C27-20 Pre-transplant Fungal Colonization and Outcomes in Lung Transplant Recipients

Rationale

Fungal infections are a significant cause of morbidity in lung transplant recipients. Infections caused by non-Aspergillus species (spp.) fungi, such as Alternaria, Cladosporium, Fusarium, Lomentospora, Mucorales, and Scedosporium, among others, occur infrequently, but recognized cases are increasing. There is a paucity of data assessing post-transplant outcomes following pre-transplant fungal colonization with these non-Aspergillus spp. fungal organisms.

Methods

We retrospectively reviewed all adult (>18 years) patients who underwent bilateral lung transplantation at either Mayo Clinic Rochester and Mayo Clinic Jacksonville between 01/01/2016 through 12/31/2024, comparing those with pre-transplant fungal colonization to those without fungal colonization. Fungal colonization was defined as positive respiratory culture in either sputum, tracheal aspirate, bronchial brush, bronchoalveolar lavage (BAL) fluid, or swab of explanted lung in asymptomatic patients without radiological or endobronchial evidence of infection. Patients who underwent single lung transplantation, multi-organ transplantation, and those who had previously undergone organ transplantation were excluded from the study. Our primary outcome was severe post-transplant fungal infection, which we defined as proven or probable invasive fungal infection (based on EORTC/MSG criteria), that required hospitalization or additional procedural intervention. Baseline characteristics were summarized using medians with interquartile ranges or counts with percentages, group balance was assessed using standardized mean differences, and associations with post-transplant fungal infection and mortality were evaluated using unadjusted risk ratios (RR) with 95% confidence intervals.

Results

Of the 449 lung transplant recipients who were included in analysis, a total of 83 patients (18.5%) had pre-transplant fungal colonization, 45 patients (10.0%) with Aspergillus spp. and 38 patients (8.5%) with non-Aspergillus fungi. Compared to those without pre-transplant fungal colonization (n = 366), those with fungal colonization differed significantly in age, gender, body mass index (BMI), Cytomegalovirus (CMV) mismatch status, and transplant indication. The pre-transplant fungal colonization cohort had 4 patients (4.8%) develop any severe fungal infection post-transplant (2 Aspergillus spp. and 2 non-Aspergillus spp.). Pre-transplant fungal colonization was not associated with severe post-transplant fungal infection [RR 1.36 (0.45-4.06)] or with severe post-transplant Aspergillus spp. infection specifically [RR 0.80 (0.18-3.55)]. Unadjusted mortality was also not statistically significant [RR 0.74 (0.47-1.17)].

Conclusions

In our cohort of bilateral lung transplant recipients, pre-transplant fungal colonization was not associated with severe post-transplant invasive fungal infection. Although limited by the retrospective nature of the study, the results provide supportive evidence that pre-transplant fungal colonization should not be a precluding factor for undergoing lung transplantation.

This abstract is funded by: None