Diagnosis of Tuberculous Meningitis Using a Combination of Peripheral Blood T-SPOT.TB and Cerebrospinal Fluid Interferon-γ Detection Methods

OBJECTIVE: To evaluate the effectiveness of combined peripheral blood T-SPOT.TB and cerebrospinal fluid interferon-γ (cIFN-γ) detection methods in the diagnosis of tuberculous meningitis (TBM). METHODS: A total of 30 individuals with TBM and 39 control individuals without TBM participated in this study. IFN-γ-secreting T cells were detected by enzyme-linked immunospot (ELISPOT), and cIFN-γ was detected by enzyme-linked immunosorbent assay (ELISA). We collected cerebrospinal fluid from 10 patients in the TBM group on initial visit and at 4 weeks, to observe changes. RESULTS: The sensitivity and specificity of peripheral-blood T-SPOT.TB testing in the diagnosis of TBM were 70% and 87%, respectively. The area under the ROC curve of cIFN-γ for TBM diagnosis was 0.819, and the corresponding sensitivity and specificity were 83% and 85%, respectively. When T-SPOT.TB and cIFN-γ results were positive, the specificity and positive predictive value of TBM diagnosis reached 100%. CONCLUSIONS: Combined use of T-SPOT.TB and cIFN-γ could improve the diagnosis efficiency of TBM. Dynamic observation of cIFN-γ is also important in monitoring TBM because the level of this analyte significantly decreases after treatment.