B70-12 Performance of Bilateral Bronchoalveolar Lavage During Routine Transplant Surveillance Bronchoscopy Changes Management: The BILaBAL Study

Abstract Rationale Surveillance bronchoscopy with bronchoalveolar lavage (BAL) is a cornerstone of post-lung transplant monitoring, yet the utility of performing bilateral versus unilateral BAL remains underexplored. Our primary aim was to determine the incidence of different pathogens identified contralaterally during the BAL procedures and how often these findings lead to changes in patient management. Methods This retrospective analysis of data from a single-center institutional biorepository consisted of 237 lung transplant recipients who underwent a total of 759 surveillance bilateral BALs from November 2014 through January 2025. A bilateral BAL was defined as “Discordant” if different pathogens were detected in the right or left lung. Common contaminants such as Strep Viridans, Candida Albicans, CN Staph, Strep Intermedius, among others, were excluded. A “Change in Management” was identified if the detection of a discordant pathogen led to an addition or change in antimicrobial therapy or immunosuppression. These changes in management were adjudicated by two different team members. Results Of the 759 bilateral BALs, 83 (10.9%) identified discordant pathogens in contralateral lungs. Of these, 43 discordant findings (5.7% of all procedures) resulted in a change in clinical management. This results in a number needed to change management of 1/18. All 43 of these changes involved initiation or adjustment of anti-microbial therapy, and 3 (7.0%) involved an adjustment in immunosuppression. The most common discordant pathogens that prompted management changes were Pseudomonas aeruginosa (14 instances) and Aspergillus species (12 instances). The overall incidence of rejection in this cohort was 13.2%, 18.6% in the change in management group, and the difference was not statistiically significant. Conclusions Bilateral BAL identifies clinically significant, discordant pathogens in over 1 in 10 surveillance procedures, with more than half of these findings directly altering patient care. Because the most common discordant organisms identified—Pseudomonas aeruginosa and Aspergillus species—are strongly associated with chronic lung allograft dysfunction, the results provide compelling evidence to support the adoption of bilateral BAL as a standard practice in post-transplant surveillance protocols. This abstract is funded by: None