Interferon-γ release assays for the diagnosis of latent Mycobacterium tuberculosis infection: a systematic review and meta-analysis

The Diagnostic Value of Interleukin-2 and Interferon-γ Induced by Fusion Protein (ESAT-6/CFP-10/Rv1985c) for Active Mycobacterium tuberculosis Infection

OBJECTIVE

This study aimed to evaluate the diagnostic ability of interleukin 2 (IL-2) and interferon gamma (IFN-γ) release assay induced by the fusion protein (ESAT-6/CFP-10/Rv1985c) for detecting active tuberculosis (ATB) in clinically visiting patients.

METHODS

A total of 970 subjects (215 in ATB group and 755 in non-ATB group) underwent both an interferon-γ release assay (IGRA) and a TB-DNA PCR assay. Using clinical diagnosis as the gold standard, both qualitative and quantitative test results for IL-2 and IFN-γ were analyzed. Subsequently, the diagnostic ability of IL-2 and IFN-γ to screen for ATB among the high-risk population was then evaluated.

RESULTS

IL-2 exhibited higher specificity, while IFN-γ demonstrated higher sensitivity in distinguishing between ATB and non-ATB subjects. The sensitivity of the serial application of IL-2 and IFN-γ had no significant difference (p = 1.000) compared with IFN-γ; the specificity of the serial application of IL-2 and IFN-γ had no significant difference (p = 0.708) compared with IL-2. Quantitative analysis of the results revealed that the IL-2 and IFN-γ values were significantly higher in the ATB group compared with the non-ATB group. Additionally, the combined predictors of IL-2 and IFN-γ did not show a significant difference compared with IL-2 alone (p = 0.324) or IFN-γ alone (p = 0.405).

CONCLUSIONS

This study demonstrated that IL-2 and IFN-γ release assays induced by the fusion protein (ESAT-6/CFP-10/Rv1985c) were valuable for distinguishing ATB from non-ATB subjects, with IL-2 exhibiting higher specificity and IFN-γ demonstrating higher sensitivity.

Utilization of kidneys from tuberculosis-infected donors in renal transplantation: A case report

Tuberculosis (TB) infection in solid organ transplantation is a non-negligible problem in TB-endemic countries, and none of the existing guidelines recommend using organs from individuals with active TB infections. Here, we describe three cases of utilization of kidneys from TB-infected donors in renal transplantation at our center, two of whom had active TB. In these three cases, all recipients had good graft function and negative TST results during the 1-4 year follow-up period. This case report emphasizes the critical role of early diagnosis, prophylaxis and treatment of TB in renal transplantation, demonstrates the potential for utilizing kidneys from donors with active TB, and opens up a new possibilities for solid organ transplantation.

Comparison of Two Interferon-Gamma Release Assays for Pediatric Tuberculosis Infection

INTRODUCTION

Identifying tuberculosis infection (TBI) using interferon-gamma release assays (IGRAs) is a primary component of clinical and public health efforts to prevent pediatric tuberculosis (TB). Pediatric data comparing the 2 IGRAs in the United States are very limited. We compared the performance of the 2 IGRAs among a large pediatric cohort tested for TBI and assessed whether discordance might be due to quantitative results close to test cutoff values.

METHODS

Children aged 0-15 years with both T-SPOT.TB (T-SPOT) and QuantiFERON-TB Gold In-Tube (QFT-GIT) tests were identified from a US multicenter study enrolling people at elevated risk of TBI or progression to TB disease. Results were compared using McNemar's Chi-square tests with stratification by age category and testing reason. Percent agreement and kappa statistics were also calculated. We characterized quantitative test results among children with discordant QFT-GIT-positive/T-SPOT-negative results.

RESULTS

Among 3793 children, a higher number had positive QFT-GIT than T-SPOT (10.1% vs 7.4%, P < .001). This difference was noted for all age categories except <2 years, and for children with close-contact and non-close contact test indications. Among discordant QFT-GIT-positive/T-SPOT-negative children, lowering the positive threshold for T-SPOT to include borderline spot counts (5-7) did not eliminate the discordance, nor were QFT-GIT antigen-minus-nil results concentrated in the range just above the standard cutoff of 0.35 IU/mL.

CONCLUSIONS

In a large pediatric cohort tested for TBI, QFT-GIT had a higher proportion of positive results than T-SPOT, and discordance was not related to quantitative results close to the established diagnostic cutoffs.

Diagnostic performance of biomarkers for differentiating active tuberculosis from latent tuberculosis: a systematic review and Bayesian network meta-analysis

Background

PCR and culture tests are used together to confirm the diagnosis of active tuberculosis (TB). Due to the long culture period, if the PCR test is negative, it takes a significant amount of time for the culture result to be available. Interferon-γ release assays (IGRAs), which are widely used to diagnose TB or latent tuberculosis infection (LTBI), cannot effectively discriminate TB from LTBI. The purpose of this study is to analyze the diagnostic performance of various markers for differentiating between TB from LTBI.

Methods

PubMed-Medline, EMBASE, Cochrane Library, and Web of Science were searched up to the end of May 2024, without restrictions on publication date and population. Articles describing the diagnostic value of at least one biomarker for differentiating between TB and LTBI were included. The QUADAS-2 tool was used to assess study quality. Two independent researchers assessed the articles using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The network meta-analysis (NMA) was performed for diagnostic tools of 11 groups used to differentiate TB from LTBI.

Results

Out of 164 identified articles, 159 reports were included in the systematic review and 58 in the meta-analysis. Seventy results from 58 reports accounting for 9,291 participants were included. When measuring interleukin-2 (IL-2) after stimulation with latency antigen, the most significant odds ratio was shown in terms of sensitivity, specificity, positive predictive value and negative predictive value. The values were 9.46, 18.5, 11.30, and 9.61, respectively.

Conclusion

This study shows that the IL-2 level after stimulation with latent antigen is a potential biomarker for differentiating TB from LTBI.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024542996.

Systematic review of the economic impact of novel Mycobacterium tuberculosis specific antigen-based skin tests for detection of TB infection compared with tuberculin skin test and interferon-gamma release assays

The Purified Protein Derivative tuberculin skin tests (TST) and blood-based Mycobacterium tuberculosis (M.tb) specific interferon-gamma release assays (IGRA) are the currently used tests for identifying individuals with TB infection for preventive treatment. However, challenges around access and implementation have limited their use. Novel M.tb specific skin tests (TBST) such as Diaskintest, ESAT6-CFP10 (C-TST), C-Tb (also known as Cy-Tb), and DPPD may provide accurate and scalable options but evidence synthesis on their economic impact is lacking. We conducted two separate systematic reviews to compare the costs and cost-effectiveness of (1) the novel skin tests TBST (primary), and (2) TST and IGRA tests (secondary), to support WHO guideline development. We searched for articles presenting economic evaluations of the diagnostic tests using a health provider perspective and related to TB infection in humans. We considered papers written in English, Chinese or Russian. In the primary review, eight studies for novel TBST were found. One study in Brazil assessed cost-effectiveness of C-TST and Diaskintest and seven in Russia assessed the Diaskintest, while none evaluated C-Tb or DPPD. The review showed on average, Diaskintest kit costs (in 2021 USD) $1.60 (1.50 - 1.70), while full unit costs were estimated at $5.07. C-TST unit cost was $9.96. The second review found 32 articles on IGRA and/or the TST. These presented an average TST full unit cost of $37.88, and $87.81 for IGRA. Studies' quality for TBST was limited while high-quality studies were found for TST and IGRA tests. In conclusion, there is limited evidence regarding the costs and cost-effectiveness of novel TBST. Conversely, there is substantial evidence for TST and IGRA tests, but most studies were performed in high-income and low-TB burden settings and their cost-effectiveness varied between and within risk groups without clear economic consensus.

Advances in tuberculosis biomarkers: unravelling risk factors, active disease and treatment success

Tuberculosis (TB) is a major global health threat and demands improved diagnostic and treatment monitoring methods. Conventional diagnostics, such as sputum smear microscopy and culture, are limited by slow results and low sensitivity, particularly in certain patient groups. Recent advances in biomarker research offer promising solutions in three key areas: risk of disease, diagnosis of active disease and monitoring of treatment response. For risk assessment, novel genetic signatures and metabolites show potential in predicting the progression from TB infection to active TB. A 16-gene signature, for example, predicts this progression with significant accuracy. In diagnosing active TB, RNA-based transcriptomic signatures provide higher diagnostic accuracy than traditional methods. These signatures, such as a three-gene RNA sequence, effectively differentiate active TB from other diseases and infections, addressing issues of specificity and sensitivity. Monitoring treatment response is crucial, given the varying response rates in treating TB. Emerging biomarkers focus on bacterial burden and host response. They offer more precise and timely assessments of treatment efficacy, enhance personalised treatment approaches and potentially improve patient outcomes. These advancements in biomarkers for TB risk, diagnosis and treatment response represent significant steps towards more effective TB management and control, aligning with global efforts to decrease the burden of TB. Here we aim to highlight several promising biomarkers used to predict risk of disease progression, active TB disease and treatment success.

Risk factors for tuberculosis among close IGRA-negative contacts of persons with infectious tuberculosis in Singapore

OBJECTIVES

Contacts of patients with infectious tuberculosis (TB) testing positive on interferon-gamma release assay (IGRA) are followed up to exclude active disease. However, identifying factors that predispose IGRA-negative contacts to TB could improve screening and follow-up strategies in a medium TB burden country such as Singapore.

METHODS

We conducted a retrospective study of IGRA-negative contacts aged ≥2 years identified during contact investigation between January 2014 and December 2022. We examined the risk factors associated with developing active TB among contacts previously testing IGRA-negative, using univariate and multivariable logistic regression and odds ratios with 95% confidence intervals.

RESULTS

Of 60,377 IGRA-negative contacts, 150 developed TB disease, and half were notified within 23 months of index patient diagnosis. IGRA-negative contacts of a smear-positive index patient were more likely to develop TB. Independent risk factors for TB were age >50 years, Malay ethnicity, having diabetes or end-stage renal failure, a "family" relationship with the index patient, or exposure in a dormitory or nursing home.

CONCLUSIONS

Identifying risk factors could help optimise follow-up strategies and preventive treatment in IGRA-negative individuals. The incidence rate of TB in this group was 150 per 100,000 population, substantially higher than in the community, with a median 92 weeks to develop disease. Findings suggest that follow-up should be extended to 24 months for contacts with these risk factors.

Whole-blood culture-derived cytokine combinations for the diagnosis of tuberculosis

Introduction

The diagnosis of tuberculosis (TB) disease and TB infection (TBI) remains a challenge, and there is a need for non-invasive and blood-based methods to differentiate TB from conditions mimicking TB (CMTB), TBI, and healthy controls (HC). We aimed to determine whether combination of cytokines and established biomarkers could discriminate between 1) TB and CMTB 2) TB and TBI 3) TBI and HC.

Methods

We used hemoglobin, total white blood cell count, neutrophils, monocytes, C-reactive protein, and ten Meso Scale Discovery analyzed cytokines (interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, interferon (IFN)-ɣ, and tumor necrosis factor (TNF)-α) in TruCulture whole blood tubes stimulated by lipopolysaccharides (LPS), zymosan (ZYM), anti-CD3/28 (CD3), and unstimulated (Null) to develop three index tests able to differentiate TB from CMTB and TBI, and TBI from HC.

Results

In 52 persons with CMTB (n=9), TB (n=23), TBI (n=10), and HC (n=10), a combination of cytokines (LPS-IFN-ɣ, ZYM-IFN-ɣ, ZYM-TNF-α, ZYM-IL-1β, LPS-IL-4, and ZYM-IL-6) and neutrophil count could differentiate TB from CMTB with a sensitivity of 52.2% (95% CI: 30.9%-73.4%) and a specificity of 100 % (66.4%-100%). Null- IFN-ɣ, Null-IL-8, CD3-IL-6, CD3-IL-8, CD3-IL-13, and ZYM IL-1b discriminated TB from TBI with a sensitivity of 73.9% (56.5% - 91.3%) and a specificity of 100% (69.2-100). Cytokines and established biomarkers failed to differentiate TBI from HC with ≥ 98% specificity.

Discussion

Selected cytokines may serve as blood-based add-on tests to detect TB in a low-endemic setting, although these results need to be validated.

Suárez-Mutis M, Gomes-Silva A. Clinical and parasitological features of Leishmania infection among gold miners in the Oiapoque basin, an international Brazil-French Guiana border

Gold miners working illegally in mines live in poor health conditions related to their strenuous work and precarious housing. Therefore, they are at higher risk for infectious diseases. American tegumentary leishmaniasis (ATL) appears to be of great concern to the population living in the Guiana Shield region. Our aim was to describe their demographic characteristics, the clinical features of cutaneous leishmaniasis (CL), and the frequency of Leishmania infection in people working in illegal gold mines in French Guiana. A cross-sectional study was carried out from October to December 2019 in Oiapoque city, Amapá, Brazil. Indeed, many gold miners working in French Guiana are originally from Brazil, and from Oiapoque in particular. A total of 105 participants from 31 different mining sites in French Guiana were recruited. Suspected Leishmania infection was confirmed by the following: detection of kDNA in blood or the lesion site; detection of specific antibodies; or detection of IFN-γ release after blood incubation with leishmanial antigens (IGRA-Leish). Nine active CL cases, 38 healed ATL (hATL) and 58 cases with no history of ATL (noATL), were identified. Only half of the treated hATL (50.0%; n = 14) reported having been assisted by a health care unit and the others treated themselves. PCR-kDNA for Leishmania was positive in the blood of 100% of CL cases. Curiously, blood PCR-kDNA was positive in 13% of hATL patients and in 15.5% of noATL patients. The IGRA-Leish was positive in 60.5% of hATL and in 37.9% of noATL. In addition to scars suggestive of CL, 71% of hATL had laboratory evidence of Leishmania infection. Restriction fragment polymorphism (RFLP) of the hsp70 gene identified a sympatric circulation of L. (V.) guyanensis (n = 4), L. (V.) braziliensis (n = 1), L. (L.) amazonensis (n = 2), L. (V.) shawi (n = 1) and L. (V.) naiffi/shawi (n = 1). Taking the laboratory techniques and the clinical evaluations together, 76% (n = 80) of the 105 participants had evidence of Leishmania infection. These results suggests that illegal gold miners working in French Guiana are at high risk for infection with different species of Leishmania, but their illegal condition and remoteness make it difficult for them to access health services.

Latent tuberculosis diagnostics: current scenario and review

This review presents a comprehensive examination of the contemporary landscape pertaining to latent tuberculosis infection (LTBI) diagnostics, with a particular emphasis on the global ramifications and the intricacies surrounding LTBI diagnosis and treatment. It accentuates the imperative of bolstering diagnostic, preventive, and treatment modalities for tuberculosis (TB) to fulfill the ambitious targets set forth by the World Health Organization aimed at reducing TB-related mortalities and the incidence of new TB cases. The document underscores the significance of addressing LTBI as a means of averting the progression to active TB, particularly in regions burdened with high TB prevalence, such as India. An in-depth analysis of the spectrum delineating latent and active TB disease is provided, elucidating the risk factors predisposing individuals with LTBI to progress towards active TB, including compromised immune functionality, concurrent HIV infection, and other immunosuppressive states. Furthermore, the challenges associated with LTBI diagnosis are elucidated, encompassing the absence of a definitive diagnostic assay, and the merits and demerits of tuberculin skin testing (TST) and interferon-γ release assays (IGRAs) are expounded upon. The document underscores the necessity of confronting these challenges and furnishes a meticulous examination of the advantages and limitations of TST and IGRAs, along with the intricacies involved in interpreting their outcomes across diverse demographics and settings. Additionally, attention is drawn towards the heritability of the interferon-γ response to mycobacterial antigens and the potential utility of antibodies in LTBI diagnosis.

Screening for latent tuberculosis in migrants-status quo and future challenges

OBJECTIVES

To review the evidence that migrants from tuberculosis (TB) high-incidence countries migrating to TB low-incidence countries significantly contribute to active TB cases in the counties of destination, primarily through reactivation of latent TB.

METHODS

This is a narrative review. The different screening programs in the countries of destination are reviewed either based on screening and preventive treatment of latent TB pre or more commonly - post arrival.

RESULTS

Screening can be performed using interferon-gamma release assays (IGRA) or tuberculin skin tests (TST). Preventive treatment of latent TB is using either monotherapy with isoniazid, or in combination with rifampicin or rifapentine. We discuss the ethical issues of preventive treatment in asymptomatic individuals and how these are addressed in different screening programs.

CONCLUSION

Screening migrants from TB high endemic countries to TB low endemic countries is beneficial. There is a lack of standardization and agreement on screening protocols, follow up and treatment.

Disseminated tuberculosis after anti-TNF alpha treatment: Do not blindly trust the IGRA test

INTRODUCTION

Interferon gamma release assay (IGRA) is used to detect latent tuberculosis prior to biological treatments in the context of suspected inflammatory rheumatism.

METHODS

We report the case of a 50-year-old woman with negative IGRA test before adalimumab introduction for presumed axial spondyloarthritis.

RESULTS

The worsening of symptoms under treatment led to further investigations and the diagnostic of disseminated tuberculosis (TB) was later established with miliary and multiple bone locations such as spondylitis and sacroilitis. The patient's history revealed past exposure to tuberculosis. This observation illustrates the limitations of IGRA in such situation due to its variable performance for active TB diagnosis.

CONCLUSION

Misdiagnosis is frequent in bone tuberculosis due to non-specific signs. We draw the attention to the importance of a global risk assessment prior to the introduction of biological treatment for suspected chronic inflammatory rheumatism and recall the risk factors for false-negative IGRA. An extended treatment course may be necessary after exposure to anti-TNF-alpha.

Pulmonary Tuberculosis Incidence among Interferon-Gamma Release Assay-Positive Individuals with Latent Tuberculosis Infection and Fibrotic Lesions in a Vulnerable Urban Population in Osaka City, Japan, 2015-2021

Latent tuberculosis infection (LTBI) with fibrotic lesions (FL) can progress to active tuberculosis (TB). Most previous studies have used tuberculin skin tests, which have lower specificity than interferon-gamma release assays (IGRAs), for LTBI diagnosis. This study evaluated the incidence of active TB among individuals with LTBI (diagnosed using IGRAs) and FL in Nishinari District, Osaka City. In total, 54 men (mean age: 68.7 years) were enrolled, of whom 10 (18.5%) were homeless, and 36 (66.7%) were welfare recipients. The median observation period was 1,084 days (range: 64-2,907 days). The incidence rate of active TB among individuals with LTBI and FL was 1.18 (95% confidence interval: 0.32-4.29) cases per 100 person-years. Among the 19 participants who had not been treated with anti-TB therapy, one (5.3%) progressed to active TB, and among the 30 participants who had completed anti-TB treatment, one (3.3%) progressed to active TB. The other 5 participants did not have TB. This study revealed the incidence of active TB among individuals with LTBI, diagnosed using IGRAs, and FL in a vulnerable urban population. The higher incidence than that reported in previous studies reinforces the importance of improved LTBI management strategies, including chest radiography screening, and LTBI treatment.

A novel chemokine biomarker to distinguish active tuberculosis from latent tuberculosis: a cohort study

BACKGROUND

Interferon-γ release assays (IGRAs), which are widely used to diagnose tuberculosis (TB), cannot effectively discriminate latent TB infection (LTBI) from active TB (ATB). This study aimed to identify potential antigen-specific biomarkers for differentiating LTBI cases from ATB cases.

METHODS

Ongoing recruitment was conducted of individuals meeting study inclusion criteria at Beijing Chest Hospital from May 2020 to April 2022; 208 participants were enrolled and assigned to three groups: HC (60 healthy controls), LTBI (52 subjects with LTBI) and ATB (96 ATB patients). After participants were assigned to the discovery cohort (20 or 21 subjects/group), all others were assigned to the verification cohort. Discovery cohort blood levels of 40 chemokines were measured using Luminex assays to identify chemokines that could be used to discriminate LTBI cases from ATB cases; candidate biomarkers were verified using enzyme-linked immunosorbent assay-based testing of validation cohort samples.

RESULTS

Luminex results revealed highest ATB group levels of numerous cytokines, growth factors and chemokines. Receiving operating characteristic curve-based analysis of 40 biomarkers revealed CCL8 (AUC = 0.890) and CXCL9 (AUC = 0.883) effectively discriminated between LTBI and TB cases; greatest diagnostic efficiency was obtained using both markers together (AUC = 0.929). Interpretation of CCL8 and CXCL9 levels for validation cohort IGRA-positive subjects (based on a 0.658-ng/ml cutoff) revealed ATB group CCL8-based sensitivity and specificity rates approaching 90.79% and 100.00%, respectively.

CONCLUSION

TB-specific chemokines hold promise as ATB diagnostic biomarkers. Additional laboratory confirmation is needed to establish whether CCL8-based assays can differentiate between ATB and LTBI cases, especially for bacteriologically unconfirmed TB cases.

[Tuberculosis Infection Control & Hygiene - Recommendations of the DZK]

Preventing the spread of the disease is an essential goal in the care and treatment of tuberculosis. In addition to early diagnosis and effective therapies, isolation of infectious patients and adequate hygiene measures are of particular importance for infection prevention. The present recommendations replace the previous recommendations "tuberculosis infection control" from 2012 and take into account the current national and international recommendations and as well as new scientific findings. After a description of the infection and the transmission pathways, the necessary prevention and hygiene measures in health care facilities are comprehensively presented. Since the last revision of the recommendations on infection prevention, international recommendations and the KRINKO recommendation on ending isolation have been changed. In accordance with this, under certain conditions in the case of sensitive tuberculosis, de-isolation in health care facilities can take place after 14 days without taking the sputum findings into account. The second part of the recommendations explains in detail the measures to be taken in special situations and areas, such as general practitioners, ambulance services and care facilities. Here, the recommendations on respiratory protection have been simplified; for staff, an FFP2 mask is now generally considered sufficient.

Vaccine development against tuberculosis before and after Covid-19

Coronavirus disease (Covid-19) has not only shaped awareness of the impact of infectious diseases on global health. It has also provided instructive lessons for better prevention strategies against new and current infectious diseases of major importance. Tuberculosis (TB) is a major current health threat caused by Mycobacterium tuberculosis (Mtb) which has claimed more lives than any other pathogen over the last few centuries. Hence, better intervention measures, notably novel vaccines, are urgently needed to accomplish the goal of the World Health Organization to end TB by 2030. This article describes how the research and development of TB vaccines can benefit from recent developments in the Covid-19 vaccine pipeline from research to clinical development and outlines how the field of TB research can pursue its own approaches. It begins with a brief discussion of major vaccine platforms in general terms followed by a short description of the most widely applied Covid-19 vaccines. Next, different vaccination regimes and particular hurdles for TB vaccine research and development are described. This specifically considers the complex immune mechanisms underlying protection and pathology in TB which involve innate as well as acquired immune mechanisms and strongly depend on fine tuning the response. A brief description of the TB vaccine candidates that have entered clinical trials follows. Finally, it discusses how experiences from Covid-19 vaccine research, development, and rollout can and have been applied to the TB vaccine pipeline, emphasizing similarities and dissimilarities.

[Recommendations for Contact Tracing for Tuberculosis - Update 2023]

The aim of contact tracing for tuberculosis is in addition to active case finding the detection of chains of infection and the prevention of the further spread of the disease. In this context, a careful selection of contact persons is necessary, depending on the type and duration of contact, to identify persons who are recently infected and therefore to increase the benefit of a preventive therapy and to avoid unnecessary testing of persons who are not at risk of infection. Since the last update of the recommendations on contact tracing, data on the use of interferon-y release assays (IGRAs) in children has been improved markedly. These are the preferred test in contact tracing of adults. For children, both IGRAs and the tuberculin skin test can be used equivalently. Rifampicin for 4 months, rifampicin and isoniazid for 3 months, or isoniazid for 9 months are recommended as preventive therapy in cases of confirmed infection.The implementation of the contact tracing in different age groups as well as legal framework conditions and socio-medical aspects and challenges are dealt with in detail. In addition, special cases, such as environmental screening in day-care centers, schools, or other community facilities, are discussed separately.

Enhancing bovine tuberculosis screening at Dhaka city in Bangladesh: Integrating gamma interferon blood test as ancillary testing with tuberculin skin test

Tuberculin skin test (TST) is the standard method for screening of bovine tuberculosis (bTB). However, gamma interferon blood test has been introduced in the bTB control program as an ancillary testing with TST in many countries of the world. The objective of this study was to recommend this screening test as an ancillary testing with TST for field application in Bangladesh. In this study 577 cattle of different age, sex and breeds from twenty nine (29) cattle herds were examined to determine skin response against bTB through single intradermal comparative tuberculin test (SICTT) that comprised of positive (n = 81), inconclusive (n = 44) and negative (n = 452) animals. Of which 74 animals that included positive (n = 63), inconclusive (n = 8) and negative (n = 3) animals were taken under this study. Blood samples were collected in heparinized tube and stimulated overnight with bovine and avian purified protein derivatives (PPDs) for the secretion of gamma interferon, and measured via sandwich ELISA. Cohen's kappa statistics was performed for the evaluation of agreement between the two tests. The agreement obtained between two tests was fair (Kappa agreement, K = 24.0%, 95% CI = 16.9-30.5%, P = 0.037). Of positive (n = 63), inconclusive (n = 8) and negative (n = 3) status of animals at SICTT, 82.54% (n = 52), 62.50% (n = 5), and 33.33% (n = 1) were found to be bTB positive respectively through this ancillary test. This test notably corroborates to TST result. A considerable number of inconclusive TB status animals were found to be positive through this gamma interferon assay. Therefore, this test could be used as an ancillary test with TST to maximize the proportion of bTB estimation in the infected cattle herd for early detection of zoonotic tuberculosis in Bangladesh before transmission at the animal-human interface.

[Recommendations for contact tracing for tuberculosis - update 2023]

The aim of contact tracing for tuberculosis is in addition to active case finding the detection of chains of infection and the prevention of the further spread of the disease. In this context, a careful selection of contact persons is necessary, depending on the type and duration of contact, to identify persons who are recently infected and therefore to increase the benefit of a preventive therapy and to avoid unnecessary testing of persons who are not at risk of infection. Since the last update of the recommendations on contact tracing, data on the use of interferon-y release assays (IGRAs) in children has been improved markedly. These are the preferred test in contact tracing of adults. For children, both IGRAs and the tuberculin skin test can be used equivalently. Rifampicin for 4 months, rifampicin and isoniazid for 3 months, or isoniazid for 9 months are recommended as preventive therapy in cases of confirmed infection.The implementation of the contact tracing in different age groups as well as legal framework conditions and socio-medical aspects and challenges are dealt with in detail. In addition, special cases, such as environmental screening in day-care centers, schools, or other community facilities, are discussed separately.

Tuberculosis screening practices and outcomes in an australian dialysis unit

BACKGROUND

The World Health Organisation (WHO) recommends all dialysis patients undertake routine screening for latent tuberculosis infection (LTBI) in high income countries such as Australia. However, we employ a targeted screening approach in our Australian dialysis unit in line with local and some international guidelines. We analysed our practices to assess the validity of our approach.

METHODS

A retrospective review of new dialysis patients during the period 2012-2018 was undertaken. Patient records were reviewed for basic demographic data, comorbidities, LTBI screening using Quantiferon Gold (QFG), and outcomes, including episodes of active TB, to June 2020.

RESULTS

472 patients were included. WHO high risk country of origin patients accounted for 22% (n = 103). 229 patients (48.5%) were screened using QFG. The single main indication for screening was transplantation waitlisting. 34 patients had a positive QFG result. Active tuberculosis developed in two patients during the observation period. Both occurred in the screened cohort, the cases having previously tested negative via QFG at 11 and 16 months, prior to the development of active tuberculosis. No patients in the unscreened cohort developed active tuberculosis during the observation period. WHO high risk country of origin was associated with positive QFG status, odds ratio 10.4 (95% CI 3.3-31.2).

CONCLUSION

The data failed to show a benefit from widening of the screening program within our dialysis unit. However, a much larger sample size will be required to confidently assess the impact of the current approach on patient outcomes. Analysis of current screening practices and outcomes across all Australian dialysis services is warranted to assess the risks and benefits of widening the screening practices to include all dialysis patients as recommended by the WHO.

Screening for Latent Tuberculosis Infection in Solid Organ Transplant Recipients to Predict Active Disease: A Systematic Review and Meta-Analysis of Diagnostic Studies

BACKGROUND

This is a systematic review and meta-analysis of diagnostic test accuracy studies to assess the predictive value of both tuberculin skin test (TST) and interferon-gamma release assays (IGRA) for active tuberculosis (TB) among solid organ transplantation (SOT) recipients.

METHODS

Medline, Embase, and the CENTRAL databases were searched from 1946 until June 30, 2022. Two independent assessors extracted data from studies. Sensitivity analyses were performed to investigate the effect of studies with high or low risk of bias. Methodological quality of each publication was assessed using QUADAS-2.

RESULTS

A total of 43 studies (36 403 patients) with patients who were screened for latent TB infection (LTBI) and who underwent SOT were included: 18 were comparative and 25 noncomparative (19 TST, 6 QuantiFERON-TB Gold In-Tube [QFT-GIT]). For IGRA tests taken together, positive predictive value (PPV) and negative predictive value (NPV) were 1.2% and 99.6%, respectively. For TST, PPV was 2.13% and NPV was 95.5%. Overall, PPV is higher when TB burden is higher, regardless of test type, although still low in absolute terms. Incidence of active TB was similar between studies using LTBI prophylaxis (mean incidence 1.22%; 95% confidence interval [CI], .2179-2.221) and those not using prophylaxis (mean incidence 1.045%; 95% CI, 0.2731-1.817; P = .7717). Strengths of this study include the large number of studies available from multiple different countries; limitations include absence of gold standard for diagnosis of latent TB and low incidence of active TB.

CONCLUSIONS

We found both TST and IGRA had a low PPV and high NPV for the development of active TB posttransplant. Further studies are needed to better understand how to prevent active TB in the SOT population.

Tuberculosis Infection and Disease Among Pregnant People Living in Sweden With Origin in Tuberculosis-Endemic Countries

Background

Pregnancy has been associated with elevated incidence of tuberculosis (TB) disease. Since 2014, people living in Sweden with origin in TB-endemic countries have been offered screening for TB infection in antenatal care (ANC) using Quantiferon-TB assays. We assessed factors associated with TB infection in this population and determined the incidence of TB disease during pregnancy and postpartum periods with regard to ANC Quantiferon-TB results.

Methods

Quantiferon-TB results obtained during ANC in Sweden, 2014-2018, were linked to data from national registers (Pregnancy Register, Patient Register and Tuberculosis Register). Factors associated with TB infection (defined as Quantiferon-TB ≥0.35 IU/mL) were identified using logistic regression analysis. Incidence of TB disease was determined with regard to pregnancy, postpartum and subsequent periods, and ANC Quantiferon-TB results.

Results

Among 7638 screened individuals, 1424 (18.6%) had TB infection. Tuberculosis infection was independently associated with higher age at immigration (adjusted odds ratio, 1.04 [95% confidence interval, 1.03-1.05]; P < .001), and was more common among people originating from Africa compared to other world regions (845/3088 [27.4%] vs 579/4550 [12.7%]; P < .001). In total, 16 participants were diagnosed with TB disease (10 during pregnancy, 4 at <6 months after delivery, 2 at >6 months after delivery); among these, all diagnosed during pregnancy/postpartum had positive ANC Quantiferon-TB results (constituting 14/1424 [1%] of people with TB infection).

Conclusions

Among pregnant people screened in Swedish ANC, TB infection was associated with higher age and African origin. All cases of TB disease reported in persons with TB infection at ANC screening occurred during pregnancy or postpartum.

Latent Tuberculosis Infection and Associated Factors in Patients with Systemic Lupus Erythematosus: a Multicenter, Cross-Sectional Study

The objectives of this study were to screen for latent tuberculosis infection (LTBI) among patients with systemic lupus erythematosus (SLE) using the T-SPOT.TB assay and to identify factors affecting the assay results. SLE patients were enrolled from 13 tertiary hospitals in eastern, central, and western China from September 2014 to March 2016 and were screened using the T-SPOT.TB assay to detect LTBI. Basic information about the subjects was collected, including gender, age, body mass index (BMI), course of disease, evidence of previous tuberculosis, Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score, and the use of glucocorticoids and immunosuppressants. Univariate analysis and multivariable logistic regression were performed to identify factors affecting the results of the T-SPOT.TB assay. In all, 2,229 SLE patients were screened using the T-SPOT.TB assay, of whom 334 patients tested positive, yielding a positivity rate of 15% (95% confidence interval [CI], 13.5% to 16.5%). The positivity rate was higher in male than female patients and had an increasing trend with age. Multivariable logistic regression analysis showed that patients over 40 (odds ratio [OR], 1.65; 95% CI, 1.29 to 2.10) and with evidence of previous tuberculosis (OR, 4.43; 95% CI, 2.81 to 6.99) were more likely to have positive T-SPOT.TB results, while patients with a SLEDAI-2K score of ≥10 (OR, 0.61; 95% CI, 0.43 to 0.88), a glucocorticoid dose of ≥60 mg/d (OR, 0.62; 95% CI, 0.39 to 0.98), leflunomide (LEF) treatment (OR, 0.51; 95% CI, 0.29 to 0.88), or tacrolimus (FK506) treatment (OR, 0.40; 95% CI, 0.16 to 1.00) were more likely to have negative T-SPOT.TB results. The frequencies of CFP-10-specific gamma interferon (IFN-γ)-secreting T cells were significantly lower in SLE patients with severe disease activity or high-dose glucocorticoids (P < 0.05). The positivity rate of the T-SPOT.TB assay was 15% among SLE patients. Severe, active SLE disease and the use of high-dose glucocorticoids and some types of immunosuppressants are likely to result in negative T-SPOT.TB results. For SLE patients with the above conditions, diagnosing LTBI based on a positive T-SPOT.TB result may lead to underestimation of the prevalence. IMPORTANCE The burden of tuberculosis and systemic lupus erythematosus in China ranks among the top three in the world. Therefore, active screening for LTBI and preventive intervention in SLE patients are of great significance in China. In view of the lack of relevant data in a large sample, we conducted a multicenter, cross-sectional study using T-SPOT.TB as a screening method for LTBI, to investigate the prevalence of LTBI and analyze the factors affecting the results of the T-SPOT.TB assay in SLE patients. Our study showed that the overall positivity rate of the T-SPOT.TB assay in SLE patients was 15.0%, which was lower than the estimated LTBI prevalence in the general population in China (~20%). For SLE patients with severe, active disease, high-dose glucocorticoids, and some types of immunosuppressants, a diagnosis of LTBI based on only positive T-SPOT.TB results may lead to underestimation of the prevalence.

Smoking is a Factor in Discordance Between QuantiFERONTB Gold Assay and Tuberculosis Etiology: Especially in Older Patients

Purpose

Exploring whether smoking is an influencing factor for the inconsistency between QuantiFERONTB Gold assay (QFT-GIT) and tuberculosis etiology.

Patients and Methods

The clinical data of patients who were confirmed positive for Mycobacterium tuberculosis (MTB) after undergoing QFT-GIT testing from September 2017 to August 2021 were retrospectively analyzed. Chi-square and rank-sum tests were used to compare the differences in characteristics between smokers and non-smokers. Logistic regression was used to adjust for confounding factors affecting smoking. Propensity score matching (PSM) was used to verify the above conclusions again.

Results

Positive results of tuberculosis etiology were adopted as the standard, the incidence of inconsistent results between QFT-GIT and tuberculosis etiology was 8.90% (108/1213), of which the false negative rate was 6.27% (76/1213) and the indeterminate rate was 2.64% (32/1213). In the overall population, the smokers had a lower level of basal IFN-γ (Z=-2.079, P=0.038). Among 382 elderly (≥65 years old) patients, the smokers had lower levels of antigen-stimulated IFN-γ (Z=-2.838, P=0.005). After performing BOX-COX transformation on all non-normally distributed data, logistic stepwise regression was used to adjust confounding factors. The results showed that smoking was an influencing factor for the inconsistency between QFT-GIT and tuberculosis etiology results (OR=1.69, P=0.020). Using PSM for 1:2 matching, the results showed that smoking was still an independent risk factor for the inconsistent results of QFT-GIT and tuberculosis etiology (OR= 1.95, P=0.019). Age-stratified analysis showed that smoking was an independent risk factor in discordance between QFT-GIT and tuberculosis etiology in patients aged ≥65 years (OR=2.40, P=0.005), but not in patients aged <65 years (P > 0.05).

Conclusion

Smoking can reduce the body's IFN-γ release ability, and smoking (especially the elderly) is an influencing factor for the inconsistency between QFT-GIT and tuberculosis etiological results.

Screening for Latent Tuberculosis Infection in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance

Latent tuberculosis infection (LTBI) can progress to active tuberculosis disease, causing morbidity and mortality.

Objective

To review the evidence on benefits and harms of screening for and treatment of LTBI in adults to inform the US Preventive Services Task Force (USPSTF).

Data Sources

PubMed/MEDLINE, Cochrane Library, and trial registries through December 3, 2021; references; experts; literature surveillance through January 20, 2023.

Study Selection

English-language studies of LTBI screening, LTBI treatment, or accuracy of the tuberculin skin test (TST) or interferon-gamma release assays (IGRAs). Studies of LTBI screening and treatment for public health surveillance or disease management were excluded.

Data Extraction and Synthesis

Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings; meta-analyses conducted when a sufficient number of similar studies were available.

Main Outcomes and Measures

Screening test accuracy; development of active tuberculosis disease, transmission, quality of life, mortality, and harms.

Results

A total of 113 publications were included (112 studies; N = 69 009). No studies directly evaluated the benefits and harms of screening. Pooled estimates for sensitivity of the TST were 0.80 (95% CI, 0.74-0.87) at the 5-mm induration threshold, 0.81 (95% CI, 0.76-0.87) at the 10-mm threshold, and 0.60 (95% CI, 0.46-0.74) at the 15-mm threshold. Pooled estimates for sensitivity of IGRA tests ranged from 0.81 (95% CI, 0.79-0.84) to 0.90 (95% CI, 0.87-0.92). Pooled estimates for specificity of screening tests ranged from 0.95 to 0.99. For treatment of LTBI, a large (n = 27 830), good-quality randomized clinical trial found a relative risk (RR) for progression to active tuberculosis at 5 years of 0.35 (95% CI, 0.24-0.52) for 24 weeks of isoniazid compared with placebo (number needed to treat, 112) and an increase in hepatotoxicity (RR, 4.59 [95% CI, 2.03-10.39]; number needed to harm, 279). A previously published meta-analysis reported that multiple regimens were efficacious compared with placebo or no treatment. Meta-analysis found greater risk for hepatotoxicity with isoniazid than with rifampin (pooled RR, 4.22 [95% CI, 2.21-8.06]; n = 7339).

Conclusions and Relevance

No studies directly evaluated the benefits and harms of screening for LTBI compared with no screening. TST and IGRAs were moderately sensitive and highly specific. Treatment of LTBI with recommended regimens reduced the risk of progression to active tuberculosis. Isoniazid was associated with higher rates of hepatotoxicity than placebo or rifampin.

The Interferon-Gamma Release Assay versus the Tuberculin Skin Test in the Diagnosis of Mycobacterium tuberculosis Infection in BCG-Vaccinated Children and Adolescents Exposed or Not Exposed to Contagious TB

BACKGROUND

Children have an increased risk of developing active tuberculosis (TB) after exposure to Mycobacterium tuberculosis (M.tb), and they are more likely to develop the most severe forms of TB. Rapid diagnosis and treatment of latent M.tb infection (LTBI) is essential to lessen the devastating consequences of TB in children.

OBJECTIVE

The aim of the study was to evaluate TST (tuberculin skin test) and IGRA (interferon-gamma release assay) utility in identifying LTBI in a cohort of Bacille Calmette-Guérin (BCG)-vaccinated Polish children and adolescents exposed or not exposed to contagious TB. In addition, we asked whether quantitative assessment of IGRA results could be valuable in predicting active TB disease.

RESULTS

Of the 235 recruited volunteers, 89 (38%) were TST-positive (TST+), 74 (32%) were IGRA-positive (IGRA+), and 62 (26%) were both TST+ and IGRA+. The frequency of TST positivity was significantly higher in the group with (59%) than without TB contact (18%). The percentage of TST+ subjects increased with age from 36% in the youngest children (<2 years) to 47% in the oldest group (>10 years). All positive IGRA results were found solely in the group of children with TB contact. There was a significant increase in the rate of positive IGRA results with age, from 9% in the youngest to 48% in the oldest group. The 10 mm TST cutoff showed good sensitivity and specificity in both TB exposed and nonexposed children and was associated with excellent negative predictive value, especially among nonexposed volunteers. Mean IFN-γ concentrations in IGRA cultures were significantly higher in the group of LTBI compared to the children with active TB disease, both TST+ and TST-.

CONCLUSIONS

Both TST and IGRA can be used as screening tests for BCG-vaccinated children and adolescents exposed to contagious TB.

Interferon-gamma release assay and chest X-ray to classify intraocular tuberculosis among clinically undifferentiated uveitis

BACKGROUND Tuberculosis (TB) is a common cause of intraocular inflammation in Indonesia. As no accurate biomarker can confirm the diagnosis, ophthalmologists often rely on systemic findings, such as tuberculin skin test, interferon-gamma release assay (IGRA), and chest X-ray (CXR) for TB suspicion. This study aimed to evaluate IGRA and CXR in classifying intraocular TB among patients with a clinically undifferentiated cause of uveitis. METHODS This cross-sectional study included 116 patients (a total of 163 affected eyes) with a clinically undifferentiated cause of uveitis. IGRA and CXR were performed as part of the workup. Data on visual acuity, anterior chamber inflammation grade, and anatomical classification of uveitis were recorded. As there were no confirmed ocular tuberculosis (OTB) in our cases, eyes were classified into probable OTB, possible OTB, and unclassified. RESULTS Overall, 93 patients (80.2%) with a clinically undifferentiated cause of uveitis had positive IGRA, whereas 10 (8.6%) had CXR results suggestive of TB. More than one-third of the patients were blind (visual acuity <3/60), and panuveitis was the commonest anatomical classification. A trend was identified in patients with panuveitis, who often showed ≥2+ cell anterior chamber inflammation (p for trend = 0.023), according to OTB criteria (probable OTB = 3/4, 75.0%; possible OTB = 44/67, 65.7%; unclassified = 2/9, 22.2%). Furthermore, the clinically undifferentiated uveitis cases were eligible to be stratified into probable (8.6%) and possible (75.0%) OTB categories after IGRA and CXR examinations. CONCLUSIONS The combination of IGRA and CXR is valuable for classifying and diagnosing TB-related uveitis. A multidisciplinary approach is essential when the cause of uveitis is unknown.

Secretion Function Analysis of Ex Vivo Immune Cells in an Integrated Microfluidic Device

Immune cells play a major role in the development of cancer, from being able to inhibit it by secreting pro-inflammatory mediators, to assist in its development by secreting growth factors, immunosuppressive mediators, and ECM-modifying enzymes. Therefore, the ex vivo analysis of the secretion function of immune cells can be employed as a reliable prognostic biomarker in cancer. However, one limiting factor in current approaches to probe the ex vivo secretion function of cells is their low throughput and the consumption of large quantities of sample. Microfluidics provides a unique advantage, by being able to integrate different components, such as cell culture and biosensors in a monolithic microdevice; it can increase the analytical throughput and leverage it with its intrinsic low sample requirement. Furthermore, the integration of fluid control elements also allows this analysis to be highly automatable, leading to increases in consistency in the results. Here, we describe an approach to analyze the ex vivo secretion function of immune cells using a highly integrated microfluidic device.

Activities of plasma indoleamine-2, 3-dioxygenase (IDO) enzyme in Nigerian patients with lung diseases: basis for tryptophan supplementation or IDO inhibitor use

Background

Clinical trial of IDO inhibitor or uses of micro-nutrient supplements during management of diseases is commonly done without having adequate basis for the practise. Tryptophan (Trp) is an essential amino acid needed for T-lymphocyte function, and indoleamine-2,3-dioxygenase (IDO) is a potent immunoregulatory molecule that catalyses the rate-limiting step of Trp degradation in the kynurenine (Kyn) pathway.

Materials and methods

Human IDO in the plasma samples was measured using ELISA in patients with non-infectious (asthma) and infectious diseases (pulmonary tuberculosis and COVID-19) compared with corresponding un-infected controls.

Results

Mean IDO activity in COVID-19 patients was significantly higher compared with corresponding control (p = 0.001) while mean IDO activity in pulmonary tuberculosis patients was non-significantly higher compared with corresponding control (p = 0.520), and mean IDO activity in asthma patients was non-significantly lower compared with corresponding control (p = 0.102).

Conclusion

Our data suggest that IDO activity as an innate immune factor is increased in infectious lung diseases (COVID-19 and pulmonary tuberculosis) but reduced in non-infectious disease (asthma) and that use of tryptophan supplementation or IDO inhibitor may not be necessary in all lung diseases.

A systematic review of cost-utility analyses of screening methods in latent tuberculosis infection in high-risk populations

Background

The World Health Organisation (WHO) recommends that testing and treatment for latent tuberculosis infection (LTBI) should be undertaken in high-risk groups using either interferon gamma release assays (IGRAs) or a tuberculin skin test (TST). As IGRAs are more expensive than TST, an assessment of the cost-effectiveness of IGRAs can guide decision makers on the most appropriate choice of test for different high-risk populations. This current review aimed to provide the most up to date evidence on the cost-effectiveness evidence on LTBI testing in high-risk groups—specifically evidence reporting the costs per QALY of different testing strategies.

Methods

A comprehensive search of databases including MEDLINE, EMBASE and NHS-EED was undertaken from 2011 up to March 2021. Studies were screened and extracted by two independent reviewers. The study quality was assessed using the Bias in Economic Evaluation Checklist (ECOBIAS). A narrative synthesis of the included studies was undertaken.

Results

Thirty-two studies reported in thirty-three documents were included in this review. Quality of included studies was generally high, although there was a weakness across all studies referencing sources correctly and/or justifying choices of parameter values chosen or assumptions where parameter values were not available. Inclusions of IGRAs in testing strategies was consistently found across studies to be cost-effective but this result was sensitive to underlying LTBI prevalence rates.

Conclusion

While some concerns remain about uncertainty in parameter values used across included studies, the evidence base since 2010 has grown with modelling approaches addressing the weakness pointed out in previous reviews but still reaching the same conclusion that IGRAs are likely to be cost-effective in high-income countries for high-risk populations. Evidence is also required on the cost-effectiveness of different strategies in low to middle income countries and countries with high TB burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02149-x.

Interferon gamma release assays for diagnosis of osteoarticular tuberculosis: A systematic review and meta-analysis

Background

Although the Interferon Gamma Release Assays (IGRA) is often used to identify latent tuberculosis, it also plays a crucial role in diagnosing active extrapulmonary tuberculosis. Some studies have assessed the use of IGRA as a biomarker for osteoarticular tuberculosis (OATB), which is elevated following TB infection. Still, conclusive results about its effectiveness have not been reported.

Method

We searched PubMed, Embase, and Cochran databases. We obtained literature related to the diagnosis of OATB by IGRA, and the retrieval period was from the establishment of the database to June 2021. The bivariate random effect model was used to summarize the sensitivity, specificity, and accuracy of other indicators in diagnosing OATB by IGRA, and the forest plot and receiver operating characteristic (ROC) curve were used for testing.

Results

We included seven studies involving 643 subjects in diagnosing OATB by IGRA. The comprehensive sensitivity and specificity were 0.84 (95% CI, 0.70–0.92) and 0.78 (95% CI, 0.66–0.87), respectively. The area under the curve (AUC) was 0.87.

Conclusion

In blood samples, the diagnostic accuracy of IGRAS is poor in patients with suspected OAT. We conclude that IGRA may not be appropriate for patients with OATB.

Interferon-Inducible Protein-10 as a Marker to Detect Latent Tuberculosis Infection in Patients with Inflammatory Rheumatic Diseases

It is important to identify cases of latent tuberculosis infection (LTBI) who are at risk for tuberculosis (TB) reactivation. We aimed to evaluate the performance of interferon (IFN)-gamma-inducible protein 10 (IP-10) as a marker to detect LTBI in patients with inflammatory rheumatic diseases (IRD). This study comprised 76 consecutive subjects with IRD. Patients with a history of TB or having active TB were excluded. In all patients, IP-10 level was measured and tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube test (QFT-GIT) were performed. Seventy patients with complete test results were analyzed. Twenty-one (30%) QFT-GIT-positive patients were defined as having LTBI. IP-10 yielded 2197 pg/mL cut-off point. At this cut-off point, IP-10 showed 89% specificity with a sensitivity of 91% (AUC: 0.950, 95% CI 0.906–0.994). TST, QFT-GIT, and IP-10 were positive in 77.1%, 30%, and 44.3% of the patients, respectively. Concordance among the results of TST, QFT-GIT, and IP-10 tests was evaluated. Agreement was poor between IP-10 and TST (58.6%, κ = 0.19), whereas it was good between QFT-GIT and IP-10 (84.3%, κ = 0.65). The results of the present study demonstrated that sensitivity and specificity of released IP-10 were as high as those of QFT-GIT in indicating LTBI in IRD patient group.

Aural tuberculosis at the start of the 21st century. Literature review according to SWiM guidelines. Part 1: Clinical and diagnostic data

OBJECTIVES

Review of the scientific literature dedicated to clinical data and diagnosis modalities for aural tuberculosis published since the start of the 21st century.

MATERIAL AND METHODS

Search of the Medline, Cochrane and Embase databases for the period 2000-2020. Selection of articles in English, French and Spanish devoted to clinical cases and series documenting clinical data and diagnosis for aural tuberculosis of articles by two authors. Analysis performed according to SWiM guidelines. Extraction of data on pre-established files documenting clinical and diagnostic data.

RESULTS

In total, 173 articles: 163 case reports (228 patients) and 10 cohorts (177 patients) from 49 countries were analyzed. Female/male sex ratio was 1.05, with ages ranging from less than 1 month to 87 years. Tuberculosis involved another site in 35.1% of cases. Aural involvement was bilateral in 19.7% of cases. Clinical presentation corresponded to otitis media (prior antibiotic treatment and auricular surgery in 41.4% and 10.1% of cases, respectively) without any pathognomonic symptoms or signs. Associated severe locoregional complications were seen in 32% of cases, with 23.2% and 13% incidence of peripheral facial palsy and severe intracranial complications, respectively. Time to diagnosis ranged from less than 1 month to 384 months, and was longer than 12 months in 26.5% of case reports, without significant correlation (P=0.29) with severe revelatory locoregional complications. Incidence of Mycobacterium tuberculosis detection ranged from 33.4% of documented cases in auricular secretions to 64.6% in polyps, granulomas, and/or biopsies. In the case reports, diagnosis with certainty was done in 58.3% of cases, while it was based on involvement of another site and on indirect criteria or positive clinical progression after treatment in the other 10.1% and 31.6%, respectively.

CONCLUSION

Aural tuberculous must always be considered in case of unfavorable progression of otitis. Definitive diagnosis is based on multiple auricular sample sites, polymerase chain reaction, and γ interferon blood assay.

Diagnostic accuracy of interferon-gamma release assays for diagnosis of smear-negative pulmonary tuberculosis: a systematic review and meta-analysis

Introduction

The diagnosis of smear-negative pulmonary tuberculosis (SNPTB) is challenging. Interferon gamma-release assays (IGRAs) may be helpful in early diagnosis among these patients resulting in prompt treatment and favorable outcomes.

Methods

We performed a comprehensive search from each databases’ inception to April 5, 2021. The studies that provided sufficient data regarding the sensitivity and specificity of IGRAs included QuantiFERON-TB Gold In-Tube (QFT-GIT), T-SPOT.TB, or QuantiFERON-TB Gold Plus for diagnosis of SNPTB were included.

Results

Of 1,312 studies screened, 16 studies were included; 11 QFT-GIT, 2 T-SPOT.TB, and 3 QFT-GIT and T-SPOT.TB. For diagnosis of SNPTB, QFT-GIT had sensitivity of 0.77 (95% CI 0.71–0.82), specificity of 0.70 (95% CI 0.58–0.80), diagnostic odds ratio (DOR) of 8.03 (95% CI 4.51–14.31), positive likelihood ratio (LR) of 2.61 (95% CI 1.80–3.80), negative LR of 0.33 (95% CI 0.25–0.42), and area under receiver operating characteristic (AUROC) of 0.81 (95% CI 0.77–0.84). T-SPOT.TB had sensitivity of 0.74 (95% CI 0.71–0.78), specificity of 0.71 (95% CI 0.49–0.86), DOR of 6.96 (95% CI 2.31–20.98), positive LR of 2.53 (95% CI 1.26–5.07), negative LR of 0.36 (95% CI 0.24–0.55), and AUROC of 0.77 (95% CI 0.73–0.80). The specificity seemed lower in the subgroup analyses of studies from high tuberculosis burden counties compared to the studies from low tuberculosis burden.

Conclusion

IGRAs do have insufficient diagnostic performance for SNPTB. However, the tests are still helpful to exclude tuberculosis among patients with low pre-test probability.

Registry: PROSPERO: CRD42021274653.

Elevated IP-10 at the Protein and Gene Level Associates With Pulmonary TB

There is an urgent need for accurate and sensitive diagnostic tools that can overcome the current challenge to distinguish individuals with latent tuberculosis infection (LTBI) from individuals with active tuberculosis (TB). Recent literature has suggested that a group of cytokines may serve as biomarkers of TB disease progression. Using a multiplex ELISA, we quantified 27 circulatory markers present within the unstimulated plasma of individuals in Durban, South Africa who were healthy (n=20), LTBI (n=13), or had active TB (n=30). RT-qPCR was performed to measure gene expression of the cytokines of interest, using RNA isolated from healthy (n=20), LTBI (n=20), or active TB (n=30). We found that at the protein level, IL-1RA, IL-6, and IP-10 were significantly more abundant in participants with active TB (p< 0.05) compared to those with LTBI individuals. IP-10 also showed the strongest association with active TB compared to healthy and LTBI at mRNA level. Our data shows that these proteins may serve as biomarkers of TB at both the protein and gene level.

Tuberculin skin test before biologic and targeted therapies: does the same rule apply for all?

This study aimed to compare Tuberculin Skin Test (TST) and QuantiFERON®-TB Gold In-Tube (QFT-GIT) test in rheumatoid arthritis (RA) and spondyloarthritis (SpA) patients scheduled for biological and targeted synthetic disease modifying anti-rheumatic drugs (DMARDs) in a Bacillus Calmette-Guérin-vaccinated population. Adult RA (n = 206) and SpA (n = 392) patients from the TReasure database who had both TST and QFT-GIT prior to initiation of biological and targeted synthetic DMARDs were included in the study. Demographic and disease characteristics along with pre-biologic DMARD and steroid use were recorded. The distribution of TST and performance with respect to QFT-GIT were compared between RA and SpA groups. Pre-biologic conventional DMARD and steroid use was higher in the RA group. TST positivity rates were 44.2% in RA and 69.1% in SpA for a 5 mm cutoff (p < 0.001). Only 8.9% and 15% of the patients with RA and SpA, respectively, tested positive by QFT-GIT. The two tests poorly agreed in both groups at a TST cutoff of 5 mm and increasing the TST cutoff only slightly increased the agreement. Among age, sex, education and smoking status, pre-biologic steroid and conventional DMARD use, disease group, and QFT-GIT positivity, which were associated with a 5 mm or higher TST, only disease group (SpA) and QFT-GIT positivity remained significant in multiple logistic regression. TST positivity was more pronounced in SpA compared to that in RA and this was not explainable by pre-biologic DMARD and steroid use. The agreement of TST with QFT-GIT was poor in both groups. Using a 5 mm TST cutoff for both diseases could result in overestimating LTBI in SpA.

Ulcerative Tuberculosis in a Patient Treated with Adalimumab

Abstract is missing (Short Communication)

Treatment in Latent Tuberculosis Uveitis-Is Immunosuppression Effective or Is Conventional 3- or 4-Drug Antituberculosis Therapy Mandatory?

Background/Aims: Controversy exists regarding 3- or 4 drug antituberculosis therapy (conventional ATT) in uveitis patients having latent tuberculosis (LTB), especially while initiating therapy with corticosteroids and/or other immunosuppressants. Methods: We performed a monocentral retrospective analysis of posterior uveitis patients with latent TB. Latent TB was diagnosed, in case of a positive QuantiFERON®-TB-Gold test and normal chest imaging, after ruling out other causes of infectious and noninfectious uveitis. Patients with active TB were excluded. From 2016 to 2020 we included 17 patients. Ophthalmological evaluation consisted of Best corrected visual acuity (BCVA), slit lamp examination, fundoscopy, OCT, and fluorescein- and indocyaningreen- angiography before and at months 3, 6, 12, 24, and the last follow-up after treatment. Results: Initially, all patients had active posterior uveitis with occlusive (n = 5 patients) and nonocclusive retinal vasculitis (n = 12 patients). Mean follow up was 28 ± 15 months. Therapy was started with systemic corticosteroids (mean prednisolone equivalent 71.3 mg/d) and already after 3 months it could be tapered to a mean maintenance dosage of 8.63 mg/d. Additional immunosuppressive treatment with cs- or bDMARDs was initiated in 14 patients (82%) due to recurrences of uveitis while tapering the corticosteroids <10 mg per/day or because of severe inflammation at the initial visit. While being on immunosuppression, best corrected visual acuity increased from 0.56 logMAR to 0.32 logMAR during follow-up and only three patients had one uveitis relapse, which was followed by switch of immunosuppressive treatment. As recommended, TB prophylaxis with 300 mg/d isoniazid was administered in 11 patients for at least 9 months while being on TNF-alpha-blocking agents. No patient developed active tuberculosis during immunosuppressive therapy. Conclusion: Mainly conventional ATT is strongly recommended—as monotherapy or in combination with immunosuppressives—for effective treatment in patients with uveitis due to latent TB. Although in our patient group no conventional ATT was initiated, immunosuppression alone occurred as an efficient treatment. Nevertheless, due to possible activation of TB, isoniazid prophylaxis is mandatory in latent TB patients while being on TNF-alpha blocking agents.

Diagnostic Performance of a Novel CXCL10 mRNA Release Assay for Mycobacterium tuberculosis Infection

One-fourth of the world’s population has been infected with Mycobacterium tuberculosis (M.tb). Although interferon-gamma release assays (IGRAs) have been shown to be valid methods for identifying M.tb infection and auxiliary methods for diagnosis of active tuberculosis (TB), lower sensitivity and higher indeterminate rate were often detected among immunosuppressed patients. IP-10 was an alternative biomarker due to the higher expression level after M.tb antigen stimulation, but whether CXCL10 mRNA (the gene that transcribes for the IP-10 protein) can be used as a target for M.tb infection diagnosis was limited. Therefore, we aimed to evaluate the performance of a novel M.tb-specific CXCL10 mRNA release assay in diagnosis of M.tb infection. Suspected TB patients and healthy controls were prospectively recruited between March 2018 and November 2019 from three hospitals in China. CXCL10 mRNA release assay and traditional interferon-gamma release assay (T-SPOT.TB) were simultaneously performed on peripheral blood. Of the 1,479 participants enrolled in the study, 352 patients with definite TB and 153 healthy controls were analyzed. CXCL10 mRNA release assay provided a sensitivity of 93.9% (95% CI = 90.8–96.2%) and a specificity of 98.0% (95% CI = 94.3–99.6%) in the diagnosis of M.tb infection, respectively, while T-SPOT.TB gave a sensitivity of 94.5% (95% CI = 91.5–96.6%) and a specificity of 100% (95% CI = 97.6–100.0%) in the diagnosis of M.tb infection, respectively. The diagnostic performance of CXCL10 mRNA release assay was consistent with T-SPOT.TB, with a total coincidence rate of 95.0% (95% CI = 93.0–96.9%) and a Cohen’s kappa value of 0.89 (0.84–0.93, p < 0.001). However, among TB patients with HIV co-infection (n = 14), CXCL10 mRNA release assay presented significantly higher positive rate [92.9% (66.1–99.8%) vs. 61.5% (31.6–86.1%), p = 0.029] than those of T-SPOT.TB. These results suggested that M.tb-specific CXCL10 mRNA was a novel and useful target in the diagnosis of M.tb infection.

Infectious Posterior Uveitis - Toxoplasmosis, Treponema, Tuberculosis (TTT)

Toxoplasma gondii, Treponema pallidum and Mycobacterium tuberculosis are the most important infectious causes of posterior uveitis. The epidemiology, clinical picture, diagnostic and treatment strategies of these diseases are presented.

AutoCellANLS: An Automated Analysis System for Mycobacteria-Infected Cells Based on Unstained Micrograph

The detection of Mycobacterium tuberculosis (Mtb) infection plays an important role in the control of tuberculosis (TB), one of the leading infectious diseases in the world. Recent advances in artificial intelligence-aided cellular image processing and analytical techniques have shown great promises in automated Mtb detection. However, current cell imaging protocols often involve costly and time-consuming fluorescence staining, which has become a major bottleneck for procedural automation. To solve this problem, we have developed a novel automated system (AutoCellANLS) for cell detection and the recognition of morphological features in the phase-contrast micrographs by using unsupervised machine learning (UML) approaches and deep convolutional neural networks (CNNs). The detection algorithm can adaptively and automatically detect single cells in the cell population by the improved level set segmentation model with the circular Hough transform (CHT). Besides, we have designed a Cell-net by using the transfer learning strategies (TLS) to classify the virulence-specific cellular morphological changes that would otherwise be indistinguishable to the naked eye. The novel system can simultaneously classify and segment microscopic images of the cell populations and achieve an average accuracy of 95.13% for cell detection, 95.94% for morphological classification, 94.87% for sensitivity, and 96.61% for specificity. AutoCellANLS is able to detect significant morphological differences between the infected and uninfected mammalian cells throughout the infection period (2 hpi/12 hpi/24 hpi). Besides, it has overcome the drawback of manual intervention and increased the accuracy by more than 11% compared to our previous work, which used AI-aided imaging analysis to detect mycobacterial infection in macrophages. AutoCellANLS is also efficient and versatile when tailored to different cell lines datasets (RAW264.7 and THP-1 cell). This proof-of concept study provides a novel venue to investigate bacterial pathogenesis at a macroscopic level and offers great promise in the diagnosis of bacterial infections.

Whole blood-based measurement of SARS-CoV-2-specific T cells reveals asymptomatic infection and vaccine immunogenicity in healthy subjects and patients with solid-organ cancers

Accurate assessment of SARS-CoV-2 immunity is critical in evaluating vaccine efficacy and devising public health policies. Whilst the exact nature of effective immunity remains incompletely defined, SARS-CoV-2-specific T-cell responses are a critical feature that will likely form a key correlate of protection against COVID-19. Here, we developed and optimized a high-throughput whole blood-based assay to determine the T-cell response associated with prior SARS-CoV-2 infection and/or vaccination amongst 231 healthy donors and 68 cancer patients. Following overnight in vitro stimulation with SARS-CoV-2-specific peptides, blood plasma samples were analysed for TH 1-type cytokines. Highly significant differential IFN-γ+ /IL-2+ SARS-CoV-2-specific T-cell responses were seen amongst previously infected COVID-19-positive healthy donors in comparison with unknown / naïve individuals (p < 0·0001). IFN-γ production was more effective at identifying asymptomatic donors, demonstrating higher sensitivity (96·0% vs. 83·3%) but lower specificity (84·4% vs. 92·5%) than measurement of IL-2. A single COVID-19 vaccine dose induced IFN-γ and/or IL-2 SARS-CoV-2-specific T-cell responses in 116 of 128 (90·6%) healthy donors, reducing significantly to 27 of 56 (48·2%) when measured in cancer patients (p < 0·0001). A second dose was sufficient to boost T-cell responses in the majority (90·6%) of cancer patients, albeit IFN-γ+ responses were still significantly lower overall than those induced in healthy donors (p = 0·034). Three-month post-vaccination T-cell responses also declined at a faster rate in cancer patients. Overall, this cost-effective standardizable test ensures accurate and comparable assessments of SARS-CoV-2-specific T-cell responses amenable to widespread population immunity testing, and identifies individuals at greater need of booster vaccinations.

Prevalence of Latent Tuberculosis Infection Among Healthy Young Children and Adolescents and a Two-step Approach for the Diagnosis of Tuberculosis Infection in Chengdu, China

BACKGROUND

China has a high burden of tuberculosis and latent tuberculosis infection (LTBI). The aim of this study was to estimate the prevalence of LTBI among healthy young children and adolescents and test a 2-step approach to explore the threshold for the diagnosis of tuberculosis infection in Chengdu, China.

METHODS

Healthy preschool children and school-going children in Chengdu, Sichuan Province, were screened for LTBI using the tuberculin skin test (TST). Preschool children with TST ≥ 5 mm also underwent interferon-γ release assay (IGRA) to explore the threshold of this 2-step approach.

RESULTS

In total, 5667 healthy young children and adolescents completed TST test between July 2020 and January 2021 and were included in the present analysis. The age of the participants ranged from 2.4 to 18 years (median 7.25 ± 4.514 years), of which 2093 (36.9%) were younger than 5 years. The overall prevalence of LTBI was 6.37% and 6.64% in children younger than 5 years old. Fourteen of the 341 preschool children with TST ≥5 mm were interferon-γ release assay positive, of which 4 showed a TST result of 5-10 mm, and 6 preschool children received preventive treatment for LTBI.

CONCLUSIONS

Healthy young children and adolescents should also be considered as important target populations for LTBI screening. TST can be recommended for first-line screening as part of a 2-step approach for LTBI screening using a positive threshold of 5 mm.

Comparison of the QuantiFERON-TB® Gold Plus on LIAISON® XL and T-SPOT.TB for the diagnosis of latent Mycobacterium tuberculosis infection in a low tuberculosis incidence population

The current study compared the QuantiFERON-TB® Gold Plus on LIAISON® XL to the T-SPOT.TB for the diagnosis of latent Mycobacterium tuberculosis infection on 125 patient samples. A high agreement of qualitative results (90%) was observed between both methods with 3% major discrepancies, half of which were false negative results with the T-SPOT.TB.

Performance of 4 methods for screening of latent tuberculosis infection in patients with chronic inflammatory arthritis under TNFα inhibitors: a 24-month prospective study

BACKGROUND

The reactivation rate of tuberculosis in patients with chronic inflammatory arthritis (CIA) on TNFα inhibitors (TNFi) and baseline negative screening for latent tuberculosis infection (LTBI) is higher than in the general population.

AIM

To compare the performance of tuberculin skin test (TST), TST-Booster, ELISPOT (T-SPOT.TB) and QuantiFERON-TB Gold in tube (QFT-IT) to detect LTBI in patients with CIA on TNFi.

PATIENTS AND METHODS

A total of 102 patients with CIA [rheumatoid arthritis (RA), n = 40; ankylosing spondylitis (AS), n = 35; psoriatic arthritis (PsA), n = 7; and juvenile idiopathic arthritis (JIA), n = 20] were prospectively followed-up for 24 months to identify incident LTBI cases. Epidemiologic data, TST, T-SPOT.TB, QFT-IT and a chest X-ray were performed at baseline and after 6 months of LTBI treatment.

RESULTS

Thirty six percent (37/102) of patients had positive TST or Interferon Gamma Release Assays (IGRAs) tests. Agreement among TST and IGRAs was moderate (k = 0.475; p = 0.001), but high between T-SPOT.TB and QFT-IT (k = 0.785; p < 0.001). During the 24-Month follow-up, 15 (18.5%) incident cases of LTBI were identified. In comparison to TST, the IGRAs increased the LTBI diagnosis power in 8.5% (95% CI 3.16-17.49). TST-Booster did not add any value in patients with negative TST at baseline. After 6-Month isoniazid therapy, IGRAs results did not change significantly.

CONCLUSIONS

Almost 20% of CIA patients had some evidence of LTBI, suggesting higher conversion rate after exposition to TNFi. TST was effective in identifying new cases of LTBI, but IGRAs added diagnostic power in this scenario. Our findings did not support the repetition of IGRAs after 6-Month isoniazid therapy and this approach was effective to mitigate active TB in 2 years of follow-up.

Targeting screening and treatment for latent tuberculosis infection towards asylum seekers from high-incidence countries - a model-based cost-effectiveness analysis

BACKGROUND

Enhancing tuberculosis (TB) prevention and care in a post-COVID-19-pandemic phase will be essential to ensure progress towards global TB elimination. In low-burden countries, asylum seekers constitute an important high-risk group. TB frequently arises post-immigration due to the reactivation of latent TB infection (LTBI). Upon-entry screening for LTBI and TB preventive treatment (TPT) are considered worthwhile if targeted to asylum seekers from high-incidence countries who usually present with higher rates of LTBI. However, there is insufficient knowledge about optimal incidence thresholds above which introduction could be cost-effective. We aimed to estimate, among asylum seekers in Germany, the health impact and costs of upon-entry LTBI screening/TPT introduced at different thresholds of country-of-origin TB incidence.

METHODS

We sampled hypothetical cohorts of 30-45 thousand asylum seekers aged 15 to 34 years expected to arrive in Germany in 2022 from cohorts of first-time applicants observed in 2017-2019. We modelled LTBI prevalence as a function of country-of-origin TB incidence fitted to data from observational studies. We then used a probabilistic decision-analytic model to estimate health-system costs and quality-adjusted life years (QALYs) under interferon gamma release assay (IGRA)-based screening for LTBI and rifampicin-based TPT (daily, 4 months). Incremental cost-effectiveness ratios (ICERs) were calculated for scenarios of introducing LTBI screening/TPT at different incidence thresholds.

RESULTS

We estimated that among 15- to 34-year-old asylum seekers arriving in Germany in 2022, 17.5% (95% uncertainty interval: 14.2-21.6%) will be latently infected. Introducing LTBI screening/TPT above 250 per 100,000 country-of-origin TB incidence would gain 7.3 (2.7-14.8) QALYs at a cost of €51,000 (€18,000-€114,100) per QALY. Lowering the threshold to ≥200 would cost an incremental €53,300 (€19,100-€122,500) per additional QALY gained relative to the ≥250 threshold scenario; ICERs for the ≥150 and ≥ 100 thresholds were €55,900 (€20,200-€128,200) and €62,000 (€23,200-€142,000), respectively, using the next higher threshold as a reference, and considerably higher at thresholds below 100.

CONCLUSIONS

LTBI screening and TPT among 15- to 34-year-old asylum seekers arriving in Germany could produce health benefits at reasonable additional cost (with respect to international benchmarks) if introduced at incidence thresholds ≥100. Empirical trials are needed to investigate the feasibility and effectiveness of this approach.

Occupational Infections among Dental Health Workers in Germany-14-Year Time Trends

Dental health workers (DHW) are at increased risk of acquiring occupational infections. Due to various protective measures, it can be assumed that infections have decreased over the past 14 years. Secondary data from a German accident insurance company was analyzed in terms of reported and confirmed occupational diseases (OD) in DHW from 2006 to 2019. A total of 271 claims were reported, of which 112 were confirmed as OD, representing an average of eight per year. However, the number of claims and confirmed ODs has decreased by 65.6% and 85.7%, respectively. The decrease was most evident for hepatitis B (HBV) and C (HCV) infections, while tuberculosis (TB) infections were stable. A total of 44 HCV, 33 HBV, 6 TB and 24 latent TB infections were confirmed as ODs. For DHW, 0.05, and for hospital workers, 0.48 claims per 1000 full-time equivalents (FTE) were registered in 2019. In a separate documentation system, between March 2020 and February 2021, 155 COVID-19 claims were registered, and 47 cases were confirmed as ODs. For DHW, 0.7, and for hospital workers, 47.3 COVID-19 claims per 1000 FTE were registered since 2020. Occupational infectious diseases rarely occur among DHW. Nevertheless, new infectious diseases such as COVID-19 pose a major challenge for DHW. Continued attention should be paid to infectious disease prevention.

Combined IFN-γ and IL-2 release assay for detect active pulmonary tuberculosis: a prospective multicentre diagnostic study in China

BACKGROUND

We performed a prospective multicentre diagnostic study to evaluate the combined interferon-γ (IFN-γ) and interleukin-2 (IL-2) release assay for detect active pulmonary tuberculosis (TB) in China.

METHODS

Adult patients presenting symptoms suggestive of pulmonary TB were consecutively enrolled in three TB-specialized hospitals. Sputum specimens and blood sample and were collected from each participant at enrolment. The levels of Mycobacterium tuberculosis (MTB)-specific antigen-stimulated IFN-γ and IL-2 were determined using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Between July 2017 and December 2018, a total of 3245 patients with symptoms suggestive of pulmonary TB were included in final analysis. Of 3245 patients, 2536 were diagnosed as active TB, consisting of 1092 definite TB and 1444 clinically diagnosed TB. The overall sensitivity and specificity of IFN-γ were 83.8% and 81.5%, respectively. In addition, compared with IFN-γ, the specificity of IL-2 increased to 94.3%, while the sensitivity decreased to 72.6%. In addition, the highest sensitivity was achieved with parallel combination of IFN-γ/IL-2, with a sensitivity of 87.9%, and its overall specificity was 79.8%. The sensitivity of series combination test was 68.5%. Notably, the sensitivity of series combination test in definite TB (72.1%) was significantly higher than that in clinically diagnosed TB (65.8%).

CONCLUSION

In conclusion, we develop a new immunological method that can differentiate between active TB and other pulmonary diseases. Our data demonstrates that the various IFN-γ/IL-2 combinations provides promising alternatives for diagnosing active TB cases in different settings. Additionally, the diagnostic accuracy of series combination correlates with severity of disease in our cohort.