Severe intravascular haemolysis following minor group mismatched peripheral blood stem cell transplantation

Passenger Lymphocyte Syndrome After Pediatric Liver Transplantation

BACKGROUND

Passenger lymphocyte syndrome (PLS) is a less known etiology of acute onset anemia following ABO-compatible (ABO-c) liver transplantation (LT). Available literature on PLS after pediatric LT is limited. Therefore, we evaluated the prevalence, clinical course, and risk factors of PLS in children following ABO-c LT.

METHODS

A single-center retrospective review of all children who underwent LT between 2000 and 2017 was performed. PLS was defined as a drop-in hemoglobin >20 g/L within 30 days of LT, with positive direct antiglobulin test and 1 laboratory test confirming hemolysis. Chi square and student t tests compared variables between subjects with and without PLS.

RESULTS

Amongst 333 pediatric LT performed, 51 children received an ABO-c graft. PLS was diagnosed in 7 (14%) subjects at a median of 10 days after LT. There were no significant differences in patient demographics, graft type, or immunosuppression between those who did and did not develop PLS. Recipient blood group A+ receiving a donor O+ graft was a risk factor for PLS (P = 0.015). All PLS subjects recovered with blood transfusions (median 2), and no additional interventions. Three subjects initially received recipient (instead of donor) blood group red cells.

CONCLUSIONS

We report a 14% prevalence of PLS following pediatric ABO-c LT. Recipient blood group A+ receiving a donor O+ graft is a risk factor for PLS. Recognition of PLS as a cause of early acute anemia in pediatric ABO-c LT enables timely transfusion with donor (rather than recipient) blood group red cells.

Immune hemolysis following ABO-mismatched stem cell or solid organ transplantation

PURPOSE OF REVIEW

Limitations in donor availability for stem cell or organ transplantation require that ABO-incompatible donors be used. Crossing ABO lines can have immune consequences characterized by immediate or delayed hemolysis.

RECENT FINDINGS

The use of peripheral blood as a stem cell source has essentially eliminated the risk for ABO-mediated hemolysis during infusion. Delayed red cell engraftment is expected after a major ABO-incompatible transplant and may be associated with pure red cell aplasia. The incidence of hemolysis associated with minor ABO incompatibility, the passenger lymphocyte syndrome, is waning because anti-B-cell immunosuppressive therapy is increasingly a component of graft versus host disease prophylaxis. The impact of ABO mismatching on stem cell recipient survival remains an area of active investigation. Although major ABO-incompatible organs are not used routinely for transplantation, minor ABO-incompatible organs are frequently used to meet the demand for organs. Passenger lymphocyte syndrome in this setting is a common complication, and has now been observed with every organ type and increasingly with non-ABO antibodies. Hemolysis can occur, but it is uncommonly severe.

SUMMARY

ABO-mismatched donors are commonly used for transplantation, and immune hemolysis remains the main complication. Clinicians must be vigilant in order to recognize hemolysis and implement appropriate therapy.