Morsing SKH, Zeeuw van der Laan E, van Stalborch AD, van Buul JD, Kapur R, Vlaar AP. A pulmonary endothelial amplification loop aggravates ex-vivo transfusion-related acute lung injury via increased toll-like receptor 4 and intra-cellular adhesion molecule-1 expression.
Transfusion 2022;
62:1961-1966. [PMID:
36004763 PMCID:
PMC9804532 DOI:
10.1111/trf.17076]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 07/27/2022] [Accepted: 07/27/2022] [Indexed: 01/05/2023]
Abstract
BACKGROUND
Transfusion-Related Acute Lung Injury (TRALI) is a life-threatening complication of blood transfusions characterized by pulmonary endothelial cell damage and edema, with a high incidence in critically ill patients. The pathophysiology of TRALI is unresolved, but can generally be hypothesized to follow a 2-hit model in which the first hit is elicited by the underlying clinical condition of the patient (e.g., inflammation, which can be reflected by LPS in experimental models), and the second hit is delivered by the blood transfusion product (e.g., HLA class I antibodies). Here, we report a synergistic role for LPS and HLA class I antibody binding to pulmonary endothelium resulting in enhanced inflammatory responses.
MATERIALS AND METHODS
Pulmonary endothelial cells were treated with PBS or low-dose LPS, exclusively or in combination with anti-HLA class I. Endothelial surface expression of HLA class I, TLR4, and inflammatory marker ICAM-1 were measured, and trans-endothelial migration (TEM) of neutrophils was investigated.
RESULTS
LPS treatment of pulmonary endothelium enhanced HLA class I antibody binding, and combined LPS and HLA class I antibody binding enhanced TLR4 (LPS receptor) and ICAM-1 expression on the endothelial cell surface. Low-dose LPS and HLA antibody together also increased neutrophil TEM under physiological flow by on average 5-fold.
CONCLUSION
We conclude that LPS and anti-HLA class I antibody have the ability to activate the pulmonary endothelium into a spiral of increasing inflammation, opening the opportunity to potentially block TLR4 to prevent or reduce the severity of TRALI in vivo.
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