The diagnostic value of Xpert,acid-fast bacillus smear,and mycobacterium culture in bronchoalveolar lavage fluid for sputum Xpert negative tuberculosis:A comparative study
Objective:To explore the diagnostic value of 3 detection methods in bronchoalveolar lavage fluid(BALF)for sputum Xpert MTB/RIF(Xpert)-negative pulmonary tuberculosis.Methods:A total of 121 suspected pulmonary tuberculosis patients with negative sputum of Xpert from Wenzhou Central Hospital who were treated between January 2021 and June 2023 were enrolled and all patients were sent for examinations of BALF-Xpert,acid-fast bacillus(AFB)smear,and mycobacterium culture.Retrospective comparative analysis of the diagnostic value of 3 tests was made based on clinical diagnostic results as the diagnostic criteria.Results:Seventy-three of 121 suspected patients were diagnosed with pulmonary tuberculosis.Compared with the non-tuberculosis group,patients in the tuberculosis group were significantly younger(P<0.05).The AUC of BALF-Xpert was 0.774,sensitivity 54.79%and specificity 100%.The AUC of BALF-AFB smear was 0.510,and the sensitivity and specificity was 8.22%and 93.75%.BALF mycobacterium culture had AUC of 0.667,sensitivity of 52.05%,and specificity of 80.85%.The combination of 3 methods achieved AUC of 0.721,sensitivity of 63.01%,specificity of 81.25%.No significant difference was found in AUC between Xpert and the combination of 3 methods,with both higher than those in mycobacterium culture and AFB smear.The combination of 3 methods yielded the highest sensitivity,followed by Xpert,with AFB smear had the lowest.Conclusion:Combined testing of BALF-Xpert,AFB smear,and mycobacterium culture can improve the diagnostic performance of sputum Xpert-negative pulmonary tuberculosis,and reduce the underdiagnosis of pulmonary tuberculosis.