Diagnosis of Active Tuberculosis in China Using an In-House Gamma Interferon Enzyme-Linked Immunospot Assay

Abstract

Gamma interferon (IFN-␥) release assays have been proven to be useful in the diagnosis of 5%). In conclusion, the IFN-␥ ELISPOT assay is a useful adjunct to current tests for diagnosis of active TB in China. The ELISPOT assay is more accurate than TST in identifying TB infections.Tuberculosis (TB) is a leading cause of morbidity and mortality throughout the world, with 95% of cases and 97% of all deaths occurring in high-prevalence countries, such as China, where the prevalence of active TB is as high as 367/100,000 population (10). For the effective and efficient control of TB in these countries, rapid diagnosis and treatment for active-TB patients are the mainstays of the TB control program. However, the current widely used tests, including acid-fast staining of sputum, mycobacterial culture, and antibody test, are not satisfactory for this purpose (4).Recently, commercial immunodiagnostic tests for TB infection have been introduced. These tests are based on the Mycobacterium tuberculosis-specific antigens early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10

IP-10 and MIG Are Compartmentalized at the Site of Disease during Pleural and Meningeal Tuberculosis and Are Decreased after Antituberculosis Treatment

“…Due to the shortage of available methods for diagnosis of TB, IGRAs have increasingly been used as an auxiliary diagnostic tool for active TB in clinical practice in China (18,(31)(32)(33). Indeed, it has been reported that detection of IFN-␥ in pleural fluid mononuclear cells is useful for diagnosis of tuberculous pleurisy (31,32).…”

“…A total of 16 healthy controls (HC) and 33 subjects with LTBI were recruited from household contacts of active TB patients, all of whom had no evidence of disease or history of TB. A previously described in-house M. tuberculosis antigen-specific IFN-␥ enzyme-linked immunosorbent spot (ELISPOT) assay was used to diagnose LTBI (17,18). The detailed clinical characteristics of patients are summarized in Table 1.…”

Exploration of Novel Cellular and Serological Antigen Biomarkers in the ORFeome of Mycobacterium tuberculosis

“…Diagnosis also included clinical signs and symptoms and radiographic findings (chest x-ray and/or HRCT) (20). All recruited individuals were also examined for antigenspecific IFN-␥ secretion using a well-established ELISPOT kit (21). Patients determined to be positive based on bacteriological examination were recruited for a second or third round of experiments to identify antigenicity.…”

“…Cellular Antigen-specific IFN-␥ ELISPOT Assay-An IFN-␥ ELISPOT assay was performed using a human IFN-␥ cytokine precoated ELISPOT kit (Dakewe Biotech Company, Shenzhen, China) as previously described (21). Briefly, the plates were seeded with 2.5 ϫ 10 5 freshly separated PBMCs per well.…”

Mycobacterium tuberculosis Region of Difference (RD) 2 Antigen Rv1985c and RD11 Antigen Rv3425 Have the Promising Potential To Distinguish Patients with Active Tuberculosis from M. bovis BCG-Vaccinated Individuals

“…In our study, the QFT-IT assay was used to detect LTBI, and only QFT-IT assay-negative subjects were included as healthy controls; this could lead to an overassessment of QFT-IT assay specificity. Considering the high prevalence of TB infection in China, LTBI can be detected even in low-risk communities (33,34). Thus, one cannot exclude the possibility that the one healthy control that appeared to generate a falsepositive response to the combination of Rv1985c pool2 and Rv1985c pool4 might represent an individual with a true LTBI that was missed with the QFT-IT test.…”