Humoral immune responses against the Mycobacterium tuberculosis 38-kilodalton, MTB48, and CFP-10/ESAT-6 antigens in tuberculosis.

Institute for Tuberculosis Research, 309th Hospital of Chinese PLA, Beijing 100091, China.
Clinical and vaccine Immunology: CVI (Impact Factor: 2.37). 03/2010; 17(3):372-5. DOI: 10.1128/CVI.00287-09
Source: PubMed

ABSTRACT The diagnosis of smear-negative and culture-negative patients with active tuberculosis (TB) is challenging. The detection of Mycobacterium tuberculosis-specific antibodies in human sera has been an important diagnostic aid. However, detection of antibody responses to a single antigen usually has a low sensitivity for diagnosis of TB. In this study, humoral immune responses against recombinant M. tuberculosis 38-kDa, MTB48, and CFP-10/ESAT-6 (culture filtrate protein 10/6-kDa early secreted antigen target of M. tuberculosis) antigens in 250 Chinese TB patients and 260 healthy subjects were evaluated by an enzyme-linked immunosorbent assay (ELISA). The levels of antibodies against those antigens in TB patients, even in bacterium-negative ones, were significantly higher than those in healthy subjects (P < 0.001). The serodiagnostic sensitivities to detect antibodies against individual antigens, i.e., recombinant M. tuberculosis 38-kDa, MTB48, and CFP-10/ESAT-6 antigens, in TB patients were 73.6%, 73.2%, and 60.4%, respectively, with specificities of 85.4%, 77.7%, and 73.8%, respectively. Importantly, the sensitivity to positively detect humoral responses to one of the antigens increased further. Our data suggest that the humoral immune responses to M. tuberculosis antigens in TB patients are heterogeneous. The 38-kDa, MTB48, and CFP-10/ESAT-6 antigens can be used as the cocktail antigens in the serodiagnosis of active TB, especially for smear- or culture-negative TB cases.


Available from: Xueqiong Wu, May 30, 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: Beijing/W lineage strains of Mycobacterium tuberculosis spread faster than other strains, tend to be more virulent and frequently associated with drug resistance. In this study, to distinguish the characteristics of Beijing/W lineage and non-Beijing/W lineage M. tuberculosis, we assessed the growth between the two groups under conditions of hypoxia, nutrient starvation, and intracellular growth in murine macrophages. We also examined the DNA, RNA, and protein levels of 5 major M. tuberculosis proteins, including HspX, Hsp65, 38 kDa, Ag85B, and MPT64 of the different types of strains by sequencing, quantitative RT-PCR, and Western blotting. The results showed that Beijing/W and non-Beijing/W lineage strains of M. tuberculosis have similar viability in ex vivo culture but differ in their ability to survive within macrophages, and the intracellular viability of the Beijing/W lineage strains was significantly more than the viability of the non-Beijing/W lineage strains at 2, 3, and 5 days after infection (P < 0.05). Psts1 and fbpB were expressed at statistically lower levels in Beijing/W lineage strains in their mRNA expression levels (P < 0.05). The expression of their corresponding 38 kDa and Ag85B was lower in the Beijing/W lineage strains than the non-Beijing/W lineage strains (P < 0.05). The expression of HspX and Hsp65 was higher in the Beijing/W lineage strains in their protein expression levels at 24 h after infection of RAW264.7 macrophages (P < 0.05). In conclusion, the increased viability of the Beijing/W lineage strains might be related to the expression levels of these proteins.
    Current Microbiology 02/2015; 70(5). DOI:10.1007/s00284-015-0776-z · 1.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Serodiagnostic potential of four recombinant proteins (38kDa[Rv0934], MPT64[Rv1980c], Adk[Rv0733], and BfrB[Rv3874]) was evaluated in Healthy control subjects (HCS), Healthy household contacts (HHC), Pulmonary tuberculosis patients (PTB), and Human immuno deficiency virus & Tuberculosis co-infected patients (HIV-TB). All the antigens tested individually for the detection of serum IgG by indirect ELISA. All the four antigens have a significantly higher antibody response in PTB compared to healthy controls (P<0.05). The sensitivity of individual antigens ranged from 20% to 52.5% for the prefixed specificity of 95%. When results of all 4 antigens were combined the sensitivity was increased to 75% and specificity was reduced 89% in HCS. In smear- and culture-positive (S+C+) PTB, four antigen combination gives maximum sensitivity (89.6%) with 89% specificity. In smear negative culture negative (S-C+) PTB, three antigen combination (38kDa with MPT64 and BfrB).gives maximum sensitivity (69.5%) and specificity (91.6%). In HIV-TB, 4 antigen combinations give the maximum sensitivity of 51.2% with 89% specificity. Combining serology (Four antigen combination) with smear was able to increase the sensitivity from 70% to 92.5% in culture positive PTB. So, we propose that this serology test can be used as adjunct test along with smear for rapid diagnosis of PTB.
    Tuberculosis 10/2014; 94(6). DOI:10.1016/ · 3.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background The detection of Mycobacterium tuberculosis (Mtb) specific human antibodies has been an important diagnostic aid in the diagnosis of tuberculosis (TB) cases with smear-negative sputum samples, especially for the screening of high-risk population. This study focused on the analysis and comparison of the four potential Mtb-secreted proteins (ESAT6, CFP10, Ag85B, Hsp16.3) and the fusion protein Ag85B-Hsp16.3 as new markers in the serodiagnosis between active TB and latent TB infection (LTBI).Methods These five recombinant proteins were produced and used in optimized ELISA to detect IgG serum antibodies against the four secreted proteins. The capacity of identifying infection was evaluated either in active TB patients or LTBI individuals, which was compared with the control groups consisting of hospitalized non-TB individuals.ResultsThe results showed that Ag85B-Hsp16.3/ESAT6 and Hsp16.3/ESAT6 were the best-associated antigens for serology diagnosis of the active TB and LTBI individuals because of their specificity, sensitivity, YI values, and positive rates, respectively. ELISA test demonstrated that 41.67% (25/60) of blood donors respond to Ag85B-Hsp16.3/ESAT6. The consistency of this positive respond with clinical diagnosis almost reached 84% (21/25).Conclusion Thus, a combined test of multiple Mtb-secreted proteins Ag85B, Hsp16.3, and ESAT6 may be the ascendant preliminary screening antigens for active TB or LTBI patients.
    Journal of Clinical Laboratory Analysis 08/2014; DOI:10.1002/jcla.21782 · 1.14 Impact Factor