Evaluation of Xpert MTB Host Response assay for the diagnosis of patients with Active tuberculosis in China

Objective : The World Health Organization regards the development of rapid non-sputum diagnostic reagents as a high priority for TB diagnosis(1). The host peripheral blood 3-gene (GBP5, DUSP3 and KLF2) was found and verified to have high diagnostic value for active tuberculosis (ATB)(2, 3). The clinical diagnostic value of the new 3-genes ( GBP5, DUSP3 and TBP ) modified by Cepheid company has not been evaluated Methods: We used a retrospective cohort study of 297 clinical ATB patients, 103 patients with other pulmonary diseases (OPD), and 79 healthy subjects are used as healthy controls (HC).The receiver operating characteristic curve ( ROC curve ) was used to analyze the value of TB score in the diagnosis of ATB. Results: The AUC of TB score between ATB group and HC group was 0.879 and OPD group, respectively. The treatment duration and bacterial burden of ATB will affect the diagnostic efficacy of TB score. When only ATB patients within 3 days were included, the AUC was 0.895 and 0.715 and 0.715 for ATB and AUC was 0.952 and 0.778, respectively. Positive patients within 3 days were included, the TB score AUC was 0.936 and 0.788 for ATB from HC and OPD. Conclusion : 3-gene TB score test can be used as a rapid blood screening test for clinical ATB patients, and its own bacterial load is an important factor affecting its detection. In addition, with increasing treatment duration in ATB patients, TB scores have increased, with some potential to monitor treatment response.