The Diagnostic Value Of Metagenomic Next Generation Sequencing(mNGS)、GeneXpert And TB-LAMP Combined Within Bronchoalveolar Lavage Fluid For Tracheobronchial Tuberculosis

ObjectiveTo evaluate the diagnostic value of bronchoalveolar lavage solution for early tracheobronchial tuberculosis by the combination of bronchobronchial tuberculosis(T-SPOT.TB)and bronchoalveolar lavage solution with second generation sequencing(m NGS),rifampicin resistance real-time fluorescence quantitative nucleic acid amplification assay(Gene Xpert)and loop-mediated isothermal amplification assay(TB-LAMP).The aim is to provide a more timely,accurate and effective examination method for the diagnosis of tracheobronchial tuberculosis.MethodsA total of 120 patients with tracheobronchial tuberculosis and 40 patients with non-tracheobronchial tuberculosis were collected from Shenyang Chest Hospital.The general characteristics and clinical manifestations of the two groups were analyzed.Liquid culture of MGIT960 in bronchoalveolar lavage solution,m NGS detection,Gene Xpert detection,TB-LAMP detection and peripheral blood T-SPOT.TB detection were performed.The positive liquid culture of MGIT960 in bronchoalveolar-alveolar-perfusion fluid was used as the gold standard for the diagnosis of bronchobronchial tuberculosis.The positive rates of m NGS,Gene Xpert,TB-LAMP,T-SPOT.TB were compared in the diagnosis of bronchobronchial tuberculosis and in the subtypes of bronchobronchial tuberculosis.The sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,positive predictive value,negative predictive value,accuracy and AUC value of m NGS,Gene Xpert,TB-LAMP,T-SPOT.TB independent detection and different combination schemes(double and triple detection)for the diagnosis of tracheobronchial tuberculosis were calculated.To evaluate the diagnostic value of each detection method in the early diagnosis of tracheobronchial tuberculosis.Results1.There was no statistical significance in the gender and age of patients in the tracheobronchial tuberculosis group and the non-tracheobronchial tuberculosis group(P > 0.05).There was no significant difference in the incidence of major clinical manifestations between 2 groups(P > 0.05).2.Comparison of positive detection rate between tracheobronchial tuberculosis group and non-tracheobronchial tuberculosis group: Positive MGIT960 liquid culture in bronchoalveolar-lavage fluid was the gold standard for the diagnosis of tracheobronchial tuberculosis.The positive detection rate of m NGS,Gene Xpert,TB-LAMP,T-SPOT.TB in tracheobronchial tuberculosis group was significantly higher than that in non-tracheobronchial tuberculosis group(P < 0.05).The positive rate of m NGS was the highest in tracheobronchial tuberculosis group(95.83%),followed by T-SPOT.TB(75%).The most common types of tracheobronchial tuberculosis were typeⅠand type Ⅳ,and the positive rate of m NGS in both types was the highest,followed by T-SPOT.TB.3.Comparison of diagnostic efficiency of dual detection for tracheobronchial tuberculosisThe sensitivity of m NGS+T-SPOT.TB parallel detection(97.50%)was higher than that of single detection,the rate of missed diagnosis was the lowest(2.50%),and the AUC value was 0.97,which was the highest diagnostic efficiency among all the combined detection.The specificity,misdiagnosis rate and positive predictive value of m NGS+T-SPOT.TB tandem detection were97.50%,2.50% and 98.87%.Gene Xpert+T-SPOT.TB,TB-LAMP+T-SPOT.TB parallel detection sensitivity was higher than single detection(AUC value was 0.70).The specificity of Gene Xpert+T-SPOT.TB and TB-LAMP+T-SPOT.TB tandem detection was 97.5%,and the misdiagnosis rate of these two tests was 2.5%.The positive predictive values of Gene Xpert and Gene Xpert+T-SPOT.TB tandem tests were 97.78% and 97.37%,respectively.4.Comparison of diagnostic efficiency of triple test for tracheobronchial tuberculosisThe AUC value of m NGS,Gene Xpert and TB-LAMP triple detection(parallel)was the highest,reaching 0.94,which showed high sensitivity,specificity and positive predictive value.The specificity and positive predictive value of the triple detection(tandem)of m NGS,Gene Xpert and TB-LAMP were100%,and the misdiagnosis rate was 0.The AUC values of m NGS,Gene Xpert and T-SPOT.TB triple detection(parallel)and m NGS,TB-LAMP and T-SPOT.TB triple detection(parallel)were all 0.78,with the highest sensitivity(98.33%)and the lowest missed diagnosis rate(1.67%).The misdiagnosis rate of the above triple test(series)was 0,the specificity and positive predictive value were 100%,the missed diagnosis rate was high,and the sensitivity and accuracy were not as good as that of the triple test(parallel).The AUC value of Gene Xpert,TB-LAMP and T-SPOT.TB triple detection(parallel)was 0.71.Compared with the previous triple detection(parallel),the sensitivity was not high,the rate of missed diagnosis was high,and the positive predictive value was low.The AUC value of Gene Xpert,TB-LAMP,T-SPOT.TB triple(tandem detection)was 0.63,and the specificity and misdiagnosis rate were not ideal.Conclusions1.The single positive detection rate of m NGS in bronchoalveolar lavage solution was the highest.2.Bronchoalveolar lavage fluid m NGS+T-SPOT.TB dual detection(parallel)has the highest diagnostic efficacy.3.Bronchoalveolar lavage fluid m NGS+Gene Xpert+TB-LAMP triple detection(parallel)has the highest diagnostic efficacy,and triple detection(series)can reduce the misdiagnosis rate.4.The dual detection of bronchoalveolar lavage solution m NGS+T-SPOT.TB(parallel)has greater value in the early diagnosis of tracheobronchial tuberculosis.m NGS alone detection in bronchoalveolar lavage fluid m NGS+Gene Xpert+TB-LAMP triple detection is also valuable for the early diagnosis of tracheobronchial tuberculosis.