GeneXpert MTB/RIF for rapid diagnosis and rifampin resistance detection of endobronchial tuberculosis

Performance of Raman Spectroscopy in biopsy tissue for rapid diagnosis of Tracheobronchial Tuberculosis: A prospective study

Tracheobronchial tuberculosis (TBTB) is a specific form of pulmonary tuberculosis characterized by Mycobacterium tuberculosis involvement in the tracheobronchial tree. Rapid and accurate diagnostic tools for TBTB are crucial. Raman spectroscopy (RS) is a noninvasive tool that accesses molecular vibrations and sample characteristics, enabling the creation of a molecular fingerprint of biological samples, which has enormous potential on clinical diagnosis for TBTB. This study aimed to develop and validate a diagnostic model based on RS in bronchial biopsies for identifying TBTB. The training set included patients with TBTB (n = 18), airway malignant diseases (n = 20), and normal mucosal tissue biopsies as the healthy controls (n = 20). The spectral analysis results indicated that differential changes in tissue biomolecules, particularly certain amino acids, among the three groups. K-Nearest Neighbors (KNN), principal component analysis-linear discriminant analysis (PCA-LDA), principal component analysis-support vector machine (PCA-SVM) and decision tree methods were implemented to classify this same spectral data set. The PCA-SVM method exhibited highest classification accuracy, with a sensitivity of 88.89 % and an area under the receiver operating characteristic curve (AUROC) of 0.919. Subsequently, an independent validation set comprising 121 patients with suspected TBTB was enrolled to evaluate the performance of RS model using the PCA-SVM method. The sensitivity of RS model was 87.69 % (57/65) for diagnosing TBTB, higher than that of sputum smear, bronchial brush smear, the Bactec MGIT 960 Culture of bronchoalveolar lavage fluid, and comparable to GeneXpert sensitivity. In conclusion, the RS model using bronchial tissue provides a rapid and accurate method of identifying TBTB, showing potential as a powerful noninvasive tool for TBTB diagnosis under bronchoscopy.

Analysis of care-seeking and diagnosis delay among pulmonary tuberculosis patients in Beijing, China

Background

Tuberculosis (TB) remains a significant public health challenge in China. Early detection and diagnosis of TB cases are crucial to interrupt disease transmission and prevent its progression. This study aims to describe the delay in seeking care and diagnosis among patients with pulmonary tuberculosis (PTB) and identify the influencing factors in two counties in Beijing.

Methods

A retrospective analysis was carried out to investigate care-seeking and diagnosis delay in two counties in Beijing. Basic information of PTB patients from January 1 to December 31, 2021, was extracted from the Tuberculosis Information Management System of China (TBIMS), and all enrolled patients were interviewed via telephone using a standard questionnaire. Statistical description was performed using the median and interquartile range (IQR). Chi-square test and multivariate logistic regression model were used to analyze the influencing factors.

Results

537 patients were enrolled. The median duration of care-seeking and diagnosis delay was 11 (IQR: 5-26) days and 8 (IQR: 0-18) days, with 41.71 and 35.20% of patients experiencing delays (>14 days). The study found that being asymptomatic (OR = 2.791, 95%CI: 1.710-4.555) before seeking medical care and not attending work during treatment (OR = 2.990, 95%CI: 1.419-6.298) were identified as risk factors for care-seeking delay. Patients who were tracked (OR = 2.632, 95%CI: 1.062-6.521) and diagnosed at tuberculosis control and prevention institutions (OR = 1.843, 95%CI: 1.061-3.202) had higher odds of diagnostic delays. 44.69% of patients presented a total delay (>28 days), with a median duration of 25 (IQR: 13-39) days. A multivariate logistic regression analysis showed that healthy examination (OR = 0.136, 95%CI: 0.043-0.425) was a protective factor for total delay.

Conclusion

Public interventions are necessary to improve the efficiency of PTB patients detection and treatment in Beijing. Medical services should focus on the target population and improve access to medical care to further reduce delays for PTB patients.

Diagnostic value of chemiluminescence for urinary lipoarabinomannan antigen assay in active tuberculosis: insights from a retrospective study

Purpose

This study aimed to assess the efficacy of chemiluminescence-based urinary lipoarabinomannan (LAM) antigen assay as a diagnostic tool for identifying active tuberculosis.

Methods

A retrospective study was conducted on 166 Tuberculosis (TB), 22 Non-Tuberculous Mycobacteria (NTM), 69 Non-TB cases, and 73 healthy controls from Zhangjiagang First Peoples Hospital between July 2022 and November 2022. Clinical and laboratory data were collected, including urine samples for LAM antigen detection, sputum samples and pleural effusion for GeneXpert, TB-DNA, and culture.

Results

TB group exhibited a higher LAM positivity rate (P < 0.001). CD4 count and diabetes as independent factors influencing the diagnostic accuracy of LAM. The LAM assay showed a sensitivity of 50.6% and a specificity of 95.65%. Notably, LAM's sensitivity was superior to TB-DNA (50.60% vs. 38.16%, P < 0.05). LAM's PTB detection rate was 51.7%, superior to TB-DNA (P = 0.047). Moreover, in EPTB cases, the LAM detection rate was 42.11%, surpassing Gene Xpert (P = 0.042), as well as exceeding the detection rates of TB-DNA and sputum culture.

Conclusion

LAM antigen detection using chemiluminescence has demonstrated outstanding clinical diagnostic value for active TB, especially in the diagnosis of extrapulmonary TB. The convenience of sample collection in this diagnostic approach allows for widespread application in the clinical diagnosis of active tuberculosis, particularly in cases of EPTB and sputum-negative patients.

Differences in epidemiological and clinical features between adult and pediatric tracheobronchial tuberculosis patients in Southwest China

Background

Tracheobronchial tuberculosis (TBTB) is a common form of extrapulmonary tuberculosis that affects the tracheobronchial tree. However, the mechanism has not been fully elucidated. Comparisons of clinical characteristics in various age groups can aid in the understanding of TBTB.

Methods

This retrospective study was conducted at the Public Health Clinical Center of Chengdu between July 2017 and December 2021, including adults and children with TBTB. Clinical data were extracted from medical records. T/T' test, Mann-Whitney U test, Chi-square test, or Fisher's exact test were used in this study.

Results

This study enrolled 347 patients with TBTB (175 adults and 172 children). Adult females were more susceptible to TBTB, whereas gender-based differences were not observed in children. Children had a higher occurrence of irritant dry cough and fever, and acute hematogenous disseminated PTB, and specific types of EPTB, but a shorter interval before diagnosis, and lower diagnostic yields compared to adults (P < 0.05). Adults presented more extensive lung lesions and cavitations as compared to children. Granulation hyperplasia and lymph fistula were more frequently observed in children, as well as airway stenosis, but less severe.

Conclusions

The study revealed important variations exist in multiple respects between adults and children with TBTB.

Comparison of Performances of GeneXpert MTB/RIF, Bactec MGIT 960, and Bactec Myco/F Systems in Detecting Mycobacterium tuberculosis in Biopsy Tissues: a Retrospective Study

Tuberculosis remains a major global public concern as a leading cause of health care-associated infections. The detection of Mycobacterium tuberculosis (MTB) is challenging due to the paucibacillary nature of the pathogen. For suspected pulmonary and extrapulmonary tuberculosis patients, if sputum, bronchoalveolar lavage fluid (BALF), related samples are negative for MTB, or suspected tumors, biopsy tissues may provide a better diagnostic yield. This study was aimed at comparing the performances of three methods in identifying MTB in biopsy tissues, including the Bactec mycobacterial growth indicator tube 960 (MGIT 960) system, the GeneXpert MTB/RIF assay (GeneXpert), and the Bactec Myco/F lytic culture (Myco/F) system. Biopsy samples from 3,209 nonduplicated patients were retrospectively enrolled between January 2018 and September 2021, of which 180 (5.6%) were positive for MTB by at least one method. GeneXpert revealed the highest recovery rate (134/162, 82.7%), followed by MGIT 960 (99/135, 73.3%) and Myco/F (26/143, 18.1%), and the composite positive rate for GeneXpert and MGIT 960 was 96.6% (173/179). Pairwise comparisons were conducted after completion of both tests, and the results showed that Myco/F had significantly lower detection rates than GeneXpert and MGIT 960 (16.4% versus 82.8%, P < 0.001; 14.3% versus 71.4%, P < 0.001). In summary, GeneXpert was the most sensitive and recommended method for MTB detection in biopsy tissues, and the combination of GeneXpert and MGIT 960 could improve the overall diagnostic yield. IMPORTANCE Mycobacterium tuberculosis (MTB) poses a severe threat to public health worldwide. The diagnosis of tuberculosis is challenging due to the low load of the microorganism in samples. Biopsy tissues are sometimes collected via invasive procedures with limited size, and additional samples are often inaccessible. The GeneXpert MTB/RIF assay, Bactec MGIT 960 system, and Bactec Myco/F lytic system have been used in detecting MTB in our laboratory. Here, we evaluated the performances of these three methods in 3,209 biopsy tissues samples to establish a more effective protocol based on clinical requirements. Attempts for a locally optimized protocol should be always made.

The Value of GeneXpert MTB/RIF for Detection in Tuberculosis: A Bibliometrics-Based Analysis and Review

With the continuous development of medical science and technology, especially with the advent of the era of precision diagnosis and treatment, molecular biology detection technology is widely valued and applied as an aid to early diagnosis of tuberculosis. The GeneXpert Mycobacterium tuberculosis Branching (MTB) technology is a suite of semi-nested real-time fluorescent quantitative PCR in vitro diagnostic technologies developed by Cepheid Inc. It targets the rifampicin resistance gene, rpoB, and can detect both MTB and resistance to rifampicin within 2 h. This review analyzed the papers related to GeneXpert using bibliometric software CiteSpace and Bibliometrix. A total of 151 articles were analyzed, spanning from 2011 to 2021. This bibliometrics-based review summarizes the history of the development of GeneXpert in tuberculosis diagnosis and its current status. Contributions of different countries to the topic, journal analysis, key paper analysis, and clustering of keywords were used to analyze this topic.

Evaluation of whole-genome sequence to predict drug resistance of nine anti-tuberculosis drugs and characterize resistance genes in clinical rifampicin-resistant Mycobacterium tuberculosis isolates from Ningbo, China

Setting

Controlling drug-resistant tuberculosis in Ningbo, China.

Objective

Whole-genome sequencing (WGS) has not been employed to comprehensively study Mycobacterium tuberculosis isolates, especially rifampicin-resistant tuberculosis, in Ningbo, China. Here, we aim to characterize genes involved in drug resistance in RR-TB and create a prognostic tool for successfully predicting drug resistance in patients with TB.

Design

Drug resistance was predicted by WGS in a "TB-Profiler" web service after phenotypic drug susceptibility tests (DSTs) against nine anti-TB drugs among 59 clinical isolates. A comparison of consistency, sensitivity, specificity, and positive and negative predictive values between WGS and DST were carried out for each drug.

Results

The sensitivities and specificities for WGS were 95.92 and 90% for isoniazid (INH), 100 and 64.1% for ethambutol (EMB), 97.37 and 100% for streptomycin (SM), 75 and 100% for amikacin (AM), 80 and 96.3%for capreomycin (CAP), 100 and 97.22% for levofloxacin (LFX), 93.33 and 90.91% for prothionamide (PTO), and 70 and 97.96% for para-aminosalicylic acid (PAS). Around 53 (89.83%) and 6 (10.17%) of the isolates belonged to lineage two (East-Asian) and lineage four (Euro-American), respectively.

Conclusion

Whole-genome sequencing is a reliable method for predicting resistance to INH, RIF, EMB, SM, AM, CAP, LFX, PTO, and PAS with high consistency, sensitivity, and specificity. There was no transmission that occurred among the patients with RR-TB in Ningbo, China.

Early and Regular Bronchoscopy Examination on Effect of Diagnosis and Prognosis for Patients With Tracheobronchial Tuberculosis

BACKGROUND

Bronchoscopy is the main method for the diagnosis of tracheobronchial tuberculosis (TBTB). However, it is not well-used in patients with pulmonary tuberculosis (PTB), leading to misdiagnosis. The aim of this study is to verify the value and feasibility of bronchoscopy for an early diagnosis and treatment of TBTB.

MATERIALS AND METHODS

A prospective observational study was performed in patients with active PTB. The ratios of TBTB and tracheobronchial stenosis were analyzed with propensity score matching (PSM) for baseline characteristics, and a Cox regression model was further employed to adjust for residual confounding factors.

RESULTS

A total of 656 patients with active PTB were enrolled in the study that included 307 patients in the active group and 349 patients in the non-active group. The ratio of TBTB was significantly higher in the active group than that in the non-active group [hazard ratio (HR), 2.31; 95% CI, 1.70-3.14; p < 0.001]. With PSM, the proportion of tracheobronchial stenosis in the non-active group was significantly higher than that in the active group (HR, 1.84; 95% CI, 1.15-2.95; p = 0.011). Moreover, the number of patients with moderate to severe stenosis were significantly higher than that in the active group (HR, 4.13; 95% CI, 2.25-7.63; p < 0.001). Similar results were obtained with multivariate analysis. With 12 months of treatment, both therapeutic effective rate (84.7 vs. 68.2%; p = 0.009) and improvement rate of non-fibrotic tracheobronchial stenosis (79.1 vs. 47.4%; p = 0.022) were higher in the active group than that in the non-active group.

CONCLUSION

Active and regular bronchoscopy is conducive to early diagnosis of TBTB, combined with prompt anti-tuberculosis therapy, greatly reducing the occurrence of tracheobronchial stenosis and improving prognosis.

Efficacy and safety of CO2 cryotherapy in the treatment of infants with tracheobronchial tuberculosis

OBJECTIVE

This study aimed to investigate the efficacy and safety of CO₂ cryotherapy for lymph node fistula tracheobronchial tuberculosis (TBTB) in infants.

PATIENTS AND METHODS

A retrospective analysis was undertaken on seven patients with lymph node fistula tracheobronchial tuberculosis who underwent fiberoptic bronchoscopy (FB) interventional therapy in the respiratory department of Tianjin Children's Hospital from July 2012 to July 2020. The efficacy, safety, and prognosis of CO₂ cryotherapy intervention for the treatment of lymph node fistula TBTB in infants were summarized and analyzed.

RESULTS

Seven patients with lymph node fistula TBTB were included in this study. Their ages ranged from 6-13 months. The course of the disease from onset to TBTB ranged from 20 to 70 days. The pathological diagnoses of seven cases by FB combined with tissue biopsy were lymph node fistula TBTB, of which 28.57% (two cases) were in the early stage of rupture and 71.43% (five cases) were in the rupture stage. All patients were treated with CO₂ cryotherapy combined with foreign body forceps and local injection drugs based on systemic antituberculosis chemotherapy. Two patients were treated once with CO₂ cryotherapy, and five were treated three times. According to the comparison of the clinical symptoms, imaging results, and endoscopic presentations before and after the intervention, six patients achieved clinical cure, and one achieved clinical improvement. No severe intraoperative or postoperative complications were observed. The clinical symptoms, endoscopic findings, radiological manifestations, and quality of life of all patients showed marked improvement. No recurrence occurred after 3-6 months of follow-up with FB.

CONCLUSION

CO₂ cryotherapy can improve the treatment effect of lymph node fistula in infants with TBTB and reduce the incidence of complications. This treatment is safe and reliable in infants.

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

Background: The Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assay has shown good diagnostic efficacy in brushing and biopsy tissue samples from patients with tracheobronchial tuberculosis (TBTB). However, its diagnostic value in bronchoalveolar lavage fluid (BALF) is still unclear. Therefore, the present retrospective study aimed to evaluate the diagnostic value of the Xpert MTB/RIF assay in BALF.

Methods: The clinical data of 266 patients with suspected TBTB from January 2018 to October 2020 were pooled with complete details of bronchial brush and bronchoalveolar lavage samples. Smears of the bronchial brushings were stained with Auramine O stain to detect acid-fast bacilli (AFB), and BALF samples were used for culturing MTB with the BACTEC MGIT 960 system and the Xpert MTB/RIF assay. The diagnostic performance of these methods was assessed and compared.

Results: A total of 266 patients suspected to have TBTB were enrolled in the final analysis. Of these patients, 179 patients were confirmed to have TBTB and 87 patients were non-TBTB. The sensitivity of the Xpert MTB/RIF assay in BALF (87.2%) was significantly higher than that of the brush smear for AFB (35.2%, p < 0.001). No significant difference was observed between the sensitivities of the Xpert MTB/RIF assay in BALF and MTB culture in BALF (87.2 vs. 84.9%, p = 0.542). The specificities of the Xpert MTB/RIF assay in BALF, MTB culture in BALF, and the bronchial brush smear were 97.7, 97.7, and 98.9%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of the Xpert MTB/RIF assay in BALF, MTB culture in BALF, and the bronchial brush smear were 98.7 and 78.7%, 98.7 and 75.9%, and 98.4 and 42.6%, respectively. Among the MTB culture-positive patients with TBTB detected by the Xpert assay, 27.0% (20/74) were identified to be resistant to RIF.

Conclusions: The Xpert MTB/RIF assay in BALF enables a rapid and accurate diagnosis of TBTB and identification of RIF resistance, which is crucial for timely and proper treatment. Moreover, in patients with TBTB, BALF could be used as an alternative to bronchial brushing and biopsy tissues for the Xpert MTB/RIF assay.

Acute mediastinitis associated with tracheobronchial tuberculosis and aspergillosis: a case report and literature review

Acute mediastinitis (AM) is a rare but life-threatening disease. Here, we report a case of AM secondary to endobronchial tuberculosis (EBTB) and pseudomembranous Aspergillus tracheobronchitis (PMATB) co-infection. EBTB was confirmed by tissue culture for Mycobacterium tuberculosis and GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) detection (simultaneous detection of M. tuberculosis and resistance to rifampin) using endobronchial biopsies; PMATB was confirmed by histopathology. Even with antibiotic treatment and systemic support treatment, the patient died of massive hemoptysis on day 10 after admission. When immunocompromised hosts have AM, especially with central airway involvement, EBTB and aspergillosis should be considered potential causes. Bronchoscopy is helpful for rapid diagnosis and administering precise treatment.

Bronchial brushing Xpert improves the diagnostic efficiency of sputum Xpert in patients with pulmonary tuberculosis

BACKGROUND

The role of bronchial brushing Xpert MTB/RIF (hereafter referred to as Xpert) in patients with pulmonary tuberculosis (PTB) remains unclear. Therefore, a retrospective study was conducted aiming to evaluate the diagnostic efficiency of bronchial brushing Xpert in patients with PTB.

METHODS

Between July 2018 and August 2019, suspected PTB patients who were admitted to our hospital and had bronchial brushing and matched sputum collection for acid-fast bacilli (AFB) smear, mycobacterial culture, and Xpert were included for further analysis. Subsequently, PTB was defined based on mycobacterial culture, and if an alternative diagnosis was established, 'non-tuberculosis (TB)' was considered. Comparison of bronchial brushing and matched sputum examination was performed between groups. Then, the differences in the sensitivities between bronchial brushing and sputum Xpert were examined using the chi-square test.

RESULTS

A total of 111 patients were included and divided into TB and non-TB groups (52 versus 59 patients). The sensitivities of Xpert against culture were calculated as follows: sputum, 44.2% (23/52); bronchial brushing, 59.6% (31/52); sputum and bronchial brushing, 69.2% (36/52). The specificities of all Xpert assays were the same (100.0%, 59/59). A significant difference was found in the comparison of the sensitivities of Xpert using sputum, bronchial brushing and both, and the sensitivity of Xpert on both sputum and bronchial brushing was higher than that on sputum alone (p < 0.05). Moreover, it appears that bronchial brushing Xpert was more sensitive than sputum Xpert in the detection of PTB.

CONCLUSION

Bronchial brushing Xpert improves the diagnostic efficiency of sputum Xpert in the detection of PTB.

Utility of the GeneXpert Mycobacterium tuberculosis/Rifampin (MTB/RIF) Assay on Paraffin-Embedded Biopsy Tissue Samples for Detecting Tuberculosis: Comparison With Histopathology

Introduction The Xpert Mycobacterium tuberculosis/Rifampin (MTB/RIF) assay is a qualitative nested real-time polymerase chain reaction (PCR) performed on the GeneXpert instrument system. Although, the utility of this technique for detecting tuberculosis (TB) in sputum and pus samples is well established, however, the usefulness of GeneXpert on biopsy samples is still a matter of debate. Therefore, in this study, we evaluated the utility of GeneXpert for detecting MTB in biopsy specimens diagnosed with TB. Methods A retrospective observational study was conducted at the Department of Pathology, Liaquat National Hospital and Medical College. The data collection period was between January 2016 and December 2018 over a period of three years. Specimens included trucut/incisional biopsies and lymph node excisions. Cases with a favoured histopathological diagnosis of TB were included in the study. The Xpert MTB/RIF assay was performed on the samples obtained from paraffin-embedded biopsy tissue material, and comparison of histological features with Xpert MTB/RIF assay was performed. Results A total of 114 cases were included in the study. The mean age of the patients was 40.53±16.83 years, and 57.9% of patients were male. 68.4% of cases were extra-nodal with the lung being the most common extra-nodal site. On histopathological analysis, caseation necrosis, epithelioid granulomas and Langhan's giant cells were present in 64.9%, 70.2%, and 59.6% cases, respectively. On GeneXpert PCR assay, MTB was detected in 26.3% cases. A significant association of MTB detection on Xpert PCR assay was noted with the presence of necrosis on histopathology. Conclusion In our study, we noted that the MTB detection rate by GeneXpert assay on histopathologically diagnosed cases of TB was only 26.3%, and the detection rate was significantly increased in the presence of caseation necrosis on a biopsy tissue sample. Despite the low detection rate due to rapid turnover time, GeneXpert assay is an excellent adjunctive tool for detecting MTB in paraffin-embedded tissue samples.

Incidence, laboratory diagnosis and predictors of tracheobronchial tuberculosis in patients with pulmonary tuberculosis in Chongqing, China

Tracheobronchial tuberculosis (TBTB) is reported in 10-40% of patients with pulmonary tuberculosis (PTB). Due to its non-specific presentation, the diagnosis and management are frequently delayed. The aim of the present study was to investigate the incidence, predictors and laboratory diagnosis of concomitant TBTB and PTB in Chongqing, China. Bronchoscopy was performed in all patients with newly diagnosed or relapsed PTB in order to detect TBTB between January 2018 and April 2019 in a sub-tertiary hospital in Chongqing, China. The clinical characteristics and laboratory data were analyzed to identify predictors and determine the diagnostic yield of TBTB. A total of 341 (31.4%) of the 1,085 patients with PTB who underwent the bronchoscopic examination presented with concomitant TBTB. The parameters of female sex [odds ratio (OR)=2.57], clinical symptoms (OR=6.26) and atelectasis (OR=4.3) were independent predictors of TBTB. Cough (OR=32.48) and atelectasis (OR=3.14) were independent predictors of TBTB-associated tracheobronchial stenosis. The diagnostic yields of sputum smear, bronchial brush smear, sputum culture, GeneXpert Mycobacterium tuberculosis/rifampicin resistance (GX) using sputum, GX using brushings and in bronchial brush culture used for the diagnosis of TBTB were 44.2, 44.2, 63.5, 57.7, 71.2 and 75%, respectively. GX brushings had higher diagnostic yields compared with sputum or brush smears; however, there was no significant difference between sputum/brushings cultures and GX with sputum. The incidence of TBTB in PTB was 31.4% in Chongqing, China. The parameters of female sex, atelectasis and cough were the major predictors of concomitant TBTB and associated tracheobronchial stenosis. Although GX is an accurate and rapid test to detect TBTB, additional laboratory techniques should also be adopted to improve diagnostic yields in the detection of TBTB in patients with PTB.

A 76-Year-Old Woman With Incidental Right Middle Lobe Atelectasis

CASE PRESENTATION

A 76-year-old nonsmoking woman visiting from Honduras for the last 6 months with no known medical history originally presented to the ED complaining of abdominal pain. While in the ED, an incidental right middle lobe collapse was found on CT abdomen scan. Review of systems was positive for a chronic productive cough with white sputum for 3 years. She denied association with fevers, chills, night sweats, hemoptysis, appetite changes, or weight loss.