2663. Impact of Pre-Transplant Microbiology on Acute Outcomes in Cystic Fibrosis Patients Receiving Bilateral Lung Transplants

BACKGROUND: Lung transplantation is a life-prolonging intervention for cystic fibrosis (CF) patients; however, their tendency to be colonized with multiple respiratory pathogens poses a unique risk for post-transplant complications. While infections with certain CF-related pathogens have been identified as contraindications for transplant, much remains uncertain about the influence of pre-transplant microbiological factors on post-transplant outcomes. METHODS: A retrospective cohort study was performed for all CF patients receiving bilateral lung transplants at a single center during the 2016–2018 period. Patient and microbiological data were collected and analyzed from 1 year pre-transplant to 3 months post-transplant. Patients were categorized according to pre-transplant microbiology, with consideration to multidrug-resistant organisms (MDROs) and chronic organisms (positive culture in ≥ 50% of encounters). RESULTS: Twenty-seven CF patients received a transplant during this time period. Twenty-five patients (92.6%) had re-isolation with ≥ 1 pre-transplant organism in the 3 month period post-transplant, with 16 (59.3%) developing infectious complications, and 11 (40.7%) developing rejection. Isolates associated with chronic infections were the principal factor in determining re-isolation post-transplant (OR = 4.353, 95% CI = 1.455–13.027, P = 0.009). Multidrug-resistance (P = 0.095) and species (P > 0.3) were not significant predictors of re-isolation. There was no difference in early post-transplant outcomes (infectious complications, rejection, FEV1% predicted, ICU and hospital LOS) for patients chronically infected with MDROs vs. those who were not (P > 0.3). Chronic infections with Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus were not predictors of poor outcomes (P > 0.3). However, chronic fungal infections (n = 7) produced more infectious complications (median 2 vs. 0, P = 0.0453) and longer ICU stays (median 22 days vs. 5 days, P = 0.0191). CONCLUSION: Chronic infections are associated with a greater risk of post-transplant re-isolation of pathogens in CF patients, more so than drug resistance or species. Chronic infections with fungi were associated with worse transplant outcomes. DISCLOSURES: All authors: No reported disclosures.