title: Serodiagnosis of tuberculous lymphadenitis using a combination of antigens.
abstract: BACKGROUND
  The diagnosis of extra-pulmonary tuberculosis (EPTB) by conventional methods such as culture and microscopy has low sensitivity and requires an invasive procedure. A simple rapid serological test would be of great value.
  
  
  METHODS
  Six antigens (ESAT-6, Ag85A, TB10.4, Rv3881c, lipoarabinomannan (LAM) and Ara6-BSA) were tested in an ELISA to detect antigen specific IgG and IgM antibodies in sera from 54 culture and histology-confirmed tuberculous lymphadenitis (TBLN) patients, among whom four were HIV seropositive, sera from 25 smear positive pulmonary tuberculosis (PTB) patients, 15 culture and histology-negative lymphadenitis (non-TBLN) patients (n=15) and 22 healthy controls (HCs).
  
  
  RESULTS
  The sensitivities of the antigens for the detection of IgG in sera of TBLN patients ranged from 4 to 30 %. Specificities ranged from 91 to 100 % with sera from HCs. Sensitivities of the antigens for detection of IgM ranged from 0 to 15 % and specificities ranged from 91 to 100 %. LAM was the most potent antigen followed by ESAT-6 and Rv3881c for detection of IgG. However, the sensitivity for antigen specific IgG antibody detection was improved when LAM was combined with ESAT-6 and Rv3881c.The sensitivity was 54 % and the specificity 91 %.
  
  
  CONCLUSIONS
  The study suggests that the combined use of LAM, ESAT-6 and Rv3881c for the detection of IgG in sera of TBLN patients could be a supplement to microscopy of fine- needle aspirate (FNA) to diagnose EPTB.
authors.affiliation: Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia. beyene@gmail.com
authors.forename: Demissew
authors.initials: D
authors.lastname: Beyene
authors.forename: Kees
authors.initials: K
authors.lastname: Lumc Franken
authors.forename: Lawrence
authors.initials: L
authors.lastname: Yamuah
authors.forename: Abraham
authors.initials: A
authors.lastname: Aseffa
authors.forename: Harald G
authors.initials: HG
authors.lastname: Wiker
authors.forename: Arend
authors.initials: A
authors.lastname: Kolk
authors.forename: Howard
authors.initials: H
authors.lastname: Engers
authors.forename: Paul
authors.initials: P
authors.lastname: Klatser
authors.forename: Lisbet
authors.initials: L
authors.lastname: Sviland
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008070:Lipopolysaccharides / Q000097:blood; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D014388:Tuberculosis, Lymph Node / Q000150:complications / Q000175:diagnosis*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D008070:Lipopolysaccharides; C050016:lipoarabinomannan