Abstract:

Objective: To analyze the monitoring effect of real-time fluorescent RNA isothermal detection (SAT-TB) and real-time fluorescent quantitative PCR (qRT-PCR) in the early antituberculosis chemotherapy of patients with tracheobronchial tuberculosis. Methods: Data of 168 patients with initial treatment tracheobronchial tuberculosis who had been treated in Xi’an Chest Hospital were collected from January to December, 2021. We analyzed the results of mycobacterium MGIT 960 liquid culture, SAT-TB and qRT-PCR of 94 etiologically positive patients who had been treated with tracheoscopy and had alveolar lavage fluid sample collected every 2 weeks (2nd, 4th, 6th, 8th, 10th and 12th week) after admission (baseline), and the dynamic changes of SAT-TB, qRT-PCR and their detection efficiency using the MGIT 960 liquid culture test as reference. Then the relationship between the negative conversion time of MGIT 960 culture and the dt value of the first SAT-TB results of the 168 patients was analyzed. Results: For the 94 patients who undertook tracheoscopy every 2 weeks, the positive rates of MGIT 960 culture at baseline, 2nd, 4th, 6th, 8th, 10th and 12th week declined by 98.78% (81/82), from 87.23% (82/94) to 1.06% (1/94); and the results of qRT-PCR test decreased by 67.81% (59/87), from 92.55% (87/94) to 29.79% (28/94). In addition, the positive rates of SAT-TB decreased by 82.95% (73/88), from 93.62% (88/94) to 15.96% (15/95). The declines of positive rates of qRT-PCR and SAT-TB were less than MGIT 960 culture, the differences were statistically significant (χ²=28.472, 12.469; Ps<0.001). Taking MGIT 960 test as the reference standard, the consistency (Kappa values) of qRT-PCR and MGIT 960 test were 0.044-0.416, and the area under curve (AUC) were 0.553-0.715 at different test points, these were significantly lower than that of SAT-TB and MGIT 960 test at every test point (Kappa values were 0.107-0.620, AUC were 0.642-0.814). For all 168 patients, the average dt values of patients in the negative conversion time within 1-4 weeks group (7.264 (4.891, 10.990)) was longer than the 5-8 weeks group(5.113 (3.520, 6.390)) and the 9-weeks and above group (5.222 (4.068, 6.886)), respectively. The differences were statistically significant (Z=-4.318, P<0.001; Z=-2.017, P=0.044). Conclusion: SAT-TB did better than qRT-PCR in monitoring the early curative effect of etiologically positive tracheobronchial tuberculosis patients.

Key words: Tuberculosis,bronchus, Nucleic acid amplification technology, Treatment outcome, Monitoring, Comparative study