Clinical utility of tuberculosis RNA in the rapid diagnosis of bone and joint tuberculosis

OBJECTIVES: To evaluate the diagnostic accuracy of tuberculosis RNA (TB-RNA) for the rapid diagnosis of bone and joint tuberculosis (BJTB). METHODS: We conducted a retrospective study to evaluate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of TB-RNA and acid-fast bacillus (AFB) smear against the final clinical diagnosis. RESULTS: A total of 268 patients were included. The overall sensitivity, specificity, PPV, NPV, and AUC of AFB smear for BJTB were 0.7%, 100.0%, 100.0%, 49.3%, and 0.50, respectively, whereas those of TB-RNA were 59.6%, 100.0%, 100.0%, 70.6%, and 0.80, respectively; for cases of confirmed (culture-positive) BJTB, these values were 82.8%, 99.4%, 99.7%, 89.2%, and 0.91, respectively. CONCLUSIONS: The diagnostic accuracy of TB-RNA in the rapid diagnosis of BJTB was relatively good, especially in culture-positive BJTB. The use of TB-RNA could be an effective technique for the rapid diagnosis of BJTB.