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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

QuantiFERON-TB reversion in children and adolescents with tuberculosis

We analyzed 136 children with tuberculosis disease or infection and a positive QuantiFERON-TB (QFT) assay, followed-up for a median of 21 months (0.4-11years). QFT reversed in 16.9% of cases, with significant decreases in TB1 (-1.72 vs. -0.03 IU/ml, p=0.001) and TB2 (-1.65 vs. -0.43 IU/ml, p=0.005) levels compared to non-reverters. We found a higher QFT reversion rate among children under 5 years (25.0% vs 11.9%, p=0.042), and those with TST induration <15mm (29% vs 13.3%, p=0.055). Our data reveal that, although QFT test remained positive in the majority of children, reversion occurred in 16% of cases in a progressive and stable pattern. Younger age and reduced TST induration were associated with QFT reversion.

Risk of progression to active tuberculosis for indeterminate interferon-gamma release assay in immunocompromised individuals: a systematic review and meta-analysis

BACKGROUND

Limited data exist on assessing the risk of active tuberculosis (TB) in immunocompromised individuals during screening for latent tuberculosis infection (LTBI).

OBJECTIVES

To assess the risk of progression to active TB for indeterminate interferon-γ release assays (IGRA) results in immunocompromised individuals during screening for LTBI.

DATA SOURCES

PubMed, Embase, Web of Science, and the Cochrane Library were searched without start date or language restrictions on 18 April 2023.

STUDY ELIGIBILITY CRITERIA

Cohort study or randomized controlled trials that investigated the risk of progression to active TB for indeterminate IGRA during LTBI screening.

PARTICIPANTS

Immunocompromised individuals. TEST: IGRA (T-SPOT.TB and QuantiFERON).

REFERENCE STANDARD

None.

ASSESSMENT OF RISK OF BIAS

A modified version of the Newcastle-Ottawa Scale.

METHODS OF DATA SYNTHESIS

Fixed effects meta-analysis was used to obtain two pooled risk ratios (RRs). RR-ip represented disease progression rate in untreated individuals with indeterminate IGRA versus positive IGRA. RR-in represented disease progression rate in untreated individuals with indeterminate IGRA versus negative IGRA.

RESULTS

Among the 5102 identified studies, 28 (14 792 immunocompromised individuals) were included. The pooled RR-ip and RR-in for cumulative incidence were 0.51 (95% CI, 0.32-0.82; I2 = 0%) and 2.94 (95% CI, 1.78-4.85; I2 = 0%), respectively. In addition, 11 studies reporting person-year data were included to verify the reliability of cumulative incidence results. The pooled RR-ip and RR-in for person-year incidence were 0.40 (95% CI, 0.19-0.82; I2 = 13%) and 2.67 (95% CI, 1.24-5.79; I2 = 23%), respectively.

DISCUSSION

Indeterminate IGRA results in immunocompromised individuals may represent an intermediate risk of progression to active TB, with half the risk for positive results and three times for negative results. Proper follow-up and management of patients with indeterminate results are crucial for mitigating progression risk and improving patient outcomes.

Chemoprophylaxis for the prevention of tuberculosis in kidney transplant recipients: A systematic review and meta-analysis

Background: A systematic review and meta-analysis was performed to investigate the efficacy and safety of isoniazid (INH) prophylaxis to prevent tuberculosis (TB) infection in kidney transplant recipients (KTRs).

Methods: Web of Science, SCOPUS, and PubMed were searched to identify relevant studies that compared the effects among patients who received INH prophylaxis after transplantation.

Results: A total of 13 studies (involving 6,547 KTRs) were included in our analysis. We found that the risk of active TB infection (RR: 0.35, 95%CI 0.27–0.45, p &lt; 0.01) for KTRs was lower in the INH treatment group than in those without prophylaxis. However, there was no significant difference between the two groups in mortality (RR: 0.93, 95%CI 0.67–1.28, p = 0.64), acute rejection (RR: 0.82, 95%CI 0.44–1.51, p = 0.52), and hepatotoxicity (RR: 1.25, 95%CI 0.94–1.65, p = 0.12).

Conclusion: Isoniazid prophylaxis is a safe and effective for KTRs on reactivation of latent TB infection.

Donor-derived TB after kidney transplantation: a case report

INTRODUCTION

Tuberculosis (TB) is a possible serious complication of solid organ transplantation, associated with high mortality and morbidity. Post-transplant TB has varied pathogenesis with many approaches to its prevention, which is the most important way to reduce its incidence. Treatment of TB in organ recipients is challenging because of drug toxicity and interaction with immunosuppressants.

CASE REPORT

an 18-year-old woman that underwent kidney transplantation from a deceased donor and was discharged with fair renal function was readmitted at 37th postoperative day with fever. CT showed signs of miliary TB and fluid collection besides graft fistulization through the skin. The patient presented positive BAAR in the drained fluid and Koch's bacillus in the urine. She was treated with a four-drug regimen (rifampicin, isoniazid, pyrazinamide, and etambutol), with great response and preserved graft function. We were informed that the recipient of the contralateral kidney also presented post-transplant TB, implying in a donor-derived origin.

CONCLUSION

TB is an important differential diagnosis for infectious complications in patients after solid-organ transplantation, especially in endemic regions. Its initial clinical presentation can be unspecific and it should be suspected in the presence of fever or formation of fluid collections. The suspicion of TB is the key to early diagnosis and satisfactory outcomes in post-transplant TB.

Mycobacterium tuberculosis in solid organ transplant donors and recipients

PURPOSE OF REVIEW

Due to impaired immune response, solid organ transplant (SOT) recipients are susceptible to tuberculosis (TB) and its subsequent morbidity and mortality. Current prevention strategies, diagnostic and treatment approach to TB infection in donors and recipients were reviewed in this article.

RECENT FINDINGS

Screening of latent tuberculosis infection (LTBI) in donors and recipients is the cornerstone of TB-preventive strategy in recipients and requires an assessment of TB risk factors, TB-specific immunity testing, and radiographic evaluation. Interferon-gamma release assay has superseded the tuberculin skin test in LTBI evaluation despite its recognized limitations. LTBI treatment should be offered to transplant candidates and living donors before transplantation and donation, respectively. Diagnosis of TB disease can be challenging because of nonspecific clinical presentation in the recipient and is limited by the sensitivity of current diagnostics. The approach to LTBI and TB disease treatment is similar to the general population, but can be challenging because of potential drug interactions and toxicities.

SUMMARY

The appropriate evaluation of donors and recipients for TB can mitigate posttransplant TB disease. Current approaches to diagnosis and treatment parallels that of immunocompetent hosts. Future research evaluating existing and novel diagnostics and treatment in transplant recipients is needed.

Latent Tuberculosis in Hematopoietic Stem Cell Transplantation: Diagnostic and Therapeutic Strategies to Prevent Disease Activation in an Endemic Population

Latent tuberculosis infection (LTBI) affects one-fourth of the world´s population. Hematopoietic stem cell transplantation (HSCT) recipients are at an elevated risk of developing active tuberculosis infection (ATBI). In this retrospective study of donors and HSCT recipients who underwent transplantation between February 2000 and June 2018, our aim was to determine the prevalence of LTBI and ATBI and to describe diagnostic and therapeutic strategies in an HSCT population in an endemic region. The cohort of 409 participants included 125 allogeneic HSCT (allo-HSCT) recipients, 165 autologous HSCT (auto-HSCT) recipients, and 119 HSCT donors. Patients were evaluated pre-HSCT with tuberculin skin test and thoracic imaging. LTBI was diagnosed in 26.2% of the cohort. Cases represented 20% of the auto-HSCT population, 20% of the allo-HSCT population, and 41.2% of the donor population. Pre-HSCT evaluation to rule out ATBI was performed in 62.6% of the cohort; all results were negative. Isoniazid was administered to 73.3% of those with LTBI. Within subgroups, 91.7% of HSCT recipients and 51% of donors received treatment. The median duration of therapy pre-HSCT was 70 days in recipients and 48 days in donors. The incidence of post-HSCT ATBI was 0 at 1-year follow-up. The incidence of LTBI in our population was higher than expected and still might have been underestimated owing to diagnostic test limitations. The absence of incident ATBI suggests that recipients, as opposed to donors, must receive LTBI treatment. Prevention of infectious complications in the HSCT population should be prioritized to improve clinical outcomes. Prospective data from collaborative working groups is needed to determine the best diagnostic and therapeutic approaches in this vulnerable patient population.

Conversion and Reversion Rates of Tuberculosis Screening Assays in Patients With Rheumatic Diseases and Negative Baseline Screening Under Long-Term Biologic Treatment

Background:

To determine the conversion and reversion rates of tuberculosis (TB) screening tests (Tuberculin Skin Test-TST, Interferon Gamma Release Assay-IGRA: T-SPOT.TB) during biologic treatment in patients with rheumatic diseases and negative baseline screening.

Methods:

This was a long-term, longitudinal cohort study of 50 patients with rheumatic diseases and negative baseline TB screening (TST: < 5 mm, negative T-SPOT.TB) treated with tumor necrosis factor inhibitors (TNFi) or other non-TNFi biologics. Patients were rescreened at a mean time of 1.4 (first rescreening) and 6.9 (second rescreening) years from baseline, with both assays. The conversion (negative to positive) and reversion (positive to negative) rate was calculated for each TB screening test.

Results:

Fifty patients (mean age = 60 years) with various rheumatic diseases (rheumatoid arthritis: n = 24, spondyloarthropathies: n = 23, other: n = 3) were enrolled. During the first phase (baseline to first rescreening), all patients were treated with TNFi while during the second phase (first to second rescreening), TNFi (54%) and non-TNFi (46%) were used. Fifteen patients (30%) displayed conversion of at least 1 screening assay during follow-up (10 at the first and 5 at the second rescreening). This conversion rate was higher with TST (n = 11, 22% or 3.47/100 patient-years) compared to T-SPOT.TB (n = 4, 8% or 1.74/100 patient-years). Among the 10 converters at the first rescreening, 5 received isoniazid (INH) preventive therapy and 5 did not; an equal number of patients (3/5, 60%) reverted to negative with or without INH therapy. None of the patients developed active TB during follow-up (6.9 ± 1.0 years).

Conclusions:

Approximately one-third of patients with rheumatic diseases and negative baseline TB screening developed conversion of at least 1 screening test during long-term biologic treatment. This occurred most often with TST and was usually a transient event. These findings do not support routine serial TB retesting in biologic-treated patients with rheumatic diseases in the absence of TB risk factors.

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.

A case report of mucocutaneous tuberculosis after orthotopic liver transplantation: a challenging diagnosis

Background

Mycobacterium tuberculosis is responsible for high morbidity and mortality in immune-compromised hosts.

Case presentation

We present a rare case of cutaneous tuberculosis after orthotopic liver transplantation without involvement of any other organs.

Conclusion

TB risk-factors assessment, careful LTBI screening and treatment according to national guidelines, as well as a reduction in missed opportunity for prevention are necessary to avoid MTB related disease in fragile patients.

Tuberculosis after liver transplantation in a large center in New York City: QuantiFERON® -TB Gold-based pre-transplant screening performance and active tuberculosis post-transplant

INTRODUCTION

Pre-transplant screening for latent tuberculosis infection (LTBI) is a complex consideration that varies by institution. Inconsistent performance of interferon-gamma release assay (IGRA) further complicates screening. Data regarding LTBI screening outcomes and test characteristics in a large, foreign-born pre-transplant population within the United States are limited.

METHODS

In this retrospective study, patients who received QuantiFERON^® -TB Gold (QFT) prior to liver transplantation (LT) were included. Characteristics of patients were compared by QFT result, and predictors of indeterminate results were evaluated. Similar comparisons were performed between patients who developed active TB and those who did not.

RESULTS

Of 148 patients screened, the rate of positive, indeterminate, and negative testing was 13.5% (20/148), 27% (40/148), and 59% (88/148), respectively. An indeterminate QFT result was more than 16 times more likely in patients with a Model for End-stage Liver Disease score >25 (odds ratio [OR] 16.7; 95% confidence interval [CI], 2.1-132.0; P = .008) and more than 4 times when performed in our institution's lab compared with commercial lab (OR 4.1; 95% CI, 1.34-12.44; P = .013). The overall TB incidence was 1102/100 000 transplant cases. No patient who developed active TB had a positive QFT. All were born outside of the United States (P = .06) and had pre-transplantation chest imaging demonstrating granulomatous disease (P = .006).

CONCLUSION

Our experience further highlights the challenges of LTBI screening prior to LT and suggests that QFT may be a poor predictor of active TB in higher risk pre-transplant populations. Candidates should be screened as early as possible to optimize QFT performance, and local epidemiological data should be used to create institution-specific screening protocols in areas with large populations from TB-endemic regions. Management should consider TB risk factors, QFT, and imaging instead of reliance on QFT testing alone.

Precision monitoring of immunotherapies in solid organ and hematopoietic stem cell transplantation

Pharmacological immunotherapies are a key component of post-transplant therapy in solid-organ and hematopoietic stem cell transplantation. In current clinical practice, immunotherapies largely follow a one-size fits all approach, leaving a large portion of transplant recipients either over- or under-immunosuppressed, and consequently at risk of infections or immune-mediated complications. Our goal here is to review recent and rapid advances in precision and genomic medicine approaches to monitoring of post-transplant immunotherapies. We will discuss recent advances in precision measurements of pharmacological immunosuppression, measurements of the plasma and gut microbiome, strategies to monitor for allograft injury and post-transplant malignancies via circulating cell-free DNA, and comprehensive measurements of the B and T cell immune cell repertoire.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.