Characteristics and risk factor analysis of 410 cases of tracheobronchial tuberculosis

Key determinants of misdiagnosis of tracheobronchial tuberculosis among senile patients in contemporary clinical practice: A retrospective analysis

BACKGROUND

Tracheobronchial tuberculosis (TBTB) is a common subtype of pulmonary tuberculosis. Concomitant diseases often obscure the diagnosis of senile TBTB.

AIM

To characterize senile patients with TBTB and to identify the potential causes of misdiagnosis.

METHODS

One hundred twenty patients with senile TBTB who were admitted to the Anhui Chest hospital between May 2017 and May 2019 were retrospectively analyzed. Patients were classified as diagnosed group (n = 58) and misdiagnosed group (n = 62). Clinical manifestations, laboratory results, radiographic data, and endoscopic findings were compared between the two groups.

RESULTS

Patients in the misdiagnosed group were most commonly diagnosed as pulmonary tuberculosis (non-TBTB, 29/62, 46.8%), general pneumonia (9/62, 14.5%), chronic obstructive pulmonary disease (8/62, 12.9%), and tracheobronchial carcinoma (7/62, 11.3%). The time elapsed between disease onset and confirmation of diagnosis was significantly longer in the misdiagnosed group [median (first quartile, third quartile): 6.32 (4.94, 16.02) mo vs 3.73 (2.37, 8.52) mo]. The misdiagnosed group had lower proportion of patients who underwent bronchoscopy [33.87% (21/62) vs 87.93% (51/58)], chest computed tomography (CT) scan [69.35% (43/62) vs 98.28% (57/58)], and those who showed CT signs of tuberculosis [27.91% (12/62) vs 50% (29/58)] as compared to that in the diagnosed group (P < 0.05). There were no significant between-group differences with respect to age, gender, occupation, clinical manifestations, or prevalence of comorbid chronic diseases (P > 0.05).

CONCLUSION

Insufficient or inaccurate radiographic or bronchoscopic assessment was the predominant cause of delayed diagnosis of TBTB. Increased implementation and better interpretation of CT scan and early implementation of bronchoscopy can help reduce misdiagnosis of senile TBTB.

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.

Performance of the Xpert® MTB/RIF assay in the rapid diagnosis of tracheobronchial tuberculosis using bronchial washing fluid

Objective

To assess the diagnostic value of the Xpert® MTB/RIF (GeneXpert) assay for tracheobronchial tuberculosis (TBTB) using bronchial washing fluid (BWF).

Methods

This retrospective study enrolled patients suspected of having TBTB and patients with non-TB pulmonary disease as controls. BWF were used to undertake acid-fast bacillus (AFB) smears, the GeneXpert assay and the Lӧwenstein–Jensen (LJ) culture method. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were compared among BWF AFB smears, BWF GeneXpert and the BWF LJ culture method.

Results

A total of 130 patients with TBTB and 102 patients with non-TB pulmonary disease were enrolled in the study. Sputum AFB smears were positive in 62 of 130 patients (47.7%) with TBTB. Using the clinical diagnosis of TBTB as the gold standard, the sensitivity, specificity, PPV and NPV of the three methods using BWF were as follows: 93.1%, 99.0%, 99.2% and 91.8% for BWF GeneXpert; 73.1%, 100.0%, 100.0% and 74.5% for BWF LJ cultures; 53.8%, 99.0%, 98.6% and 62.7% for BWF AFB smears. The diagnostic yield of BWF GeneXpert was significantly higher compared with BWF cultures for type III and IV TBTB.

Conclusion

The Xpert® MTB/RIF assay using BWF exhibited higher sensitivity than bacteriological diagnostic methods and was particularly useful for the early diagnosis of smear-negative TBTB.

Initial airflow obstruction in new cases of pulmonary tuberculosis: Complication, comorbidity or missed?

Tuberculosis (TB) may have a similar spirometry findings as a chronic obstructive pulmonary disease but the prevalence of TB-induced airflow obstruction (AO) is still unknown.

OBJECTIVES

To measure frequency of AO in new TB cases at the beginning of treatment and to evaluate factors associated with obstructive abnormalities following TB diagnosis.

MATERIALS AND METHODS

317 patients that have no history of prior AO were recruited into the study with a median age of 39.0 years (IQR, 30.0-49.0). AO was defined using the FEV₁/F(VC)<LLN.

RESULTS

AO was detected in 29.97% (95/317) new TB cases. These patients had a more severe clinical manifestation of TB with a greater likelihood of cough, OR=5.47 (95%CI 1.90-15.70) and wheezing, OR=10.51 (95%CI 5.72-19.27), p<0.001. The frequency of AO was positively associated with bronchoscopic evidence of narrowing of the main airways. Furthermore, from multiple logistic regression analysis we would assume that higher FEV₁ value in TB patients with AO was related to greater BMI and inversely associated with older age, female sex and radiographic extent (p<0.05).

CONCLUSIONS

Obstructive pattern on spirometry frequently occurs in new TB cases without previously detected AO. This category of patients should be targeted for detailed follow-up, particularly, in high TB burden countries.