Validation of a Rapid Molecular Assessment Platform and Cytokine Score for Integration with Ex Vivo Lung Perfusion (EVLP) Assessment

Abstract

EVLP has been adopted as a method to evaluate donor lungs prior to transplantation. The inclusion of an objective, protein-based assessment of lung quality during EVLP has remained elusive due to current slow time-to-answer technology. Our team has recently reported a cytokine-based score that can more accurately reflect donor lung injury. In this study, we evaluated the ability of a novel diagnostic platform to provide a timely multiplexed cytokine score that reflects lung quality during EVLP. To compare the accuracy of our testing methods, cytokine levels of interleukin-6 (IL-6), IL-8, IL-10, and IL-1β were simultaneously measured in perfusate samples prospectively collected every 15 minutes from five clinical EVLP cases on a standard ELISA and a custom rapid (<45min) platform (n=79). For cytokine assay validation, perfusate samples collected at 4 hours of EVLP from 2018-19 were retrospectively tested on the rapid platform (n=62). Diagnostic performance was then compared between the new cohort on the rapid platform and our previously reported inflammation score performance (n=346). In our prospective cohort, the rapid cytokine assessment platform provided equivalent performance to standard ELISA (R2=0.97 (IL-6); R2=0.96 (IL-8); R2=0.95 (IL-10); R2=0.95 (IL-1β)). Using the rapid platform, the classification of lungs declined for transplant using our cytokine-based score of lung injury was the same in our retrospective cohort compared to our previously reported scores (lung score=45 vs. 40, p=0.50; AUROC=69% vs. 68%, p=0.87). Also consistent with our prior results, donor organs with the best cytokine scores (Category 1: Top 25th percentile) had the shortest ICU length of stay (3 days [95%CI: 2-6]). We have performed a retrospective validation and initial prospective test of a rapid perfusate diagnostic platform that measures lung injury biomarkers in less than 45 minutes-well within the typical 4-6 hour EVLP assessment and decision-making time frame. Data from our EVLP cytokine score performance on the rapid diagnostic platform will serve as a foundation for future integration into the clinical EVLP operating room. By enabling molecular testing during EVLP, these results represent another step towards better-assisting clinicians to more precisely select suitable lungs for transplantation.