Malignancies following lung transplantation

Factors affecting complications development and mortality after single lung transplant

Lung transplantation (LT) is a life-saving therapeutic procedure that prolongs survival in patients with end-stage lung disease. Furthermore, as a therapeutic option for high-risk candidates, single LT (SLT) can be feasible because the immediate morbidity and mortality after transplantation are lower compared to sequential single (double) LT (SSLTx). Still, the long-term overall survival is, in general, better for SSLTx. Despite the great success over the years, the early post-SLT period remains a perilous time for these patients. Patients who undergo SLT are predisposed to evolving early or late postoperative complications. This review emphasizes factors leading to post-SLT complications in the early and late periods including primary graft dysfunction and chronic lung allograft dysfunction, native lung complications, anastomosis complications, infections, cardiovascular, gastrointestinal, renal, and metabolite complications, and their association with morbidity and mortality in these patients. Furthermore, we discuss the incidence of malignancy after SLT and their correlation with immunosuppression therapy.

Chest CT in patients after lung transplantation: A retrospective analysis to evaluate impact on image quality and radiation dose using spectral filtration tin-filtered imaging

OBJECTIVES

The purpose of this study was to investigate the impact of a 150kV spectral filtration chest imaging protocol (Sn150kVp) combined with advanced modeled iterative reconstruction (ADMIRE) on radiation dose and image quality in patients after lung-transplantation.

METHODS

This study included 102 patients who had unenhanced chest-CT examinations available on both, a second-generation dual-source CT (DSCT) using standard protocol (100kVp, filtered-back-projection) and, on a third-generation DSCT using Sn150kVp protocol with ADMIRE. Signal-to-noise-ratio (SNR) was measured in 6 standardized regions. A 5-point Likert scale was used to evaluate subjective image quality. Radiation metrics were compared.

RESULTS

The mean time interval between the two acquisitions was 1.1±0.7 years. Mean-volume-CT-dose-index, dose-length-product and effective dose were significantly lower for Sn150kVp protocol (2.1±0.5mGy;72.6±16.9mGy*cm;1.3±0.3mSv) compared to 100kVp protocol (6.2±1.8mGy;203.6±55.6mGy*cm;3.7±1.0mSv) (p<0.001), equaling a 65% dose reduction. All studies were considered of diagnostic quality. SNR measured in lung tissue, air inside trachea, vertebral body and air outside the body was significantly higher in 100kVp protocol compared to Sn150kVp protocol (12.5±2.7vs.9.6±1.5;17.4±3.6vs.11.8±1.8;0.7±0.3vs.0.4±0.2;25.2±6.9vs.14.9±3.3;p<0.001). SNR measured in muscle tissue was significantly higher in Sn150kVp protocol (3.2±0.9vs.2.6±1.0;p<0.001). For SNR measured in descending aorta there was a trend towards higher values for Sn150kVp protocol (2.8±0.6 vs. 2.7±0.9;p = 0.3). Overall SNR was significantly higher in 100kVp protocol (5.0±4.0vs.4.0±4.0;p<0.001). On subjective analysis both protocols achieved a median Likert rating of 1 (25th-75th-percentile:1-1;p = 0.122). Interobserver agreement was good (intraclass correlation coefficient = 0.73).

CONCLUSIONS

Combined use of 150kVp tin-filtered chest CT protocol with ADMIRE allows for significant dose reduction while maintaining highly diagnostic image quality in the follow up after lung transplantation when compared to a standard chest CT protocol using filtered back projection.

Devastating fast-growing lung cancer after single lung transplantation

Patients receiving lung transplantation are at increasing risk for the development of cancer due to the administration of immunosuppressive drugs. We hereby report the case of a patient with a devastating fast-growing lung cancer after single lung transplantation for pulmonary fibrosis.

Tacrolimus Levels Are Not Associated with Risk of Malignancy in Lung Transplant Recipients

BACKGROUND Lung transplant (LTx) recipients suffer from high rates of malignancy. Exposure to immunosuppressive medication such as tacrolimus has been proposed as a risk factor for tumorigenesis. We hypothesized that chronically high levels of tacrolimus would be associated with risk of malignancy. MATERIAL AND METHODS The study was performed in a transplant center in Israel, with a nested case-control design. Cases were LTx recipients who were diagnosed with any solid or hematological malignancy except non-melanoma skin cancer. Controls were tumor-free during their entire follow-up after LTx and had at least the same follow-up time as their matched case. Controls were matched to cases by age and type of transplant received (single/double). Tacrolimus levels were extracted and analyzed for median drug level and also integrated over time (area under the curve - AUC-tacrolimus). RESULTS We reviewed 412 LTx recipients in our registry. Thirty-nine cases of malignancy were diagnosed and 160 controls were matched, giving a crude tumor incidence rate of 26/100 000/year. Lung cancers were the commonest diagnosis. Cases and controls were well matched by age, smoking status, and LTx type. Median tacrolimus levels were 11.0 ng/ml and 11.3 ng/ml in cases and controls, respectively (p=0.88). The median log (AUC-tacrolimus) was 9.4 in the cases and 9.5 in the controls (p=0.59). CONCLUSIONS In this nested case-control study, exposure to tacrolimus was similar in tumor cases and non-tumor controls. These data, based on a cohort with modest size, suggest either that tumorigenesis in LTx recipients is unrelated to tacrolimus exposure or that levels in these patients are above an unknown threshold at which the dose-response effect is saturated.

Lung cancer in lung transplantation: incidence and outcome

Introduction

Malignancies are one of the causes of mortality after lung transplantation. However, little is known about lung cancer outcome after lung transplantation.

Methods

We performed a retrospective search of the lung transplantation database at our institution to identify patients diagnosed with lung cancer after lung transplantation.

Results

Out of 633 lung transplant patients, lung cancer was detected in 23 of them (3.63%). The most common causes for transplantation were idiopathic pulmonary fibrosis (47.8%) and emphysema (43.4%). A total of 18 patients were diagnosed during follow-up, 12 cases in the native lung (52.2%) and 6 cases in the donor lung (26.1%). The diagnosis was evidenced in the explanted lung in five patients (21.7%). The median of time from transplantation to cancer diagnosis was 39.7 months (24.356.6). Lung cancer was the cause of death in 16 patients. Survival rate at1year from diagnosis of lung cancer was 45.64% (95% CI 0.2431 to 0.6473).

Conclusions

Lung transplant recipients constitute a high-risk group for developing lung cancer. Among our patients, lung cancer was predominantly diagnosed in the native lung and at an advanced stage. The primary tumour was the main cause of death in most of these patients.

Endobronchial ultrasonography-guided transbronchial needle aspiration, an effective modality for sampling targeted thoracic lesions in adult lung transplant recipients

INTRODUCTION

Lung transplantation (LTx) is performed for end-stage lung diseases that would be otherwise fatal. Pulmonary allograft recipients are a unique patient population as they are at high risk for malignancy and infectious complications due to the need for immunosuppression. Endobronchial ultrasonography (EBUS)-guided fine-needle aspiration (FNA) is a minimally invasive technique for evaluating abnormalities of the mediastinum/lungs. To our knowledge, this report is the first in the literature addressing targeted EBUS-FNA biopsies in patients who have undergone LTx.

MATERIAL AND METHODS

During 5 years from May 1, 2009 to May 1, 2014, 582 patients underwent LTx at the Cleveland Clinic. A review of records indicated that 14 of these patients later underwent EBUS-FNA. Demographic and diagnostic parameters were recorded.

RESULTS

A total of 14 patients (mean age 64 years) underwent EBUS-FNA after LTx. The mean interval between LTx and EBUS-FNA was 15 months. EBUS-FNA yielded cytologic material diagnostic of malignancy in 10 patients (71%) with one-half of those cases being squamous carcinomas.

CONCLUSIONS

EBUS-FNA is a useful diagnostic modality in lung allograft recipients and is of value in confirming and staging thoracic malignancies in this population. Carcinoma subtyping is feasible by EBUS-FNA, and performance of ancillary studies to confirm clonality in post-transplant lymphoproliferative disorders is possible.

Lung transplantation: a treatment option in end-stage lung disease

BACKGROUND

Lung transplantation is the final treatment option in the end stage of certain lung diseases, once all possible conservative treatments have been exhausted. Depending on the indication for which lung transplantation is performed, it can improve the patient's quality of life (e.g., in emphysema) and/ or prolong life expectancy (e.g., in cystic fibrosis, pulmonary fibrosis, and pulmonary arterial hypertension). The main selection criteria for transplant candidates, aside from the underlying pulmonary or cardiopulmonary disease, are age, degree of mobility, nutritional and muscular condition, and concurrent extrapulmonary disease. The pool of willing organ donors is shrinking, and every sixth candidate for lung transplantation now dies while on the waiting list.

METHOD

We reviewed pertinent articles (up to October 2013) retrieved by a selective search in Medline and other German and international databases, including those of the International Society for Heart and Lung Transplantation (ISHLT), Eurotransplant, the German Institute for Applied Quality Promotion and Research in Health-Care (Institut für angewandte Qualitätsförderung und Forschung im Gesundheitswesen, AQUA-Institut), and the German Foundation for Organ Transplantation (Deutsche Stiftung Organtransplantation, DSO).

RESULTS

The short- and long-term results have markedly improved in recent years: the 1-year survival rate has risen from 70.9% to 82.9%, and the 5-year survival rate from 46.9% to 59.6%. The 90-day mortality is 10.0%. The postoperative complications include acute (3.4%) and chronic (29.0%) transplant rejection, infections (38.0%), transplant failure (24.7%), airway complications (15.0%), malignant tumors (15.0%), cardiovascular events (10.9%), and other secondary extrapulmonary diseases (29.8%). Bilateral lung transplantation is superior to unilateral transplantation (5-year survival rate 57.3% versus 47.4%).

CONCLUSION

Seamless integration of the various components of treatment will be essential for further improvements in outcome. In particular, the follow-up care of transplant recipients should always be provided in close cooperation with the transplant center.

Interobserver variability in grading transbronchial lung biopsy specimens after lung transplantation

BACKGROUND

Acute rejection remains a major source of morbidity after lung transplantation. Given the importance of this diagnosis, an international grading system was developed to standardize the diagnosis of acute lung-allograft rejection. The reliability of this grading system has not been adequately assessed by previous studies.

METHODS

We examined the level of agreement in grading transbronchial biopsy specimens obtained from a large multicenter study (AIRSAC [Comparison of a Tacrolimus/Sirolimus/Prednisone Regimen vs Tacrolimus/Azathioprine/Prednisone Immunosuppressive Regimen in Lung Transplantation] trial). Biopsy specimens were initially graded for acute rejection and lymphocytic bronchiolitis by the site pathologist and subsequently graded by a central pathologist. Reliability of interobserver grading was evaluated using Cohen κ coefficients.

RESULTS

A total of 481 transbronchial biopsy specimens were graded by both the site and central pathologists. The overall concordance rates were 74% and 89% for grade A and grade B biopsy specimens, respectively. When samples from biopsies performed at different time points after transplantation were assessed, there was a higher level of agreement early (≤ 6 weeks) after transplant compared with later time points for acute rejection. However, there was still only moderate agreement for both grade A (κ score 0.479; 95% CI, 0.29-0.67) and grade B (κ score 0.465; 95% CI, 0.08-0.85) rejection.

CONCLUSIONS

These results expand upon previous reports of interobserver variability in grading transbronchial biopsy specimens after lung transplantation. Given the variability in grading these specimens, we advocate further education of the histopathologic findings in lung transplant biopsy specimens, as well as revisiting the current criteria for grading transbronchial biopsy specimens to improve concordance among lung transplant pathologists.

TRIAL REGISTRY

ClinicalTrials.gov; No. NCT00321906; URL: www.clinicaltrials.gov.

Modulation of immune responses following solid organ transplantation by microRNA

Organ transplantation, an accepted treatment for end stage organ failure, is often complicated by allograft rejection and disease recurrence. In this review we will discuss the potential role of microRNAs in allograft immunity especially leading to rejection of the transplanted organ. microRNAs (miRNAs), originally identified in C. elegans, are short non-coding 21-24 nucleotide sequences that bind to its complementary sequences in functional messenger RNAs and inhibits post-translational processes through RNA duplex formation resulting in gene silencing (Lau et al., 2001). Gene specific translational silencing by miRNAs regulates pathways for immune responses such as development of innate immunity, inflammation, T-cell and B-cell differentiation and signaling that are implicated in various stages of allograft rejection. miRNAs also play a role in development of post-transplant complicacies like fibrosis, cirrhosis, carcinogenesis often leading to graft loss and poor patient outcome. Recent advancements in the methods for detecting and quantifying miRNA in tissue biopsies, as well as in serum and urine samples, has led to identification of specific miRNA signatures in patients with allograft rejection and have been utilized to predict allograft status and survival. Therefore, miRNAs play a significant role in post-transplant events including allograft rejection, disease recurrence and tumor development impacting patient outcome.

New concepts and best practices for management of pre- and post-transplantation cancer

Solid-organ transplant recipients are at increased risk of developing cancer compared with the general population. Tumours can arise de novo, as a recurrence of a preexisting malignancy, or from the donated organ. The ATOS (Aula sobre Trasplantes de Órganos Sólidos; the Solid-Organ Transplantation Working Group) group, integrated by Spanish transplant experts, meets annually to discuss current advances in the field. In 2011, the 11th edition covered a range of new topics on cancer and transplantation. In this review we have highlighted the new concepts and best practices for managing cancer in the pre-transplant and post-transplant settings that were presented at the ATOS meeting. Immunosuppression plays a major role in oncogenesis in the transplant recipient, both through impaired immunosurveillance and through direct oncogenic activity. It is possible to transplant organs obtained from donors with a history of cancer as long as an effective minimization of malignancy transmission strategy is followed. Tumour-specific wait-periods have been proposed for the increased number of transplantation candidates with a history of malignancy; however, the patient's individual risk of death from organ failure must be taken into consideration. It is important to actively prevent tumour recurrence, especially the recurrence of hepatocellular carcinoma in liver transplant recipients. To effectively manage post-transplant malignancies, it is essential to proactively monitor patients, with long-term intensive screening programs showing a reduced incidence of cancer post-transplantation. Proposed management strategies for post-transplantation malignancies include viral monitoring and prophylaxis to decrease infection-related cancer, immunosuppression modulation with lower doses of calcineurin inhibitors, and addition of or conversion to inhibitors of the mammalian target of rapamycin.