Qianzhe Zhao ^*

• Intelligent Medical Laboratory, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China

Passenger lymphocyte syndrome (PLS) is most commonly observed after solid organ transplantation with minor ABO blood group incompatibility. It consists of a set of clinical symptoms brought on by the remaining lymphocytes of the donor organ developing antibodies against the recipient's antigens. Here, we describe a typical case of PLS in a type A+ recipient receiving a liver transplant from a type O+ donor. She suffered from jaundice, abnormally decreased hemoglobin level, and severe hemolytic anemia without bleeding. During hemolysis, we detected a positive direct antiglobulin test (DAT), and the thermal elution test revealed the presence of IgG anti-A antibodies in her serum. When immunosuppressive agents and blood transfusion were used together, cross-matched O+ washing red blood cells led to an expected outcome without side effects.