Passenger lymphocyte syndrome with or without immune hemolytic anemia in all Rh-positive recipients of lungs from rhesus alloimmunized donors: three new cases and a review of the literature.

The passenger lymphocyte syndrome (PLS) is an unusual complication of solid organ transplantation, in which donor lymphocytes produce antibodies reactive with host red blood cell (RBC) antigens. Risks for PLS include highly lymphoid grafts, past sensitization of the donor against relevant RBC antigens, and donor lymphocyte escape of host immune clearance. For a 1-year period at our center, we observed an uncommonly high frequency of post-lung transplant Rhesus PLS, occurring once in every 31 cases. Passenger lymphocyte syndrome resulted from 2 alloimmunized cadaveric donors, in 3 of 3 D+, ABO-identical but HLA-unmatched recipients who initially had nonreactive RBC antibody screens. In case 1, the right lung of a group A, D-negative donor, with antibodies against D, C, and E antigens, was transplanted into a group A, R1R1 recipient. The recipient developed severe hemolytic anemia, direct antiglobulin test (DAT)-positive, on postoperative day (POD) 17. Anti-D and anti-C were identified on both the indirect antiglobulin test (IAT) and the RBC eluate. She required 10 U of RBCs in 40 days as well as plasmapheresis (POD 36-40). When transfusion dependence ceased, anti-D +/- C remained detectable on DAT and IAT for another 6.5 months. In case 2, the group A, R1r recipient of the same donor's left lung exhibited anti-D for the first time at posttransplant month 4 on both IAT and DAT. This activity persisted until a rejection episode 5 months later, without ever causing any evidence of hemolysis. In case 3, the group O, R1R1 recipient of both lungs of a group O, D-negative donor, with antibodies against D, C, and V antigens, developed a nonhemolytic DAT and IAT with anti-D +/- C at postoperative month 2, which remained positive at last follow-up (6 months posttransplant). In conclusion, this report suggests a high incidence of Rhesus antibody PLS after lung transplantation, with wide variations in the timing of antibody onset, persistence, and severity. A review of the phenomenon and its implications are discussed.