Background Despite increasing data on the impact of the microbiome on cancer, the dynamics and role of the microbiome in infection during acute myelogenous leukemia (AML) therapy are unknown. Thus, we sought to determine relationships between microbiome composition and infectious outcomes in AML patients receiving induction chemotherapy (IC). Methods Buccal and fecal specimens (478 samples) were collected twice weekly from 34 AML patients undergoing IC. Oral and stool microbiomes were characterized by 16S rRNA V4 sequencing using Illumina MiSeq. Microbial diversity and genera composition were associated with clinical outcomes. Results Baseline stool α-diversity was significantly lower in patients that developed infections during IC compared to those that did not (P = 0.047). Significant decreases in both oral and stool microbial α-diversity were observed over the course of IC, with a linear correlation between α-diversity change at the two sites (P = 0.02). Loss of both oral and stool α-diversity was significantly associated with carbapenem receipt (P < 0.01). Domination events by the majority of genera were transient (median duration = 1 sample), while the number of domination events by pathogenic genera significantly increased over the course of IC (P=0.002). Moreover, patients who lost microbial diversity over the course of induction chemotherapy were significantly more likely to contract a microbiologically documented infection within the 90 days post-IC neutrophil recovery (P=0.04). Conclusion These data present the largest longitudinal analyses of oral and stool microbiomes in AML patients and suggest that microbiome measurements could assist with mitigation of infectious complications of AML therapy.

The ability to distinguish allogeneic hematopoietic cell transplant (allo-HCT) recipients at risk for cytomegalovirus (CMV) reactivation from those who are not is central for optimal CMV management strategies. Interferon γ (IFN-γ) produced by CMV-challenged T cells may serve as an immune marker differentiating these 2 populations. We prospectively monitored 63 CMV-seropositive allo-HCT recipients with a CMV-specific enzyme-linked immunospot (ELISPOT) assay and for CMV infection from the period before transplantation to day 100 after transplantation. Assay results above certain thresholds (50 spots per 250 000 cells for immediate early 1 or 100 spots per 250 000 cells for phosphoprotein 65) identified patients who were protected against CMV infection as long as they had no graft-versus-host disease and/or were not receiving systemic corticosteroids. Based on the multivariable Cox proportional hazards regression model, the only significant factor for preventing CMV reactivation was a CMV-specific ELISPOT response above the determined thresholds (adjusted hazard ratio, 0.21; 95% confidence interval, .05–.97; P = .046). Use of this assay as an additional tool for managing allo-HCT recipients at risk for CMV reactivation needs further validation in future studies. Application of this new approach may reduce the duration and intensity of CMV monitoring and the duration of prophylaxis or treatment with antiviral agents in those who have achieved CMV-specific immune reconstitution.

Disease can be conceptualized as the result of interactions between infecting microbe and holobiont, the combination of a host and its microbial communities. It is likely that genomic variation in the host, infecting microbe, and commensal microbiota are key determinants of infectious disease clinical outcomes. However, until recently, simultaneous, multiomic investigation of infecting microbe and holobiont components has rarely been explored. Herein, we characterized the infecting microbe, host, micro- and mycobiomes leading up to infection onset in a leukemia patient that developed invasive mucormycosis. We discovered that the patient was infected with a strain of the recently described Mucor velutinosus species which we determined was hypervirulent in a Drosophila challenge model and has a predisposition for skin dissemination. After completing the infecting M. velutinosus genome and genomes from four other Mucor species, comparative pathogenomics was performed and assisted in identifying 66 M. velutinosus-specific putatively secreted proteins, including multiple novel secreted aspartyl proteinases which may contribute to the unique clinical presentation of skin dissemination. Whole exome sequencing of the patient revealed multiple non-synonymous polymorphisms in genes critical to control of fungal proliferation, such as TLR6 and PTX3. Moreover, the patient had a non-synonymous polymorphism in the NOD2 gene and a missense mutation in FUT2, which have been linked to microbial dysbiosis and microbiome diversity maintenance during physiologic stress, respectively. In concert with host genetic polymorphism data, the micro- and mycobiome analyses revealed that the infection developed amid a dysbiotic microbiome with low α-diversity, dominated by staphylococci. Additionally, longitudinal mycobiome data showed that M. velutinosus DNA was detectable in oral samples preceding disease onset. Our genome-level study of the host-infecting microbe-commensal triad extends the concept of personalized genomic medicine to the holobiont-infecting microbe interface thereby offering novel opportunities for using synergistic genetic methods to increase understanding of infectious diseases pathogenesis and clinical outcomes.

Immunotherapies vary in their pathophysiology and offer potential to be highly effective for the management of a wide array of cancer types. Understanding the unique pathophysiology and toxicities is necessary to assess, manage, and provide safe, effective patient-focused care.

As the use of immunotherapeutic agents increases in single-agent and multimodality treatment regimens, oncology nurses face the challenge of administering and caring for patients receiving new and unique agents. Oncology Nursing Society clinical staff and clinical nurses collaborated to produce a set of recommendations to educate nurses involved with the monitoring of patients receiving immunotherapy on administration procedures and safe handling of these agents to ensure patient and staff safety and to reduce risk of error. The recommendations are meant to provide clinical nurses with a framework on which to build policies and procedures for administering new treatment modalities.
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