Review of Epstein–Barr virus and post-transplant lymphoproliferative disorder post-solid organ transplantation (Review Article)

Dendritic Cells: A Bridge between Tolerance Induction and Cancer Development in Transplantation Setting

Dendritic cells (DCs) are a heterogeneous group of antigen-presenting cells crucial for fostering allograft tolerance while simultaneously supporting host defense against infections and cancer. Within the tumor microenvironment, DCs can either mount an immune response against cancer cells or foster immunotolerance, presenting a dual role. In immunocompromised individuals, posttransplant malignancies pose a significant health concern, with DCs serving as vital players in immune responses against cancer cells. Both recipient- and donor-derived DCs play a critical role in the rejection process, infiltrating the transplanted organ and sustaining T-cell responses. The use of immunosuppressive drugs represents the predominant approach to control this immunological barrier in transplanted organs. Evidence has shed light on the immunopharmacology of these drugs and novel strategies for manipulating DCs to promote allograft survival. Therefore, comprehending the mechanisms underlying this intricate microenvironment and the effects of immunosuppressive therapy on DCs is crucial for developing targeted therapies to reduce graft failure rates. This review will delve into the fundamental immunobiology of DCs and provide a detailed exploration of their clinical significance concerning alloimmune responses and posttransplant malignancies.

The pathobiology of select adolescent young adult lymphomas

Lymphoid cancers are among the most frequent cancers diagnosed in adolescents and young adults (AYA), ranging from approximately 30%-35% of cancer diagnoses in adolescent patients (age 10-19) to approximately 10% in patients aged 30-39 years. Moreover, the specific distribution of lymphoid cancer types varies by age with substantial shifts in the subtype distributions between pediatric, AYA, adult, and older adult patients. Currently, biology studies specific to AYA lymphomas are rare and therefore insight into age-related pathogenesis is incomplete. This review focuses on the paradigmatic epidemiology and pathogenesis of select lymphomas, occurring in the AYA patient population. With the example of posttransplant lymphoproliferative disorders, nodular lymphocyte-predominant Hodgkin lymphoma, follicular lymphoma (incl. pediatric-type follicular lymphoma), and mediastinal lymphomas (incl. classic Hodgkin lymphoma, primary mediastinal large B cell lymphoma and mediastinal gray zone lymphoma), we here illustrate the current state-of-the-art in lymphoma classification, recent molecular insights including genomics, and translational opportunities. To improve outcome and quality of life, international collaboration in consortia dedicated to AYA lymphoma is needed to overcome challenges related to siloed biospecimens and data collections as well as to develop studies designed specifically for this unique population.

Post-transplant lymphoproliferative disorders (PTLD) in adolescents and young adults: A category in need of definition

Post-transplant lymphoproliferative disorders are a well-recognized complication of solid organ and stem cell transplantation. Much data has accumulated with respect to the pathobiology and clinical behavior of these lesions in the general post-transplant population as well as in the pediatric and adult age groups. However, information as to these lesions in the adolescent and young adult populations, which bridge the pediatric and adult groups, is limited. In this review, the focus is on this unique population of PTLD patients and their proliferations.

Advances in therapeutic strategies for primary CNS B-cell lymphomas

INTRODUCTION

Primary CNS lymphoma (PCNSL) has traditionally been treated with induction HD-MTX-based chemotherapy, followed by consolidation whole-brain radiotherapy. However, this approach is associated with significant neurocognitive complications, especially in older patients. Therefore, different consolidation protocols have been evaluated. High-dose chemotherapy followed by autologous stem cell transplantation (HD-ASCT) has the best long-term survival outcomes in younger patients.

AREAS COVERED

In this review of the literature, we focus on the overall therapeutic strategy and advances in the management of the aggressive primary CNS B-cell lymphomas.

EXPERT OPINION

In young and fit PCNSL patients, HD-ASCT is the preferred consolidation strategy to achieve long-term survivals. Older patients with good performance status should also be evaluated for MTX-based induction polychemotherapy followed by ASCT. However, management of PCNSL patients remains challenging, and new avenues with targeted therapies are under investigation. To date, ibrutinib, lenalidomide, and immune checkpoint inhibitors appearto be promising in PCNSL. However, as monotherapy, durable responses are less likely to be achieved. Unfortunately, when combined with chemoimmunotherapy, considerable toxicity and mortality have been reported. Clinical trials on these molecules are aiming to reduce toxicity and maintain responses. CAR-T-cell therapy has recently emerged as a further option. It has shown efficacy in patients with secondary CNS lymphoma, with few but encouraging results in primary CNSL.

Successful treatment of hemophagocytic syndrome in a patient with T cell lymphoma, EBV infection, and bone marrow necrosis: A case report

RATIONALE

Hemophagocytic syndrome (HPS) is associated with a high mortality rate, and Epstein-Barr virus infection and hematological malignancies, especially T/natural killer cell lymphomas, are the most common causes; however, due to the complexity of clinical manifestations, the diagnosis is usually delayed. There are few reports of lymphoma-associated HPS (LAPS) in combination with bone marrow necrosis, and there is still no standard treatment for LAPS.

PATIENT CONCERNS

A 64-year-old man developed a fever, mild jaundice, fatigue, and bone pain. Positron emission tomography and bone marrow biopsy with immunohistochemistry were performed.

DIAGNOSIS

Imaging analysis and bone marrow examinations were compatible with HPS, T-cell lymphoma, and bone marrow necrosis.

INTERVENTIONS

The patient received combination therapy of rituximab and Cyclophosphamide, epirubicin, vincristine, glucocorticoid, etoposide.

OUTCOMES

The patient achieved complete remission and a disease-free survival of 52 months.

LESSONS

HPS and its potential diseases should be diagnosed and treated as soon as possible. Clinicians should be aware of the presence of lymphoma in patients with HPS. Rituximab plays an important role in the prognosis of HPS, particularly Epstein-Barr virus positivity. Cyclophosphamide, epirubicin, vincristine, glucocorticoid remains an effective regimen for the treatment of T-cell LAPS. This study provides a better understanding of the diagnosis and treatment of LAPS.

Facial Paralysis From Post-transplant Lymphoproliferative Disorder

OBJECTIVE

We report a case of facial paresis and profound hearing loss from post-transplant lymphoproliferative disorder (PTLD) in a pediatric patient with neuroblastoma.

PATIENT

Three-year-old boy with rapidly progressive right facial paresis and sensorineural hearing loss. High-risk neuroblastoma had been diagnosed 1 year earlier, treated with chemotherapy and resection of the adrenal primary tumor. Two months after two autologous hematopoietic stem cell transplantations (HSCT), the patient developed facial paralysis. Magnetic resonance imaging (MRI) showed bilateral progressive internal auditory canal (IAC) enhancing lesions with a mass lesion on the right and wispy enhancement on the left and enhancement within the right cochlea. Lumbar puncture (LP) was positive for Epstein-Barr virus (EBV) making the diagnosis of PTLD most probable. Biopsy of the right IAC lesion was deferred because of potential procedural risks including intradural spread of tumor or fungus. The patient was treated with anti-fungal therapy and systemic rituximab without improvement. Subsequent intrathecal rituximab resulted in improvement of lesions on MRI and clearance of EBV from the cerebrospinal fluid (CSF).

INTERVENTIONS

Mastoidectomy for biopsies from the mastoid and middle ear. Intrathecal treatment with rituximab.

MAIN OUTCOME MEASURES

Imaging assessment of IAC lesion, CSF EBV titers, facial nerve function.

RESULTS

Gradual resolution of IAC mass lesions, remission of PTLD, and facial improvement from House-Brackmann score of 4 to 3.

CONCLUSIONS

PTLD causing facial paresis after autologous HSCT has not been previously reported and may be considered in the differential diagnosis of lesions causing facial paresis in patients who have received a stem cell or solid organ transplant.

A single-center experience of post-transplant lymphomas involving the central nervous system with a review of current literature

Background

Central Nervous System (CNS) lymphoma is a rare presentation of post-transplantation lymphoproliferative disorder (PTLD).

Methods

This single center retrospective study reviewed presentations, management and outcomes of CNS lymphomas in kidney transplant patients transplanted 1968 to 2015, and reviews relevant current literature.

Results

We identified 5773 adult kidney transplant recipients of who 90 had a PTLD diagnosis confirmed. CNS disease was diagnosed in 6/90 (7%). Median age at presentation was 60 years and time from transplant 4.5 years. Immunosuppression at diagnosis included mycophenolate mofetil and prednisolone without calcineurin inhibitor in 5/6 patients. Histological analysis diagnosed monomorphic disease in 5/6, and one polymorphic case with tissue positive for Epstein-barr virus (EBV) in 5/6 cases. Despite this 2/4 EBV positive cases had no detectable EBV in peripheral blood or CSF at diagnosis. Treatment strategies included reduction in immunosuppression in all, chemotherapy (n=5), radiotherapy (n=3), Cytotoxic T-Lymphocytes and Craniotomy (n=2). Patient survival was 40% at 1 year with CTL treated patients surviving beyond three years from diagnosis.

Conclusion

This study supports observational data suggesting MMF treated patients without CNI may have increased risk of disease. Peripheral blood screening for EBV DNAemia does not seem helpful in early identification of those at risk.

Post-transplant lymphoproliferative disorder of the cauda equina in a kidney transplant recipient

Introduction

Post-transplant lymphoproliferative disorder (PTLD) is a condition associated with post-transplant immunosuppression that can develop in various organs, including the grafted one. However, it has rarely been reported in nerve tissue. We encountered an unexpected case of PTLD in the cauda equina of a kidney transplant recipient who was being treated with chronic immunosuppressive therapies.

Case presentation

The patient was a 39-year-old woman in whom lower limb muscle weakness appeared and progressed rapidly 10 years after kidney transplantation for glomerulonephritis. Magnetic resonance imaging (MRI) findings were suggestive of an intradural extramedullary tumor. Diagnosis of PTLD was established on open biopsy. Culprit immunosuppressants (tacrolimus, mycophenolate mofetil, and prednisolone) were discontinued, and rituximab and radiation therapy were started. The paraplegia gradually improved after drug discontinuation, and the lesion diminished in size 3 months after this series of treatment, and finally disappeared on MRI as of 1 year after treatment.

Discussion

PTLD in the cauda equina is extremely rare, and only one case involving the cauda equina has been reported previously. Biopsy should be performed initially for definitive diagnosis, after which the suspected culprit immunosuppressants should be immediately discontinued.

Bilateral Central Retinal Artery Occlusion Associated with Bilateral Lymphoproliferative Infiltrative Optic Neuropathy

BACKGROUND

Leukemic infiltration of the optic nerve is relatively rare. While previously described in acute leukemia, the infiltration in our case represents central nervous system (CNS) metastasis of Burkitt-type lymphoma that developed as a complication of solid-organ transplantation, resulting in a bilateral infiltrative optic neuropathy with sequential, bilateral central retinal artery occlusion (CRAO) and devastating vision loss.

METHODS

The medical record, serial ophthalmic examination findings, clinical course, and imaging including magnetic resonance imaging (MRI), fundus photographs, and fluorescein angiography of a single patient were retrospectively reviewed.

RESULTS

MRI demonstrated multifocal cortical and leptomeningeal CNS involvement, including the left optic nerve. Serial fundus examination/photography and fluorescein angiography showed that despite urgent whole-brain irradiation and systemic chemotherapy, CNS disease progressed to bilateral optic nerve infiltration and CRAO with no light perception vision in both eyes.

CONCLUSION

CRAO can occur as a devastating and irreversible complication of lymphoproliferative optic nerve infiltration.

Relapsing EBV encephalitis in a renal transplant recipient

In solid organ transplant recipients, Epstein-Barr virus (EBV) can cause active central nervous system (CNS) infection or malignant transformation of latently infected cells in the CNS, known as post-transplant lymphoproliferative disease (PTLD). Reduction of T-cell immunosuppression is the cornerstone of management. The role of antivirals with in-vitro activity against herpesviruses in EBV-related CNS syndromes is controversial, as they have no effect on latent virus. We report an unusual case of relapsing EBV encephalitis in a donor-positive, EBV-negative renal transplant recipient, with response to valganciclovir. Our report supports the utility of antiviral treatment for EBV encephalitis, as adjunct to reducing immunosuppression, and highlights the need for a systematic approach and long-term, multi-disciplinary follow-up of such patients.

Overview of Infections in the Immunocompromised Host

Understanding the components of the immune system that contribute to host defense against infection is key to recognizing infections that are more likely to occur in an immunocompromised patient. In this review, we discuss the integrated system of physical barriers and of innate and adaptive immunity that contributes to host defense. Specific defects in the components of this system that predispose to particular infections are presented. This is followed by a review of primary immunodeficiency diseases and secondary immunodeficiencies, the latter of which develop because of a specific illness or condition or are treatment-related. The effects of treatment for neoplasia, autoimmune diseases, solid organ and stem cell transplants on host defenses are reviewed and associated with susceptibility to particular infections. In conclusion, an approach to laboratory screening for a suspected immunodeficiency is presented. Knowledge of which host defects predispose to specific infections allows clinicians to prevent, diagnose, and manage infections in their immunocompromised patients most effectively.

Rapid and Early Diagnosis of Posttransplant Lymphoproliferative Disease Using Cross-Sectional Nuclear Medicine Imaging and Laparoscopic Lymph Node Biopsy: A Report of 2 Cases

Posttransplant lymphoproliferative disease is a complication of organ transplant with a myriad clinical and anatomic manifestations, thus making diagnosis difficult without histologic confirmation. In cases of lymphadenopathy confined to the abdomen, the diagnosis can be delayed because of late presentation and difficulty obtaining a tissue for histologic analyses. We describe the use of cross-sectional nuclear medicine imaging to locate enlarged abdominal lymph nodes; this facilitated minimally invasive laparoscopic lymph node excision biopsy to rapidly diagnose 2 cases of post-transplant lymphoproliferative disease. Prompt diagnosis has enabled early effective treatment, resulting in good patient outcomes.

Donor-Derived Infections: Incidence, Prevention, and Management

Organ donors reflect the diverse US population, and there are an increasing number of donors born in, who have resided in, or who have traveled to underdeveloped areas of the world or areas with geographically restricted infections. As such, these donors are exposed to pathogens that can potentially be transmitted to recipients of the donor’s organs. Additionally, there are newer techniques to identify many pathogens that may be transmitted from the donor to the transplant recipients. Finally, high-profile reports of several donor-derived infections have heightened awareness of donor-derived infections and have likely contributed to increased recognition. In this chapter, the incidence, methods of identification and prevention, and management of unexpected donor-derived infections will be reviewed.

Cerebral Lymphoma in a Kidney Transplant: A Case Report

Posttransplant lymphoproliferative disorder is a serious complication during a solid-organ transplant. A 28-year-old Asiatic man developed a cerebral lesion that was considered an abscess, while undergoing a kidney transplant. The lesion diameter did not go down with antibiotic therapy, so he underwent a complete surgical mass excision. Pathology showed a B-cell lymphoma. The Epstein-Barr virus-DNA by polymerase chain reaction in plasma was negative. He began chemotherapy with methotrexate and rituximab, and radiation therapy. He had to be restarted on regular hemodialysis 1 year after surgery. Three years after receiving the diagnosis, he was alive and had not developed any other posttransplant lymphoproliferative disorder. This report presents case of a patient who developed primary central nervous system B-cell lymphoma, 2 years after undergoing a kidney transplant. A combination of chemotherapy and radiotherapy is the best option for treatment of brain posttransplant lymphoproliferative disorder.

Severe post-transplant lymphoproliferative disorder after living donor liver transplantation

Post-transplant lymphoproliferative disorder (PTLD) is a well-known complication after transplantation. A living donor liver transplantation was performed on a 31-year-old man for fulminant hepatitis. He again developed liver dysfunction after 7 months. He was diagnosed as having acute cellular rejection and the steroid pulse therapy introduced resulted in little improvement. He gradually developed a high fever and right axillary lymphadenopathy appeared. Chest computed tomography (CT) was performed revealing small lung nodules and axillary lymphadenopathy. Because his serological status for Epstein-Barr virus was positive, PTLD was highly suspected and immunosuppression treatment was withdrawn with little improvement. One week later, he developed tachycardia. Chest CT was re-performed revealing an infiltration to the left cardiac chamber. For diagnosis, axillary lymph node biopsy was performed and during the procedure, he developed ventricular tachycardia (VT). Immunohistological staining revealed PTLD of T lymphocytes, and chemotherapy was introduced on the same day he developed VT. After two cycles of tetrahydropyranyl, adriamycin, cyclophosphamide, vincristine, prednisolone and etoposide treatment, he completely recovered. This is a first case report of severe PTLD with VT, and our case implies the feasibility of chemotherapy after the appearance of dissemination symptoms.

Post-transplant lymphoproliferative disorders

Post-transplant lymphoproliferative disorders (PTLD) are a serious complication after solid organ or allogeneic hematopoietic stem cell transplantation and include a range of diseases from benign proliferations to malignant lymphomas. Risk factors for developing PTLD include Epstein-Barr virus (EBV) infection, recipient age, transplanted organ, type of immunosuppression, and genetics. Uncontrolled proliferation of EBV-infected B cells is implicated in EBV-positive PTLD, whereas the pathogenesis of EBV-negative PTLD may be similar to non-Hodgkin's lymphoma in the general population. The World Health Organization (WHO) classifies PTLD into four categories: early lesions, polymorphic PTLD, monomorphic PTLD, and classical Hodgkin's lymphoma (cHL). Treatment is aimed at cure of PTLD, while maintaining transplanted organ function. However, there are no established guidelines for the treatment of PTLD. Immune suppression reduction (ISR) is the first line of treatment in most cases, with more recent data suggesting early use of rituximab. In more aggressive forms of PTLD, upfront chemotherapy may offer a better and more durable response. Sequential therapy using rituximab followed by chemotherapy has demonstrated promising results and may establish a standard of care. Novel therapies including anti-viral agents, adoptive immunotherapy, and monoclonal antibodies targeting cytokines require further study in the prevention and treatment of PTLD.

Epstein-Barr virus-associated posttransplant lymphoproliferative disorder involving the central nervous system following autologous hematopoietic stem cell transplantation for neuroblastoma

Introduction

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication following solid organ or hematopoietic stem cell transplantation (HSCT). Although extranodal involvement of PTLD is common, its isolated involvement in the central nervous system (CNS) is extremely rare. To date, primary CNS-PTLD has been reported in 13 patients who underwent allogeneic HSCT, but no cases have been reported in autologous HSCT recipients.

Case Description

Herein, we report the first report of a patient with neuroblastoma that progressed to CNS-PTLD after autologous peripheral blood stem cell transplantation (auto-PBSCT). A 27-month-old boy with stage IV neuroblastoma of the left adrenal gland received auto-PBSCT after intensive chemotherapy, tumor resection, and radiation of tumor bed and regional lymph node. An intracranial tumor in his left parietal lobe was detected by magnetic resonance imaging 99 days posttransplantation, and the tumor was completely resected. The histological diagnosis of the intracranial tumor was diffuse large B-cell lymphoma with latency type III Epstein-Barr virus infection. The patient has maintained tumor free status 3 years after auto-PBSCT.

Discussion and Evaluation

Given the rarity of CNS-PTLD, there is no consensus on the optimal treatment. Historically, the outcome of CNS-PTLD has been very poor. However, our patient remains free from PTLD after only total resection. The prognosis for PTLD following auto-HSCT may depend upon the underlying malignancy, immune state, EBV immune status, and treatments.

Conclusions

The outcome of PTLD following auto-HSCT is not necessarily poor prognosis. Further research is required to establish the optimal treatment strategy for CNS-PTLD.

(18)F-FDG PET/CT in the management of patients with post-transplant lymphoproliferative disorder

OBJECTIVES

Post-transplant lymphoproliferative disorder (PTLD) is a rare but serious complication in transplant patients. Although fluorine-18 2-fluoro-2-deoxyglucose PET and computed tomography ((18)F-FDG PET/CT) has been used for the evaluation and management of patients with PTLD, its utility has yet to be documented. We were therefore prompted to review our experience with (18)F-FDG PET/CT in PTLD.

MATERIALS AND METHODS

We retrospectively reviewed the records of consecutive patients who had undergone (18)F-FDG PET/CT for evaluation of PTLD from January 2004 to June 2012 at our institution. (18)F-FDG PET/CT scans were compared with other imaging modalities performed concurrently. A chart review of pertinent clinical information was also conducted.

RESULTS

A total of 30 patients were identified (14 female and 16 male; 1.7-76.7 years of age, average: 23.8 years). Twenty-seven participants had biopsy-proven PTLD and another three had been treated for PTLD because of high clinical suspicion of disease and positive (18)F-FDG PET/CT findings in the absence of histological diagnosis. Eighty-three percent of these PTLD patients had extranodal involvement. In 57% of the cases, (18)F-FDG PET/CT detected occult lesions not identified on other imaging modalities or suggested PTLD in equivocal lesions. The more aggressive PTLD histological subtypes demonstrated higher SUVmax compared with the less aggressive subtypes.

CONCLUSION

(18)F-FDG PET/CT is beneficial in the diagnostic evaluation of patients with PTLD. (18)F-FDG PET/CT has the ability to detect occult lesions not identified on other imaging modalities, particularly extranodal lesions. In addition, (18)F-FDG PET/CT may predict the PTLD subtype, as the lesions with higher pathologic grade presented with significantly higher SUVmax compared with the less aggressive forms.

Epstein-barr virus-negative post-transplant lymphoproliferative diseases: three distinct cases from a single center

Three cases of Epstein-Barr virus (EBV)-negative post-transplant lymphoproliferative disease that occurred 6 to 8 years after renal transplantation are reported. The patients respectively had gastric mucosa-associated lymphoid tissue lymphoma, gastric diffuse large B-cell lymphoma, and atypical Burkitt lymphoma. Absence of EBV in the tissue samples was demonstrated by both in situ hybridization for EBV early RNA and polymerase chain reaction for EBV DNA. Patients were treated with reduction in immunosuppression and combined chemotherapy plus an anti-CD20 monoclonal antibody, rituximab. Despite the reduction in immunosuppression, patients had stable renal functions without loss of graft functions. The patient with atypical Burkitt lymphoma had an abnormal karyotype, did not respond to treatment completely, and died due to disease progression. The other patients are still alive and in remission 5 and 3 years after diagnosis, respectively. EBV-negative post-transplant lymphoproliferative diseases are usually late-onset and are reported to have poor prognosis. Thus, reduction in immunosuppression is usually not sufficient for treatment and more aggressive approaches like rituximab with combined chemotherapy are required.

Malignancies: pre and post transplantation strategies

The overall incidence of cancer is increased 2-3 fold in solid organ transplant recipients compared to the general population. The increase in risk is not uniform for all malignancies, in all ages or in all regions of the world. Several cancers are greatly increased, many are increased 2-4 fold and others do not appear to be increased at all. The pattern of increase is similar to patients with acquired immunodeficiency syndrome and those cancers most increased are associated with viral infections. These observations support the concept that much of the increased risk is from immunosuppression. Nonetheless there are differences between specific organ groups that deserve further examination. Those with advanced organ failure are also at increased risk for certain malignancies, which suggest either organ damage per se may pre-dispose to cancers or there are exposures to carcinogens in common. The purpose of this review to examine cancer incidence and mortality in solid organ transplantation and the role of pre transplant screening and post-transplant surveillance to reduce the burden of disease and improve patient outcomes. This review will focus on cancers that are common, associated with significant case fatality rates and have potential screening strategies to reduce burden of disease.

Risk of posttransplant lymphoproliferative disorder associated with use of belatacept

Purpose

Published evidence on a rare but serious malignancy associated with use of the first biological agent approved for long-term maintenance immunosuppression in renal transplant recipients is reviewed.

Summary

Belatacept (Nulojix, Bristol-Myers Squibb) is approved by the Food and Drug Administration for use in combination therapy to prevent renal graft rejection in patients who are Epstein-Barr virus seropositive. Belatacept appears to offer some advantages over calcineurin inhibitor-based regimens (e.g., no need for therapeutic drug monitoring), but its use poses a risk of posttransplant lymphoproliferative disorder (PTLD), a rapidly progressing and often lethal malignancy. The efficacy and safety of more-intensive and less-intensive belatacept regimens were established in two Phase III clinical trials, which found that rates of patient and graft survival were comparable to those in cyclosporine users; belatacept was shown to be superior in preserving renal function. The occurrence of PTLD, particularly PTLD involving the central nervous system, in 0–4% of belatacept-treated patients in clinical trials prompted postmarketing initiatives: (1) implementation of a risk evaluation and mitigation strategy (REMS) program to help ensure the safe and proper use of belatacept, (2) longitudinal studies to better define the risks and outcomes of belatacept therapy, and (3) a manufacturer-created patient registry to track belatacept use and encourage voluntary reporting of associated adverse events.

Conclusion

Appropriate patient selection and adherence to REMS requirements, including patient counseling and facilitation of registry enrollment, are essential in mitigating the increased risk of PTLD associated with belatacept therapy.

Chemoimmunotherapy and withdrawal of immunosuppression for monomorphic posttransplant lymphoproliferative disorders

BACKGROUND

Monomorphic PTLDs are the most aggressive type of PTLD occurring after SOT. Current guidelines for treatment suggest a stepwise approach that includes a reduction of immunosuppression (RIS) with or without rituximab, followed by chemotherapy if there is no response. Nevertheless, recommendations regarding the extent and duration of RIS are nonstandardized and RIS as an initial strategy might be associated with an unacceptably high frequency of graft loss and disease progression.

PATIENTS AND METHODS

We reviewed the outcome of a combination program of aggressive chemoimmunotherapy and complete withdrawal of immunosuppression in treating 22 patients with monomorphic PTLD between January 1995 and August 2012.

RESULTS

Twelve of 22 patients (55%) received CHOP-R (cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab) every 2 weeks (dose-dense CHOP-R) and 10 patients received other doxorubicin-based regimens. There was no treatment-related mortality. Complete response was seen in 91% of patients. Median OS was 9.61 years (95% confidence interval (CI), 5.21-10.74). Median progression-free survival was 5.39 years (95% CI, 2.10-10.74). The graft rejection rate was 18% (95% CI, 0.03-0.34).

CONCLUSION

The use of aggressive chemoimmunotherapy in combination with the withdrawal of immunosuppression approach yields excellent results and should be prospectively studied in a multi-institutional setting.

Sudden unexpected death due to hemophagocytic lymphohistiocytosis syndrome

The hemophagocytic lymphohistiocytosis (HLH) syndrome is a hyperimmune disorder characterized by lymphohistiocytic infiltrations, elevated cytokine levels in the blood, macrophage activation, and hemophagocytosis, frequently presenting with a febrile septic picture. This unusual disease is more common in infancy and childhood than adulthood. It is classified as primary or familial when a genetic defect is identified and secondary or acquired when triggered by certain infections, autoimmune disorders, or malignancies. If or when such patients expire, they typically do so within a hospital or under a physician's care and so such cases rarely come to the attention of forensic pathologists. We report on the unexpected deaths of two hospitalized adult cases of HLH brought to autopsy without a premortem diagnosis. Postmortem examination demonstrated marked hepatosplenomegaly and lymphadenopathy in association with hemophagocytosis. Although very uncommon HLH must be considered in infants, children, or adults who die unexpectedly with an undiagnosed septic presentation.

A 16-year multi-institutional study of the role of age and EBV status on PTLD incidence among pediatric heart transplant recipients

The objective was to determine the incidence and hazard for posttransplant lymphoproliferative disease (PTLD) in a study of 3170 pediatric primary heart transplants between 1993 and 2009 at 35 institutions in the Pediatric Heart Transplant Study. 147 of 151 reported malignancy events were classified as PTLD. Overall freedom from PTLD was 98.5% at 1 year, 94% at 5 years and 90% at 10 years. Freedom from PTLD was lowest in children (ages 1 to < 10 years) versus infants (<1 year) and adolescents (10 to < 18 years) with children at highest risk for PTLD with a relative risk of 2.4 compared to infants and 1.7 compared to adolescents. Positive donor EBV status was a strong risk factor for PTLD in the seronegative recipient, but risk magnitude was dependent on recipient age at the time of transplantation. Nearly 25% of EBV seronegative recipients of EBV+ donors at ages 4-7 at transplantation developed some form of PTLD. The overall risk for PTLD declined in the most recent transplant era (2001-2009, p = 0.003). These findings indicate that EBV status and the age of the recipient at the time of transplantation are important variables in the development of PTLD in the pediatric heart transplant recipient.

Viremia after lung transplant: a cohort study on risk factors and symptoms associated with detection of Epstein-Barr virus

Background-The frequency and impact of detection of Epstein-Barr virus in the blood of lung and heart-lung transplant recipients in the postoperative period is poorly characterized.Objective-To investigate the frequency of virus detection, associated clinical symptoms and risk factors, and influence of virus detection on outcome.Methods-A cohort of 98 lung transplant recipients were monitored for Epstein-Barr virus in blood before transplant and during their posttransplant hospital stay (median 4 weeks, range 1-21 weeks). Patients were followed up for retransplant or death for a median of 17 months.Results-Epstein-Barr virus DNA was detected in 15 recipients (18.1%) before and in 39 recipients (41.5%) after transplant. Median viral load after transplant was 2300 copies per milliliter of blood (range, 900-45 000 copies/mL). Detection of Epstein-Barr virus DNA before transplant and mechanical ventilation before transplant were associated with detection of Epstein-Barr virus DNA after transplant. Shortness of breath, fatigue, and hoarseness were associated with detection of viral DNA after transplant. The incidence of retransplant or death was not increased in recipients who had viral DNA detected in their blood.Conclusions-Epstein-Barr virus DNA in the blood before transplant and mechanical ventilation before transplant were associated with detection of viral DNA after transplant. Detection of viral DNA after transplant was frequent and clinically relevant.

Post-transplantation lymphoproliferative disorder in pediatric kidney-transplant recipients - a national study

PTLD is the most common malignancy in pediatric kidney-transplant recipients. We examined the prevalence, clinical features, and outcome of PTLD in Israel. Twelve (4.4%) of 272 pediatric (<19 yr) kidney-transplant recipients retrieved from a search of the NIKTR for 1991-2008 had acquired PTLD at a median of 3.2 yr post-transplantation. PTLD-affected patients were younger at transplantation (4.2 vs. 12.5 yr, p = 0.02), had a higher rate of OKT3 therapy for acute rejection (25% vs. 4%, p = 0.015), and 5/12 were EBV-seropositive at transplantation. Graft dysfunction was the presenting sign in six (50%). PTLD was predominantly abdominal (83%) and B-cell type (67%); T-cell PTLD occurred exclusively in EBV-seropositive patients. Treatment consisted of immunosuppression cessation (6/12, 50%), antiviral agents (7/12, 58%), anti-CD20 monoclonal antibodies (4/12, 33%), and chemotherapy (6/12, 50%). Survival was 100% in the EBV-naïve patients and 40% in the EBV-seropositive patients. Graft loss occurred in three of eight survivors (37.5%). PTLD-associated mortality risk was older age: 11.2 vs. 3.4 yr, longer dialysis: 15 vs. 6.5 months, T-cell type disease (75%), later PTLD onset: 6.35 vs. 1.9 yr post-transplantation and era of transplantation (43% mortality before vs. 20% after 2001). Pretransplantation EBV-seronegative status might confer a survival benefit with early detected PTLD. EBV-seropositive patients are at risk for aggressive late-onset lethal PTLD.

Successful treatment of monomorphic primary central nervous system post-transplantation lymphoproliferative disorder 5 years after kidney transplantation

A 31-year-old man underwent living-related kidney transplantation in 2004 as a consequence of primary focal segmental glomerulosclerosis (FSGS). Four years after the transplantation, we confirmed nephrotic syndrome caused by recurrent FSGS. We performed plasmapheresis and low-density lipoprotein adsorption. We also combined steroid therapy with a reduction in the dose of tacrolimus and an increased dose of mycophenolate mofetil. The nephrotic syndrome improved dramatically with this combined therapeutic approach. However, 10 months after these treatments, he revisited our hospital because of altered consciousness. We detected multiple tumor masses in his brain that were ring enhanced on contrast magnetic resonance imaging. Consequently, we suspected primary central nervous system post-transplantation lymphoproliferative disorder (CNS-PTLD). We performed a craniotomy to biopsy the brain tumors. The biopsy specimen showed Epstein-Barr virus-associated diffuse large B-cell lymphoma. There is no definitive treatment for CNS-PTLD. Therefore, we treated the primary CNS-PTLD successfully with whole-brain radiation and discontinuation of immunosuppression therapy.

Thymoma and solid-organ transplantation

Solid-organ-transplant recipients are at high risk of developing cancer, including thoracic malignancies. Herein, we report on two cases of thymoma in solid-organ recipients. One case was a female kidney-transplant recipient who had a type B2, Masaoka stage IVA thymoma that was treated by extended surgical resection followed by postoperative radiation therapy. The second case was type A Masaoka II thymoma that occurred after a liver transplant. The role of EBV in the oncogenesis of thymoma is controversial. We suggest that viruses may induce neoplasms in this specific population, as observed in post-transplant lymphoproliferative disorders. However, Epstein-Barr-encoded RNA (EBER) was negative in both patients.

Long-term carriers generate Epstein-Barr virus (EBV)-specific CD4(+) and CD8(+) polyfunctional T-cell responses which show immunodominance hierarchies of EBV proteins

T cells simultaneously producing multiple cytokines and possessing cytotoxic capacity termed polyfunctional cells (PFCs) are increasingly recognized as the immune correlate of protection against pathogenic viruses. We investigated co-expression of four cytokines (interferon-γ, macrophage inflammatory protein 1-α, tumour necrosis factor-α and interleukin-2) and degranulation capacity (CD107a surface expression) of Epstein-Barr virus (EBV) -specific CD4(+) and CD8(+) T cells upon stimulation by overlapping peptides of EBV lytic (BZLF1) and latent (EBNA1, EBNA3 and LMP2) proteins, in 20 healthy Chinese long-term carriers. Two patients with post-transplant lymphoproliferative disorder (PTLD), who had impaired T-cell immunity, were studied for comparison. Both EBV-specific CD4(+) and CD8(+) PFCs were readily generated in long-term carriers and showed immunodominance hierarchies of latent proteins (EBNA1 > EBNA3/LMP2 and EBNA3 > LMP2 > EBNA1 for CD4(+) and CD8(+) T cells, respectively), as evidenced by a higher proportion of PFCs generated by immunodominant EBV proteins than by subdominant viral proteins. In contrast, the proportion of EBV-specific PFCs was markedly decreased in patients with PTLD. The EBV-specific PFCs produced more cytokine per cell than single-functional T cells and comprised different subsets. Five-functional CD4(+) and CD8(+) T cells were detected and four-functional CD4(+) T cells were mainly CD107a negative and expressed all four cytokines whereas four-functional CD8(+) T cells were mainly CD107a positive and expressed three of the four cytokines (interleukin-2-negative). We conclude that EBV-specific PFCs are generated in much higher proportions in the long-term carriers than in the patients with PTLD and maintain the immunodominant characteristics of the virus.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

EBV-encoded miRNAs

The Epstein-Barr virus (EBV) is an oncogenic Herpes virus involved in the induction of a variety of human tumours. It was the first virus found to encode microRNAs (miRNAs). MiRNAs are short, non-coding RNAs that in most cases negatively regulate gene expression at the post-transcriptional level. EBV-transformed cells express at least 44 mature viral miRNAs that target viral and cellular genes. In addition, EBV-infection severely deregulates the miRNA profile of the host cell. The presently available information indicates that the virus uses its miRNAs to inhibit the apoptotic response of the infected cell as a means to establish a latent infection. Likewise, EBV-encoded miRNAs interfere in the expression of viral genes in order to mask the infected cell from the immune response. Cellular targets of viral miRNAs are involved in protein traffic within the cell and regulate innate immunity. MiRNA profiling of diffuse large B-cell lymphoma (DLBCL) and nasal NK/T-cell lymphoma (NKTL) showed that only 2% of the miRNAs are derived from the virus, while viral miRNAs comprise up to 20% of the total miRNA in nasopharyngeal carcinoma (NPC) and probably contribute to the formation or maintenance of NPC. The presence of viral miRNAs in exosomes raises the fascinating possibility that virus-infected cells regulate gene expression in the surrounding tissue to avert destruction by the immune system. This article is part of a Special Issue entitled: MicroRNAs in viral gene regulation.

Increased incidence of early de novo cancer in liver graft recipients treated with cyclosporine: an association with C2 monitoring and recipient age

The goal of this study was to determine the risk factors for de novo cancer after liver transplantation (LTx). Retrospective analyses were performed in 385 LTx patients who underwent transplantation between 1986 and 2007. In total, 50 (13.0%) recipients developed de novo malignancy. The cumulative incidence of de novo cancer at 1, 5, 10, and 15 years after LTx was 2.9% +/- 0.9%, 10.5% +/- 1.8%, 19.4% +/- 3.0%, and 33.6% +/- 6.8%, respectively. The standardized incidence ratio of malignancy in LTx patients compared to the general population was 2.2 (95% confidence interval: 1.6-2.8). After excluding posttransplant lymphoproliferative disorder and skin cancer, patients with de novo cancer had a significantly lower survival rate compared to recipients who remained cancer-free. The identified univariate risk factors for de novo cancer were cyclosporine A (CsA) treatment, time period of LTx, and recipient age. In multivariate analysis, only CsA treatment emerged as an independent risk factor for de novo cancer, which was attributed to more aggressive cancer types. A surprising finding was that CsA treatment specifically enhanced cancer risk in patients who underwent transplantation after 2004, when C(2) monitoring (blood concentration at 2 hours postdose) was introduced. In addition, these patients showed a significantly lower acute rejection rate, which might reflect a more robust immunosuppressive status caused by the CsA-C(2) regimen. When age was considered, only patients < or =50 years had a higher cancer rate when treated with CsA compared to treatment with tacrolimus. Our data suggest that, compared to tacrolimus treatment, CsA treatment with C(2) monitoring or in younger patients of < or =50 years is associated with a higher early de novo cancer risk after LTx.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

Primary central nervous system post-transplantation lymphoproliferative disorder: an International Primary Central Nervous System Lymphoma Collaborative Group Report

BACKGROUND

Primary central nervous system (CNS) post-transplantation lymphoproliferative disorder (PCNS-PTLD) is a rare complication of solid organ transplantation. The objectives of this study were to define the clinical, radiologic, and pathologic features of this disease and to explore the impact of treatment on patient outcomes.

METHODS

The authors reviewed the databases of participating institutions of the International Primary CNS Lymphoma Collaborative Group for cases of PCNS-PTLD. Thirty-four patients who had pathologically confirmed PCNS-PTLD without evidence of systemic PTLD were investigated retrospectively.

RESULTS

The median time from transplantation to diagnosis of PCNS-PTLD was 4.4 years. Disease usually was multifocal and involved any location of the brain but was most common in the cerebral hemispheres, usually in the subcortical white matter or basal ganglia. Radiographically, all lesions enhanced either homogenously or in a ring-enhancing pattern. Cerebral biopsy was required to establish diagnosis in most patients. Most patients had monomorphic, Epstein-Barr virus (EBV)-positive disease of B-cell origin. Response rates were high regardless of treatment type, and the median survival was 47 months. Age was the only factor predictive of survival.

CONCLUSIONS

The current study demonstrated that PCNS-PTLD is typically an EBV-induced B-cell lymphoma that is responsive to treatment with favorable survival in many patients. An aggressive approach to tissue confirmation of diagnosis and treatment with chemotherapy or radiotherapy should be strongly considered.

Epidemiology of pretransplant EBV and CMV serostatus in relation to posttransplant non-Hodgkin lymphoma

BACKGROUND.: Despite the importance of non-Hodgkin lymphoma (NHL) as a posttransplant complication, the relationship between NHL and recipient seropositivity for Epstein-Barr virus (EBV) or cytomegalovirus (CMV) is incompletely understood. METHODS.: Kidney, heart, and liver transplant recipients reported to the Collaborative Transplant Study with known pretransplant EBV and CMV serostatus were analyzed in terms of clinically manifest NHL. Cox multivariate regression analysis was performed to account for a wide range of possible confounders. RESULTS.: In total, 18,682 kidney, 2042 heart, and 2616 liver transplant recipients were analyzed. Regardless of age, pretransplant EBV serostatus was significantly associated with risk of NHL in kidney transplant recipients (P<0.001). There was no significant difference in lymphoma rates according to CMV and CMV serostatus among EBV and EBV recipients (log-rank P=0.55 and P=0.57, respectively), but hospitalization for CMV disease during year 1 posttransplant was associated with subsequent NHL (hazard ratio [HR] 6.1; 95% confidence interval [CI] 2.0-18.4; P=0.001). EBV serostatus was also associated with increased risk of NHL in heart transplant patients (HR 3.6; 95% CI 1.1-11.3; P=0.031) but, contrary to expectation, not in liver recipients (HR 0.6; 95% CI 0.1-1.7; P=0.32). CONCLUSIONS.: In view of the striking increase in risk of NHL in EBV kidney transplant recipients of all ages, EBV serostatus should be determined pretransplant in all age groups. CMV serostatus was not independently associated with risk of NHL after kidney transplantation. Surprisingly, in liver transplantation, the risk of NHL was virtually unaffected by EBV serostatus.

Generation of EBV-specific cytotoxic T cells that are resistant to calcineurin inhibitors for the treatment of posttransplantation lymphoproliferative disease

Epstein-Barr virus (EBV)-driven posttransplantation lymphoproliferative disease (PTLD) is a serious complication of immunosuppression after either stem cell transplantation (SCT) or solid organ transplantation (SOT). Adoptive transfer of EBV-specific cytotoxic T lymphocytes (EBV-CTLs) is an effective prophylaxis and treatment for PTLD after SCT, but not for PTLD after SOT when pharmacologic immunosuppression cannot be discontinued. We report the generation of calcineurin (CN) mutants that render EBV-CTL resistant to the immunosuppressants tacrolimus (FK506) and cyclosporin A (CsA): mutant CNa12 confers resistance to CsA but not FK506, and mutant CNa22 confers resistance to FK506 but not CsA, whereas mutant CNb30 renders CTLs resistant to both calcineurin inhibitors. Untransduced EBV-CTLs do not proliferate in the presence of FK506/CsA. However, EBV-CTLs transduced with a retroviral vector coding for these mutants retain the ability to both proliferate and secrete normal levels of interferon-gamma in the presence therapeutic levels of FK506 (CNa12), CsA (CNa22), or both (CNb30). The cytotoxicity and phenotype of EBV-CTL lines were unaffected by expression of these mutant CNs. This approach should allow effective immunotherapy with EBV-CTLs in the SOT setting without risking the graft by reduction in immunosuppression, and represents a generic approach to improving immunotherapy in the face of immunosuppression.

Metachronous EBV-associated B-cell and T-cell posttransplant lymphoproliferative disorders in a heart transplant recipient

Posttransplant lymphoproliferative disorders (PTLDs) may occur as a complication of immunosuppression in patients who have received solid organ or bone marrow allografts. Most PTLDs are of B-cell lineage, whereas T-cell proliferations are rare. The majority of B-cell lesions are associated with Epstein-Barr virus infection. The occurrence of both B-cell and T-cell PTLDs in the same patient is extremely rare and only 6 cases have been previously published. We report a case of a 63-year-old man who developed 2 metachronous Epstein-Barr virus-related PTLDs beginning 10 years after heart transplantation. A polymorphic B-cell PTLD developed first that completely regressed after immunosuppressive therapy was partially withdrawn. Then, a monomorphic T-cell PTLD developed 31 months later. The patient died 17 months later owing to disease progression. We highlight the diagnostic challenge of this case that required numerous ancillary studies for lineage assessment and classification. Such studies are often needed in patients with a history of immunosuppression.

Current understanding of the role of Epstein-Barr virus in lymphomagenesis and therapeutic approaches to EBV-associated lymphomas

A heterogeneous group of malignancies are associated with Epstein-Barr virus (EBV) infection. These malignancies arise in both immunosuppressed and immunocompetent individuals and can be divided into three patterns of latency depending on the viral genes that are expressed. In Type III latency malignancies, such as post-transplant lymphoproliferative disorder (PTLD), EBV has a direct role and the activated B-cell phenotype is characterised by high-level expression of all the immunodominant EBV latency proteins. Thus, EBV-infected B cells are good targets for EBV-specific cytotoxic T lymphocytes (CTLs). New immune-based treatments for PTLD include transfer of ex vivo generated autologous EBV-specific CTLs or, in the case of bone marrow transplant recipients, donor-derived EBV-specific T cells. This strategy could, perhaps, also work in Type II latency malignancies, where EBV acts like a cofactor rather than having a direct role. In initial studies, T cells specific for the weakly immunogenic latent membrane protein 2 have been expanded ex vivo and have promoted tumor regression in a subset of patients. Another potential therapeutic strategy could be to try to induce lytic EBV infection in the tumor cells. This could be done by targeting genes that switch the EBV-infected B cells from the latent to the lytic cycle.

Post-transplant lymphoproliferative disease

Post-transplant lymphoproliferative disease (PTLD) emerged in the mid-1990s as a major graft- and life-threatening complication of pediatric kidney transplantation. This condition, usually involving uncontrolled B lymphocyte proliferation, straddles the border between infection and malignancy, since Epstein-Barr virus (EBV) is intimately associated with the pathogenesis. PTLD is seen more in younger children (more likely to be EBV seronegative), Caucasian race, and in association with the more potent immunosuppression drugs. The clinical presentation typically involves multiple enlarged lymph nodes but varies based on localization of the lymphadenopathy. The diagnosis is based primarily on histopathological features. Treatment strategies include reduction of immunosuppression, use of anti-B cell antibodies, infusion of EBV-specific cytotoxic T lymphocytes, and chemotherapy. Many different strategies have been tried to prevent PTLD, ranging from serial EBV viral load monitoring and pre-emptive immunosuppression reduction to anti-viral prophylaxis. None of the major treatment or prevention strategies has been subject to randomized clinical trials, so their relative efficacy is still unknown. PTLD remains a risk factor for graft loss, though re-transplants have not, to date, been associated with repeat PTLD.

Adoptive cell therapy against EBV-related malignancies: a survey of clinical results

BACKGROUND

Epstein-Barr Virus (EBV) infection is associated with a heterogeneous group of tumors, including lymphoproliferative disorders, Hodgkin's disease, nasopharyngeal carcinoma and Burkitt's lymphoma. As such neoplastic disorders express viral antigens, they can be treated by adoptive immunotherapy strategies relying mostly on in vitro generation and expansion of virus-specific cytotoxic T lymphocytes (CTL), which can be administered to patients for both prophylaxis and treatment.

OBJECTIVE

We reviewed results obtained in all clinical trials reported thus far employing anti-EBV adoptive immunotherapy for different virus-related malignancies.

METHODS

'PTLD after HSCT', 'PTLD after SOT', 'NPC', 'HD', 'SCAEBV' and 'extranodal NK/T cell lymphoma', in combination with 'Adoptive immunotherapy' and 'Adoptive transfer', were used as search keys for papers in PubMed.

CONCLUSIONS

Although the heterogeneity of different studies precludes their collection for a meta-analysis, it can be inferred that adoptive therapy with EBV-specific CTL is safe, well tolerated and particularly effective in the case of most immunogenic tumors, like post-transplant lymphoproliferative disease.