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G. Battipaglia et al.
Figure 2. Evolution of Patient n. 5 as model of successful fecal microbiota transplantation. CP: carbapenemase-producing; FMT: fecal microbiota transplantation; HSCT: hematopoietic stem cell transplantation.
and infectious episodes exacerbated during immunosup- pressive treatment. None of the other patients presented fungal or viral infections.
Discussion
The increasing emergence and diffusion of MDRB rep- resents a major public health problem, with higher mortal- ity in patients experiencing infections. This involves high costs of prolonged in-hospital care and preventive meas- ures used to limit diffusion to other patients.6,19
Human gut microbiota, also named as “gut resistome”, is the primary site for MDRB acquisition and colonization, being an important reservoir of antibiotic resistant genes.20 Patients diagnosed with hematologic malignancies are at high risk of colonization from MDRB. In fact, condition- ing regimens for allo-HSCT and intensive chemotherapy significantly alter the gastrointestinal barrier and this modifies the composition of intestinal microbiota. Moreover, patients affected by hematologic malignancies or undergoing allo-HSCT are at particular risk for MDRB colonization or infection due to the large, prolonged and, sometimes, improper use of large spectrum antibiotics.2 Most bloodstream infections in hematologic patients derive from the gut, and infections are even more severe in those patients undergoing allo-HSCT, with high mortal- ity rates of 36-95%.3,4
It has been widely reported that microbioma modifica- tions are associated to worse survival, and higher risk of infections and GvHD in patients undergoing allo-
HSCT.21,22 Therefore, efficacious decolonization strategies in this particular setting of patients are urgently needed.
Fecal microbiota transplantation is a fascinating decolo- nization strategy that has been proved to be efficacious in patients with recurrent CDI.23,24 On the other hand, con- cerns were initially raised for the use of FMT as a decolo- nization strategy in immunocompromised patients, due to the possible risk of local or systemic infections after the inoculum of microbiota pathogens.
Recently, DeFilipp et al. investigated the use of third-party FMT with the use of oral capsules as a strategy to restore microbioma diversity in patients undergoing allo-HSCT. The authors support the safety and feasibility of this proce- dure, underlining the possibility that microbiome restora- tion early after allo-HSCT may be of benefit.25
Here we describe the results of FMT in ten patients diag- nosed with hematologic malignancies and undergoing FMT for MDRB colonization, namely CPE, CP-Pseudomonas aerug- inosa or VRE, either before or after allo-HSCT. Decolonization was achieved in seven of ten patients, this being persistent at last follow up in six of ten patients. Our retrospective study not only suggests the efficacy of this procedure, but also its safety in patients with hematologic malignancies undergoing allo-HSCT. Interestingly, despite not being a selection criterion for FMT, we also registered patients concomitantly colonized from ESBL-producing enterobacteriaceae, with decolonization in three of six cases. We also showed that, in patients experiencing failure or relapse of MDRB colonization, a second FMT is feasible and efficacious. Interestingly, only three patients experi- enced significant infections after FMT.
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haematologica | 2019; 104(8)