QuantiFERON-TB Gold In-Tube test for diagnosis of latent tuberculosis (TB) infection in solid organ transplant candidates: a single-center study in an area endemic for TB

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.

Isoniazid prophylaxis in liver transplant recipient with latent tuberculosis; Is it harmful for transplanted liver?

BACKGROUND

Liver transplantation (LT) is considered the only treatment for patients with end-stage liver disease and, despite its incredible impacts on the patients' health status, places them in an immunocompromised state in which opportunistic infection would find a way to present. Latent Tuberculosis Infection (LTBI) is the most common form of TB and can be diagnosed through Tuberculin Skin Test (TST) or Interferon-Gamma Release Assays (IGRA). LT recipients are at significant risk of TB activation. There is no strict guideline to approaching these cases though, in most centers, Isoniazid (INH) would be prescribed prophylactically. INH is a hepatotoxic medication and can have adverse effects on the transplanted liver. There is no consensus on this issue; therefore, we aimed to survey the potential hepatotoxic effects of INH among LT recipients in Shiraz, Iran.

METHODS

A retrospective cohort study was conducted among LT candidates and recipients at Abu Ali Sina Organ Transplantation Center between 1993 and 2019. All the cases underwent TST and chest X-ray to detect LTBI. All the LTBI were treated with INH from six to nine months and followed by the level of liver enzymes for quick detection of hepatotoxicity. A control group was selected among LT recipients and matched for age, gender, MELD score, and donor age.

RESULTS

Among 4895 medical records reviewed, 55 (1.12%) cases had LTBI. Neither INH-related hepatotoxicity, nor signs and symptoms that were suspicious to TB reactivation were reported. Overall, three deaths were reported, two because of myocardial infarction and one due to pneumonia. Ten patients (18.2%) experienced acute rejection as confirmed with pathology and responded to methylprednisolone. Aspartate aminotransferase (AST) was diminished from pre-LT time to the first time after transplantation; after that, it showed a steady pattern. Meanwhile, Alanine transaminase (ALT) was constant before and one stage later and decreased after that. Statistical analyses only showed significant changes in the total bilirubin titer between the case and control groups.

CONCLUSION

This survey showed prophylactic management of LTBI with INH in LT candidates and recipients was associated with no hepatotoxicity or related death. It seems INH prophylaxis is safe in LT settings and can efficiently prevent TB activation; however, careful monitoring for adverse effects and liver enzymes elevation is highly recommended. This article is protected by copyright. All rights reserved.

Evaluation of latent tuberculosis infection in liver transplant recipients

Background and Objectives:

Tuberculosis is one of the main reasons for mortality in liver transplant recipients. Since Iran is considered as a tuberculosis-endemic country, the present study aims to evaluate the outcome of latent tuberculosis infection in transplant recipients after liver transplantation.

Materials and Methods:

The present analytical cross-sectional study was performed on transplanted patients in Imam Khomeini Complex Hospital in Tehran Iran from 2006 to 2016. All patients with positive tuberculin skin test were enrolled. Variables including demographic information, therapeutic and outcome data were gathered and analyzed.

Results:

Among 675 transplant recipients, 100 patients had positive tuberculin skin test (14.8%). Sixty seven percent of recipients were men and the mean age was 72.67 ± 1.3 years. All patients’ received Isoniazid prophylaxis before transplantation. The mean duration of anti-tuberculosis prophylaxis before and after transplant were 2.7 ± 1.9 and 3.6 ± 5.5 months, respectively. Tuberculosis has not been occurred in none of these patients after a mean follow up time of 45.21 ± 3 months. During the study period, four subjects infected by Mycobacterium tuberculosis, while their skin test was negative before transplant.

Conclusion:

According to our study, tuberculin skin test is a reliable and sensitive test for diagnosis of latent tuberculosis in liver transplant candidates. Isoniazid prophylaxis is well tolerated in patients with end stage liver diseases and liver transplant recipients.

Latent tuberculosis screening before kidney transplantation in the South of Brazil

Background:

Tuberculosis (TB) is a prevalent infection after kidney transplantation (KT) in high-burden countries. Latent tuberculosis infection (LTBI) screening includes previous TB history, chest radiograph findings, and tuberculin test (TST) and/or interferon-gamma release assays (IGRAs) results. We aimed to compare our routine LTBI screening of KT candidates and living donors (LD) with their IGRA results, and evaluate if this would improve isoniazid (INH) treatment referral.

Methods:

We evaluated adult KT candidates and LD with complete routine LTBI screening and QuantiFERON-TB® Gold In-Tube (QFT) testing. Blood samples were collected from April 4th, 2014 to October 31st, 2018, with follow-up until October 31st, 2019.

Results:

There were 116 KT recipients, with 30% QFT-positive results. Positive QFT was associated with past TB history (p=0.007), positive TST (p<0.0001), residual radiographic lesions (p=0.003), and diabetes (p=0.035). There were 25 LD, 40% had positive QFT. Positive QFT was associated with a positive TST (p=0.002). Positive QFT results increased INH referral in 80%. Post-transplant TB incidence was 2.6% in a median follow-up of 2 (1-33) months. No variables were associated with post-transplant TB. TB patients had inferior, although non-significant, 5-year graft survival (66.7% vs. 76.5%) (p = 0.402).

Conclusion:

In the present study, the association of QFT to our routine LTBI screening incremented INH treatment referral, but there was still a high incidence of post-transplant TB, possibly related to other forms of infection, such as new exposure and donor transmission.

Tests for latent tuberculosis in candidates for solid organ transplantation: A systematic review and meta-analysis

Reactivation of latent tuberculosis following solid organ transplantation has serious consequences for the recipient. The most useful diagnostic test for latent TB is not clear. We conducted a systematic review and meta-analysis to assess the relative test performance of interferon gamma release assays (IGRAs) and the tuberculin skin test (TST) in people undergoing solid organ transplantation. The clinical or radiological risk factors were used as the proxy reference standard. Test performance was expressed as an odd ratio (OR). We identified 24 studies (N = 7811), 12 studies compared IGRAs with TST directly, nine studies evaluated only TST and three studies only IGRAs. Direct comparison between tests and clinical risk factors indicated both tests were strongly associated with the presence of clinical risk factors for TB (TST: OR 3.17; 95%CI 1.55-6.48, IGRA: OR 2.78; 95%CI 1.55-5.01), and radiological evidence of past TB (TST: OR 3.26; 95%CI 1.85-5.73, IGRA: OR 3.85; 95%CI 2.16-6.86). Relative comparison indicated IGRAs positivity was more strongly associated with presence of radiological evidence of TB than TST (relative OR: 3.24; 95%CI 1.10-9.56). While there is no strong evidence in supporting use of IGRAs over TST for diagnosing latent TB, IGRAs positivity is more associated with the presence of radiological evidence of previous TB.

Latent tuberculosis infection in transplant candidates: a systematic review and meta-analysis on TST and IGRA

INTRODUCTION

The diagnostic accuracy of interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST) for latent tuberculosis infection (LTBI) in transplant candidates is uncertain.

METHODS

Pubmed, Embase and Cochrane library were searched to identify relevant studies. Quality of included studies was assessed with RevMan5 software (via GUADAS2 checklist). Accuracy measures of IGRAs and TST assays (sensitivity, specificity and others) were pooled with random effects model. Data were analyzed by STATA and Meta-DiSc.

RESULTS

Twenty-eight studies were selected for full review, and 16 were included in the final analysis. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) for TST were 46% [95% confidence interval (CI) 38-54%], 86% (95% CI 75-93%), 46.3% (95% CI 40-52), 88.7% (95% CI 87-89), 3.3 (95% CI 1.6-6.4), 0.63 (95% CI 0.52-0.77) and 5 (95% CI 2-12), respectively. For QFT-G, the pooled sensitivity, specificity, PPV, NPV, PLR, NLR, and DOR were 58% (95% CI 41-73%), 89% (95% CI 77-95%), 72.7% (95% CI 68-76), 80.6% (95% CI 78-82), 5.3 (95% CI 2.0-14.0), 0.47 (95% CI 0.30-0.75) and 11 (95% CI 3-46), respectively. Likewise, for T-SPOT.TB, the pooled sensitivity, specificity, PPV, NPV, PLR, NLR, and DOR were 55% (95% CI 40-70%), 92% (95% CI 87-95%), 60.4% (95% CI 47-72), 90.2% (95% CI 86-92), 6.7 (95% CI 4.0-11.1), 0.52 (95% CI 0.31-0.85) and 16 (95% CI 7-37), respectively.

CONCLUSIONS

IGRAs were more sensitive and specific than the TST with regard to the diagnosis of LTBI in the transplant candidates. They have added value and can be complementary to TST.

Prevention and Management of Tuberculosis in Solid Organ Transplant Recipients

Solid organ transplant recipients are at an increased risk of tuberculosis and transplant candidates should be screened early in their evaluation with a detailed history, tuberculin skin test or tuberculosis interferon-gamma release assay, and chest radiograph. For latent tuberculosis treatment, isoniazid and rifamycin-based regimens have advantages and disadvantages; treatment decisions should be customized. Tuberculosis after solid organ transplantation generally occurs after months or years; early infections should raise the possibility of donor-derived infections. Tuberculosis diagnosis and treatment in solid organ transplant recipients may be complicated by protean manifestations, drug interactions, and adverse drug reactions.

Prevalence of latent tuberculosis infection in transplant candidates: A systematic review and meta-analysis

INTRODUCTION

Tuberculosis (TB) is considered as a serious complication for organ transplant recipients; therefore, the detection and appropriate treatment of latent infection are recommended for preventing active TB infections in the future. The objective of this review is to conduct a systematic review and meta-analysis of studies assessing the prevalence of latent TB infection (LTBI) in transplant candidates.

METHODS

Electronic databases, including MEDLINE (via PubMed), SCOPUS were searched until 30 June 2017. The prevalence of LTBI was estimated using the random effects meta-analysis. Heterogeneity was evaluated by subgroup analysis. Data were analyzed by STATA version 14.

RESULTS

The pooled prevalence of LTBI based on tuberculin skin test (TST) in different transplant types was as follows: liver 24% (14%-33%, 95% CI), lung 22% (18%-26%), renal 21% (16%-27%, 95% CI) and hematopoietic stem cell transplantation (HCT) 14% (9%-19%). The prevalence of LTBI based on Interferon Gamma Release Assay (IGRA) tests in renal transplant candidates was 31% (95% CI; 25-37%), which was much higher than the prevalence of LTBI in liver transplant candidates (25%, 95% CI; 17-33%) and HCT transplant candidates (13%, 95% CI; 10-16%) and there was statistically significant differences between them. The pooled prevalence of indeterminate results based on IGRAs test in different transplant types was as follows: renal 6% (4%-8%, 95% CI) and liver 12% (2%-21%, 95% CI). Subgroup analysis revealed that there were statistically significant differences between the overall prevalence of indeterminate results by using IGRA tests in liver transplant candidates (12%, 95% CI; 2-21%) and renal transplant candidates (6%, 95% CI; 4-8%). The pooled prevalence of post-transplant TB was 2% (1%-2%, 95% CI) and its occurrence was more common in renal recipients (4% (2%-7%, 95% CI)) than in the liver transplant patients (1% (0%-2%, 95% CI)). The prevalence of LTBI in the subgroup (i.e. the patients' mean age was <50 years) was significantly higher than the prevalence of LTBI by using TST/IGRAs in the other subgroup (i.e. the patients' mean age was ≥50 years).

CONCLUSION

Our study suggests fair overall agreement between IGRAs and TST in patients requiring liver and HCT transplantation, while a superiority of IGRAs over TST in patients requiring renal transplantation was seen.

Comparison of tuberculin skin test and interferon gamma release assay for diagnosis of latent tuberculosis infection in pediatric candidates of renal transplantation

IGRA has been approved as an alternative in vitro test to diagnose Mycobacterium TB infection. This study aimed to assess the diagnostic value of TST in comparison with QFT assay to detect LTBI among Iranian children candidate for renal transplantation. This cross-sectional study was performed on 31 children who were candidate for renal transplantation admitted to Ali Asghar Children's Hospital and Rasoul Akram Hospital, Tehran, Iran, from 2013 to 2014. TST and QFT were performed for all patients. QFT was negative in all patients, while TST was positive only in one case. Both tests results were negative in 30 patients, yielding an accuracy rate of 96.7% for TST to diagnose LTBI when compared to QFT. In conclusion, compared to QFT, TST is still a valuable diagnostic tool with high accuracy rate for diagnosis of LTBI in children candidates for renal transplantation and can still be used as an accurate test for screening Mycobacterium TB infection.

Accurate diagnosis of latent tuberculosis in children, people who are immunocompromised or at risk from immunosuppression and recent arrivals from countries with a high incidence of tuberculosis: systematic review and economic evaluation

BACKGROUND

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB) [(Zopf 1883) Lehmann and Neumann 1896], is a major cause of morbidity and mortality. Nearly one-third of the world's population is infected with MTB; TB has an annual incidence of 9 million new cases and each year causes 2 million deaths worldwide.

OBJECTIVES

To investigate the clinical effectiveness and cost-effectiveness of screening tests [interferon-gamma release assays (IGRAs) and tuberculin skin tests (TSTs)] in latent tuberculosis infection (LTBI) diagnosis to support National Institute for Health and Care Excellence (NICE) guideline development for three population groups: children, immunocompromised people and those who have recently arrived in the UK from high-incidence countries. All of these groups are at higher risk of progression from LTBI to active TB.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, The Cochrane Library and Current Controlled Trials were searched from December 2009 up to December 2014.

REVIEW METHODS

English-language studies evaluating the comparative effectiveness of commercially available tests used for identifying LTBI in children, immunocompromised people and recent arrivals to the UK were eligible. Interventions were IGRAs [QuantiFERON(®)-TB Gold (QFT-G), QuantiFERON(®)-TB Gold-In-Tube (QFT-GIT) (Cellestis/Qiagen, Carnegie, VA, Australia) and T-SPOT.TB (Oxford Immunotec, Abingdon, UK)]. The comparator was TST 5 mm or 10 mm alone or with an IGRA. Two independent reviewers screened all identified records and undertook a quality assessment and data synthesis. A de novo model, structured in two stages, was developed to compare the cost-effectiveness of diagnostic strategies.

RESULTS

In total, 6687 records were screened, of which 53 unique studies were included (a further 37 studies were identified from a previous NICE guideline). The majority of the included studies compared the strength of association for the QFT-GIT/G IGRA with the TST (5 mm or 10 mm) in relation to the incidence of active TB or previous TB exposure. Ten studies reported evidence on decision-analytic models to determine the cost-effectiveness of IGRAs compared with the TST for LTBI diagnosis. In children, TST (≥ 5 mm) negative followed by QFT-GIT was the most cost-effective strategy, with an incremental cost-effectiveness ratio (ICER) of £18,900 per quality-adjusted life-year (QALY) gained. In immunocompromised people, QFT-GIT negative followed by the TST (≥ 5 mm) was the most cost-effective strategy, with an ICER of approximately £18,700 per QALY gained. In those recently arrived from high TB incidence countries, the TST (≥ 5 mm) alone was less costly and more effective than TST (≥ 5 mm) positive followed by QFT-GIT or T-SPOT.TB or QFT-GIT alone.

LIMITATIONS

The limitations and scarcity of the evidence, variation in the exposure-based definitions of LTBI and heterogeneity in IGRA performance relative to TST limit the applicability of the review findings.

CONCLUSIONS

Given the current evidence, TST (≥ 5 mm) negative followed by QFT-GIT for children, QFT-GIT negative followed by TST (≥ 5 mm) for the immunocompromised population and TST (≥ 5 mm) for recent arrivals were the most cost-effective strategies for diagnosing LTBI that progresses to active TB. These results should be interpreted with caution given the limitations identified. The evidence available is limited and more high-quality research in this area is needed including studies on the inconsistent performance of tests in high-compared with low-incidence TB settings; the prospective assessment of progression to active TB for those at high risk; the relative benefits of two-compared with one-step testing with different tests; and improved classification of people at high and low risk for LTBI.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014009033.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Detecting latent tuberculosis in compromised patients

PURPOSE OF REVIEW

The detection of latent tuberculosis infection (LTBI) in different categories of compromised patients is reviewed with focus on the role of strategies incorporating immunodiagnostic tests and analysis of epidemiological and clinical risk factors.

RECENT FINDINGS

The development of active tuberculosis (TB) is increased in compromised patients and is closely related to determinants for disease reactivation or newly acquired TB infection. A targeted detection of LTBI in these high-risk groups should be performed especially if preventive treatment is planned. The performance of immunodiagnostic tests is highly variable among different groups of immunocompromised individuals. Findings of cross-sectional studies indicate a better diagnostic accuracy of interferon-γ release assays over the tuberculin skin test. The critical issue is that in low-incidence countries, the positive and negative predictive values of any of immunodiagnostic tests were very poor. A targeted testing process involving analysis of TB risk factors increases the predictive positive values of immunodiagnostic tests and may improve LTBI detection.

SUMMARY

The LTBI detection in immunocompromised patients is a challenge. The development of new immunological biomarkers and integrated clinical and epidemiological strategies are needed to identify LTBI in compromised individuals and to plan preventive chemotherapies in those at risk of developing active TB.

Infections after orthotopic liver transplantation

Opportunistic infections are a leading cause of morbidity and mortality after orthotopic liver transplantation. Systemic immunosuppression renders the liver recipient susceptible to de novo infection with bacteria, viruses and fungi post-transplantation as well to reactivation of pre-existing, latent disease. Pathogens are also transmissible via the donor organ. The time from transplantation and degree of immunosuppression may guide the differential diagnosis of potential infectious agents. However, typical systemic signs and symptoms of infection are often absent or blunted after transplant and a high index of suspicion is needed. Invasive procedures are often required to procure tissue for culture and guide antimicrobial therapy. Antimicrobial prophylaxis reduces the incidence of opportunistic infections and is routinely employed in the care of patients after liver transplant. In this review, we survey common bacterial, fungal, and viral infections after orthotopic liver transplantation and highlight recent developments in their diagnosis and management.