Detection Of Early Secreted Antigenic Target-6 And Interferon-γ In Cerbrospinal Fluid For The Diagnosis Of Tuberculous Meningitis

Tuberculous meningitis is the most serious form of extrapulmonary tuberculosis, with the high mortality and morbidity. It often presents with nonspecific signs and symptoms, and without specific imaging, which diagnosis mainly depends on the etiology of cerebrospinal fluid examination, but the early, rapid, high sensitivity and specificity of pathogenic examination in cerebrospinal fluid is still a wholeworld difficult problem. Mycobacterium tuberculosis secreted protein (also known as extracellular protein) is one of mycobacterium tuberculosis antigens, with the high specificity and content, which mycobacterium tuberculosis secrets outside the cell in the early and mid-term, and it will be the most prospective antigens in the diagnosis of mycobacterium tuberculosis. Early secreted antigenic target-6 (referred to ESAT-6) with the principal activity in all the extracellular proteins is the main target molecules of early cellular immune, which induce strongly immune response. Interferon-y secreting mycobacterium tuberculosis T-cells can recognize early secreted antigenic target-6. Interferon-y is the key type-1 cytokines, which controls the mycobacterium tuberculosis infection and increase the activity of macrophage scavenging mycobacterium tuberculosis.OBJETIVE:The study is to determine ESAT-6 and interferon-y in cerebrospinal fluid and evaluate the vaule of the two indicators in the diagnosis of tuberculous meningitis.METHODS:81 patients were checked in our hospotial or outpatients from June,2009 to June,2010, referenced to the diagnostic criteria of tuberculous meningitis were divided into 3 groups:21 patients were the suspected tuberculous meningitis; 28 patients were intracranial infection of non-tuberculous meningitis; and 32 patients healthy controls. Determine the levels of ESAT-6 and Interferon-γin cerebrospinal fluid by enzyme linked immunosorbent assay (ELISA).RESULTS:The average concentration of ESAT-6 and interferon-y in the suspected tuberculous meningitis group was 4.46pg/mL,34.86ng/L; The average concentrations of ESAT-6 and interferon-y in the intracranial infection of non-tuberculous meningitis group and control group were 1.18±0.49,1.05±0.47 pg/mL and 12.00±3.37,14.58±3.46 ng/L. The differences between the suspected tuberculous meningitis group and intracranial infection of non-tuberculous meningitis, the healthy controls group were significant (p <0.05); the intracranial infection of non-tuberculous meningitis group and the healthy controls group have no significant difference (p> 0.05). ESAT-6 and interferon-γdetected in the suspected tuberculous meningitis group were showed correlation, p<0.05.CONCLUSION:Detecting the ESAT-6, interferon-y levels in cerebro-spinal fluid is important for the diagnosis of tuberculous meningitis and the two indicators have some relevance.