OBJECTIVE To investigate the etiological characteristics detected by metagenomic next-generation sequencing (mNGS) and its impact on treatment and prognosis in patients with hematological disease complicated with agranulocytosis and fever.

METHODS A retrospective analysis was conducted on 170 hematological disease patients with hematological granulopathy and fever ineffective empiric empirical anti-infective treatment who were admitted to the Hematology Department of the First Medical Center of Chinese PLA General Hospital from Apr. 2019 to Dec. 2023. Both blood culture and blood mNGS were tested simultaneously on these patients, and the differences of mNGS and blood culture on pathogen detection rates, pathogen distribution, consistency of test results, the proportion of treatment adjustments based on etiology, and all-cause mortality were compared and analyzed.

RESULTS The detection rate of pathogens of blood culture was 12.94%, with the contamination rate of 4.12%. The pathogen detection rate of mNGS was 25.88%, with the contamination rate of 0.59%. mNGS showed higher detection rates for pathogens, gram-negative bacteria and fungi than blood culture (all P < 0.05). However, the detection rate for gram-positive bacteria by mNGS was slightly lower than that by blood culture, but there was no significant statistical difference (P=0.455). The most common pathogenic bacteria detected by blood culture was coagulase-negative Staphylococcus aureus, followed by Escherichia coli. The most common pathogenic bacteria detected by mNGS are Acinetobacter baumannii, followed by Klebsiella pneumoniae. The positive and negative coincidence rates for detecting gram-negative bacteria by blood culture and mNGS were 72.70% and 88.10%, respectively. The positive and negative coincidence rates for detecting gram-positive bacteria were 10.00% and 96.30%, respectively. No fungi were detected consistently by both methods. The viral detection rate of mNGS was 68.82%, and no virus was detected positive in blood culture. The 30-day all-cause mortality rate of the 170 patients was 22.35%. The improvement rate after treatment adjusted according to mNGS was significantly higher than that after treatment adjusted according to blood culture (48.00% vs. 20.00%, P= 0.007).

CONCLUSIONS Among patients with hematological disease accompanied by febrile neutropenia and are ineffective to empirical treatment, mNGS is significantly superior to blood culture in detecting pathogen (gram-negative bacteria, fungi, and viruses) and guiding treatment. In terms of gram-positive bacterial infections, mNGS and blood culture have their own advantages, and the combined application of the two methods has greater clinical value.