The diagnostic performance of GeneXpert MTB/RIF in tuberculosis meningitis: A multicentre accuracy study

OBJECTIVES To evaluate the performance of GeneXpert MTB/RIF (Xpert) for tuberculous meningitis (TBM) and to identify additional indicators to improve diagnostic accuracy. METHODS An accuracy study was conducted. During 2011-2019, 243 TBM with 140 non-TBM in three TB-designated facilities in China were enrolled. Microbiological evidence of M tuberculosis (Mtb) in CSF was used as the reference. Additional indicators were identified by Boosted-Classification and Regression Tree (CART), the improvement of diagnostic performance was evaluated by ROC. RESULTS The diagnostic sensitivity of Xpert was 71.1% for definite TBM, and 5.5% for probable/possible TBM. The positive rate of Xpert was improved with cerebrospinal fluid (CSF) increasing volume and was associated with CSF color (yellow). The additional indicators obtained by CART were CSF lactate and glucose and increased the sensitivity to 96.1% (definite TBM) and 84.6% (probable/possible TBM). CONCLUSIONS The diagnostic performance of Xpert was satisfactory in definite TBM and would significantly be improved by the additional use of CSF lactate and glucose.