BACKGROUND: Transfusion‐related acute lung injury (TRALI) and other posttransfusion reactions may be caused by granulocyte and/or HLA antibodies, which are often present in blood from multiparous donors. The purpose of this study was to compare the effects of plasma from multiparous donors with those of plasma from donors with no history of transfusion or pregnancy (control plasma) in a prospective, randomized, double‐blind, crossover study.

STUDY DESIGN AND METHODS: Intensive care patients, judged to need at least 2 units of plasma, were randomly assigned to receive a unit of control plasma and, 4 hours later, a plasma unit from a multiparous donor (≥3 live births) or to receive the plasma units in opposite order. The patients were closely monitored, and body temperature, blood pressure, and heart rate were recorded. Blood samples for analysis of blood gases, TNFα, IL‐1 receptor antagonist, soluble E selectin, and C3d complement factor were collected at least on four occasions (before and after the transfusion of each unit).

RESULTS: Transfusion of plasma from multiparous donors was associated with significantly lower oxygen saturation and higher TNFα concentrations than transfusion of control plasma. The mean arterial pressure increased significantly after the transfusion of control plasma, whereas plasma from multiparous donors had no effect on it. Five posttransfusion reactions were observed in 100 patients, in four cases after the transfusion of plasma from multiparous donors.

CONCLUSION: Plasma from multiparous blood donors may impair pulmonary function in intensive care unit patients.