Clinical Characteristics And Risk Factors Analysis Of Tracheobronchial Tuberculosis

BackgroundTracheobronchial tuberculosis(TBTB)is defined as a TB infection of the trachea,bronchial mucosa,submucosa,and outer membrane,is a special type of tuberculosis(TB).The diagnosis of TBTB mainly depends on endotracheal biopsy and microbiological detection.However,the risk bleeding of biopsy is high,acid-fast bacilli in sputum smear is low,and the time of Mycobacterium tuberculosis culture is long.Not all patients with tuberculosis are routinely examined by bronchoscopy.The diagnosis of TBTB is often delayed due to its non-specific clinical symptoms,and the clinical manifestations lag behind the microscopic manifestations,therefore,diagnosis is challenging and often delayed.Tracheobronchial stenosis is the most common complication of TBTB,refractory tracheobronchial stenosis and its related complications,such as pulmonary atelectasis,pneumonia,and hemoptysis,may eventually lead to a decline in pulmonary function,respiratory failure,or death.Therefore,it is very important to explore the clinical characteristics and risk factors of TBTB and to find methods for early diagnosis of TBTB to reduce the complications of TBTB.ObjectiveAnalyzing the differences between TBTB and PTB of clinical data,chest computed tomography,laboratory examinations,to explore the clinical characteristics and risk factors of tracheobronchial tuberculosis.MethodsPatients who were suspected TBTB admitted to The Chest Hospital of Henan province between January 2018 and December 2018 were examined by endoscopy.Finally,208 cases of TBTB and 111 cases of PTB were obtained,and 101cases of non-tuberculosis diseases in the same period were collected as the control group.Clinical data,chest computed tomography,laboratory examination,bronchoscopic findings and treaments were collected.All patients’bronchoalveolar lavage fluid were collectedfor acid-fast bacilli(AFB)smear and Gene Xpert MTB/RIF examination.SPSS 23.0 software was used for statistical analysis,Categorical data were expressed as numbers(percentage),and comparisons to test for statistically significant differences were made using theχ~2-test,Mann-whitney U test and kruskal-wallis test were used to compare non-normal counting data.Logistic regression analysis was used to determine the risk factors of TBTB.A value of P<0.05 was considered statistically significant.Results1.General clinical symptoms:the difference of gender was found in the there groups(χ~2=50.35,P<0.001),and there was no differences in the three groups(χ~2=2.2,P=0.33).There were differences between the TBTB group and the PTB group in smoking history,cough,active chest tightness,asthma,age≤40 years old,and the number of days from onset to treatment>30(P<0.05),but no differences in fever,weight loss,expectoration,and previous tuberculosis history(P>0.05).2.CT imaging findings:There were differences between the TBTB group and the PTB group in atelectasis,tracheobronchial thickening and stenosis,occlusion,the lesions were located in the upper lobe of both lungs and the middle lobe of the right lung(P<0.05),but no differences in cavities,consolidation,nodules,and plaques(P>0.05).3.The comparison of the positive rates of various test results between the TBTB group and the PTB group showed that there were differences in brushing,biopsy and MDR-TB bacteria.4.In the TBTB group,the yoden index of biopsy was the highest which is 0.825,with a sensitivity of 82.5%and a specificity of 100%,followed by Gene Xpert MTB/RIF test with a sensitivity of 79.3%and a specificity of 100%,the yoden index is 0.793.5.In the smear negative of TBTB,the sensitivity of Gene Xpert MTB/RIF test is70.7%and the specificity is 100%,the yoden index is 0.707.6.In the TBTB group,comparison of the sensitivity of Gene Xpert MTB/RIF test method with traditional gold standards:there were no statistical difference between Xpert and biopsy,but there was a difference between Xpert and other groups(P<0.05),which was higher than other groups.7.Diagnostic testing consistency in group of TBTB,the Kappa coefficient of biopsy and Gene Xpert MTB/RIF test is 0.857,the Kappa coefficient of rifampin resistance in the traditional drug sensitization and the test of Gene Xpert MTB/RIF is0.857.8.Multivariate analysis showed no history of smoking,female sex,clinical symptoms duration>30 days,cough,shortness of breath,drug-resistant tuberculosis bacillus,atelectasis were independent risk factors of TBTB(P<0.05),however,the age no more than 40 was not a risk factor of TBTB(P>0.05).Conclusions1.Gene Xpert MTB/RIF method has high sensitivity and specificity in the diagnosis of smear-negative TBTB,which can be used for the early diagnosis of smear-negative TBTB.2.No history of smoking,female sex,clinical symptoms duration>30 days,cough,shortness of breath,drug-resistant tuberculosis bacillus,atelectasis were independent risk factors of PTB complicated TBTB.For patients with PTB with the above risk factors,bronchoscopy should be performed as soon as possible.