UNASSIGNED: The current prophylactic tuberculosis vaccine Bacille Calmette-Guérin (BCG), was derived in the 1920s, but the humoral immune responses induced by BCG vaccination have not been fully elucidated to date. In this study, our aim was to reveal the profiles of antibody responses induced by BCG vaccination in adults and identify the potential biomarkers for evaluating the BCG vaccination response.
UNASSIGNED: Proteome microarrays were performed to reveal the serum profiles of antibody responses induced by BCG vaccination in adults. ELISA was used to validate the potential biomarkers in validation cohort (79 healthy controls and 58 BCG-vaccinated subjects). Then combined panel was established by logistic regression analysis based on OD values of potential biomarkers.
UNASSIGNED: Multiple antigens elicited stronger serum IgG or IgM antibody responses in BCG vaccinated subjects than healthy subjects at 12 weeks post BCG vaccination; among the antigens, Rv0060, Rv2026c and Rv3379c were further verified using 137 serum samples and presented the moderate performance in assessment of the BCG vaccination response by receiver operating characteristic analysis. Furthermore, a combined panel exhibited an improved AUC of 0.923, and the sensitivity and specificity were 77.59 % and 91.14 %, respectively. In addition, the antibody response against Rv0060, Rv2026c and Rv3379c was related to the clinical background to a certain extent.
UNASSIGNED: The novel antigens identified in our study could offer better knowledge towards developing a more efficacious vaccine based on humoral immune responses, and they could be potential biomarkers in assessments of BCG vaccination responses.

UNASSIGNED: Despite huge efforts, tuberculosis (TB) is still a major public health threat worldwide, it is estimated that a quarter of the global population is infected by Mycobacterium tuberculosis (Mtb). For controlling TB and reducing Mtb transmission it is fundamental to diagnose TB infection (TBI) as well as the progressors from TBI to disease to identify those requiring preventive therapy. At present, there is no gold standard test for TBI diagnosis although several new methodologies have been attempted.
UNASSIGNED: This review provides an update on the most recent approaches to develop reliable tests to diagnose TBI and progressors from infection to disease. Experimental tests are based on either the direct identification of Mtb (i.e., Mtb DNA upon host cells isolation; Mtb proteins or peptides) or host response (i.e., levels and quality of specific anti-Mtb antibodies; host blood transcriptome signatures).
UNASSIGNED: The experimental tests described are very interesting. However, further investigation and randomized clinical trials are needed to improve the sensitivity and specificity of these new research-based tests. More reliable proofs-of-concept and simplification of technical procedures are necessary to develop new diagnostic tools for identifying TBI patients and those that will progress from infection to TB disease.

The current diagnostic methods for tuberculosis (TB) have several limitations. Although commercial serological tests based on antibody detection are available, their variable accuracies limit their roles in the clinic. The aim of this study was to discover the improved biomarkers for TB disease by investigating the serum profiles of IgG and IgM antibodies against nearly all Mycobacterium tuberculosis (MTB) antigens in 36 active TB patients and 18 healthy controls (HCs) using proteome microarrays. Our results revealed that multiple antigens could induce stronger serum IgG or IgM responses in TB patients compared to HCs, among them, Rv2026c and Rv2421c were further validated by ELISA with sera from 221 samples and showed the moderate performance in diagnosing TB by receiver operating characteristic analysis. Moreover, logistic regression analysis was performed to establish a combined panel that provided better sensitivity and specificity at 82.5% and 88.12%, respectively, than single antigens in the diagnosis of active TB. Furthermore, the antibody reactivity against Rv2026c and Rv2421c was correlated with clinical backgrounds. These results suggest that the combination of different antigens and classes of antibodies could provide promise and encouragement in developing an efficient serological test for the diagnosis of active TB.

BACKGROUND: The current strategy for combating tuberculosis (TB) is based on the early detection and treatment of patients to halt transmission. The present study was conducted to evaluate the diagnostic potential of three Mycobacterium tuberculosis antigens, 45-kDa, A60, and sonicated MTB antigen (SmTB-Ag), as antibody/antigen detection methods for the rapid and accurate diagnosis of TB.
METHODS: The SmTB-Ag and 45-kDa antigens were purified and A60 antigen was supplied by Anda-Biologicals, France. The 45-kDa and A60 antigens (for antibody detection procedures) and SmTB-Ag (for antigen detection test) were tested in the same study subjects. ELISA and immunochromatographic (rapid) test were performed on 201 sputum and serum samples. Ninety-eight samples from TB patients and 103 samples from control individuals were studied.
RESULTS: The mean absorbance value of antibodies against 45-kDa antigen in the TB patients were (1.17 ± 0.44, CI 1.09-1.26), significantly higher than in the non-TB group, (0.8 ± 0.28, CI 0.74-0.85, P < 0.05). The sensitivities of tests using two antigens, 84% for the 45-kDa antigen and 65% for the A60 antigen, were lower than SmTB-Ag(93%). The rapid test yielded 93% sensitivity and 92% specificity.
CONCLUSIONS: Findings highlighted the importance of antigen detection as a diagnostic tool. The rapid test evaluated in this study may be useful for diagnosis of TB.