title: IgA antibody responses to Mycobacterium tuberculosis recombinant MPT-64 and MT-10.3 (Rv3019c) antigens in pleural fluid of patients with tuberculous pleurisy.
abstract: METHODS
  Microbiological tests lack sensitivity for pleural tuberculosis (TB) and histopathology is expensive, time consuming and needs specialised personnel. Immunoassay (ELISA) may be a promising approach in this respect.
  
  
  OBJECTIVE
  To evaluate the reactivity of IgA antibody to MPT-64 and MT-10.3 recombinant mycobacterial protein antigens in pleural fluid as a marker of pleural TB, based on the fact that IgA is the main antibody in the mucosa/serosa of the gastrointestinal and respiratory tract.
  
  
  METHODS
  Anti-MPT-64 and MT-10.3 IgA response was determined by ELISA in 72 patients with pleural TB and 27 with other pleural conditions.
  
  
  RESULTS
  High sensitivities for IgA were measured against MPT-64 (52/72, 72%) and MT-10.3 (52/72,72%) antigens. Combining the sensitivities of both antigens, further increase in sensitivity (55/72, 76%) was obtained with no loss of specificity (96%). Similar IgA reactivity was obtained from culture-negative and culture-positive specimens. In eight pleural TB patients with human immunodeficiency virus (HIV) co-infection, the sensitivity was 88% (7/8).
  
  
  CONCLUSIONS
  To our knowledge, this is the first description of the presence of IgA antibody pleural TB effusion reactive to MPT-64 and MT-10.3, with sensitivity similar to histopathological examination, which is presently considered the gold standard for pleural TB.
authors.affiliation: Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: M C
authors.initials: MC
authors.lastname: Kaisermann
authors.forename: I G
authors.initials: IG
authors.lastname: Sardella
authors.forename: A
authors.initials: A
authors.lastname: Trajman
authors.forename: t L V
authors.initials: tL
authors.lastname: Coelho
authors.forename: S
authors.initials: S
authors.lastname: Kämpfer
authors.forename: F
authors.initials: F
authors.lastname: Jonas
authors.forename: M
authors.initials: M
authors.lastname: Singh
authors.forename: M H F
authors.initials: MH
authors.lastname: Saad
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis*; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010996:Pleural Effusion / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D014396:Tuberculosis, Pleural / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007070:Immunoglobulin A; C080865:MPB64 protein, Mycobacterium; C502419:MT-10.3 protein, Mycobacterium; D011994:Recombinant Proteins