Vascular Disease Prevention
2009, 6 : 170-177Published online 2009 June 24. DOI: 10.2174/1567270001006010170
Publisher ID: VDP-6-170
Involvement of Human Leukocyte Antigen Class II Antibody in Pathogenesis of Transfusion-Related Acute Lung Injury (TRALI): Vascular Permeability Enhancement
ABSTRACT
Vascular endothelial cells regulate the passage of fluids, solutes, and cells from the vascular space to the tissues. Disruption of vascular integrity is involved in the pathogenesis of inflammatory diseases including transfusionrelated acute lung injury (TRALI), a most severe nonhemolytic transfusion reaction with symptoms such as dyspnea and/or hypotension and fever. Pulmonary edema, due to increased vascular permeability for macromolecules and plasma, is a hallmark of TRALI. The mortality rate of TRALI ranges from 5 to 10%. While donor antibodies (Abs) against human leukocyte antigen (HLA) class I and granulocytes are regarded as causative factors, various clinical studies have demonstrated the roles of anti-HLA class II-Ab on the etiology of TRALI, although the detailed mechanisms have not been clarified. Over several years we have investigated to clarify the underlying mechanism by which anti-HLA class II Abs cause an increase in endothelial permeability. In this review, we show that anti-HLA class II Ab generates proinflammatory cytokines and chemokines from HLA class II positive mononuclear cells of peripheral blood in an FcγR-dependent manner. As a result, the produced interleukin-1β and tumor necrosis factor-α lead to increased endothelial permeability via the nuclear factor-κB pathway but not apoptosis of endothelial cells. These findings provide a better understanding of the roles of anti-HLA class II Ab in the etiology of TRALI.