Influence of epidemiology, immunosuppressive regimens, clinical presentation, and treatment on kidney transplant outcomes of patients diagnosed with tuberculosis: A retrospective cohort analysis

Miliary Tuberculosis as Postmortem Diagnosis in Solid Organ Transplant Recipient: Case Report and Review of the Literature

BACKGROUND

The diagnosis of tuberculosis (TB) in solid organ transplant (SOT) recipients presents challenges that may lead to treatment delay. These include atypical clinical presentations, increased likelihood of negative tuberculin skin test or/and interferon-gamma release assays, and negative sputum smear results despite active disease. The treatment poses challenges due to pharmacokinetic interactions, allograft-related toxicity, and inadequate immune response.

CASE REPORT

We report the case of a 70-year-old man after kidney transplantation in 2012. The patient was transferred from the urology unit with deteriorating renal function and presumed urosepsis. His pulmonary chest X-ray showed hilar pulmonary infiltrates. Computed tomography of the chest/abdomen/pelvis revealed mediastinal lymphadenopathy, pulmonary infiltrates, pulmonary effusion, and splenomegaly. His blood results showed pancytopenia and high inflammatory and renal markers. He was treated with broad-spectrum antibiotics covering bacterial, fungal, and viral infections. Despite initial clinical improvement, his kidney function deteriorated, and he required hemodialysis. His temperature continued to spike. On physical examination, he was confused and lethargic. He was scheduled to have a mediastinoscopy with lymph node biopsy, but he died the day before. The postmortem examination revealed miliary tuberculosis with tuberculosis of many organs: kidney transplant, native kidney, bone marrow, mediastinal lymph nodes, lungs, and spleen.

CONCLUSIONS

The diagnosis of active TB in transplant recipients requires a high index of suspicion and invasive procedures. The majority of all cases of active TB after SOT are disseminated or occur at extrapulmonary sites. Only a small minority of patients have classic cavitary changes on pulmonary imaging.

Prevention and management of tuberculosis in solid organ transplantation: A consensus statement of the transplantation society of Taiwan

Solid organ transplant recipients have an increased risk of tuberculosis (TB). Due to the use of immunosuppressants, the incidence of TB among solid organ transplant recipients has been consistently reported to be higher than that among the general population. TB frequently develops within the first year after transplantation when a high level of immunosuppression is maintained. Extrapulmonary TB and disseminated TB account for a substantial proportion of TB among solid organ transplant recipients. Treatment of TB among recipients is complicated by the drug-drug interactions between anti-TB drugs and immunosuppressants. TB is associated with an increased risk of graft rejection, graft failure and mortality. Detection and management of latent TB infection among solid organ transplant candidates and recipients have been recommended. However, strategy to mitigate the risk of TB among solid organ transplant recipients has not yet been established in Taiwan. To address the challenges of TB among solid organ transplant recipients, a working group of the Transplantation Society of Taiwan was established. The working group searched literatures on TB among solid organ transplant recipients as well as guidelines and recommendations, and proposed interventions to strengthen TB prevention and care among solid organ transplant recipients.

Mechanisms of ag85a/b DNA vaccine conferred immunotherapy and recovery from Mycobacterium tuberculosis-induced injury

Our previous research developed a novel tuberculosis (TB) DNA vaccine ag85a/b that showed a significant therapeutic effect on the mouse tuberculosis model by intramuscular injection (IM) and electroporation (EP). However, the action mechanisms between these two vaccine immunization methods remain unclear. In a previous study, 96 Mycobacterium tuberculosis (MTB) H₃₇ Rv-infected BALB/c mice were treated with phosphate-buffered saline, 10, 50, 100, and 200 μg ag85a/b DNA vaccine delivered by IM and EP three times at 2-week intervals, respectively. In this study, peripheral blood mononuclear cells (PBMCs) from three mice in each group were isolated to extract total RNA. The gene expression profiles were analyzed using gene microarray technology to obtain differentially expressed (DE) genes. Finally, DE genes were validated by real-time reverse transcription-quantitive polymerase chain reaction and the GEO database. After MTB infection, most of the upregulated DE genes were related to the digestion and absorption of nutrients or neuroendocrine (such as Iapp, Scg2, Chga, Amy2a5), and most of the downregulated DE genes were related to cellular structural and functional proteins, especially the structure and function proteins of the alveolar epithelial cell (such as Sftpc, Sftpd, Pdpn). Most of the abnormally upregulated or downregulated DE genes in the TB model group were recovered in the 100 and 200 μg ag85a/b DNA IM groups and four DNA EP groups. The pancreatic secretion pathway downregulated and the Rap1 signal pathway upregulated had particularly significant changes during the immunotherapy of the ag85a/b DNA vaccine on the mouse TB model. The action targets and mechanisms of IM and EP are highly consistent. Tuberculosis infection causes rapid catabolism and slow anabolism in mice. For the first time, we found that the effective dose of the ag85a/b DNA vaccine immunized whether by IM or EP could significantly up-regulate immune-related pathways and recover the metabolic disorder and the injury caused by MTB.

Mycobacterium Tuberculosis Infection after Kidney Transplantation: A Comprehensive Review

Tuberculosis (TB) in kidney transplant (KT) recipients is an important opportunistic infection with higher incidence and prevalence than in the general population and is associated with important morbidity and mortality. We performed an extensive literature review of articles published between 1 January 2000 and 15 June 2022 to provide an evidence-based review of epidemiology, pathogenesis, diagnosis, treatment and outcomes of TB in KT recipients. We included all studies which reported epidemiological and/or outcome data regarding active TB in KT, and we approached the diagnostic and treatment challenges according to the current guidelines. Prevalence of active TB in KT recipients ranges between 0.3–15.2%. KT recipients with active TB could have a rejection rate up to 55.6%, a rate of graft loss that varies from 2.2% to 66.6% and a mortality rate up to 60%. Understanding the epidemiological risk, risk factors, transmission modalities, diagnosis and treatment challenges is critical for clinicians in providing an appropriate management for KT with TB. Among diagnostic challenges, which are at the same time associated with delay in management, the following should be considered: atypical clinical presentation, association with co-infections, decreased predictive values of screening tests, diverse radiological aspects and particular diagnostic methods. Regarding treatment challenges in KT recipients with TB, drug interactions, drug toxicities and therapeutical adherence must be considered.

Belatacept in Kidney Transplantation: What Are the True Benefits? A Systematic Review

The current gold standard to prevent allograft rejection for maintenance immunosuppression in kidney transplantation currently consists in glucocorticoids, an antiproliferative agent and a calcineurin inhibitor (CNI), with better outcome for tacrolimus than cyclosporin. Although, CNI drastically improved early graft survival, so far, CNI have failed to significantly improve long-term survival mainly because of nephrotoxicity. In addition, CNI carry several other side effects such as an increased risk for cardiovascular events and for diabetes mellitus. Therefore, seeking alternatives to CNI remains of paramount importance in kidney transplantation. Belatacept is a fusion protein composed of the human IgG1 Fc fragment linked to the modified extracellular domain of cytotoxic T lymphocyte–associated antigen 4. In kidney transplant recipients, pivotal phase III randomized studies suggested clinical benefits of belatacept as an initial maintenance regimen, as compared with cyclosporine, mainly on kidney function. Recently, a randomized study also suggested a clinical benefit on renal function of a conversion from a CNI-based to a belatacept-based maintenance regimen in patients. However, conversion from CNIs to belatacept is probably associated with an increased risk of biopsy-proven acute rejection and should prompt close clinical surveillance. On the other hand, other studies suggest a decrease in de novo humoral transplant immunization. Belatacept is probably associated with an increase in both risk and severity of some infectious diseases, including EBV-linked post-transplantation lymphoproliferative disorders, and with a decreased response to vaccines. Most studies on belatacept are observational, retrospective, and non-comparative. Consequently, high-quality data about the safety and efficacy profile of belatacept, as compared with the current gold standard for maintenance regimens (tacrolimus-based), is uncertain. Our review will therefore focus on the most recent published data aiming at evaluating the evidence-based or the “true” benefits and risks of belatacept-based regimens in kidney transplantation.

Association Between Cytomegalovirus Infection and Tuberculosis Disease: A Systematic Review and Meta-Analysis of Epidemiological Studies

BACKGROUND

Tuberculosis is one of the leading causes of mortality worldwide from an infectious disease. This review aimed to investigate the association between prior cytomegalovirus infection and tuberculosis disease.

METHODS

Six bibliographic databases were searched from their respective inception to 31 December 2021. Data were pooled using random-effects meta-analysis.

RESULTS

Of 5476 identified articles, 15 satisfied the inclusion criteria with a total sample size of 38 618 patients. Pooled findings showed that individuals with cytomegalovirus infection had a higher risk of tuberculosis disease compared to those not infected with cytomegalovirus (odds ratio [OR], 3.20; 95% confidence interval [CI], 2.18-4.70). Age was the only covariate that exerted a significant effect on the result of the association. Meta-analysis of risk estimates reported in individual studies showed a marked and significant correlation of cytomegalovirus infection with active tuberculosis (adjusted hazard ratio, 2.92; 95% CI, 1.34-4.51; adjusted OR, 1.14; 95% CI, .71-1.57). A clear dose-response relation was inferred between the levels of cytomegalovirus antibodies and the risks of tuberculosis events (OR for high levels of cytomegalovirus antibodies, 4.07; OR for medium levels of cytomegalovirus antibodies, 3.58).

CONCLUSIONS

The results suggest an elevated risk of tuberculosis disease among individuals with a prior cytomegalovirus infection.

Bacterial and Viral Infection and Sepsis in Kidney Transplanted Patients

Kidney transplanted patients are a unique population with intrinsic susceptibility to viral and bacterial infections, mainly (but not exclusively) due to continuous immunosuppression. In this setting, infectious episodes remain among the most important causes of death, with different risks according to the degree of immunosuppression, time after transplantation, type of infection, and patient conditions. Prevention, early diagnosis, and appropriate therapy are the goals of infective management, taking into account that some specific characteristics of transplanted patients may cause a delay (the absence of fever or inflammatory symptoms, the negativity of serological tests commonly adopted for the general population, or the atypical anatomical presentation depending on the surgical site and graft implantation). This review considers the recent available findings of the most common viral and bacterial infection in kidney transplanted patients and explores risk factors and outcomes in septic evolution.

Belatacept Use after Kidney Transplantation and Its Effects on Risk of Infection and COVID-19 Vaccine Response

Introduction: Belatacept is a common immunosuppressive therapy used after kidney transplantation (KT) to avoid calcineurin-inhibitor (CNI) use and its related toxicities. It is unclear whether its use exposes KT recipients (KTx) to a greater risk of infection or a poorer response to vaccines. Areas covered: We reviewed PubMed and the Cochrane database. We then summarized the mechanisms and impacts of belatacept use on the risk of infection, particularly opportunistic, in two settings, i.e., de novo KTx and conversion from CNIs. We also focused on COVID-19 infection risk and response to SARS-CoV-2 vaccination in patients whose maintenance immunosuppression relies on belatacept. Expert opinion: When belatacept is used de novo, or after drug conversion the safety profile regarding the risk of infection remains good. However, there is an increased risk of opportunistic infections, mainly CMV disease and Pneumocystis pneumonia, particularly in those with a low eGFR, in older people, in those receiving steroid-based therapy, or those that have an early conversion from CNI to belatacept (i.e., <six months post-transplantation). Thus, we recommend, if possible, delaying conversion from CNI to belatacept until at least six months post-transplantation. Optimal timing seems to be eight months post-transplantation. In addition, KTx receiving belatacept respond poorly to SARS-CoV-2 vaccination.

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.

Risk factors and clinical outcomes of tuberculosis among kidney transplant recipients in high endemic country

BACKGROUND

Tuberculosis (TB) is considered as a challenge issue in solid organ transplant recipients because of high morbidity and mortality. Active TB after transplant mostly occurs from reactivation of latent infection. Understanding risk factors and clinical information of TB may provide an appropriate prevention and treatment strategies in this specific patient population, however data from high endemic area is scarce.

METHODS

A matched single-center, case-control study was conducted in our institute. Cases were defined as newly diagnosed confirmed or clinical active TB in patients who underwent kidney transplant (KT) between April 1992 and October 2018. For each case, 5 controls were matched by age and sex. Risk factor associated with TB was determined using univariate and multivariate conditional logistic regression.

RESULTS

Between study period, KT was performed in 787 patients. Twenty-seven patients (3.43%) were diagnosed with active TB including 20 confirmed and 7 clinical diagnosed cases. The global incidence of TB in our population was 315 cases per 100 000 patients per year. Among 27 cases, pulmonary involvement was the most common (48.1%) followed by disseminated (18.5%), extrapulmonary (14.8%), pleura (11.1%) and pleuropulmonary (7.4%) TB. Allograft rejection was significantly associated with active TB (P < .001). The median onset duration of infection was 17 months (IQR, 4-59 months) after KT. Twenty-four (88.9%) patients received rifampicin containing regimen for treatment with median duration of 10 months (IQR, 6-12 months). All patients were cured after complete treatment, however those with TB remained having unfavorable outcomes including higher all-cause mortality and graft loss.

CONCLUSIONS

Incidence rate of TB in KT recipients is higher than normal population. Allograft rejection was identified as a significant risk factor. Increase unfavorable outcomes including graft loss and mortality were also observed among patients with TB.

Tuberculosis in Pediatric Solid Organ and Hematopoietic Stem Cell Recipients

Children undergoing solid organ and hematopoietic stem cell transplantation are at high risk of morbidity and mortality from tuberculosis (TB) disease in the post-transplant period. Treatment of TB infection and disease in the post-transplant setting is complicated by immunosuppression and drug interactions. There are limited data that address the unique challenges for the management of TB in the pediatric transplant population. This review presents the current understanding of the epidemiology, clinical presentation, diagnosis, management, and prevention for pediatric transplant recipients with TB infection and disease. Further studies are needed to improve diagnosis of TB and optimize treatment outcomes for these patients.

Agreement between the results of tuberculin skin test and Interferon-Gamma Release Assays in renal transplant candidates

Introduction:

Identification of latent tuberculosis (TB) infection is important in kidney transplant candidates. Due to the absence of a gold standard, both tuberculin skin test (TST) and interferon-gamma release assays (IGRA) are used to screen patients. The aim of this study was to evaluate the agreement of these two tests in patients undergoing renal transplantation.

Materials and Methods:

Two hundred kidney transplant candidates at a referral center in 2014–2017 were included in this study. TST and Quantiferon-Gold (QFT-G) tests were performed for all patients before transplantation. In case of a positive result in any of the tests, patients were administered a 9-month prophylaxis treatment using isoniazid. Cohen's kappa coefficient (k) test was used to determine the agreement between the two tests.

Results:

The mean age of patients was 40.72 ± 18.33. Nine (4.5%) patients had positive TST and 16 (8%) had positive IGRA. Concordance of the two tests was evaluated as medium (κ = 0.44 and P < 0.001). No association was found between the underlying causes of renal failure and skin test positive or IGRA. The tests showed a poor agreement among diabetics, candidates of re-transplantation, and those who were on dialysis for longer than a year (κ < 0.20).

Conclusion:

TST or IGRA can be used to screen TB in kidney transplant candidates with a moderate agreement. However, we suggest using both TST and QFT-G in diabetics, re-transplant candidates, and those on dialysis for >1 year.

Diagnostic Value of Flow Cytometry in Kidney Transplant Recipients With Active Pulmonary Tuberculosis

OBJECTIVES

Long-term use of immunosuppressant drugs in kidney transplant recipients leads to immunosuppression. When active pulmonary tuberculosis infection occurs, lymphocyte proliferation and function are impaired, and the clinical symptoms of patients are not typical, which often leads to delay in diagnosis.

MATERIALS AND METHODS

We collected and analyzed the peripheral blood lymphocytes of hospitalized patients with active pulmonary tuberculosis and other types of pulmonary infection after kidney transplant within 2 years. The proportion and absolute values of lymphocytes were obtained by a flow cytometer.

RESULTS

There were significant differences in the proportion of CD8+ subsets between active pulmonary tuberculosis and bacterial pneumonia in kidney transplant recipients. If the proportion of CD8+ subsets in peripheral blood is over 33.27%, then the active pulmonary tuberculosis diagnosis sensitivity is higher than 88.9% and specificity is higher than 83.3%.

CONCLUSIONS

Analysis of peripheral lymphocyte subsets is helpful in the early diagnosis of kidney transplant recipients with active pulmonary tuberculosis. It should be added into routine examinations of kidney transplant recipients who have an ambiguous diagnosis between active pulmonary tuberculosis and bacterial pneumonia.

An Inflammatory Story: Antibodies in Tuberculosis Comorbidities

Mycobacterium tuberculosis (Mtb) resides in a quarter of the world's population and is the causative agent for tuberculosis (TB), the most common infectious reason of death in humans today. Although cellular immunity has been firmly established in the control of Mtb, there is growing evidence that antibodies may also modulate the infection. More specifically, certain antibody features are associated with inflammation and are divergent in different states of human infection and disease. Importantly, TB impacts not just the healthy but also those with chronic conditions. While HIV represents the quintessential comorbid condition for TB, recent epidemiological evidence shows that additional chronic conditions such as diabetes and kidney disease are rising. In fact, the prevalence of diabetes as a comorbid TB condition is now higher than that of HIV. These chronic diseases are themselves independently associated with pro-inflammatory immune states that encompass antibody profiles. This review discusses isotypes, subclasses, post-translational modifications and Fc-mediated functions of antibodies in TB infection and in the comorbid chronic conditions of HIV, diabetes, and kidney diseases. We propose that inflammatory antibody profiles, which are a marker of active TB, may be an important biomarker for detection of TB disease progression within comorbid individuals. We highlight the need for future studies to determine which inflammatory antibody profiles are the consequences of comorbidities and which may potentially contribute to TB reactivation.

The Korean Organ Transplant Registry (KOTRY): Second Official Adult Heart Transplant Report

Background and Objectives

This second adult heart transplantation (HTx) report is based on Korean Organ Transplant Registry data submitted on 400 HTxs in recipients of all ages.

Methods

From March 2014 to December 2017, a total of 400 HTxs were performed at 4 major centers in Korea. We analyzed demographics and characteristics according to transplant years. Patterns of immunosuppression, allograft rejection, and survival after HTx were analyzed. Donor and recipient age were highlighted.

Results

Some distinct differences in HTx statistics were noted. Mean donor age increased significantly in the most recent years compared to 2014–2015, while mean recipient age did not change. The proportion of patients on pre-transplant extracorporeal membrane oxygenation (ECMO) increased over time. One-year and intermediate-term survival was significantly worse in patients on pre-transplant ECMO compared to those without mechanical support. Over the years, tacrolimus has increased to become the most frequently used calcineurin inhibitor over cyclosporine, while the number of patients using steroids both at discharge and 1-year follow-up has declined. Age did not affect 1-year survival, but significantly affected intermediate-term survival.

Conclusions

From 2014 to 2017, centers were willing to accept older donors to address increasing organ shortages and more patients received transplant under ECMO care. Increasing age was a strong independent factor for intermediate-term survival, however, post-transplant comorbidities did not differ among age groups. Further studies with longer follow-up duration are needed to better understand age-related post-transplant prognosis.