Xpert MTB_RIF assay for the differential diagnosis between sarcoidosis and tuberculosis intrathoracic lymphadenopathy

Abstract

It is difficulty in differentiating sarcoidosis and tuberculosis intrathoracic lymphadenopathy. 119 patients who were suspected as sarcoidosis or tuberculosis intrathoracic lymphadenopathy at the Shanghai Pulmonary Hospital between 1 October 2020 and 30 June 2021 were enrolled in this study. All patients received EBUS-TBNA and Xpert analysis. The differences of clinical and radiological features were analyzed. Diagnostic performances of EBUS-TBNA Xpert, AFB, culture and serum QuantiFERON-TB Gold (QFT) were analyzed in differentiating SAIL from TBIL. Of these patients, 83 patients were finally diagnosed as 50 sarcoidosis intrathoracic lymphadenopathy and 33 tuberculosis intrathoracic lymphadenopathy. Young persons were more likely to have tuberculosis than sarcoidosis (P = 0.006). Markers of inflammation including fever, leukocyte and serum ferritin were significantly higher in tuberculosis than in sarcoidosis (P < 0.01). Bilateral lungs involved, symmetry intrathoracic lymphadenopathy and the longest diameter of intrathoracic lymphadenopathy (CM) were significantly higher in sarcoidosis, but significantly shorter of the largest diameter of lung lesions (P < 0.01). The sensitivity, specificity of Xpert and QFT in differentiating the sarocidosis and tuberculosis were 69.70%, 100% and 96.43%, 91.84% respectively. The area under the ROC curve of QFT was 0.973 (95% CI, 0.938-1.000) in differentiating the two diseases. tuberculosis patients were more likely to have infection characterizations than sarcoidosis. EBUS Xpert is recommended for the diagnosis of tuberculosis intrathoracic lymphadenopathy and QFT for excluding the diagnosis of tuberculosis compared with sarcoidosis.