title: Evaluation of antigen detection test (chromatographic immunoassay): potential to replace the antibody assay using purified 45-kDa protein for rapid diagnosis of tuberculosis.
abstract: BACKGROUND
  The current strategy for combating tuberculosis (TB) is based on the early detection and treatment of patients to halt transmission. The present study was conducted to evaluate the diagnostic potential of three Mycobacterium tuberculosis antigens, 45-kDa, A60, and sonicated MTB antigen (SmTB-Ag), as antibody/antigen detection methods for the rapid and accurate diagnosis of TB.
  
  
  METHODS
  The SmTB-Ag and 45-kDa antigens were purified and A60 antigen was supplied by Anda-Biologicals, France. The 45-kDa and A60 antigens (for antibody detection procedures) and SmTB-Ag (for antigen detection test) were tested in the same study subjects. ELISA and immunochromatographic (rapid) test were performed on 201 sputum and serum samples. Ninety-eight samples from TB patients and 103 samples from control individuals were studied.
  
  
  RESULTS
  The mean absorbance value of antibodies against 45-kDa antigen in the TB patients were (1.17 ± 0.44, CI 1.09-1.26), significantly higher than in the non-TB group, (0.8 ± 0.28, CI 0.74-0.85, P < 0.05). The sensitivities of tests using two antigens, 84% for the 45-kDa antigen and 65% for the A60 antigen, were lower than SmTB-Ag(93%). The rapid test yielded 93% sensitivity and 92% specificity.
  
  
  CONCLUSIONS
  Findings highlighted the importance of antigen detection as a diagnostic tool. The rapid test evaluated in this study may be useful for diagnosis of TB.
authors.affiliation: Department of Tuberculosis, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Alireza Hadizadeh
authors.initials: AH
authors.lastname: Tasbiti
authors.forename: Ahmadreza
authors.initials: A
authors.lastname: Bahrmand
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Shokrgozar
authors.forename: Mostafa
authors.initials: M
authors.lastname: Ghanei
authors.forename: Mostafa
authors.initials: M
authors.lastname: Ghanaie
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Fateh
authors.forename: Ali
authors.initials: A
authors.lastname: Karimi
authors.forename: Shamsi
authors.initials: S
authors.lastname: Yari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology / Q000302:isolation & purification*; D002846:Chromatography, Affinity / Q000379:methods*; D002850:Chromatography, Gel; D003710:Demography; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology*; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; C072681:Mycobacterium tuberculosis antigens
keywords: ELISA; MTB antigens; TB detection markers; TB diagnosis; rapid test