Diagnostic value and influencing factors of endobronchial ultrasound-guided transbronchial needle aspiration combined with Xpert MTB/RIF for intrathoracic lymph node tuberculosis

Abstract

Objective: To evaluate the sensitivity of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) puncture to obtain intrathoracic lymph node samples combined with Xpert MTB/RIF (Xpert) detection for the diagnosis of intrathoracic lymph node tuberculosis. Methods: From March 2018 to June 2021, 106 patients [55 males and 51 females, age (45.1±18.6) years] with suspected intrathoracic lymph node tuberculosis and EBUS-TBNA were collected in Zhejiang Hospital of Integrated Traditional Chinese and Western Medicine, including 64 patients with subsequent diagnosis of intrathoracic lymph node tuberculosis and 42 patients without tuberculosis. Xpert test and traditional etiology test were performed on the patients' intrathoracic lymph node puncture specimens. The positive results of different detection methods and different methods were analyzed, and the influencing factors of Xpert independent detection positive were analyzed by univariate and multivariate logistic regression. Results: The sensitivity of Xpert was 65.6% (95%CI: 52.7%-77.1%), the specificity was 97.6% (95%CI: 87.4%-99.9%), the positive predictive value was 97.7% (95%CI: 85.7%-99.7%), the negative predictive value was 65.1% (95%CI: 57.0%-72.4%). The positive rate of Xpert alone (65.6%, 42/64) was not significantly different from that of MGIT960, histopathology and Xpert combined detection (70.3%, 45/64) (P<0.05). Multivariate logistic regression analysis showed that the location of the diseased lymph nodes in the mediastinum (OR=5.84, 95%CI: 1.112-30.704, P=0.037), necrosis in the lymph nodes (OR=6.32, 95%CI: 1.460-27.384, P=0.014), and the axial depth of the lymph nodes≥17 mm (OR=6.61, 95%CI: 1.408-30.969, P=0.017) were the promoting factors for the positive Xpert test. Conclusions: EBUS-TBNA combined with Xpert detection has a high clinical diagnostic value for intrathoracic lymph node tuberculosis. When the number of puncture samples is small, Xpert detection can be preferred. The positive rate of Xpert detection can be improved by selecting lymph nodes with mediastinal lesions, lymph nodes necrosis, and axial lymph nodes depth≥17 mm for puncture.