Modeling the Effects of IL-1β-mediated Inflammation During Ex Vivo Lung Perfusion Using a Split Human Donor Model

Abstract

Background. The association between interleukin-1β (IL-1β) concentrations during ex vivo lung perfusion (EVLP) with donor organ quality and post-lung transplant outcome has been demonstrated in several studies. The mechanism underlying IL-1β-mediated donor lung injury was investigated using a paired single-lung EVLP model. Methods. Human lung pairs were dissected into individual lungs and perfused on identical separate EVLP circuits, with one lung from each pair receiving a bolus of IL-1β. Fluorescently labeled human neutrophils isolated from a healthy volunteer were infused into both circuits and quantified in perfusate at regular timepoints. Perfusates and tissues were subsequently analyzed, with perfusates also used in functional assays. Results. Neutrophil numbers were significantly lower in perfusate samples collected from the IL-1β-stimulated lungs consistent with increased neutrophil adhesion (P = 0.042). Stimulated lungs gained significantly more weight than controls (P = 0.046), which correlated with soluble intercellular adhesion molecule-1 (R2 = 0.71, P = 0.0043) and von-Willebrand factor (R2 = 0.39, P = 0.040) in perfusate. RNA expression patterns for inflammatory genes were differentially regulated via IL-1β. Blockade of IL-1β significantly reduced neutrophil adhesion in vitro (P = 0.025). Conclusion. These data illustrate the proinflammatory functions of IL-1β in the context of EVLP, suggesting this pathway may be susceptible to therapeutic modulation before transplantation.

A Split-Lung Ex Vivo Perfusion Model for Time- and Cost-Effective Evaluation of Therapeutic Interventions to the Human Donor Lung

“…The advantages of this approach have been described in the context of hepatitis C treatment trials, as the control lung would have a similar viral load [ 12 ]. This methodology has been used in our laboratory to understand the mechanism of interleukin-1β driven inflammation during EVLP [ 7 ], and to assess the therapeutic effects of endothelial barrier protection, potential COVID-19 treatments [ 20 ], cell therapies, and, currently, extracellular vesicles, with significant results from only five lung pairs. Smaller numbers allow studies to be completed more quickly and mitigate the risk of unbalanced groups in the event of recruitment failure, as both arms are balanced throughout.…”

“…We have therefore developed a split-lung human EVLP model consisting of two identical independent perfusion circuits, each with its own ventilator. Recently mechanisms of IL-1β-mediated Inflammation [ 7 ]. Since then, we have further optimized this setup, including more comprehensive pressure monitoring, and tested Dulbecco’s Modified Eagle Medium (DMEM)-based perfusate, previously described by Shaver et al [ 8 ].…”