# Clinical Utility of Plasma Microbial Cell-Free DNA Surveillance in Neutropenic Patients with Acute Myeloid Leukemia Undergoing Outpatient Chemotherapy: A Case Series

## TL;DR

This study shows that plasma microbial cell-free DNA testing is more effective than traditional blood cultures for detecting infections in neutropenic AML patients receiving outpatient chemotherapy.

## Contribution

The study demonstrates the clinical utility of mcfDNA surveillance in outpatient neutropenic AML patients, where traditional methods often fail.

## Key findings

- mcfDNA detected pathogens in 11 of 14 patients, including bacteria and fungi.
- Traditional blood cultures identified pathogens in only 2 patients.
- mcfDNA identified actionable results in patients without standard clinical signs of infection.

## Abstract

Background/Objectives: The main objective of the study is to assess the clinical utility of microbial cell-free DNA (mcfDNA) in neutropenic patients diagnosed with acute myeloid leukemia (AML) undergoing chemotherapy in the outpatient setting. Neutropenia is a common complication in this patient cohort and enhances the risk of fatal opportunistic bacterial and fungal infections. Accurate and timely diagnosis of these infections in outpatient asymptomatic individuals is critical. Methods: Fourteen patients were studied in this prospective observational case series. Traditional blood cultures (BCs) were obtained when clinically indicated and blood samples were collected for plasma mcfDNA metagenomic sequencing up to two times a week at outpatient oncology appointments. Results were compared in identifying potential infectious agents. Results: BCs identified pathogens in only two patients, despite several cases where infection was suspected. In contrast, mcfDNA testing detected pathogens in 11 of the 14 patients, including bacteria, such as Staphylococcus aureus, and invasive fungi, such as Candida and Aspergillus species, and Pneumocystis jirovecii. Conclusions: In the outpatient setting, mcfDNA surveillance offers a more reliable method for detecting pathogens. This approach identified actionable microbiologic results in immunocompromised individuals who did not meet standard clinical criteria for suspicion of infection. Further research is required to confirm the potential of mcfDNA surveillance in an outpatient setting to guide more accurate treatment decisions, reduce extensive clinical investigations, and improve neutropenic patient outcomes.