Objective To access the clinical role of metagenomic next-generation sequencing（mNGS） for determining pathogens in patients with febrile neutropenia（FN） after chemotherapy. Methods The data of 19 patients who were clinically diagnosed with FN after chemotherapy and were treated in Xi'an Central hospital from July 2019 to September 2020 were collected. The positive rates and spending times of mNGS,microculture and immunologic test were compared. The efficiency of mNGS,microculture and immunologic test [G test,GM test and Gram-negative bacterium lipopolysaccharide（GNBL）] was analyzed by receiver operating characteristic（ROC） curve. Results Totally,19 patients were enrolled,and 8 blood samples,7 throat swab samples,1 cerebrospinal fluid sample,2 hydrothorax and ascites samples and 1 urine sample were collected. The positive rates of mNGS,microculture and immunologic test were 68.4%,26.3% and 63.2%,respectively. Among the 13 positive samples in mNGS,there were 10 cases of Gram negative bacteria,4 cases of Gram positive bacteria,4 cases of fungi,3 cases of viruses and 1 case of mycoplasma. The spending times of mNGS,microculture and immunologic test were（47.0±13.2） h,（84.0±31.6） h and（24.8±16.4） h,and mNGS spent shorter time than microculture（P<0.05）. The sensitivities of mNGS,microculture and immunologic test were 72.10%,30.70% and 70.9%,the specificities were 68.46%,82.94% and 30.70%,and the areas under curves were 0.806,0.688 and 0.550,respectively. There was statistical significance among the 3 methods（P<0.05）. Conclusions The mNGS has good efficiency,and it is reliable than microculture and immunologic test,which has advantages in determining pathogens among FN patients after chemotherapy.
