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.