ISSN 2329-9835
International Journal of Diseases and Disorders ISSN 2329-9835 Vol. 6 (5), pp. 001-008, May, 2018. © International Scholars Journals
Full Length Research Paper
Serodiagnostic value of 23 Mycobacterium tuberculosis proteins and a novel protein combination
Lingxia Zhang1, Ying Sun2, Guoqiang Zhang2, Guoli Li1, Bangyin Li1 and Xiaoxing Cheng1*
1Institute of Tuberculosis, the 309th Hospital of Chinese People’s Liberation Army, Beijing 100091, China.
2Beijing Institute of Genomics of Chinese Academy of Sciences, Airport Industry B6, Beijing 101300, China.
Accepted 09 January, 2018
Abstract
To identify novel serological targets for improving the serodiagnosis of Mycobacterium tuberculosis (MTB) infection, a total of 23 MTB proteins were clone into the Escherichia coli, and the serodiagnostic values of these proteins and a novel combined protein were evaluated. By a two-step selection process, 21 proteins having cross-reaction with TB antibody were identified. In these proteins, the most frequently recognized antigens were Rv0934 and Rv2185c, which were found in 45.6% of TB patients, while the specificity of Rv0934 was only 93.3% which was lower than that of Rv2185c. Subsequently, Rv2031c, Rv2185c, Rv2537c, Rv2785c and Rv3354 were combined equally and the combined protein had 100% specificity and relatively high sensitivity. The sensitivity of the combined protein was 76% which was close to that of purified protein derivative (PPD) test; the specificity of combined protein was 96~98%, which was higher than that of PPD test (76~92%) in the detection of 150 TB patients and 150 healthy subjects. In addition, the specificity of combined protein was significantly higher than that of PPD in the detection of TB antibody in subjects’ negative, positive and strong positive for PPD skin test, but the positive rates of the same protein were not significantly different. Three months after bacillus calmette-guerin (BCG) vaccination, the positive rate of combined protein was lower than that of PPD testing. The combination of proteins with high specificity is an effective method to improve the sensitivity of TB serological diagnosis.
Key words: Mycobacterium tuberculosis, serological diagnosis, protein.