Passenger Lymphocytic Syndrome following orthoptic diseased donor liver transplantation

Passenger lymphocytic syndrome (PLS) is a complication of solid organ and stem cell transplant where minor ABO incompatibility between the donor and the recipient (most commonly A recipient, O donor) causes a compliment mediated haemolysis of the recipient’s red blood cells (RBC). Immunocompetent donor B lymphocytes are transferred passively with the graft and generate antibodies that will bind to recipient’s RBCs causing haemolysis.  We report a case of a 58-year-old gentleman who underwent an orthoptic diseased donor liver transplantation with a minor ABO incompatibility (donor O positive, recipient A positive) who subsequently went into PLS following an A positive blood transfusion intra operatively and in the immediate post-operative period. He developed features of acute haemolysis attributable to PLS. He made a good recovery with supportive measures and subsequent O positive blood transfusion.  PLS should be suspected in a patient with a minor ABO incompatibility with drop in Haemoglobin (Hb) without evidence of active bleeding. The direct agglutination test (DAT) may not be always positive. High degree of suspicion and supportive measures can make a complete recovery in this group of patients.