Abstract:

Objective: To investigate the diagnostic value of metagenomic next-generation sequencing (mNGS) in nontuberculous mycobacterial pulmonary disease (NTM-PD). Methods: The data of 123 patients with suspected NTM-PD admitted to the Tuberculosis Diagnosis and Treatment Center of Hangzhou Chest Hospital, Zhejiang University School of Medicine from January 2020 to February 2022 were retrospectively selected. According to the diagnostic criteria, 123 suspected NTM-PD patients were finally diagnosed as NTM-PD patients (NTM-PD group; n=74) and non-NTM-PD patients (non-NTM-PD group; n=49). All the patients underwent mNGS, PCR-fluorescence probe and mycobacterial culture in alveolar lavage fluid, sputum and lung tissue simultaneously. The sensitivity and specificity of the three methods were compared. Results: Based on the final clinical diagnosis, the sensitivities of mNGS, liquid culture and PCR fluorescence probe for NTM-PD detection were 83.8% (62/74), 78.4% (58/74) and 67.6% (50/74), respectively, the specificities were 65.3% (32/49), 91.8% (45/49) and 87.8% (43/49), respectively, the consistencies in diagnosis were 76.4% (94/123), 83.7% (103/123) and 75.6% (93/123), respectively, with Kappa values of 0.524, 0.647 and 0.521, respectively. Using liquid culture results as the standard, of mNGS and PCR fluorescence probe for NTM-PD detection, the sensitivities were 87.1% (54/62) and 75.8% (47/62), and specificities were 59.0% (36/61) and 85.2% (52/61), respectively, the consistencies in diagnosis were 73.2% (90/123) and 80.5% (99/123), and the Kappa values were 0.462 and 0.587, respectively. The strains of 74 NTM-PD patients were identified by mNGS and gene chip method, and the concordance rate of two detecting methods was 63.8% (37/58) with gene chip method as the standard for strain identification. Conclusion: For the diagnosis of NTM-PD, of mNGS detection, the sensitivity is high, it can directly identify the strains; however, the specificity is low, the specificity should be focused on improving, to better serve the clinic.

Key words: Genomics, Mycobacteria, atypical, Diagnostic techniques and procedures, Comparative study