[Value of Pathogenic Detection by Next-Generation Sequencing in Bronchoalveolar Lavage Fluid on Children with Hematological Malignancies].

To investigate the application value of bronchoalveolar lavage fluid (BALF) metagenomic next-generation sequencing (mNGS) in etiological diagnosis of children with hematological malignancies complicated with pneumonia. We retrospectively analyzed the clinical data of children with hematological malignancies who underwent BALF mNGS pathogenic detection due to pneumonia. All patients underwent mNGS detection of bronchoalveolar lavage fluid as well as traditional methods(including sputum culture, bronchoalveolar lavage fluid culture, blood culture, serological detection of pathogens, etc.). By analyzing the results of mNGS and traditional methods, we compared key indicators such as the positive rate, etiological distribution. A total of 26 children with hematological malignancies enrolled in the study, including 12 males and 14 females, with a median age of 4.9 (1.8-14.9) years, underwent bronchoalveolar lavage (BAL) 35 times. A total of 17 pathogenic microorganisms were detected in BALF mNGS, including 9 cases of bacterial infection, 10 cases of viral infection, 3 cases of fungal infection, 2 cases of mycoplasma infection and 8 cases of mixed infection, and the most commonly detected bacteria, viruses and fungi were streptococcus pneumoniae, cytomegalovirus and pneumocystis jirovecii, respectively. The positive rate of mNGS detection (91.43%) was significantly higher than that of traditional methods detection (20%, P <0.001). A total of 25 cases were adjusted according to BALF mNGS results. The application of BALF mNGS technology can improve the detection rate of the pathogens in children with hematological malignancies complicated with pneumonia, initially revealed the pathogen spectrum of pulmonary infection in this group, and effectively guide clinical medication, improve treatment outcomes.