title: [A comparative study for adenosine deaminase and anti-antigen A-60 antibodies detection for the diagnosis of tuberculous meningitis].
abstract: BACKGROUND
  Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of rapid and accurate diagnostic tools. We evaluated the immunological response to Mycobacterium tuberculosis anti-A60 antibodies in cerebrospinal fluid (CSF) in comparison to adenosine deaminase (ADA) determination, for the diagnosis of TBM.
  
  
  METHODS
  A total of 63 CSF samples were analyzed by indirect ELISA for the detection of anti- A60 IgG, IgM and IgA. These include samples from 17 patients with confirmed TBM and 46 control patients with other infections.
  
  
  RESULTS
  The mean individual anti-A60 IgM, IgG and IgA CSF antibody titers were significantly higher in TBM in comparison with control groups (p < 0.01). The best discriminatory CSF antibody for confirming TBM diagnosis was IgM, with an area under the receiver operating characteristic curve of 0.928 (95%CI 0.834-0.978), compared to 0.863 (95% CI: 0.752-0.936) for ADA testing (p = NS). The sensitivity of anti- A60 IgM CSF antibody titers (cutoff > 0.06 U/ml) was 94.1% compared to 88.2% for ADA (cutoff > 6.2 U/ml), p = NS. Both anti A60 IgM and ADA showed the same moderate specificity (80.4%). Two cases of TBM were correctly identified by anti-A60 IgM but missed by ADA.
  
  
  CONCLUSIONS
  The ELISA test for anti-antigen A60 antibodies (IgM) is a rapid and sensitive tool for the rapid diagnosis of TBM that can be a complement to ALDA determination. The specificity of both tests is still a limitation in TBM diagnosis.
authors.affiliation: Departamento de Laboratorios Clínicos, Pontificia Universidad Católica de Chile, Chile.
authors.forename: Patricia
authors.initials: P
authors.lastname: García
authors.forename: Laura
authors.initials: L
authors.lastname: Bahamondes
authors.forename: Paula
authors.initials: P
authors.lastname: Reyes
authors.forename: Juan C
authors.initials: JC
authors.lastname: Román
authors.forename: Haydé
authors.initials: H
authors.lastname: Poblete
authors.forename: M Elvira
authors.initials: ME
authors.lastname: Balcells
mesh_terms: D000243:Adenosine Deaminase / Q000134:cerebrospinal fluid*; D000888:Antibodies, Anti-Idiotypic / Q000134:cerebrospinal fluid*; D000942:Antigens, Bacterial / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000134:cerebrospinal fluid*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014390:Tuberculosis, Meningeal / Q000134:cerebrospinal fluid / Q000175:diagnosis*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000942:Antigens, Bacterial; D015415:Biomarkers; D007132:Immunoglobulin Isotypes; C055539:mycobacterial A60 antigen; D000243:Adenosine Deaminase