Diagnostic value of metagenomic next-generation sequencing of lower respiratory tract specimen for the diagnosis of suspected pneumonia.

Aim: To evaluate diagnostic performance of metagenomic next-generation sequencing (mNGS) for pneumonia (PCP), in comparison with polymerase chain reaction (PCR), Gomori methenamine silver (GMS) staining and serum 1,3-β-d-Glucan (BG) assay.

Methods: 52 PCP patients and 103 patients with non-pneumocystic jirovecii pneumonia (non-PCP) were enrolled, and comparative analysis was conducted of different diagnostic tests. Clinical features and co-pathogen characteristics were reviewed.

Results: The diagnostic sensitivity (92.3%) and specificity (87.4%) of mNGS did not show significant differences compared with that of PCR while mNGS had the advantage over PCR in the detection of co-pathogens. Despite its excellent specificity, the sensitivity of GMS staining (9.3%) was inferior to that of mNGS ( < .001). The combination of mNGS with serum BG statistically outperformed mNGS or serum BG alone in the areas under the receiver operating characteristic curves (AUCs,  = .0013 and  = .0015, respectively). Notably, all the blood samples showing positive mNGS for came from PCP patients. The leading co-pathogens among patients with PCP were cytomegalovirus, Epstein-Barr virus and Torque teno virus.

Conclusions: mNGS shows superiority over several common clinical methods in the diagnosis of suspected PCP. Serum BG in conjunction with mNGS further improved the diagnostic efficacy of mNGS.