Passenger lymphocyte syndrome: Need for consensus on transfusion guidelines and direct anti-globulin test screening in post-liver transplantation period.

In post-transplant phase, liver transplant (LT) recipients may experience anemia or hemolysis due to various immune or non-immune reasons and require prompt intervention and timely management. One such instance is when recipients of minor ABO-incompatible LT (ABOiLT) experience delayed hemolysis mediated by lymphocytes present in the graft known as passenger lymphocyte syndrome (PLS). We present a case report of a PLS in a 6-month-old child who underwent ABOiLT. On postoperative day 14, there was a drop in patient's hemoglobin, and anti-human globulin crossmatch was incompatible with recipient group (A positive) red cells. No standardized consensus exists on screening for PLS in post-LT recipients. In transplant settings, it is imperative to streamline the workflow for timely recognition and management of PLS early to prevent adverse outcomes and minimize invasive therapy. We present this case of PLS in a post-LT child to highlight the need for right algorithm of immuno-hematological workup in case of post-transplant hemolysis.