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

Abstract

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.

• Authors: Parasa V Ramana Rao, Madhan Kumar Murthy, S Basirudeen, Pawan Sharma, Soumya Swaminathan, Alamelu Raja
• Journal: International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (Int J Infect Dis) Vol. 13 Issue 5 Pg. 613-22 (Sep 2009) ISSN: 1878-3511 [Electronic] Canada
• PMID: 19119038 (Publication Type: Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

• Adult
• Aged
• Aged, 80 and over
• Antigens, Bacterial (immunology)
• Bacterial Proteins (genetics, 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, diagnosis)
• Young Adult