Tuberculosis Screening Tests Research Articles

Host blood protein biomarkers to screen for tuberculosis disease: a systematic review and meta-analysis.

To our knowledge, this is the first comprehensive systematic review of host blood protein biomarkers for tuberculosis (TB), and we identified promising biomarkers for a TB screening test.

Analysis of Indeterminate QuantiFERON Assay Results in Solid Organ Transplant Candidates and Proposed Management Algorithm.

Identification and treatment of latent tuberculosis infection (LTBI) mitigate the risk of tuberculosis (TB) reactivation after transplantation. TB reactivation is higher in those with indeterminate QuantiFERON (QFT) than those with negative results. Management of indeterminate QFT results in the pretransplant period remains unclear. We conducted a retrospective study of solid organ transplant (SOT) recipients, 18 y and older, who were screened with QFT assay pretransplantation at Mayo Clinic between January 2010 and June 2023. We examined the frequency of indeterminate QFT results, results of repeat LTBI screening, treatment decisions, and rate of posttransplant TB infection. Of 13 008 patients screened for LTBI before SOT, 736 (6%) patients had indeterminate QFT results. Among these, 247 (34%) underwent a second LTBI screening test, and 39 (5%) received LTBI treatment. Among 247 patients with a repeat LTBI screening test, 185 (75%), 48 (19%), and 14 (6%) were tested by QFT, T-SPOT.TB, or TST, respectively. The repeat QFT remained indeterminate in 160 (86%) patients, whereas all T-SPOT.TB results were negative. Posttransplant TB infection occurred in 2 (0.3%) patients; neither had a second TB screening test pretransplant nor received LTBI treatment. In SOT recipients with indeterminate QFT results at pretransplant evaluation, opting for T-SPOT.TB as a second test may be preferable over repeat QFT. TB infection after transplantation in patients with a pretransplant indeterminate QFT result was rare. Patient management and LTBI treatment in those with indeterminate QFT pretransplant should account for epidemiological risk factors, and shared decision-making is recommended.

Effectiveness of C-Reactive Protein as a Tuberculosis Screening Test Among HIV-Infected Individuals - Shanghai, China, 2021-2023.

The World Health Organization (WHO) has recommended the inclusion of the C-reactive protein (CRP) test in active tuberculosis (ATB) screening algorithms among human immunodeficiency virus (HIV)-infected individuals. The performance of the CRP test in African regions has been well-documented. This study analyzed data from a big data platform of Shanghai medical records together with infectious disease surveillance systems. We simulated a screening and plotted a receiver operating characteristic (ROC) curve, which gives the optimal cut-off value of 11.115mg/L with sensitivity and specificity of 0.784 and 0.723, respectively. We obtained a promising perspective on screening for tuberculosis in people living with HIV (PLHIV) using the CRP test in Shanghai. Our study offers an original standpoint for following research.

Head-to-head comparison of diagnostic accuracy of TB screening tests: Chest-X-ray, Xpert TB host response, and C-reactive protein.

Accessible, accurate screening tests are necessary to advance tuberculosis (TB) case finding and early detection in high-burden countries. We compared the diagnostic accuracy of available TB triage tests. We prospectively screened consecutive adults with ≥2 weeks of cough presenting to primary health centers in the Philippines, Vietnam, South Africa, Uganda, and India. All participants received the index tests: chest-X-ray (CXR), venous or capillary Cepheid Xpert TB Host Response (HR) testing, and point-of-care C-reactive protein (CRP) testing (Boditech iChroma II). CXR images were processed using computer-aided detection (CAD) algorithms. We assessed diagnostic accuracy against a microbiologic reference standard (sputum Xpert Ultra, culture). Optimal cut-points were chosen to achieve sensitivity ≥90% and maximize specificity. Two-test screening algorithms were considered, using two approaches: 1) sequential negative serial screening in which the second screening test is conducted only if the first is negative and positive is defined as positive on either test and 2) sequential positive serial screening, in which the second screening test is conducted only if the first is positive and positive is defined as positive on both tests. Between July 2021 and August 2022, 1,392 participants with presumptive TB had valid results on index tests and the reference standard, and 303 (22%) had confirmed TB. In head-to-head comparisons, CAD4TB v7 showed the highest specificity when using a cut-point that achieves 90% sensitivity (70.3% vs. 65.1% for Xpert HR, difference 95% CI 1.6 to 8.9; 49.7% for CRP, difference 95% CI 17.0 to 24.3). Among the possible two-test screening algorithms, three met WHO target product profile (TPP) minimum accuracy thresholds and had higher accuracy than any test alone. At 90% sensitivity, the specificity was 79.6% for Xpert HR-CAD4TB [sequential negative], 75.9% for CRP-CAD4TB [sequential negative], and 73.7% for Xpert HR-CAD4TB [sequential positive]. CAD4TB achieves TPP targets and outperforms Xpert HR and CRP. Combining screening tests further increased accuracy. Cost and feasibility of two-test screening algorithms should be explored. NCT04923958.

Sensitivity and specificity of newly generated monoclonal antibodies to detect novel antigens of Mycobacterium tuberculosis for the diagnosis of all forms of tuberculosis

Objectives: Tuberculosis (TB) is curable if diagnosed correctly and promptly. However, the lack of effective and accessible point-of-care tests hindered the systematic screening of TB. The current TB diagnostic methods, including molecular tests, have failed to deliver the capacity needed in the endemic countries to restrict the ongoing pandemic. The detection of Mycobacterium tuberculosis by serology offers several advantages, including rapid and low-cost disease detection. Earlier, we had evaluated the diagnostic utility of five novel recombinant antigens, namely, SS-1, SS-2, SS-3, SS-4, and SS-5, with Indian patient sera. However, antibody detection has some limitations, and therefore, in the present study, we aimed to generate monoclonal antibodies and explore the utility of the most promising antibodies for the detection of TB. Materials and Methods: We used the three best recombinant antigens, that is, Rv2145c (SS-1), Rv1827 (SS-4), and Rv2970c (SS-5) for the generation of monoclonal antibodies. The monoclonal antibodies were developed using hybridoma technology. Further, the diagnostic utility of these monoclonal antibodies was evaluated in diagnosis of TB by sandwich enzyme-linked immunosorbent assay. Serum samples from bacteriologically confirmed TB cases and controls were used. Statistical Analysis: All statistical analysis was carried out using STATA-11.1 software (StataCorp LP, Texas, USA). The sensitivity and specificity were computed using an online tool (OpenEpi). Statistically significant differences between groups were defined as p<0.05. Results: A total of 384 serum samples were included in the study. This included 144 pulmonary TB cases, 68 extrapulmonary TB cases, 50 disease controls and 125 healthy controls. The sensitivity and specificity of our three monoclonal antibodies (mAb_SS-1, mAb_SS-4, and mAb_SS-5) for detecting all forms of TB ranged from 86.49% to 97.44% and 96.57% to 98.29%, respectively. The receiver operative characteristic curve showed a significant statistical difference between TB and healthy subjects (P < 0.001). Conclusions: Our data suggested that mAb_SS-1, mAb_SS-4, and mAb_SS-5 could be used as potential TB screening tests, especially in the resource-limiting setting.

EMPOWERMENT OF HOUSEWIVES IN EARLY DETECTION OF CHILDREN'S PULMONARY TB IN THE RW 8 AREA, PUTAT JAYA DISTRICT SURABAYA

Tuberculosis (TB) in Indonesia has been detected to be increasing in recent years. Community involvement in tackling TB disease is very necessary. Child TB cases are not clearly visible if the family does not understand the signs and symptoms they cause. There is a need for knowledge regarding early detection of pulmonary TB in children through TB ​​screening. In an effort to reduce the increase in children's TB, the participation of the family is needed, especially the mother who is currently the closest to the child. The aim of this community service is to increase the knowledge of housewives in early detection of TB disease in children. Community service activities include counseling, presentation of material, simulations and applying TB screening tests directly to children. This activity is carried out by 20 housewives from each RT, represented by 2 people. The activity lasts for 2 days. Empowerment and education through counseling proven to be able to increase the knowledge of housewives in carrying out TB screening in children in the area. It was found that the number screened was 152 children, consisting of cases without risk, 111 children, at risk/exposed: 26 people at risk, 15 people. It is hoped that this empowerment of housewives can continue optimally and sustainably so that the results of the discovery of suspected TB cases in children can be followed up by health workers at Community Health Centers in an effort to prevent and reduce the incidence of TB in children.

Thinking beyond diagnostic accuracy to evaluate tuberculosis screening tests

Thinking beyond diagnostic accuracy to evaluate tuberculosis screening tests

The accuracy of point-of-care C-Reactive Protein as a screening test for tuberculosis in children.

Systematic screening for TB in children, especially among those at high risk of TB, can promote early diagnosis and treatment of TB. The World Health Organization (WHO) recently recommended C-Reactive Protein as a TB screening tool in adults and adolescents living with HIV (PLHIV). Thus, we aimed to assess the performance of point-of-care (POC) CRP as a screening tool for TB in children. A cross-sectional study was conducted at 2 primary health care facilities in Lusaka, Zambia between September 2020 -August 2021. Consecutive children (aged 5-14 years) presenting for TB services were enrolled irrespective of TB symptoms. All participants were screened for the presence of TB symptoms and signs, asked about TB contact history, and undertook a POC CRP test, chest X-ray, and sputum Xpert MTB/RIF Ultra test. The accuracy of CRP (≥10 mg/L cutoff) was determined using a microbiological reference standard (MRS) and a composite reference standard (CRS). Of 280 children enrolled and with complete results available, the median age was 10 years (IQR 7-12), 56 (20.0%) were HIV positive, 228 (81.4%) had a positive WHO symptom screen for TB, 62 (22.1%) had a close TB contact, and 79 (28.2%) had a positive CRP POC test. Five (1.8%) participants had confirmed TB, 71 (25.4%) had unconfirmed TB, and 204 (72.3%) had unlikely TB. When the MRS was used, the sensitivity of CRP was 80.0% (95%CI: 28.4-99.5%) and the specificity was 72.7% (95%CI: 67.1-77.9%). When the CRS was used, the sensitivity of CRP was 32.0% (95%CI: 23.3% - 42.5%), while the specificity was 74.0% (95%CI: 67.0% - 80.3%). Using the CRS, there were no statistically significant differences in sensitivity and specificity of CRP in the HIV positive and HIV negative individuals. Among children in Zambia, POC CRP had limited utility as a screening tool for TB. There remains a continued urgent need for better tools and strategies to improve TB detection in children.

Analysis of Risk Factors for Developing Tuberculosis in Patients Who Received Prophylactic Latent Tuberculosis Infection Treatment with Experience of Biologic Medications.

Biologic medications have dramatically improved the treatment outcomes of immunological inflammatory diseases, but their immunosuppressive effects put patients at risk for tuberculosis (TB). We investigated the risk factors for developing TB in patients treated for latent tuberculosis infection (LTBI) who also had experience of using biologic medications. At Keio University Hospital, we retrospectively investigated patients treated with anti-mycobacterial drugs before or concurrently with biologic medications from January 2012 to August 2020. Patients in the 'follow-on cases group' who had a positive TB screening test after initiating biologic medications and subsequently started LTBI treatment were excluded. We researched and compared the patient characteristics for TB and non-TB patient groups. Of the 146 eligible patients, 5 (3.4%) developed TB. The incidence rate was 600/100000 person-years. There were no significant differences between TB and non-TB patient groups in the history of TB, interferon-gamma release assay (IGRA), duration of biologic medication therapy, LTBI treatment periods, concomitant use of calcineurin inhibitors or anti-rheumatic drugs. The percentage of patients who received prednisolone at a dose of ≥15 mg for more than 1 month was higher in those who developed TB than in those who did not (40.0 vs. 7.1%, p = 0.054); however, this difference was not statistically significant. Regular monitoring of TB is necessary for long-term concomitant use of high prednisolone doses during and after the administration of biologic medications.

Tuberculosis and HIV co-infection among miners at selected mining sites in Migori County, Kenya

Tuberculosis (TB) disease is caused by acid-fast bacilli called Mycobacterium tuberculosis. The emergence of drug-resistant TB variants as well as co-infection with the Human Immunodeficiency Virus (HIV) have complicated treatment for TB. Kenya currently implements TB screening and HIV testing for all patients and their caretakers, regardless of their reason for visiting the hospitals. Drug resistance is tested in all HIV-positive TB suspects to guide the choice of drugs in cases of TB-HIV co-infection and minimise delays in treatment initiation. These services are, however, confined to the health facilities, and all those who do not visit the hospitals are missed. The objective of our study was to evaluate TB missed opportunities among the mining community of Osiri-Matanda gold mines in Nyatike sub-county, Migori County, Kenya. Community health outreaches were conducted in collaboration with the Ministry of Health. Demographic information was recorded for all clients consenting to the study. HIV testing was done using the HIV rapid testing kits. Sputum samples were tested in the local laboratory using Ziel-Neelsen (ZN) staining. All TB-positive outcomes were further tested using GeneXpert MTB/RIF to determine whether or not they were resistant to Rifampicin. A total of 297 participants were enrolled in the study. Among these, 49.5% were males and 50.5% were females. The youngest participant was 15 years old, while the oldest was 63 years old. A 15.5% TB prevalence was found after testing, with the age range of 35–44 having the highest prevalence at 39%. 71.7% of TB infections were male, while 28.3% were female. HIV-TB co-infections accounted for 37% of cases. None of the TB cases were RIF-resistant. This data shows that males are more at risk of TB and HIV infections than females. Collaborative health outreaches that include screening and testing for both TB and HIV could help in early detection and minimise missed opportunities.

Cost-effectiveness of Low-complexity Screening Tests in Community-based Case-finding for Tuberculosis.

In high-burden settings, low-complexity screening tests for tuberculosis (TB) could expand the reach of community-based case-finding efforts. The potential costs and cost-effectiveness of approaches incorporating these tests are poorly understood. We developed a microsimulation model assessing 3 approaches to community-based case-finding in hypothetical populations (India-, South Africa-, The Philippines-, Uganda-, and Vietnam-like settings) with TB prevalence 4 times that of national estimates: (1) screening with a point-of-care C-reactive protein (CRP) test, (2) screening with a more sensitive "Hypothetical Screening test" (95% sensitive for Xpert Ultra-positive TB, 70% specificity; equipment/labor costs similar to Xpert Ultra, but using a $2 cartridge) followed by sputum Xpert Ultra if positive, or (3) testing all individuals with sputum Xpert Ultra. Costs are expressed in 2023 US dollars and include treatment costs. Universal Xpert Ultra was estimated to cost a mean $4.0 million (95% uncertainty range: $3.5 to $4.6 million) and avert 3200 (2600 to 3900) TB-related disability-adjusted life years (DALYs) per 100 000 people screened ($670 [The Philippines] to $2000 [Vietnam] per DALY averted). CRP was projected to cost $550 (The Philippines) to $1500 (Vietnam) per DALY averted but with 44% fewer DALYs averted. The Hypothetical Screening test showed minimal benefit compared to universal Xpert Ultra, but if specificity were improved to 95% and per-test cost to $4.5 (all-inclusive), this strategy could cost $390 (The Philippines) to $940 (Vietnam) per DALY averted. Screening tests can meaningfully improve the cost-effectiveness of community-based case-finding for TB but only if they are sensitive, specific, and inexpensive.

Advances in TB testing.

Globally, tuberculosis (TB) was the leading cause of death from a single infectious agent until the coronavirus (COVID-19) pandemic. In 2020, an estimated 10 million people fell ill with TB and a total of 1.5 million people died from the disease. About one-quarter of the global population, almost two billion people, is estimated to be latently infected with Mycobacterium tuberculosis (MTB). Although latent TB infection (LTBI) is asymptomatic and noncontagious, about 5-10% of LTBI patients have a lifetime risk of progression to active TB. The diagnosis and treatment of active cases are extremely vital for TB control programs. However, achieving the End TB goal of 2035 without the ability to identify and treat the pool of latently infected individuals will be a big challenge. To do so, improved technology to provide more accurate diagnostic tools and accessibility are crucial. Therefore, this chapter covers the current WHO-endorsed tests and advances in diagnostic and screening tests for active and latent TB.

Economic analysis of different throughput scenarios and implementation strategies of computer-aided detection software as a screening and triage test for pulmonary TB.

Artificial Intelligence (AI) systems have demonstrated potential in detecting tuberculosis (TB) associated abnormalities from chest X-ray (CXR) images. Thus, they might provide a solution to radiologist shortages in high TB burden countries. However, the cost of implementing computer-aided detection (CAD) software has thus far been understudied. In this study, we performed a costing analysis of CAD software when used as a screening or triage test for pulmonary TB, estimated the incremental cost compared to a radiologist reading of different throughput scenarios, and predicted the cost for the national scale-up plan in Pakistan. For the study, we focused on CAD software reviewed by the World Health Organization (CAD4TB, Lunit INSIGHT CXR, qXR) or listed in the Global Drug Facility diagnostics catalogue (CAD4TB, InferRead). Costing information was obtained from the CAD software developers. CAD4TB and InferRead use a perpetual license pricing model, while Lunit and qXR are priced per license for restricted number of scans. A major implementer in Pakistan provided costing information for human resource and software training. The per-screen cost was estimated for each CAD software and for radiologist for 1) active case finding, and 2) facility based CXR testing scenarios with throughputs ranging from 50,000-100,000 scans. Moreover, we estimated the scale-up cost for CAD or radiologist CXR reading in Pakistan based on the National Strategic Plan, considering that to reach 80% diagnostic coverage, 50% of TB patients would need to be found through facility-based triage and 30% through active case finding (ACF). The per-screen cost for CAD4TB (0.25 USD- 2.33 USD) and InferRead (0.19 USD- 2.78 USD) was lower than that of a radiologist (0.70 USD- 0.93 USD) for high throughput scenarios studied. In comparison, the per-screen cost for Lunit (0.94 USD- 1.69 USD) and qXR (0.95 USD-1.9 USD) were only comparable with that of the radiologists in the highest throughput scenario in ACF. To achieve 80 percent diagnostic coverage at scale in Pakistan, the projected additional cost of deploying CAD software to complement the current infrastructure over a four-year period were estimated at 2.65-19.23 million USD, whereas Human readers, would cost an additional 23.97 million USD. Our findings suggest that using CAD software could enable large-scale screening programs in high TB-burden countries and be less costly than radiologist. To achieve minimum cost, the target number of screens in a specific screening strategy should be carefully considered when selecting CAD software, along with the offered pricing structure and other aspects such as performance and operational features. Integrating CAD software in implementation strategies for case finding could be an economical way to attain the intended programmatic goals.

Questionnaire survey analysis on the screening of tuberculosis among diabetic patients in general hospitals of Hunan Province

Objective: To investigate the development of tuberculosis screening-related tests in general public hospitals(GPHs) of different levels in Hunan Province and the"awareness and practice of screening tuberculosis in diabetic patients"by doctors directly involved in diabetes diagnosis and treatment in the hospitals, aiming to provide reference for the formulation of the tuberculosis-diabetes joint prevention and control activity plan based on our national conditions. Methods: Stratified sampling was used to select 43 GPHs at three different levels in Hunan province: 14 tertiary GPHs, 13 secondary GPHs, and 16 primary GPHs. 284 endocrinologists working in enrolled hospitals were invited to participate in the on-site questionnaire-survey and 277 qualified. The study used SPSS 22.0 statistical software to analyze the data. The prevalence rate of tuberculosis screening test among hospitals at all levels was compared by chi-square test, and logistic regression was used to analyze the related factors affecting doctors' screening awareness. P≤0.05 was considered statistically significant. Results: The allocation of digital X-ray cameras, tuberculin skin tests, sputum acid-fast bacillus smears, sputum cultures for Mycobacterium tuberculosis, and interferon-gamma release assays in the 43 GPHs were 90.7% (39/43), 72.1% (31/43), 55.8% (24/43), 34.9% (15/43), 27.9% (12/43) with significant differences between the different hospital levels(P<0.05). 173 endocrinologists considered it necessary to proactively initiate tuberculosis screening for patients at first diagnosis. When admitting patients, 197 endocrinologists chose tuberculosis screening only for diabetes mellitus patients with suspected tuberculosis symptoms. The most possible reasons why diabetes mellitus patients wouldn't undergo tuberculosis screening were"patients refused(76.5%, 212/277)","patients didn't complain of the symptom(46.9%, 130/277)", and"tuberculosis screening-related tests haven't been conducted in the hospital(35.7%, 99/277)". Conclusions: Although endocrinologists displayed some tuberculosis-related knowledge and awareness of the need for proactive tuberculosis screening, the actual screening rate in the clinical setting was low. This may be related to multiple factors, including those of patients, doctors, and medical institutions.

C-Reactive Protein as a Screening Test for Tuberculosis in People Living with HIV in Southern India: A Cross-Sectional, Observational Study.

Background: Tuberculosis is the leading cause of mortality in people living with HIV(PLHIV). We assessed the utility of C-reactive protein (CRP) as a screening test for tuberculosis (TB) in PLHIV. Methods: We performed a cross-sectional, observational study on 150 HIV patients visiting the Anti-Retroviral Therapy (ART) center for the follow up of their ART treatment. Patients who screened positive on the WHO symptom screen were included in the study. C-reactive protein levels in the blood were measured, and the patients were followed up with for a confirmatory diagnosis of tuberculosis. Results: The ideal cut-off for CRP was found to be 8.25. There was a statistically significant relationship between the CRP value and tuberculosis positivity (p value < 0.001). The CRP value had a sensitivity of 70.13%, a specificity of 69.86%, a positive predictive value of 71.05%, a negative predictive value of 68.92%, and a total diagnostic accuracy of 70% in patients who screened positive on the WHO symptom screen. Conclusion: CRP is a valuable screening tool and should be added to the tuberculosis screening algorithm to improve the diagnostic accuracy of screening for tuberculosis in people living with HIV.

Rates of latent and active tuberculosis in BGC vaccinated, immunosuppressed Crohn's disease patients form Bulgaria before and during anti-tumor necrosis factor therapy.

Although the use of anti-tumor necrosis factor-alpha (anti-TNF-α) agents is highly effective in achieving and maintaining remission in patients with moderate-to-severe IBD, they place the patient at increased risk of developing opportunistic infections, including new cases of tuberculosis infection (TBI) and/or reactivation of latent tuberculosis infection (LTBI). Our study aims to determine the incidence of TBI [active tuberculosis (ATBI) and LTBI] among patients with Crohn's disease (CD) receiving anti-TNF-α therapy. We performed a retrospective analysis of consecutive CD patients undergoing anti-TNF-α (infliximab, adalimumab) treatment for a minimum of 6 months, in the period between June 2010 and December 2019, followed-up at a reference IBD center. All patients were HIV negative, and BCG vaccinated. In all patients, ATBI was excluded and all were tested for LTBI prior to initiating a biological treatment. Before starting the biological treatment, we established LTBI in 11/109 (10.1%): 8/11 (72.7%) patients were TST positive, 2/11 (18.2%) were IGRA positive and TST negative, 1/11 (9.1%) were both IGRA and TST positive. In patients undergoing biological therapy with previous negative screening test for tuberculosis, a total of 16/74 (21.6%) patients were newly diagnosed with LTBI. The median induration (not erythema) diameter of TST is 8 (IQR 5-17) mm. Active pulmonary tuberculosis infection, developed in 3/74 (4.1%) patients. One patient developed ATBI on the background of chemoprophylaxis with INH for LTBI. Specialists should thoroughly analyse all patient clinical data, chest X-ray results, epidemiological and BCG status, as well as perform a LTBI screening before initiating immunosuppressive and/or biological treatment. IBD patients have a higher risk of developing TBI in the first 12 months.

Impact of Immunosuppressive Therapy on the Performance of Latent Tuberculosis Screening Tests in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

Screening for latent tuberculosis infection (LTBI) is mandatory before commencing tumor necrosis factor (TNF)-α inhibitor use. However, the impact of immunosuppressive therapy (IST), including corticosteroids and immunomodulators, on the performance of LTBI screening in patients with inflammatory bowel disease (IBD) has not been fully elucidated. We searched all relevant studies published before November 2021 that examined the performance of interferon γ release assays (IGRAs) and tuberculin skin tests (TSTs) in patients with IBD who received IST, using the Medline, EMBASE, and Cochrane Library databases. We performed meta-analyses of positive or indeterminate rates of IGRA or TST according to IST and calculated the concordance rates between IGRA and TST results. A total of 20 studies with 4045 patients were included in the meta-analysis. The IGRA-positive rate was lower in patients on IST than in those not on IST (odds ratio (OR) (95% confidence interval (CI)) = 0.55 (0.39–0.78)), whereas the IGRA-indeterminate rate was higher in patients on IST than in those not on IST (OR (95% CI) = 2.91 (1.36–6.24)). The TST-positive rate did not differ between the on-IST and not-on-IST groups (OR (95% CI) = 0.87 (0.51–1.50)). The concordance rate between IGRA and TST was 83.3% (95% CI, 78.5–88.1%). The IGRA-negative/TST-positive rate tended to be higher than that the IGRA-positive/TST-negative rate (9.5% vs. 5.8%, respectively), although the difference was not statistically significant. In conclusion, IGRA results were negatively affected by IST in patients with IBD, supporting requirements that IGRA should be performed before initiating IST. The use of both an IGRA and TST in patients with IBD on IST may improve the diagnosis rate of LTBI.

Update of the mechanism and characteristics of tuberculosis in chronic kidney disease : Review article.

The risk of tuberculosis (TB) is significantly increased in patients with chronic kidney disease (CKD), which is closely related to hyperparathyroidism, malnutrition and oxidative stress as well as immune deficiency in patients with end-stage renal disease (ESRD). VitaminD deficiency and gender bias are independent risk factors. In the TB screening and diagnosis test of CKD, interferon-gamma release assays (IGRA), including T‑SPOT.TB test (T-SPOT) and QuantiFERON-TB Gold In-Tube (QFT-GIT) have been available. Many studies have found that they are more sensitive and specific than tuberculin skin test (TST). At present, IGRA has been used to study various types of immunocompromised patients. For CKD patients with TB, the choice and dosage of anti-TB drugs need to be reconsidered. Weekly treatment with rifapentin (RFT) and isoniazid (INH) for 3 months is an effective treatment for latent tuberculosis infection (LTBI) in hemodialysis (HD) patients. Therefore, in this review we discuss CKD and TB, its pathogenesis, clinical features, diagnosis and treatment advancements.

Conversion Rate of Tuberculosis Screening Tests among Dermatology Patients Treated with Tumor Necrosis Factor Inhibitors.

Background:The use of tumor necrosis factor-α inhibitors (TNFi) has been associated with an increased risk latent tuberculosis (TB) reactivation. The role of TB screening assays in monitoring patients during TNFi therapy remains uncertain. Spontaneous conversions and reversions have been described.Aims:This study aims to determine the conversion and reversion rate of TB screening tests among dermatology patients receiving TNFi in a country with moderate TB incidence.Subjects and Methods:A retrospective single-center study conducted on all patients in whom treatment with TNFi was initiated in our dermatology clinic in a tertiary university hospital, Riyadh, Saudi Arabia, until September 2018. Data were collected from the hospital electronic patient information system.Results:One hundred and eighteen patients were included. Majority (79.9%) of patients used adalimumab. Psoriasis was the most common indication (90%). Among patients with negative baseline TB screening who had been retested during TNFi therapy (n = 65; 55%), conversion to positive was observed in nine patients (13.8%) with a mean duration of exposure of 39.7 months, whereas among patients with positive TB testing result (n = 18), 10 (55.5%) reverted to negative.Conclusions:This study emphasizes the need for prospective large-scale multispecialty studies assessing the significance of TB retesting, which should be considered when designing rescreening protocols.

An Analysis of Xpert Test for Diagnosing Maxillofacial Tuberculosis.

Maxillofacial tuberculosis is a diagnostic challenge for surgeons. The aim of this study was to present a detailed analysis of Xpert test in diagnosing maxillofacial tuberculosis and to analyse the accuracy of Xpert test results for various tissues of maxillofacial region. In this cross-sectional study, patients were selected randomly from outpatient department. The patients who had clinical picture and differential diagnosis highly suggestive of maxillofacial tuberculosis were included. Patients were divided into three different groups depending upon the site of involvement. The samples collected from the patients were further subdivided depending upon the type of specimen. Patients were screened first by routine tests, and the negative cases were followed by Xpert test for tuberculosis. A total of 54 patients were enrolled in the study, 13 patients were found to be positive for maxillofacial tuberculosis on routine screening tests for tuberculosis, and 41 tested negative on routine test and were evaluated further through Xpert test. Specimens from bone (n12), soft tissue and skin biopsy (n15) and aspirates from lymph nodes (n14) were obtained and tested. Twenty-one samples were found to be positive, and 20 were negative upon Xpert testing. There was a statistically significant difference seen between the test groups (p < 0.01) with higher frequency of negative results in routine test. The p value for various specimens containing pus, biopsies and aspirates was 0.045, 0.023 and 0.067, respectively. Xpert test is more accurate when compared to routine test for diagnosing maxillofacial tuberculosis. Although accuracy of Xpert test is better for pus and biopsy samples in the specimens from bone and soft tissue, it gives poor accuracy for aspirated cells. The aspirates from lymph nodes were more susceptible for false negative test.