Clinical metagenomic sequencing of plasma microbial cell-free DNA for febrile neutropenia in patients with acute leukaemia

To evaluate the diagnostic performance and clinical impact of metagenomic next-generation sequencing (mNGS) of plasma microbial cell-free DNA (mcfDNA) in febrile neutropenia (FN). In a 1-year, multicentre, prospective study, we enrolled 442 adult patients with acute leukaemia with FN and investigated the usefulness of mNGS of plasma mcfDNA for identification of infectious pathogens. The results of mNGS were available to clinicians in real time. The performance of mNGS testing was evaluated in comparison with blood culture (BC) and a composite standard that incorporated standard microbiological testing and clinical adjudication. In comparison with BC, the positive and negative agreements of mNGS were 81.91% (77 of 94) and 60.92% (212 of 348), respectively. By clinical adjudication, mNGS results were categorized by infectious diseases specialists as definite (n = 76), probable (n = 116), possible (n = 26), unlikely (n = 7), and false negative (n = 5). In 225 mNGS-positive cases, 81 patients (36%) underwent antimicrobials adjustment, resulting in positive impact on 79 patients and negative impact on two patients (antibiotics overuse). Further analysis indicated that mNGS was less affected by prior antibiotics exposure than BC. Our results indicate that mNGS of plasma mcfDNA increased the detection of clinically significant pathogens and enabled early optimization of antimicrobial therapy in patients with acute leukaemia with FN.