Diagnostic performance analysis of Xpert MTB/RIF in lymph node tuberculosis: A retrospective study

AIMS: To retrospectively analyze the diagnostic efficacy of Xpert MTB/RIF (Xpert) in lymph node tuberculosis (LNTB). METHODS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) of Xpert, pathological examination and culture for LNTB were calculated. RESULTS: 421 suspected LNTB cases were categorized into the LNTB group (377 cases) and non-LNTB group (44 cases). The sensitivities of Xpert, pathological examination, and culture were 72.15%, 20.69%, 30.24%, respectively, with NPVs of 29.53%, 12.83%, 14.33%. The AUC values were 0.861, 0.603, 0.651, respectively. The sensitivity of Xpert varied across sample types: tissue (64.73%), puncture fluid (74.42%), and pus (96.05%). For specific lymph node locations, the sensitivity was head-and-neck (72.51%), mediastinal (84.21%), and axillary (45.83%). CONCLUSIONS: Xpert demonstrates high diagnostic value for LNTB, particularly in pus samples. It also performs better in mediastinal and head-and-neck lymph node samples compared to axillary lymph node samples.