*PURPOSE: Lung transplant (txp) recipients (LTR) are at risk for invasive fungal infections (IFIs). Guidelines recommend antifungal prophylaxis (AFP) for 3-6 mo post-txp, including coverage for _Aspergillus_, which causes 44% of IFIs. However, there is no consensus on the optimal AFP regimen. Our center utilizes fluconazole 50 mg PO daily, lifelong, for oropharyngeal candidiasis prophylaxis (PPX) in lieu of universal IFI PPX. This study evaluated rates of IFIs in LTR receiving low-dose fluconazole. *METHODS: This retrospective study evaluated 76 adult LTR transplanted between 1/1/16 and 7/31/21. The primary outcome determined IFI rates at 6 and 12 mo post-txp. Secondary outcomes included pre-txp risk factors, protocol adherence, rates of oropharyngeal candidiasis, rejection, chronic lung allograft dysfunction (CLAD), graft failure, mortality, fluconazole resistance, and transaminitis at 1 yr. *RESULTS: Table 1 contains demographics and outcomes. At 1 yr, 38 (50%) LTR developed IFIs, with 1 patient developing 2 separate IFIs. The majority of infections (71.8%) occurred by 3 mo; _Aspergillus _caused 61.5% of IFIs (Fig 1A). Pre-txp environmental and occupational risk factors were identified in 27/38 (71.1%) LTR who had IFIs compared to 9/38 (23.7%) who did not have IFIs. Other pre-txp risk factors including hospitalization, ECMO, mechanical ventilation, renal replacement therapy, recipient fungal colonization, and marijuana use did not increase rates of IFIs. Of all LTR, 4 (5.3%) developed oropharyngeal candidiasis, 25 (32.9%) had rejection, 9 (11.8%) developed CLAD, 2 (2.6%) had graft failure, and 12 (15.8%) died within 1 yr. Fig 1B compares secondary outcomes in LTR with IFIs versus no IFIs. No LTR developed fluconazole resistance or transaminitis. *CONCLUSIONS: In the presence of low-dose fluconazole, 50% of LTR developed IFIs within 1 yr post-txp. Higher rates of IFIs were found in LTR who owned birds or had hobbies of farming, gardening or yardwork, or woodworking pre-txp. It may be reasonable to consider low-dose fluconazole in LTR for oropharyngeal candidiasis PPX and escalate to targeted AFP with a mold-active azole in LTR with identified pre-txp risk factors. [

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]CITATION INFORMATION: Bucher B., Eiting M., Truax C., Chan A., Sirandas B., Smith L., Zukauckas K., Larson T., Heinen K., Morrell M. Evaluation of Invasive Fungal Infections in Lung Transplant Recipients Receiving Low-Dose Fluconazole AJT, Volume 23, Issue 6, Supplement 1.

Bridget Bucher PharmD

University of Utah Health

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