Utility of a combination of RD1 and RD2 antigens as a diagnostic marker for tuberculosis

Kalra, Mamta; Khuller, Gopal Krishan; Grover, Ajay; Behera, Digambar; Wanchu, Ajay; Verma, Indu

doi:10.1016/j.diagmicrobio.2009.09.005

« Previous Next »Diagnostic Microbiology & Infectious Disease
Volume 66, Issue 2 , Pages 153-161, February 2010

Utility of a combination of RD1 and RD2 antigens as a diagnostic marker for tuberculosis☆

Mamta Kalra
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
Gopal Krishan Khuller
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
Ajay Grover
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
- Present Address: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO-80523-1682, USA.
Digambar Behera
- L.R.S. Institute of TB and Respiratory Diseases, New Delhi 110030, India
Ajay Wanchu
- Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
Indu Verma
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
- Corresponding author. Tel.: +91-0172-2755180; fax: +91-0172-2744401.

Received 30 April 2009; accepted 2 September 2009. published online 16 October 2009.

Abstract

We evaluated the diagnostic potential of a cocktail of 4 antigens encoded by regions of difference (RD) 1 and 2 of Mycobacterium tuberculosis, that is, early secretory antigenic target-6, culture filtrate protein-10 (CFP-10), CFP-21, and mycobacterial protein from species tuberculosis-64 (MPT-64) on the basis of antigen and antibody detection by enzyme-linked immunosorbent assay. Parallel detection of antigens and antibodies in the serum samples of pulmonary tuberculosis (PTB) patients resulted in higher sensitivity as compared to either of the single tests in both smear-positive (90%) and smear-negative (60%) PTB patients. In addition, combined detection of antigens and antibodies in the fluids of extrapulmonary tuberculosis (EPTB) patients could detect >90% of the patients with high specificity. These results demonstrate the ability of the combination of antigen and antibody detection assays based on the cocktail of RD antigens to diagnose a substantial number of PTB and EPTB cases with high specificity.

Abbreviations: CFP-10, culture filtrate protein 10, CFP-21, culture filtrate protein 21, CICs, circulating immune complexes, CSF, cerebrospinal fluid, DDA, dimethyldioctadecylammonium bromide, EPTB, extra pulmonary tuberculosis, ESAT-6, early secretory antigenic target-6, MPT-64, mycobacterial protein from species tuberculosis-64, PBS, phosphate-buffered saline, PTB, pulmonary tuberculosis, RD, regions of difference, TB, tuberculosis, TST, tuberculin skin test