Search

Objective: To compare different criteria of Metagenomic Next-Generation Sequencing (mNGS) in bronchoalveolar lavage fluid (BALF) for diagnosing invasive pulmonary aspergillosis (IPA)., Methods: We compared the diagnostic agreement and performances of six BALF mNGS-derived criteria (SDSMRN>1, SDSMRN≥3, SMRN≥10, SMRN≥50, RPM ratio≥10, and relative abundance of genus>30 %) in pneumonia patients., Results: A total of 115 patients were analyzed, with 28 identified with IPA. Diagnostic agreement among the six mNGS-derived criteria was moderate, with a Cohen's kappa of 0.577(P < 0.001). mNGS-derived criteria had low sensitivity ranging from 21.4 % to 57.1 % and high specificity from 88 % to 92 %. The optimal threshold of SDSMRN, SMRN, RPM ratio, and relative abundance of genus for diagnosing IPA were 5, 0.25, 8, and 20 %, respectively. Although using the optimal threshold, the sensitivity of mNGS is lower than 50 %., Conclusions: All mNGS-derived criteria had low sensitivity for diagnosing IPA. A combination of mNGS and conventional mycological tests may be the best diagnostic strategy., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: The identification of Aspergillus by metagenomic next-generation sequencing (mNGS) remains a challenging task due to the difficulty of nucleic acid extraction. The objective of this study was to determine whether mNGS could provide an accurate and efficient method for detecting invasive pulmonary aspergillosis (IPA) in immunocompromised patients (ICP)., Methods: A total of 133 ICP admitted to the ICU between January 2020 and September 2022 were enrolled in the study, of which 46 were diagnosed with IPA and 87 were non-IPA cases. The bronchoalveolar lavage fluid (BALF) was analyzed for the presence of Aspergillosis and other co-pathogens using mNGS, and its diagnostic performance was compared to conventional microbial tests (CMTs) that included smear, cultures, serum and BALF galactomannan (GM) test. Clinical composite diagnosis was used as the reference standard., Results: mNGS had a sensitivity, specificity, and accuracy of 82.6%, 97.7%, and 92.5%, respectively, in diagnosing IPA. These findings were comparable to those of the combination of multiple CMTs. Interestingly, the sensitivity of mNGS was superior to that of any single CMT method, as demonstrated by comparisons with smears (8.7%, P < 0.001), culture (39.1%, P < 0.001), serum GM (23.9%, P < 0.001) and BALF GM (69.6%, P = 0.031). mNGS was capable of accurately distinguish strains of Aspergillus genus, with a consistency of 77.8% with culture. Furthermore, mNGS also identified A. fumigatus , A. flavus , A. terrestris , A. oryzae and Mucor spp. in culture-negative cases. The sequencing reads of Aspergillus by mNGS exhibited extensive variation, ranging from 11 to1702. A positive correlation was observed between the optical density index of BALF GM and unique reads by mNGS (r = 0.607, P = 0.001) in BALF-GM positive patients. Notably, mNGS was able to diagnose 35 out of 37 cases with mixed infection, with P. jirovecii and cytomegalovirus being the most common co-pathogens., Conclusions: mNGS presents a feasible and remarkably sensitive approach for detecting Aspergillus in ICP, thereby serving as a valuable adjunctive tool to CMT. Furthermore, mNGS's ability to accurately identify fungal species and co-pathogens can assist in guiding appropriate antimicrobial therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Shi, Peng, Hu, Yang and Wang.)