Diagnostic value of early secretory antigenic target⁃6 and interferon⁃γ in cerebrospinal fluid for the diagnosis of tuberculous meningitis

Objective To explore the value of early secretory antigenic target-6 (ESAT-6) and interferon-γ (IFN-γ) in cerebrospinal fluid (CSF) for the diagnosis of tuberculous meningitis (TBM). Methods Eighty-one patients were examined in our hospital or outpatient clinic. Referenced to the diagnostic criteria of TBM, patients were divided into 3 groups: 21 cases were patients with TBM; 28 were patients with intracranial infection of non-TBM; and 32 controls without nervous system disease. CSF sample was collected by standard lumbar puncture and was used for detection of ESAT-6 and IFN-γ with enzyme-linked immunosorbent assay (ELISA). Results The concentration of ESAT-6 in the CSF of TBM group was 4.46 pg/ml [(2.20-10.55) pg/ml] and the IFN-γ was 34.86 ng/L [(25.62-241.71) ng/L]. The average concentrations of ESAT-6 and IFN-γ in the intracranial infection of non-TBM group and the control group were (1.18 ± 0.49) pg/ml, (12.00 ± 3.37) ng/L and (1.05 ± 0.47) pg/ml, (14.58 ± 3.46) ng/L, respectively. The levels of ESAT-6 and IFN-γ were significantly higher in the TBM group than in the intracranial infection of non-TBM group (H = 35.695, P = 0.000) and the control group (H = 31.560, P = 0.000), but were not significantly different between the intracranial infection of non-TBM group and the control group (t ＝ 1.226, P = 0.226; t = 0.060, P = 0.952, respectively). The Spearman rank correlation analysis showed positive correlation between ESAT-6 and IFN-γ detected in the TBM group (rs = 1.000, P = 0.000). Conclusion The levels of ESAT-6 and IFN-γ in the TBM group were significantly different from the intracranial infection of non-TBM group and the control group. The 2 indicators present certain correlation and can be helpful in the clinical diagnosis of TBM. DOI：10.3969/j.issn.1672-6731.2011.05.014