Abstract:

Objective To investigate the clinical diagnostic value of GeneXpert MTB/RIF (Xpert for short) in detecting patients with coal workers’ pneumoconiosis complicated with pulmonary tuberculosis. Methods Morning sputum specimens of 64 patients diagnosed with coal workers’ pneumoconiosis complicated with pulmonary tuberculosis in Beijing Beijing Coal Cooperation General Hospital from January 2019 to December 2020 were collected continuously. Sputum smear, BACTEC MGIT 960 liquid culture (referred to as “MGIT 960 culture”) and Xpert test were performed at the same time. Using MGIT 960 culture as the standard, sensitivity and specificity of Xpert in detecting MTB from sputum samples were evaluated. Culture positive strains were tested for rifampicin resistance, compared with Xpert test results. Results Using the liquid culture results of MGIT 960 as the golden standard, the sensitivity of smear test and Xpert test in detection MTB were 27.8% (5/18) and 88.9% (16/18), respectively. The sensitivity of Xpert test was higher than that of smear test, difference was statistically significant (χ²=13.829, P=0.000).The consistency between Xpert test and MGIT 960 liquid culture was moderate (Kappa=0.537). The areas under the receiver operating characteristic curve (ROC) of Xpert test and sputum smear test were 0.836 and 0.628, respectively, which suggested that Xpert test was of good diagnostic value. Using drug sensitivity test (DST) results with MGIT 960 as the reference standard, the sensitivity, specificity and consistency of Xpert were (4/4), 78.6% (11/14) and 83.3% (15/18) for detecting rifampicin resistance. The difference between the two detection methods was statistically significant (χ²=4.889, P=0.027). The consistency of the two methods was moderate (Kappa=0.620). Conclusion Xpert has high clinical application value in the early diagnosis of coal workers’ pneumoconiosis complicated with pulmonary tuberculosis and the determination of rifampicin resistance.

Key words: Pneumoconiosis, Tuberculosis,pulmonary, Nucleic acid amplification techniques, Rifampin, Evaluation studies