Comparison of tuberculin skin test and QuantiFERON-TB gold in tube test in patients with chronic inflammatory diseases living in a tuberculosis endemic population

2022 EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in adults with autoimmune inflammatory rheumatic diseases

Objectives

To develop EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in patients with autoimmune inflammatory rheumatic diseases (AIIRD).

Methods

An international Task Force (TF) (22 members/15 countries) formulated recommendations, supported by systematic literature review findings. Level of evidence and grade of recommendation were assigned for each recommendation. Level of agreement was provided anonymously by each TF member.

Results

Four overarching principles (OAP) and eight recommendations were developed. The OAPs highlight the need for infections to be discussed with patients and with other medical specialties, in accordance with national regulations. In addition to biologic/targeted synthetic disease-modifying antirheumatic drugs (DMARDs) for which screening for latent tuberculosis (TB) should be performed, screening could be considered also before conventional synthetic DMARDs, glucocorticoids and immunosuppressants. Interferon gamma release assay should be preferred over tuberculin skin test, where available. Hepatitis B (HBV) antiviral treatment should be guided by HBV status defined prior to starting antirheumatic drugs. All patients positive for hepatitis-C-RNA should be referred for antiviral treatment. Also, patients who are non-immune to varicella zoster virus should be informed about the availability of postexposure prophylaxis should they have contact with this pathogen. Prophylaxis againstPneumocystis jiroveciiseems to be beneficial in patients treated with daily doses >15–30 mg of prednisolone or equivalent for >2–4 weeks.

Conclusions

These recommendations provide guidance on the screening and prevention of chronic and opportunistic infections. Their adoption in clinical practice is recommended to standardise and optimise care to reduce the burden of opportunistic infections in people living with AIIRD.

Systematic literature review informing the 2022 EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in adults with autoimmune inflammatory rheumatic diseases

OBJECTIVE

To conduct a systematic literature review (SLR) on the screening and prophylaxis of opportunistic and chronic infections in autoimmune inflammatory rheumatic diseases (AIIRD).

METHODS

SLR (inception-12/2021) based on the following search domains: (1) infectious agents, (2) AIIRD, (3) immunosuppressives/immunomodulators used in rheumatology, (4) screening terms and (5) prophylaxis terms. Articles were retrieved having the terms from (1) AND (2) AND (3) plus terms from (4) OR(5). Databases searched: PubMed, Embase and Cochrane Library.

EXCLUSION CRITERIA

studies on postoperative infections, paediatric AIIRD, COVID-19, vaccinations and non-Εnglish literature. Study quality was assessed with Newcastle-Ottawa scale for non-randomised controlled trials (RCTs), RoB-Cochrane for RCTs, AMSTAR2 for SLRs.

RESULTS

From 5641 studies were retrieved, 568 full-text articles were assessed for eligibility, with 194 articles finally included. For tuberculosis, tuberculin skin test (TST) is affected by treatment with glucocorticoids and conventional synthetic disease modifying anti-rheumatic drugs (DMARDs) and its performance is inferior to interferon gamma release assay (IGRA). Agreement between TST and IGRA is moderate to low. For hepatitis B virus (HBV): risk of reactivation is increased in patients positive for hepatitis B surface antigen. Anti-HBcore positive patients are at low risk for reactivation but should be monitored periodically with liver function tests and/or HBV-viral load. Risk for Hepatitis C reactivation is existing but low in patients treated with biological DMARDs. For Pneumocystis jirovecii, prophylaxis treatment should be considered in patients treated with prednisolone ≥15-30 mg/day for >2-4 weeks.

CONCLUSIONS

Different screening and prophylaxis approaches are described in the literature, partly determined by individual patient and disease characteristics.

Diagnostic Tests for Latent Tuberculosis Infection

Diagnosing latent tuberculosis (TB) infection (LTBI) is important globally for TB prevention. LTBI diagnosis requires a positive test for infection and negative evaluation for active disease. Current tests measure an immunologic response and include the tuberculin skin test (TST) and interferon-gamma release assays (IGRAs), T-SPOT.TB and QuantiFERON. The IGRAs are preferred in bacille Calmette-Guérin-vaccinated populations. The TST is still used when cost or logistical advantages over the IGRAs exist. Both TST and IGRAs have low positive predictive values. Tests that differentiate the TB spectrum and better predict future TB risk are needed.

Interferon-gamma release assay for the diagnosis of latent tuberculosis infection: A latent-class analysis

BACKGROUND

Accurate diagnosis and subsequent treatment of latent tuberculosis infection (LTBI) is essential for TB elimination. However, the absence of a gold standard test for diagnosing LTBI makes assessment of the true prevalence of LTBI and the accuracy of diagnostic tests challenging. Bayesian latent class models can be used to make inferences about disease prevalence and the sensitivity and specificity of diagnostic tests using data on the concordance between tests. We performed the largest meta-analysis to date aiming to evaluate the performance of tuberculin skin test (TST) and interferon-gamma release assays (IGRAs) for LTBI diagnosis in various patient populations using Bayesian latent class modelling.

METHODS

Systematic search of PubMeb, Embase and African Index Medicus was conducted without date and language restrictions on September 11, 2017 to identify studies that compared the performance of TST and IGRAs for LTBI diagnosis. Two IGRA methods were considered: QuantiFERON-TB Gold In Tube (QFT-GIT) and T-SPOT.TB. Studies were included if they reported 2x2 agreement data between TST and QFT-GIT or T-SPOT.TB. A Bayesian latent class model was developed to estimate the sensitivity and specificity of TST and IGRAs in various populations, including immune-competent adults, immune-compromised adults and children. A TST cut-off value of 10 mm was used for immune-competent subjects and 5 mm for immune-compromised individuals.

FINDINGS

A total of 157 studies were included in the analysis. In immune-competent adults, the sensitivity of TST and QFT-GIT were estimated to be 84% (95% credible interval [CrI] 82-85%) and 52% (50-53%), respectively. The specificity of QFT-GIT was 97% (96-97%) in non-BCG-vaccinated and 93% (92-94%) in BCG-vaccinated immune-competent adults. The estimated figures for TST were 100% (99-100%) and 79% (76-82%), respectively. T-SPOT.TB has comparable specificity (97% for both tests) and better sensitivity (68% versus 52%) than QFT-GIT in immune-competent adults. In immune-compromised adults, both TST and QFT-GIT display low sensitivity but high specificity. QFT-GIT and TST are equally specific (98% for both tests) in non-BCG-vaccinated children; however, QFT-GIT is more specific than TST (98% versus 82%) in BCG-vaccinated group. TST is more sensitive than QFT-GIT (82% versus 73%) in children.

CONCLUSIONS

This study is the first to assess the utility of TST and IGRAs for LTBI diagnosis in different population groups using all available data with Bayesian latent class modelling. Our results challenge the current beliefs about the performance of LTBI screening tests, and have important implications for LTBI screening policy and practice. We estimated that the performance of IGRAs is not as reliable as previously measured in the general population. However, IGRAs are not or minimally affected by BCG and should be the preferred tests in this setting. Adoption of IGRAs in settings where BCG is widely administered will allow for a more accurate identification and treatment of LTBI.

Biologic Agents and Tuberculosis

Treatment with biologic agents, in particular tumor necrosis factor alpha (TNF-α) inhibitors, is associated with an increased risk of tuberculosis (TB), and screening and treatment for latent TB infection (LTBI) in patients undergoing such treatment is therefore indicated. The risk of TB associated with different biologics varies significantly, with the highest relative risks, 29.3 and 18.6, associated with adalimumab and infliximab, respectively. The risk of TB with newer TNF-α inhibitors and other biologics appears to be lower. Performance of LTBI screening tests is affected by immune-mediated inflammatory diseases and immunosuppressive therapy in patients due to commence TNF-α inhibitor treatment. Interferon gamma release assays (IGRAs) have a higher specificity than the tuberculin skin test (TST) in patients with Bacillus Calmette–Guérin (BCG) vaccination and have probably a better sensitivity than TST in immunosuppressed patients. LTBI screening programs prior to commencement of anti-TNF-α treatment significantly reduce the incidence of TB, but the optimal screening algorithm, in particular the question of whether a combination of IGRA and TST or a single test only should be used, is a matter of ongoing debate. Use of TST in combination with IGRA is justified to increase sensitivity. Repeat testing for LTBI should be limited to patients at increased risk of TB. If TB develops during anti-TNF-α treatment, it is more likely to be disseminated and extrapulmonary than are other TB cases. Discontinuation of anti-TNF-α treatment in patients diagnosed with TB is associated with an increased risk of immune reconstitution inflammatory syndrome, which is probably best managed by reintroduction of anti-TNF-α treatment.

Interferon-Gamma Release Assays versus Tuberculin Skin Testing for the Diagnosis of Latent Tuberculosis Infection: An Overview of the Evidence

A profusion of articles have been published on the accuracy and uses of interferon-gamma releasing assays. Here we review the clinical applications, advantages, and limitations of the tuberculin skin test and interferon-gamma release assays and provide an overview of the most recent systematic reviews conducted for different indications for the use of these tests. We conclude that both tests are accurate to detect latent tuberculosis, although interferon-gamma release assays have higher specificity than tuberculin skin testing in BCG-vaccinated populations, particularly if BCG is received after infancy. However, both tests perform poorly to predict risk for progression to active tuberculosis. Interferon-gamma release assays have significant limitations in serial testing because of spontaneous variability and lack of a validated definition of conversion and reversion, making it difficult for clinicians to interpret changes in category (conversions and reversions). So far, the most important clinical evidence, that is, that isoniazid preventive therapy reduces the risk for progression to disease, has been produced only in tuberculin skin test-positive individuals.

Corticosteroids and immunosuppressive therapy influence the result of QuantiFERON TB Gold testing in inflammatory bowel disease patients

INTRODUCTION

Latent tuberculosis infection is detected by the tuberculin skin test before treating with anti-Tumour-Necrosis factor alpha (anti TNFα) reagents. More accurate are Interferon gamma release assays (IFNγ release assays) to identify patients with latent tuberculosis. Because of a positive control in this assay, it is possible to identify those patients in which a result of tuberculosis testing is not available due to a lack of stimulation capacity of lymphocytes (indeterminate result). Patients suffering from IBD are often treated with immunosuppressive agents, which may influence the results of tuberculosis testing.

AIM

The aim is to investigate the influence of immunosuppressive agents on the outcome of IFNγ-release assay.

METHODS

50 consecutive patients were documented before introducing anti-TNF-treatment in this single centre study between April 2009 and April 2010. Data of INFγ release assay for latent tuberculosis, skin test and laboratory data and current medication were enrolled.

RESULTS

For the period of one year data of 45 consecutive patients was available for statistical analysis. 24 patients out of 45 (corresponding to 53.3%) received at least low doses of corticoid treatment and 27 patients out of 45 (corresponding to 60.0%) received immunosuppressive agents. 13 patients out of 45 (corresponding to 28.9%) had an indeterminate result of the QuantiFERON test. A correlation between the indeterminate result and combination therapy of corticosteroids was found. The concomitant therapy of immunosuppressive agents lead to a lower IFN release but no significance was found.

CONCLUSIONS

Steroid treatment and further combination therapy with immunosuppressive agents lead to a high risk of indeterminate QuantiFERON test.

Comparison of QuantiFERON-TB Gold test and tuberculin skin test for the identification of latent Mycobacterium tuberculosis infection in lupus patients

The tuberculin skin test (TST) has low sensitivity for the diagnosis of tuberculosis (TB). QuantiFERON-TB Gold (QFT-G) is an IFN-gamma-release assay that measures the release of interferon-gamma after stimulation in vitro by Mycobacterium tuberculosis antigens using ELISA. The main advantage of this assay compared with TST is the lack of cross-reaction with Bacillus Calmette-Guérin (BCG) as well as most of non-tuberculous mycobacteria. The aim of our study is to compare QFT-G with TST for the detection of latent tuberculosis infection (LTBI) among patients with systemic lupus erythematosus (SLE).

Methods: Seventy-eight patients with SLE and 49 healthy subjects (HCs) participated in the study. All patients and controls were interviewed for a history of TB then BCG vaccinations were recorded and chest X-rays were examined for a sign of TB infection. QTF-G and TST were performed on both patients and controls. QTF-G results were recorded as positive, negative or indeterminate. A positive TST for SLE was defined as ≥5 mm.

Results: Seventy-six SLE patients (97.4%) had been BCG vaccinated. Similar to the HC (28.5%), 19 of 78 (24.3%) SLE patients had positive QTF-G. Two patients had an indeterminate result. The agreement between QTF-G and TST was 49/76 (64.4%) (κ = 0.33). There were fewer positive QFT-G test results than positive TST results (24.3% vs. 50%; p < 0.01). Twenty-two (28.9%) patients were TST(+)/QTF-G(−) while only 3(3.9%) patients were TST(−)/QTF-G(+). When the positive TST was defined as ≥10 mm indurations, which is the cut-off in screening for LTBI in Turkey, the agreement between two tests increased up to 58/76 (76.3%) with a κ value of 0.47. The mean TST measurements was higher in QTF-G positive patients (13.4 ± 8.8 mm) than the QTF-G negative patients (4 ± 5.3 mm) ( p < 0.001).

Discussion: In a TB-endemic and BCG vaccinated population, the QuantiFERON-TB Gold assay seemed to be a more accurate test for the detection of LTBI in SLE patients. Although 5 mm is usually accepted to be the standard cut-off for TST in immunocompromised patients such as SLE, the level of agreement between QTF-G and TST was better with a 10 mm cut-off in our population.

[Comparative performance of QuantiFERON(®)-TB Gold IT versus tuberculin skin test among contact investigations for latent tuberculosis infection]

BACKGROUND AND OBJECTIVE

Until recently, the only tool for detection of latent tuberculosis infection (LTI) was the tuberculin skin test (PPD). QuantiFERON(®)-TB Gold In-Tube (QF), as well as other Mycobacterium tuberculosis-specific interferon-γ release assays (IGRAs), appears to be an alternative or adjunct to the PPD. The goal of the study was to compare QF with PPD to evaluate de accuracy of QF for routinely identifying LTI in contact investigations.

PATIENTS AND METHOD

We performed a descriptive and prospective study with contacts of culture-confirmed tuberculosis source cases in Bizkaia and Araba from May 2007 through February 2008 who underwent QF and PPD. Concordance between both tests was analyzed using the kappa statistic (κ).

RESULTS

376 contacts were found: 8 were high-risk children (age < 15), 30 low-medium risk children, 46 high-risk adults (age>14) and 270 low-medium risk adults. PPD was positive in 160 subjects (42.5%) at PPD ≥ 5mm, 141 (37.5%) at PPD ≥ 10mm and 95 (25.3%) at PPD ≥ 15 mm. In QF analysis 94 subjects were positive, 279 negative and 3 indeterminate. Overall agreement between QF and PPD was good at PPD ≥ 10mm (κ=0.53; p<0.0001) but agreement was poor when the index case had positive baciloscopy at PPD ≥ 5mm (κ=0.28; p<0.001) and high-risk contacts at PPD ≥ 15 mm (κ=0.048; p=0.36).

CONCLUSIONS

IGRAs are an accurate indicator of LTI, providing a more specific way of diagnostic and reducing the number of subjects to be treated. QF appears to be a valuable public health tool with potential advantages over the PPD and improving resources.

Clinical experience of QuantiFERON(®) -TB Gold testing in patients with psoriasis treated with tumour necrosis factor blockers in Taiwan

BACKGROUND

In Taiwan, an intermediate tuberculosis burden country, around 9·3% of patients with rheumatoid arthritis treated with adalimumab develop tuberculosis despite prescreening with the tuberculin skin test. Within the Asia-Pacific region, the tuberculosis risk in patients with psoriasis who use tumour necrosis factor (TNF) blockers is unknown.

OBJECTIVES

This study reports the use of QuantiFERON(®) -TB Gold (QFT-G) (Cellestis, Melbourne, Vic., Australia) as a screening method for latent tuberculosis infection (LTBI) in patients with psoriasis.

METHODS

This retrospective review evaluated 216 patients with psoriasis in whom TNF blockers were considered between 2004 and 2009 in a tertiary referral hospital in Taiwan. Beginning in 2007, QFT-G was performed on all patients who were candidates for TNF blockers.

RESULTS

Seventeen patients who used TNF blockers for less than 4 weeks were excluded. Of the 147 assessed patients receiving TNF blockers, 110 (75%) underwent QFT-G tests. A total of 126 (86%) patients used etanercept and 40 (27%) patients used adalimumab. Nineteen patients switched between both. Overall, patients had a median of 24 weeks (range 4-307) exposure to TNF blockers. Twelve patients (11%) who were treated with TNF blockers and eight (15%) without TNF blockers had positive QFT-G results. Of all TNF blocker users, only one patient (0·68%) developed tuberculosis.

CONCLUSIONS

QFT-G can be used to screen for LTBI in a tuberculosis endemic area where bacille Calmette-Guérin vaccination coverage is high. Isoniazid prophylaxis is recommended for those who have positive QFT-G test results.