Endothelial permeability is increased by the supernatant of peripheral blood mononuclear cells stimulated with HLA Class II antibody.

Background: The generation of inflammatory mediators from monocytes activated by HLA Class II antibodies is thought to play important roles in the etiology of nonhemolytic transfusion reactions. Increased permeability of endothelial cells contributes to the pathogenesis of rash, urticaria, angioedema, and pulmonary edema, which are symptoms of transfusion reactions.

Study Design And Methods: We investigated whether inflammatory mediators released from monocytes upon stimulation by HLA Class II antibodies could increase endothelial permeability.