patient’s antibody screen was positive (1+) with a negative extended panel. On post-operative day two, antibody screen remained positive (1+) and was identified as anti-Jkᵃ on the extended panel. Antibody screen was 2+ on post-operative day five, 1+ by day eight, and negative on day twenty-two. Between post-operative day six and ten, indirect bilirubin levels were elevated. DAT was positive for C3d (1+), and negative for IgG, with a negative eluate. As hemoglobin levels remained stable, an extensive hemolytic workup was not pursued.

Discussion: Findings in this case are consistent with PLS mediated by anti-Jkᵃ, a rarely reported specificity. The detection of transient complement-binding alloantibody is attributed to donor-derived lymphocytes, despite early graft non-function. These results raise the possibility of a transient complement-mediated hemolysis that did not result in clinically significant anemia.