Improved diagnosis of tuberculosis in HIV-positive patients using RD1-encoded antigen CFP-10

Int J Infect Dis. 2009 Sep;13(5):613-22. doi: 10.1016/j.ijid.2008.09.022. Epub 2008 Dec 31.


Objective: The present study was aimed at determining the serodiagnostic potential of 38-kDa (Rv0934, Mycobacterium tuberculosis complex-specific antigen) and CFP-10 (Rv3874, RD1 antigen) antigens among HIV-positive and HIV-negative patients with pulmonary TB.

Methods: The diagnostic potential of native 38-kDa (n38-kDa) and recombinant CFP-10 (rCFP-10) antigens was ascertained in terms of sensitivity and specificity using an indirect ELISA. The study included 508 HIV-seronegative TB patients (TB), 54 HIV-seropositive TB patients (HIV-TB), 30 HIV-positive patients without TB (HIV), and 256 controls.

Results: In HIV-TB, the sensitivities for individual antigens ranged from 14.8% to 31.5% and the specificity was >98% for IgG. When IgA results were added to IgG, the sensitivity increased to 25.9% for 38-kDa and 57.4% for CFP-10; specificity changed to 97.5% for 38-kDa and 98.1% for CFP-10. The combined results of both the antigens gave 59.3% sensitivity and 95.6% specificity. In TB, the sensitivity was 82.8% when the antigen results were combined. None of the HIV-infected controls showed positivity for IgG to either of the two antigens.

Conclusion: Use of CFP-10 enhances the sensitivity of 38-kDa, and therefore the 38-kDa and CFP-10 antigen combination can be a diagnostic marker in HIV-TB.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antigens, Bacterial* / immunology
  • Bacterial Proteins* / genetics
  • Bacterial Proteins* / immunology
  • Female
  • HIV Seronegativity
  • HIV Seropositivity / complications*
  • Humans
  • Immunoglobulin A / blood
  • Immunoglobulin G / blood
  • Lipoproteins* / immunology
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Recombinant Proteins / immunology
  • Sensitivity and Specificity
  • Serologic Tests
  • Tuberculosis, Pulmonary / complications
  • Tuberculosis, Pulmonary / diagnosis*
  • Young Adult


  • Ag38 antigen, Mycobacterium tuberculosis
  • Antigens, Bacterial
  • Bacterial Proteins
  • CFP-10 protein, Mycobacterium tuberculosis
  • Immunoglobulin A
  • Immunoglobulin G
  • Lipoproteins
  • Recombinant Proteins