The Value Of Gene Chip Detection Of Bronchoalveolar Lavage Fluid In The Diagnosis Of Nontuberculous Mycobacterial Lung Disease

Background: Nontuberculous mycobacteria (NTM) are mycobacteria other than mycobacterium tuberculosis complex (MTBC) and mycobacterium leprae. NTM can cause infection in many human tissues and organs and is most commonly seen in the lungs. Clinically, the symptoms and signs of nontuberculous mycobacteria lung disease (NMLD) are very similar to those of tuberculosis (TB). Because most NTMs are resistant to conventional anti-TB drugs, the rapid diagnosis of NMLD is the key to treatment. This study aimed to use gene chip technology to examine bronchoalveolar lavage fluid (BALF) from NMLD patients to explore the value of this technique for the rapid diagnosis of NMLD in BALF. Methods: A retrospective analysis of 308 patients with NMLD treated at Fuzhou Pulmonary Hospital from January 2018 to June 2020 was performed. BALF was collected from the patients. Gene chip detection (Capital Bio Corporation, Chengdu, China) and BACTEC MGIT960 (Becton, Dickinson and Company, MD, USA) liquid culture were performed to compare the NTM positive detection rates between the two methods. The NTM strain isolated from liquid culture were identified by rDNA sequencing and the results of identification were compared with those of gene chip detection using BALF specimens. Results: A total of 221 cases of NTM were detected in 308 BALF specimens by the gene chip method; the positive rate was 71.75% (221/308). A total of 218 cases of NTM were detected by the liquid culture method, and the positive rate was 70.78% (218/308). There was no significant difference in the positive rate of NTM detected in BALF specimens between the two methods (chi(2)=0.138 P=0.804>0.05); 187 cases were detected with both sequencing and gene chip detection, and the coincidence rate of strain identification with the two methods reached 96.79% (181/187). Sequencing of 218 strains of NTM was carried out; eight species were identified, and the top four species were M. intracellulare (131/218, 60.09%), M. avium (48/218, 22.02%), M. abscessus (27/218, 12.38%), and M. kansasii (5/218, 2.29%). Conclusions: Gene chip technology can rapidly detect NTM in BALF and accurately identify bacterial species. It has important clinical value in the early diagnosis and treatment of NMLD.