Frequency of Invasive Fungal Infections in Patients Undergoing Allogeneic Stem Cell Transplantation Conditioned with Reduced BUCY2 and Antifungal Prophylaxis with Low Dose Amphotericin B

Introduction: Invasive fungal infection (IFI) is a major cause of morbidity and mortality in patients with allogeneic stem cell transplantation (allo-SCT). One well-known risk factor for fungal infection includes bowel mucosal damage due to conditioning chemotherapy regimens. The use of reduced-intensity conditioning may favorably impact the epidemiology of IFI after allo-SCT. Data for IFI in this population are scarce. On the other hand, despite the low incidence of IFI with the use of the new antifungal drugs, the costs remain to be high and sometimes unaffordable for the patients.

Objective: To analyze the frequency of invasive fungal infections in patients who underwent stem cell transplantation conditioned with reduced BUCY2, at INCMNSZ, from November 1998 to December 2014.

Material and methods: A retrospective analysis was performed in 58 patients receiving reduced BUCY2 as part of their SCT conditioning regimen. Most of the patients received antifungal prophylaxis with low dose of amphotericin B (˂20 mg/day) during the neutropenia following transplant.

Results: Fifty eight patients undergoing allo-SCT with conditioning regimen reduced BUCY2, from November 1998 to December 2014, were included. Patients (male, 57%) had a median age of 39 years (range 17-67). The median follow-up was 90 months. The patients had a following range of underlying diseases: myelodysplastic syndrome (n=14, 24.1%), chronic myeloid leukemia (CML, n=14, 24.1%), acute myeloid leukemia (AML, n=12, 21%), acute lymphoblastic leukemia (LLA, n=10, 17%), lymphomas (n=3, 5.2%), myelofibrosis (n=2, 3.4%), or others (n=3, 5.2%). All patients were conditioned with 12mg/kg of busulfan and 80mg/kg of cyclophosphamide. 22% of patients presented mucositis grade III-IV. 85% (50/59) of patients received fungal prophylaxis with low dose amphotericin B. Four patients (6.8%) presented IFI during the first 100 days post-transplant, and one (1.7%) presented late IFI. The mortality secondary to IFI was 5%. Transplant related mortality (TRM) was 17%.

Conclusion: From the beginnings of our transplant program we have had a low incidence of IFI and low TRM, with the prophylactic use of low dose amphotericin B and the modified conditioning regimen reduced BUCY2, compared to the reported literature. The use of reduced BUCY2 and low dose amphotericin B can be cost-effective in medical centers in developing countries.