Evaluation of a primary antifungal prophylaxis protocol for preventing invasive mold infections after allogeneic hematopoietic stem cell transplantation

Introduction Invasive mold infections contribute to morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation. The optimal strategy for primary antifungal prophylaxis in this patient population remains uncertain. Methods Medical records of patients who underwent allogeneic hematopoietic stem cell transplantation between 1 January 2013 and 31 December 2017 were retrospectively reviewed. Adult patients were included if they received micafungin followed by fluconazole, with the option to escalate to voriconazole, for antifungal prophylaxis. The primary outcome was the incidence rate of proven or probable invasive mold infection. Secondary outcomes were time to invasive mold infection diagnosis, invasive mold infection-related mortality, and risk factors associated with invasive mold infection. Results Two hundred patients were included in the study, a majority of whom underwent matched unrelated (46%) or matched related (33%) donor transplants. The incidence rate of proven or probable invasive mold infection was 18.4 cases per 100 patient-years, with a one-year cumulative incidence of 14%. Median time to proven or probable invasive mold infection was 94 days post-transplant (IQR 26-178), with invasive mold infection-related mortality occurring in 18 (64%) of 28 patients diagnosed with invasive mold infection. Comparison of invasive mold infection-free survival by potential risk factors failed to show any significant differences. Conclusions In this real-life cohort of allogeneic hematopoietic stem cell transplantation recipients, the incidence of proven or probable invasive mold infection was higher than expected based on previous literature. In the absence of standard guidance on anti-mold prophylaxis in this patient population and given that unique risk factors for invasive mold infection may differ between institutions, it is essential that centers performing allogeneic hematopoietic stem cell transplantation routinely monitor their antifungal prophylaxis strategies for effectiveness.