Diagnosis Of Tuberculosis Infection Research Articles

Case report: Difficult diagnosis of Mycobacterium tuberculosis infection in patients after allogeneic hematopoietic stem cell transplantation: two case reports and a literature review

BackgroundMycobacterium tuberculosis (MTB) is a relatively infrequent infection encountered during hematopoietic stem-cell transplantation (HSCT). The identification of MTB following HSCT remains a complex task, with delayed detection and misdiagnosis potentially resulting in unfavorable outcomes. Metagenomic next-generation sequencing (mNGS) represents a novel, highly sensitive, and rapid diagnostic tool in clinical settings for discerning intricate infections and detecting exceedingly rare pathogensMethodsWith the aid of mNGS, we diagnosed MTB in the lymph nodes and lungs of two patients with hematological diseases following allogeneic peripheral blood hematopoietic stem cell transplantation. Both patients presented with a fever, localized symptoms, and clinical signs. Following inconclusive results from routine tests, impractical biopsy procedures, and unsuccessful responses to empirical treatments, mNGS was employed as a final recourse, revealing DNA fragments of MTB in blood samples.ResultsThe diagnoses were ultimately confirmed in conjunction with additional clinical evidence. The application of mNGS in MTB cases after allogeneic HSCT has rarely been reported. The mNGS technique can provide a prompt and highly sensitive indication leading to the definitive diagnosis of MTB in complex post-transplant scenarios.

Impact of COVID-19 pandemic on tuberculosis and latent tuberculosis infection diagnosis in healthcare workers.

To compare the prevalence of LTBI and TB in the pre-pandemic period (2017-2019) with the pandemic period (2020-2022), in a group of HCW. Retrospective study. Data on TB diagnosis was retrieved from the hospital information system database. All HCWs who underwent tuberculin skin test (TST) from January 2017 to December 2022 were included in the study. In the pre-pandemic period (2017-2019), 163 HCW out of 710 were TST positive (22.9%), and in the pandemic period (2020-2022), 85 HCW out of 449 were TST positive (18.9%) (p = 0.11). There were 10 HCW diagnosed with TB in the pre-pandemic period (incidence: 41.7/100,000) and 2 in the pandemic period (incidence: 8.3/100,000) (p < 0.0001). This study showed that TB incidence was reduced during the pandemic period in HCW. TST positivity was also reduced, although not statistically significant.

Differentiation of Bovine Tuberculosis and Paratuberculosis Infections with Antemortem Diagnostic Methods

In this study, based on the results of tuberculin skin tests (Bovine and Avian PPD) used in the antemortem diagnosis and differentiation of Bovine Tuberculosis, the animals in the farms with suspected Tuberculosis were serologically examined to diagnose Paratuberculosis infection and fecal bacterioscopy was performed. In addition, it was aimed to obtain data that will contribute to the eradication studies of Bovine Tuberculosis disease by comparing the antemortem diagnostic methods of Bovine Tuberculosis disease, which is endemic in Türkiye and by determining the sensitivity and specificity values of the interferon gamma (IFN-γ) test. In this context, intradermal tuberculin test was applied to 423 cattle with suspected Tuberculosis in a total of 5 dairy cattle farms, one each from Çankırı, Çorum, Ankara, Eskişehir and Konya regions, and this test was determined as the gold standard method and the sensitivity and specificity of the IFN-γ test were determined as 86% and 97%, respectively. For the diagnosis of Paratuberculosis infection, antibody ELISA, fecal bacterioscopy and IFN-γ ELISA were performed on these animals and the prevalence of these tests were 10.4%, 5.44% and 4.96% respectively and 4 (0.95%) of the cattle were positive for each of the diagnostic methods for Map infection. As a result, it was concluded that IFN-γ test, which gives similar results to intradermal tuberculin test results, can also be used in the antemortem diagnosis of Bovine Tuberculosis. Also, in the comparative intradermal tuberculin test for the diagnosis of Tuberculosis infection, avian PPD positive animals were found to play a decisive role in the detection of nonspecific reactions or Paratuberculosis infected animals, supported by other tests used for the diagnosis of Paratuberculosis.

Construction of Immune-Related Diagnostic Model for Latent Tuberculosis Infection and Active Tuberculosis.

Tuberculosis (TB) is one of the most infectious diseases caused by Mycobacterium tuberculosis (M. tb), and the diagnosis of active tuberculosis (TB) and latent TB infection (LTBI) remains challenging. Gene expression files were downloaded from the GEO database to identify the differentially expressed genes (DEGs). The ssGSEA algorithm was applied to assess the immunological characteristics of patients with LTBI and TB. Weighted gene co-expression network analysis, protein-protein interaction network, and the cytoHubba plug-in of Cytoscape were used to identify the real hub genes. Finally, a diagnostic model was constructed using real hub genes and validated using a validation set. Macrophages and natural killer cells were identified as important immune cells strongly associated with TB. In total, 726 mRNAs were identified as DEGs. MX1, STAT1, IFIH1, DDX58, and IRF7 were identified as real hub immune-related genes. The diagnostic model generated by the five real hub genes could distinguish active TB from healthy controls or patients with LTBI. Our study may provide implications for the diagnosis and drug development of M. tb infections.

Cost-effectiveness of diagnostic tools and strategies for the screening and diagnosis of tuberculosis disease and infection: a scoping review

Cost-effectiveness of diagnostic tools and strategies for the screening and diagnosis of tuberculosis disease and infection: a scoping review

Diagnosis and management of tuberculosis infection in inclusion health populations in London

BackgroundTuberculosis in the UK is more prevalent in people with social risk factors– e.g. previous incarceration, homelessness - and in migrants from TB endemic countries. The management of TB infection is part of TB elimination strategies, but is challenging to provide to socially excluded groups and the evidence base for effective interventions is small.MethodsWe evaluated a TB infection screening and treatment programme provided by a peer-led service (Find&Treat) working in inclusion health settings (e.g. homeless hostels) in London. IGRA (interferon-gamma release assay) testing and TB infection treatment were offered to eligible adults using a community-based model. The primary outcome was successful progression through the cascade of care. We also evaluated socio-demographic characteristics associated with a positive IGRA.Results42/312 (13.5%) participants had a positive IGRA and no one had evidence of active TB. 35/42 completed a medical evaluation; 22 started treatment, and 17 completed treatment. Having a positive IGRA was associated with previous incarceration and being born outside of the UK.DiscussionProvision of TB infection diagnosis and management to this socially excluded population has several challenges including maintaining people in care and drug-drug interactions. Peer-support workers provided this service safely and effectively with appropriate support. Further work to generate data to inform risks and benefits of treatment for TB infection in this group is needed to facilitate joint decision making.

Pediatric Tuberculosis Infection Care Facilitators and Barriers: A Qualitative Study.

A total of 700 000 US children and adolescents are estimated to have latent tuberculosis (TB) infection. Identifying facilitators and barriers to engaging in TB infection care is critical to preventing pediatric TB disease. We explored families' and clinicians' perspectives on pediatric TB infection diagnosis and care. We conducted individual interviews and small group discussions with primary care and subspecialty clinicians, and individual interviews with caregivers of children diagnosed with TB infection. We sought to elicit facilitators and barriers to TB infection care engagement. We used applied thematic analysis to elucidate themes relating to care engagement, and organized themes using a cascade-grounded pediatric TB infection care engagement framework. We enrolled 19 caregivers and 24 clinicians. Key themes pertaining to facilitators and barriers to care emerged that variably affected engagement at different steps of care. Clinic and health system themes included the application of risk identification strategies and communication of risk; care ecosystem accessibility; programs to reduce cost-related barriers; and medication adherence support. Patient- and family-level themes included TB knowledge and beliefs; trust in clinicians, tests, and medical institutions; behavioral skills; child development and parenting; and family resources. Risk identification, education techniques, trust, family resources, TB stigma, and care ecosystem accessibility enabled or impeded care cascade engagement. Our results delineate an integrated pediatric TB infection care engagement framework that can inform multilevel interventions to improve retention in the pediatric TB infection care cascade.

QuantiFERON Gold-In-Tube for the diagnosis of mycobacterial tuberculosis infection in children under 5 years of age: A systematic review and meta-analysis.

Previous meta-analysis regarding the performance of QuantiFERON Gold-In-Tube in children have yielded contrasting results. Emerging data in children younger than 5 years of age necessitates a new analysis. Systematic searches were conducted of MedLINE, EMBASE and Cochrane databases between 1998-2023. Pooled estimates of sensitivities and specificities of QFT-GIT compared to tuberculin skin test (TST) were calculated. The Kappa (k) coefficient was calculated for each study to determine the degree of congruence between TST and QFT-GIT results. Studies including patients co-infected with HIV or other immune compromising conditions or those treated with anti-tubercular treatment were excluded. Seventeen studies (4335 patients) were included in quantitative analysis. All studies were conducted in middle to high income countries. They were conducted across 14 countries and 4 studies in countries with high TB incidence. The pooled sensitivity, specificity and DOR were 0.45 (0.42-0.48), 0.96 (0.96-0.97) and 18.84 (7.33-48.41) respectively. The ability of QFT-GIT to discriminate with disease and no disease was "good" as demonstrated by a summary receiver operating characteristic curve with area under curve of 0.7812. The average Kappa (k) co-efficient was 0.501 with a wide variety of values between studies (0.167 to 0.800). The findings of this meta-analysis support the judicious use of QFT-GIT in children 5 years and under, with caution as a sole test to exclude Tuberculosis in this age group. The heterogeneity and methodological quality of diagnostic studies limits the generalisability of results.

Long non-coding RNA expression in PBMCs of patients with active pulmonary tuberculosis.

Mycobacterium tuberculosis (Mtb) infection is the primary cause of the chronic infectious illness tuberculosis (TB). Long non-coding RNAs (lncRNAs) are functional RNA molecules that cannot be translated into proteins and play a crucial role in regulating the immune system's innate and adaptive responses. It has been demonstrated that the dysregulation of lncRNA expression is associated with various human diseases. However, the mechanism underlying the involvement of so many lncRNAs in the immune response to TB infection remains unclear. The objective of our current study was to identify a number of significantly differentially expressed lncRNAs in peripheral blood mononuclear cells (PBMCs) from TB patients and to select the most indicative lncRNAs as potential biomarkers for active pulmonary tuberculosis. Microarray analysis was performed to determine the lncRNA and mRNA expression profiles in TB patients using a case-control model. The differentially expressed lncRNAs were subjected to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to investigate potential roles and pathways associated with the pathogenesis of TB infection, and to screen lncRNAs specifically linked to TB infection. Using real-time fluorescence quantitative PCR (QRT-PCR), specific lncRNAs were identified in TB patients and latent infections. Our findings revealed that various signaling pathways were differentially expressed in TB-infected individuals, suggesting a potential role for lncRNAs in the immunological responses driven by TB infection. This study provides crucial guidelines for future functional research. Upregulated lncRNAs were mainly enriched in Neutrophil extracellular trap formation and Chemokine signaling pathways, while downregulated lncRNAs were enriched in Neuroactive ligand-receptor interaction and Cushing syndrome in TB PBMCs. Furthermore, we found that lnc-XPNPEP1-5, lnc-CASKIN2-2, lnc-HSPA13-6, lnc-CLIC5-1, and LINC02502 were significantly downregulated in TB-infected patients, while LINC00528, lnc-SLC45A4-3, and LINC00926 were significantly upregulated in TB patients and latent infections. These eight lncRNAs, identified as novel biological marker candidates for diagnosing TB infection, were validated by real-time fluorescence quantitative PCR (QRT-PCR). The abnormally expressed lncRNAs identified in this research may provide crucial information for understanding the pathophysiological characteristics of TB patients and the dysfunction of PBMCs. Our findings reveal potential targets for early TB diagnosis and therapy, as well as offer new insights into the mechanisms underlying TB infection.

The use of urine lipoarabinomannan for establishing pulmonary TB in HIV patient: case report and systematic review

Introduction: Indonesia is still the country that provides the second-largest estimated number of TB cases worldwide. Several patients had TB with HIV-positive. HIV-positive patients with symptoms suggestive of pulmonary tuberculosis often difficult to produce sputum of sufficient quality. Lateral flow lipoarabinomannan examination with urine specimens is expected to be easy, inexpensive, fast, and accurate point-of-care testing. The aim of this research was to assess the sensitivity and specificity of the lateral flow method in detecting lipoarabinomannan (LAM) from urine specimens in HIV-positive patients with suspected pulmonary tuberculosis. Sputum cultures were utilised as a reference standard. Case Description: A 21-year-old male patient came to the clinic complaining of a cough that had not subsided since the previous month. Cough felt throughout the day with a little white phlegm. The patient admitted to having high-risk sexual behavior and had been tested positive for HIV but had not started antiretroviral therapy. The laboratory examination results showed that the leukocyte count was 3600/mm3 and the radiological examination revealed a chest X-ray within normal limits. The patient had been tested for sputum smears with negative results but was still advised to start TB treatment. The patient has not started treatment because he feels that his sputum smear test results are negative. Currently, the patient is not willing to have his sputum checked again. The polyclinic doctor knows the lipoarabinomannan (LAM) examination that uses urine specimens to diagnose TB but does not yet know its effectiveness for this patient. Conclusion: In this case report, the patient was unwilling to do a diagnostic test related to the TB. The systematic review was that the Alere Determine™ TB LAM Ag may not be clinically applicable for diagnosing tuberculosis infection in patients living with HIV at this time. However, Fujifilm SILVAMP TB LAM® could be regarded as a supplementary tool to the established diagnostic protocol for tuberculosis in HIV-positive patients.

New Coronavirus Pneumonia COVID-19 in Patients with Newly Diagnosed Tuberculosis on the Background of HIV Infection (Case Report)

The article discusses the issues of radiation diagnosis of coronavirus pneumonia COVID-19 in patients with newly diagnosed tuberculosis against the background of HIV infection using the example of the clinical case of 50-year-old patient who treated with respiratory complaints and fever, who had pronounced changes in the lungs according to radiological methods. The diagnosis of coronavirus infection, tuberculosis and HIV infection was confirmed morphologically. The course of newly diagnosed TB in a patient with HIV infection was complicated by severe bilateral viral pneumonia. A feature of this case was the atypical localization and unusual manifestation of tuberculous changes on the background of HIV infection according to multispiral computed tomography, as well as a long relapsing course of viral pneumonia, with long-term persistence of the SARS-CоV-2 coronavirus.

Diagnosis and Management of Tuberculosis Infection in Pregnant Women: A Narrative Review

Diagnosis and Management of Tuberculosis Infection in Pregnant Women: A Narrative Review

Differential levels of anti-Mycobacterium tuberculosis-specific IgAs in saliva of household contacts with latent tuberculosis infection.

Mucosal immunity is strongly elicited in early stages of many respiratory and enteric infections; however, its role in tuberculosis pathogenesis has been scarcely explored. We aimed to investigate Mycobacterium tuberculosis (Mtb) specific IgA levels in saliva in different stages of latent Tuberculosis Infection (TBI). A multiplex bead-based Luminex immunoassay was developed to detect specific IgA against 12 highly immunogenic Mtb antigens. A prospective cohort of household contacts (>14 years) of pulmonary TB cases was established in Santiago, Chile. Contacts were classified as Mtb-infected or not depending on serial interferon-γ release assay results. Saliva samples were collected and tested at baseline and at a 12-week follow-up. Mtb-specific IgA was detectable at all visits in all participants (n = 168), including the "non-Mtb infected" (n = 64). Significantly higher median levels of IgA were found in the "Mtb infected" compared to the uninfected for anti-lipoarabinomannan (LAM) (110 vs. 84.8 arbitrary units (AU), p < 0.001), anti-PstS1 (117 vs. 83 AU, p < 0.001), anti-Cell Membrane Fraction (CMF) (140 vs. 103 AU, p < 0.001) and anti-Culture Filtrate Proteins (CFP) (median 125 vs. 96 AU, p < 0.001), respectively. Nonetheless, the discriminatory performance of these specific mucosal IgA for TBI diagnosis was low. Saliva holds Mtb-specific IgA against several antigens with increased levels for anti-LAM, anti-PstS1, anti-CMF and anti-CFP found in household contacts with an established TBI. The role of these mucosal antibodies in TB pathogenesis, and their kinetics in different stages of Mtb infection merits further exploring.

EBUS-GS with the GeneXpert MTB/RIF assay for diagnosis of Mycobacterium tuberculosis infection of isolated pulmonary nodules

ObjectiveInvestigate the use of endobronchial ultrasonography with a guide sheath (EBUS-GS) combined with Gene Xpert MTB/RIF (Xpert) for diagnosis of Mycobacterium tuberculosis (MTB) infection in isolated pulmonary nodules.MethodsPatients who had isolated pulmonary nodules and unknown diagnoses at our institution from October 2020 to December 2021 were prospectively examined using EBUS-GS and Xpert. The diagnostic values of using EBUS-GS or bronchoalveolar lavage fluid (BALF) with acid-fast staining, MGIT 960 culture, pathological examination, and Xpert for isolated pulmonary nodules caused by MTB infection were compared using receiver operating characteristic (ROC) analysis.ResultsThere were 135 patients, 64 with isolated pulmonary tuberculomas and 71 with non-tuberculous lesions. The sensitivity of EBUS-GS with Xpert was significantly higher than BALF with Xpert (57.81% vs. 34.78%, P = 0.017). Use of EBUS-GS with Xpert and MGIT 960 culture further increased the sensitivity to 62.50% (95%CI 50.64–74.36) and increased the specificity to 100%. The AUC values of BALF with MGIT 960 culture was 0.663(95%CI 0.543–0.783) and BALF with Xpert was 0.674 (95%CI 0.556–0.792). The AUC values of EBUS-GS with MGIT 960 culture was 0.680 (95%CI 0.554–0.743), with pathological examination was 0.713 (95%CI 0.573–0.760), and with Xpert was 0.789 (95%CI 0.655–0.829).ConclusionUse of EBUS-GS with Xpert had high sensitivity and specificity in the diagnosis of isolated pulmonary tuberculoma. This method has significant potential for use in clinical practice.

Comparative performance evaluation of QIAreach QuantiFERON-TB and tuberculin skin test for diagnosis of tuberculosis infection in Viet Nam

Current WHO-recommended diagnostic tools for tuberculosis infection (TBI) have well-known limitations and viable alternatives are urgently needed. We compared the diagnostic performance and accuracy of the novel QIAreach QuantiFERON-TB assay (QIAreach; index) to the QuantiFERON-TB Gold Plus assay (QFT-Plus; reference). The sample included 261 adults (≥ 18 years) recruited at community-based TB case finding events. Of these, 226 underwent Tuberculin Skin Tests and 200 returned for interpretation (TST; comparator). QIAreach processing and TST reading were completed at lower-level healthcare facilities. We conducted matched-pair comparisons for QIAreach and TST with QFT-Plus, calculated sensitivity, specificity and area under a receiver-operating characteristic curve (AUC), and analyzed concordant-/discordant-pair interferon-gamma (IFN-γ) levels. QIAreach sensitivity and specificity were 98.5% and 72.3%, respectively, for an AUC of 0.85. TST sensitivity (53.2%) at a 5 mm induration threshold was significantly below QIAreach, while specificity (82.4%) was statistically equivalent. The corrected mean IFN-γ level of 0.08 IU/ml and corresponding empirical threshold (0.05) of false-positive QIAreach results were significantly lower than the manufacturer-recommended QFT-Plus threshold (≥ 0.35 IU/ml). Despite QIAreach’s higher sensitivity at equivalent specificity to TST, the high number of false positive results and low specificity limit its utility and highlight the continued need to expand the diagnostic toolkit for TBI.

Reversions of QuantiFERON-TB Gold Plus in tuberculosis contact investigation: A prospective multicentre cohort study.

Interferon-y Release Assays (IGRA) reversions have been reported in different clinical scenarios for the diagnosis of tuberculosis (TB) infection. This study aimed to determine the rate of QuantiFERON-TB Gold Plus (QFT-Plus) reversions during contact investigation as a potential strategy to reduce the number of preventive treatments. Prospective, multicentre cohort study of immunocompetent adult contacts of patients with pulmonary TB tested with QFT-Plus. Contacts with an initial positive QFT-Plus (QFT-i) underwent a second test within 4 weeks (QFT-1), and if negative, underwent a repeat test 4 weeks later (QFT-2). Based on the QFT-2 result, we classified cases as sustained reversion if they remained negative and as temporary reversion if they turned positive. We included 415 contacts, of whom 96 (23.1%) had an initial positive test (QFT-i). Following this, 10 had negative QFT-1 results and 4 (4.2%) of these persisted with a negative result in the QFT-2 (sustained reversions). All four sustained reversions occurred in contacts with IFN-γ concentrations between ≥0.35 and ≤0.99 IU•mL-1 in one or both QFT-i tubes. In this study, TB contact investigations rarely reveal QFT-Plus reversion. These results do not support retesting cases with an initial positive result to reduce the number of preventive treatments.

Clinical case of diagnosis of generalized tuberculosis in a child with a positive result of an intradermal test

At present day, generalized forms are rarely found in the structure of tuberculosis in children. A significant risk factor for the development of generalized lesions is prolonged contact with a tuberculosis patient. The diagnosis of a specific etiology is often complicated by the absence of pathognomonic symptoms. Immunodiagnostics, microbiological and molecular genetic research play an important role in the diagnosis of tuberculosis infection in children. The purpose of this study was to analyze the case of the development and diagnosis of generalized tuberculosis in a child of primary school age (7 years and 11 months) with lesions of the lungs, larynx, middle ear. The examination methods included immunological intradermal tests (Mantoux test, RTA test), in vitro test (QuantiFERON-TB), multispiral computed tomography, bronchoscopy and laboratory methods of examination. The manifestation of the disease occurred gradually with the occurrence of hypochromic anemia with a further increase in symptoms of intoxication. A comprehensive examination established a disseminated process in the lungs, larynx and middle ear lesions. Family tuberculosis contact was established when the disease was detected in a child. During the examination, the evaluation result of the Mantoux test showed an increase in sensitivity to tuberculin. The hyperergic result of the RTA test indicated the activity of MBT in the body. At the same time, the irregular conduct of immunodiagnostics using the Mantoux test, the monotony of the test did not allow timely measures to be taken in relation to the in-depth examination of the child for tuberculosis. The specific etiology of the disease was reliably confirmed by cultural and molecular genetic research methods. The child was diagnosed with generalized tuberculosis, disseminated pulmonary tuberculosis in the infiltration phase, MBT (+) with drug resistance to isoniazid, streptomycin, paraaminosalicylic acid, tuberculosis of the larynx and vocal apparatus, PCR (+) with drug resistance to isoniazid, tuberculous right-sided otitis media, MBT (+) with drug resistance to isoniazid, streptomycin, paraaminosalicylic acid. The presented clinical case indicates the need for timely detection of tuberculosis contacts, regular immunodiagnostics, and compliance with phthisiological alertness of doctors of all specialties in relation to children with long-lasting symptoms of various diseases. The complete physical examination using an intradermal RTA test (Diaskintest), microbiological and molecular genetic research methods allows to establish the tuberculous etiology of the lesion.

Use of Interferon-Gamma Release Assays in Children

While interferon-gamma release assays (IGRAs) are widely used for detecting tuberculosis (TB) infection, tuberculin skin tests (TSTs) remain preferred for children under the age of 2 years. The preference for TST stems from concern over IGRA sensitivity in young children. However, TSTs are susceptible to false-positive results following Bacille Calmette-Guérin (BCG) vaccination, which is common in infancy, and exposure to nontuberculous mycobacteria. We reviewed available data for IGRA performance in children under age 2 years. Across four cohorts of high-risk children under age 2 (mostly case contacts or those born in tuberculosis endemic regions), 0 of 575 untreated children with negative IGRA test results progressed to tuberculosis disease-including 0 of 70 who were TST positive but IGRA negative. While neither TSTs nor IGRAs are perfectly sensitive for the diagnosis of tuberculosis infection, IGRAs are an acceptable alternative to TST in children <2 years of age.

Skin test based on &lt;i&gt;Mycobacterium tuberculosis&lt;/i&gt; antigens (ESAT-6 and CFP-10) for the detection of tuberculosis infection in world practice

According to experts, 2 billion people in the world are infected with the causative agent of tuberculosis. A priority task in the diagnosis of tuberculosis infection is the use of accurate, accessible and scalable tools. The tuberculin skin test (TST), or Mantoux test, and the interferon gamma release assay (IGRA) are currently used to diagnose tuberculosis infection. In 2022, the World Health Organization (WHO) identified a fundamentally new class of skin tests for the early detection of tuberculosis infection, the so-called Mycobacterium tuberculosis antigen-based skin tests (TBST). These tests include Diaskintest (Russia), C-Tb (India), and C-TST (China) and pose an alternative to the tuberculin skin test and the IGRA. The aim of this work was to conduct a systematic review of domestic and foreign literature sources on the use of a new skin test based on M. tuberculosis antigens (ESAT-6 and CFP-10) to detect tuberculosis infection (Diaskintest) in world practice. Conclusion. According to the literature data, including the published results of meta-analyzes on the use of skin tests, it has been shown that recombinant tuberculous allergen test, as a new skin test based on M. tuberculosis antigens (ESAT-6 and CFP-10), or TBST, has high sensitivity and specificity for the detection of tuberculosis infection. Its sensitivity and specificity are significantly higher than those of the tuberculin test. TBST skin test results are comparable to those of IGRA, have a favorable safety profile, combined with high laboratory test specificity and ease of performance and assessment of the result in one cut (cut-off &gt; 0 mm – any size papule is considered positive). Thus, TBST is a valuable tool for early detection of TB infection. Taking into account the volume of scientific clinical studies on recombinant tuberculous allergen test in the world practice, more than 10 years of experience in clinical practice in Russia and the CIS countries, it can be concluded that recombinant tuberculous allergen test is currently the leading test for mass diagnosis of tuberculosis infection not only in Russia, but also in the world.

A CRISPR-Cas12a-based platform for ultrasensitive rapid highly specific detection of Mycobacterium tuberculosis in clinical application.

Tuberculosis, caused by Mycobacterium tuberculosis (MTB), is the second leading cause of death after COVID-19 pandemic. Here, we coupled multiple cross displacement amplification (MCDA) technique with CRISPR-Cas12a-based biosensing system to design a novel detection platform for tuberculosis diagnosis, termed MTB-MCDA-CRISPR. MTB-MCDA-CRISPR pre-amplified the specific sdaA gene of MTB by MCDA, and the MCDA results were then decoded by CRISPR-Cas12a-based detection, resulting in simple visual fluorescent signal readouts. A set of standard MCDA primers, an engineered CP1 primer, a quenched fluorescent ssDNA reporter, and a gRNA were designed targeting the sdaA gene of MTB. The optimal temperature for MCDA pre-amplification is 67°C. The whole experiment process can be completed within one hour, including sputum rapid genomic DNA extraction (15 minutes), MCDA reaction (40 minutes), and CRISPR-Cas12a-gRNA biosensing process (5 minutes). The limit of detection (LoD) of the MTB-MCDA-CRISPR assay is 40 fg per reaction. The MTB-MCDA-CRISPR assay does not cross reaction with non-tuberculosis mycobacterium (NTM) strains and other species, validating its specificity. The clinical performance of MTB-MCDA-CRISPR assay was higher than that of the sputum smear microscopy test and comparable to that of Xpert method. In summary, the MTB-MCDA-CRISPR assay is a promising and effective tool for tuberculosis infection diagnosis, surveillance and prevention, especially for point-of-care (POC) test and field deployment in source-limited regions.