Diagnostic Efficacy of Xpert MTB/RIF Assay in Bronchoalveolar Lavage Fluid for Tracheobronchial Tuberculosis: A Retrospective Analysis

Determination of the diagnostic accuracy of nanopore sequencing using bronchoalveolar lavage fluid samples from patients with sputum-scarce pulmonary tuberculosis

PURPOSE

The early and efficient diagnosis of patients suspected of having pulmonary tuberculosis (PTB) remains challenging. This study aimed to evaluate the accuracy of nanopore sequencing for PTB diagnosis using bronchoalveolar lavage fluid (BALF) samples and compared it with other techniques such as acid-fast bacilli smear, culture, Xpert MTB/RIF, and CapitalBio Mycobacterium reverse transcription-polymerase chain reaction (MTB RT-PCR).

METHODS

We retrospectively analyzed the clinical data of 195 patients with suspected PTB who were admitted to our hospital. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC) of these assays were calculated and compared.

RESULTS

The overall sensitivity, specificity, PPV, NPV, and AUC of nanopore sequencing were 90.70%, 84.85%, 92.13%, 82.35%, and 0.88; those of acid-fast bacilli smear were 12.40%, 98.48%, 94.12%, 36.52%, and 0.55; those of culture were 36.43%, 100%, 100%, 44.59%, and 0.68; those of Xpert MTB/RIF were 41.09%, 100%, 100%, 46.48%, and 0.71; and those of CapitalBio MTB RT-PCR were 34.88%, 98.48%, 97.83%, 43.62%, and 0.67, respectively.

CONCLUSION

The nanopore sequencing assay using BALF samples showed the best diagnostic accuracy for sputum-scarce PTB. Moreover, it can improve the clinical diagnosis of PTB.

EBUS-GS with the GeneXpert MTB/RIF assay for diagnosis of Mycobacterium tuberculosis infection of isolated pulmonary nodules

OBJECTIVE

Investigate the use of endobronchial ultrasonography with a guide sheath (EBUS-GS) combined with Gene Xpert MTB/RIF (Xpert) for diagnosis of Mycobacterium tuberculosis (MTB) infection in isolated pulmonary nodules.

METHODS

Patients who had isolated pulmonary nodules and unknown diagnoses at our institution from October 2020 to December 2021 were prospectively examined using EBUS-GS and Xpert. The diagnostic values of using EBUS-GS or bronchoalveolar lavage fluid (BALF) with acid-fast staining, MGIT 960 culture, pathological examination, and Xpert for isolated pulmonary nodules caused by MTB infection were compared using receiver operating characteristic (ROC) analysis.

RESULTS

There were 135 patients, 64 with isolated pulmonary tuberculomas and 71 with non-tuberculous lesions. The sensitivity of EBUS-GS with Xpert was significantly higher than BALF with Xpert (57.81% vs. 34.78%, P = 0.017). Use of EBUS-GS with Xpert and MGIT 960 culture further increased the sensitivity to 62.50% (95%CI 50.64-74.36) and increased the specificity to 100%. The AUC values of BALF with MGIT 960 culture was 0.663(95%CI 0.543-0.783) and BALF with Xpert was 0.674 (95%CI 0.556-0.792). The AUC values of EBUS-GS with MGIT 960 culture was 0.680 (95%CI 0.554-0.743), with pathological examination was 0.713 (95%CI 0.573-0.760), and with Xpert was 0.789 (95%CI 0.655-0.829).

CONCLUSION

Use of EBUS-GS with Xpert had high sensitivity and specificity in the diagnosis of isolated pulmonary tuberculoma. This method has significant potential for use in clinical practice.

EBUS-GS with the GeneXpert MTB/RIF assay for diagnosis of Mycobacterium tuberculosis infection of isolated pulmonary nodules.. [DOI: 10.21203/rs.3.rs-2571545/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Objective Investigate the use of endobronchial ultrasonography with a guide sheath (EBUS-GS) combined with Gene Xpert MTB/RIF (Xpert) for diagnosis of Mycobacterium tuberculosis (MTB) infection in isolated pulmonary nodules. Methods Patients who had isolated pulmonary nodules and unknown diagnoses at our institution from October 2020 to December 2021 were prospectively examined using EBUS-GS and Xpert. The diagnostic values of using EBUS-GS or bronchoalveolar lavage fluid (BALF) with acid-fast staining, MGIT 960 culture, pathological examination, and Xpert for isolated pulmonary nodules caused by MTB infection were compared using receiver operating characteristic (ROC) analysis. Results There were 135 patients, 64 with isolated pulmonary tuberculomas and 71 with non-tuberculous lesions. The diagnostic sensitivity of EBUS-GS was significantly higher than that of BALF with Xpert (57.81% vs. 25%, P < 0.001), MGIT 960 culture (35.94% vs. 23.44%, P = 0.039), and acid-fast staining (17.19% vs. 6.25%, P = 0.016). Use of EBUS-GS with Xpert and MGIT 960 culture further increased the sensitivity to 62.50% (95%CI: 50.64–74.36) and increased the specificity to 100%. The AUC values of BALF with MGIT 960 culture was 0.617 (95%CI: 0.521–0.713) and BALF with Xpert was 0.625(95%CI: 0.529–0.721). The AUC values of EBUS-GS with MGIT 960 culture was 0.680 (95%CI: 0.554–0.743), with pathological examination was 0.713 (95%CI: 0.573–0.760), and with Xpert was 0.789 (95%CI: 0.655–0.829). Conclusion Use of EBUS-GS with Xpert had high sensitivity and specificity in the diagnosis of isolated pulmonary tuberculoma. This method has significant potential for use in clinical practice.

The Usefulness of Bronchoscopy in the Diagnosis of Mycobacterium tuberculosis Complex Species Infection

BACKGROUND: Pulmonary tuberculosis is an active chronic infection of the lungs. It is still a public health problem globally caused by the Mycobacterium tuberculosis Complex (MTBC). These species are difficult to determine only by conventional tests. The clinical manifestations are almost similar between the strains and cause diagnosis delays. Prolonged and intolerable MTBC therapy inhibits infection control. AIM: This study aims to evaluate the usefulness of bronchoscopy in diagnosing the MTBC species infection. METHODS: This study recruited patients with difficulty expectorating sputum. Pulmonary tuberculosis was diagnosed with the Xpert MTB/RIF assay. This study assessed sputum Acid Fast Bacilli (AFB) staining, chest X-rays with active pulmonary tuberculosis, characteristics of Bronchoalveolar lavage (BAL), and bronchoscopic findings based on the Chung classification. The BAL of polymerase chain reaction analysis using RD9 and TbD1 primers to determine MTBC species. RESULTS: Out of the 30 cases, M. tuberculosis and Mycobacterium bovis 24 (80.0%) and 6 (20.0%) were identified in BAL fluid. There were 12 cases (40.0%) with AFB sputum test, and 25 (83.3%) of the Xpert MTB/RIF detected tuberculosis cases. All chest X-rays showed infiltrated and 22 (73.3%) pulmonary ectasis. There was a significant difference in MTBC species between sputum and BAL fluid (p < 0.05). The ulcerative type of bronchoscopy findings was significantly different in MTBC species (p < 0.05) and there was no macroscopic BAL fluid difference (p > 0.05). CONCLUSIONS: Bronchoscopy is a specimen collection technique that is beneficial in determining the diagnosis of MTBC. Analysis of BAL with molecular methods contributes to identifying MTBC species quickly and accurately.

Diagnostic accuracy of different bronchoscopic specimens in sputum Xpert MBT/RIF- negative pulmonary TB patients

Background

Tuberculosis (TB) control remains a critical public health problem worldwide. Rapid diagnosis and proper treatment are beneficial for the effective control of tuberculosis transmission. Diagnostic challenges arise when a patient has a clinical and radiological suspicion of tuberculosis but cannot produce sputum, sputum acid-fast bacilli, or Xpert Mycobacterium tuberculosis/rifampicin (Xpert MTB/RIF) is negative, resulting in suboptimal management. As a result, more invasive techniques must be used on these patients to establish the diagnosis.

Methods

A retrospective study recruited 330 suspected pulmonary TB patients with negative sputum of Xpert MBT/RIF who underwent bronchoscopy between March 2018 and December 2021. The diagnostic yields of bronchoalveolar lavage fluid (acid-fast bacilli, Xpert MTB/RIF, and culture) and histopathologic examination (HPE) were calculated and compared to the final diagnosis and culture as a gold standard.

Results

Out of 330 suspected pulmonary TB patients, 181 had a final diagnosis of TB, and 149 had non-TB. The sensitivity of BALF (culture, Xpert, acid-fast bacilli) and trans-bronchial lung biopsy (HPE) was 80.7%, 72.9%, 21.1%, and 87.1%, respectively. Multiple nodules were associated with significantly higher BALF Xpert MTB, bronchoalveolar lavage fluid culture, and trans-bronchial lung biopsy (HPE) positivity.

Conclusions

Bronchoscopic specimens are essential for accurate and rapid diagnosis of sputum Xpert MBT/RIF negative patients with high clinical and radiological suspicion of tuberculosis.