Comparison of Antifungal Prophylaxis in Pediatric Stem Cell Transplant Recipients

Background Patients are at high risk for invasive fungal infections (IFI) after allogeneic hematopoietic stem cell transplant (HCT), with the most common being Candida and Aspergillus infections. Prior to 2020 guidelines recommending the use of mold-active azole or echinocandin prophylaxis for pediatric patients undergoing allogeneic HCT, the standard of care at our institution was to administer a non-mold active antifungal for prophylaxis. Methods This was a single center, retrospective study. We compared incidence of IFIs within six months of transplant between patients who received antifungal prophylaxis without mold coverage, (e.g. fluconazole and itraconazole), versus those who received prophylaxis with mold coverage (e.g. posaconazole, voriconazole, or isavuconazole). All patients followed by our pediatric bone marrow transplant team who received an allogeneic HCT between January 1, 2010 and April 30, 2023 were included in the analysis. Descriptive statistics were used for baseline characteristics and the primary outcome. Results Ninety-five patients receiving 100 transplants were included in the analysis; 26 transplants in the mold-active prophylaxis group and 74 in the non-mold active prophylaxis group. In the non-mold active prophylaxis group, most of the patients were white (n=63, 85.1%), the mean age was 10.7 years (range 0 to 24 years), and the most common diagnoses were B-cell acute lymphoblastic leukemia (n=15, 20.3%), acute myeloid leukemia (n=13, 17.6%), and aplastic anemia (n=11, 14.8%). In the mold-active prophylaxis group, most of the patients were white (n=22, 84.5%), the mean age was 12.2 years (range 0 to 23 years), and the most common diagnoses were B-cell acute lymphoblastic leukemia (n=9, 34.6%), aplastic anemia (n=4, 15.4%), and adrenoleukodystrophy (n=3, 11.5%). Within six months of transplant, five patients (6.8%) and one patient (3.8%) had an IFI in the non-mold active and the mold-active cohorts, respectively. The most common IFI was invasive aspergillosis (n=3, 50%). Notably, the only patient in the mold-active cohort who developed an IFI had subtherapeutic posaconazole levels. Conclusion A numerically higher proportion of patients in the non-mold active group had an IFI compared to the mold-active group. Prospective data is needed to confirm these results, but this data suggests a lower rate of IFIs in pediatric HCT patients receiving antifungal prophylaxis with mold coverage.