Nonhemolytic passenger lymphocyte syndrome: donor-derived anti-M in an M+ recipient of a multiorgan transplant.

Passenger lymphocyte syndrome (PLS) is a well-recognized complication that may follow a hematopoietic progenitor cell or solid-organ transplant. Typically, the syndrome presents as acute hemolysis of the recipient's RBCs, which have become serologically incompatible with blood group antibodies formed by passively transfused donor-origin B lymphocytes. Most cases involve anti-A or anti-B. However, there are cases involving non-ABO serologic incompatibility, as well as cases in which the serologic incompatibility was not associated with clinical evidence of hemolysis. This report describes a case of passenger lymphocyte syndrome in an M+ recipient who developed anti-M after receiving a multiorgan transplant from an M- cadaver donor. Although the temporal events and serologic findings were consistent with a diagnosis of PLS, there was no evidence of in vivo hemolysis associated with the identification of a newly formed anti-M. This report includes a literature review of other case reports of PLS associated with non-ABO antibodies in solid-organ and hematopoietic progenitor cell transplant recipients.