Epstein-Barr virus and post-transplant lymphoproliferative disease

Seeking beyond rejection: an update on the differential diagnosis and a practical approach to liver allograft biopsy interpretation

Pathologic evaluation of liver allograft biopsies plays an integral role in the management of patients after liver transplantation. This review summarizes the clinical context and classical histology of different types of allograft rejection and also the common entities that enter the differential diagnosis of allograft rejection, and provides practical approaches to liver allograft biopsy interpretation. In addition, some of the new developments in the field of liver transplant pathology are updated. The purpose of this review is to provide guidance for pathologists interpreting liver allograft biopsies, particularly those interested in developing expertise in the field of liver transplant pathology.

Pediatric liver transplantation

In previous decades, pediatric liver transplantation has become a state-of-the-art operation with excellent success and limited mortality. Graft and patient survival have continued to improve as a result of improvements in medical, surgical and anesthetic management, organ availability, immunosuppression, and identification and treatment of postoperative complications. The utilization of split-liver grafts and living-related donors has provided more organs for pediatric patients. Newer immunosuppression regimens, including induction therapy, have had a significant impact on graft and patient survival. Future developments of pediatric liver transplantation will deal with long-term follow-up, with prevention of immunosuppression-related complications and promotion of as normal growth as possible. This review describes the state-of-the-art in pediatric liver transplantation.

Evaluation and management of end-stage liver disease in children

End-stage liver disease in children presents a challenging array of medical and psychosocial problems for the health care delivery team. Many of these problems are similar to those encountered by caregivers of adults with end-stage liver disease, such as the development of complications of cirrhosis, including ascites, spontaneous bacterial peritonitis, and esophageal variceal hemorrhage. However, the natural history of disease progression in children and their responses to medical therapy can differ significantly from that of their adult counterparts. Children with end-stage liver disease are especially vulnerable to nutritional compromise; if not effectively managed, this can seriously impact long-term outcomes and survival both before and after liver transplantation. Moreover, close attention must be given to vaccination status and the clinical setting at which health care is delivered to optimize outcomes and the delivery of high-quality pediatric health care. In this review, we address important components of the evaluation and management of children with chronic end-stage liver disease.

Complete remission of a primary rectal lymphoma on ulcerative colitis, after withdrawal of azathioprine and infliximab

A 45-year-old woman was diagnosed with ulcerative colitis and treated with mesalazine, prednisone and, finally, azathioprine and infliximab. Colonoscopy revealed a rectal ulcer, identified by biopsy as a large cell B-lymphoma, positive for leukocyte common antigen (LCA), CD 20 and LMP-1 and negative for CD 3. Three months after withdrawal of all immunosuppressors, a proctocolectomy was performed. The resection specimen contained an area of B-cell polymorphic hyperplasia, but no residual tumour. The patient remains well after 2 years of follow-up, without any further antineoplastic therapy.

Care of the acutely ill pediatric heart transplant recipient

Young children may present to the emergency department after undergoing orthotopic heart transplantation. Emergency department care of pediatric heart transplant recipients with an acute illness is not clearly defined. To assist the emergency physician with treating these children, 2 cases are detailed to demonstrate the variation in outcome of young children presenting to the emergency department with acute illness months after their transplant. The cases typify the varied outcomes possible after emergency department presentation. After the cases, a review of the medical conditions common in transplant recipients precedes a description of management suggestions.

Lymphoma risk in inflammatory bowel disease: is it the disease or its treatment?

With the increasingly widespread use of immunosuppressive and biologic agents for the treatment of Crohn's disease and ulcerative colitis come concerns about potential long-term consequences of such therapies. Disentangling the potential confounding effects of the underlying disease, its extent, severity, duration, and behavior, and concomitant medical therapy has proven to be exceedingly difficult. Unlike the case in rheumatoid arthritis, the overwhelming preponderance of population-based evidence suggests that a diagnosis of inflammatory bowel disease (IBD) is not associated with an increased relative risk of lymphoma. However, well-designed studies that evaluate the potential modifying effect of IBD severity have yet to be performed. Although the results from hospital- and population-based studies have conflicted, the results of a recent meta-analysis suggest that patients receiving purine analogs for the treatment of IBD have a lymphoma risk approximately 4-fold higher than expected. Analyses of lymphoma risk in patients receiving biologic agents directed against tumor necrosis factor-alpha are confounded by concomitant use of immunosuppressive agents in most of these patients. Nevertheless, there may be a small but real risk of lymphoma associated with these therapies. Although the relative risk of lymphoma may be elevated in association with some of the medical therapies used in the treatment of IBD, this absolute risk is low. Weighing the potential risk of lymphoma associated with select medical therapies against the risk of undertreating IBD will help physicians and patients to make more informed decisions pertaining to the medical management of IBD.

Renal pathology in the pediatric transplant patient

Renal transplantation is a therapeutic goal for children with advanced chronic kidney disease. There are many causes of renal dysfunction in children with allografts--the transplanted kidney can develop a variety of morphologic alterations leading to dysfunction. Evaluation of the kidney biopsy is one of the best methods of determining the cause of graft dysfunction. Rejection is a major cause of renal allograft failure in children. The morphologic hallmarks of acute antibody-mediated and cell-mediated rejection and chronic allograft nephropathy have been codified in classification strategies that are useful in adults and children. Viral infection and Epstein-Barr virus-driven posttransplant lymphoproliferative disease also occur in the pediatric transplanted kidney. Drug toxicity from immunosuppressive agents also causes characteristic morphologic alterations in the renal allograft. As the survival of pediatric heart and liver transplant patients improves, the incidence of immunosuppression therapy-related disease in the native kidney in these patients will likely become more important clinically. In addition to renal lesions related to the allograft state, glomerular disease can recur or occur de novo in renal allografts. Here, we describe the pathology of the more common morphologic lesions in kidneys of children with a renal allograft.

Sustained Epstein-Barr virus detection in paediatric liver transplantation. Insights into the occurrence of late PTLD

Epstein-Barr virus (EBV) infection is the main cause of post-transplant lymphoproliferative disease (PTLD). Little is known on chronic carrier state and its relation with late PTLD. We aimed to study EBV infection in the long-term after paediatric liver transplantation (OLT). We conducted a retrospective review of 34 children monitored for a median of 5.8 years (range 1.5-17.7). 21 were IgG seronegative (group A) and 13 seropositive (group B) before OLT. Primary infection was the appearance of VCA-IgM or VCA-IgG or Real-Time Polymerase Chain Reaction (RT-PCR) in patients previously IgG seronegative; positive VCA-IgM or EA-IgG or RT-PCR lasting longer than 6 months was defined sustained viral detection (SVD). 18/21 patients of group A had a primary infection at a median time of 3 months after transplant (0.5-60). 14/18 of group A and 0/13 of group B had a SVD (P < 0.0001). Viral loads greater than 500 copies/10(5) mononuclear cells occurred in 12/18 patients in group A and 0/13 patients in group B (P < 0.0001). The 3 patients who developed late PTLD (median time after OLT 47 months, range 15-121) were from group A, and presented with SVD before developing PTLD. In conclusion, EBV infection in seronegative patients at OLT is associated with greater viral loads and sustained viral detection. Late PTLD occurred only in naïve patients with markers of SVD. Three to 4 monthly long-term monitoring of EBV in pre-OLT naïve patients might help preventing the occurrence of late PTLD.

Rituximab therapy for Epstein-Barr virus-related chronic hepatitis following living donor kidney transplantation

A patient who underwent living donor kidney transplantation was infected with Epstein-Barr virus (EBV) that resulted in persistent EBV infection and EBV-associated chronic hepatitis, determined by abnormally elevated anti-EBV antibody titers and high frequency of EBV-infected B lymphocytes. Despite decreases in immunosuppressant doses, persistent EBV infection and chronic hepatitis persisted for several years. Therapy using anti-CD20 monoclonal antibody (rituximab) virtually eliminated peripheral B lymphocytes and EBV-encoded small RNA 1 (EBER-1)-positive cells. Moreover, hepatic enzyme levels normalized and histological findings indicated marked improvement in hepatic inflammation. Although peripheral CD20(+) B lymphocyte and EBER-1-positive cell levels began to increase 4 months after the end of therapy, the number of EBER-1-positive cells remained very low, and liver function test results remained within normal ranges. The present case illustrates the significance of early diagnosis, monitoring of viral load, and vigorous management of EBV-related disorders associated with organ transplantation.

Pediatric liver transplantation

Liver transplantation has become the accepted standard of care in the treatment of a child with a failing liver. Advances in the management of critical care and immunosuppression along with the development of innovative operative procedures have improved outcome such that 5-year survival rates of 80% to 90% are expected following liver transplantation. Organ allocation schemes have evolved in an effort to better stratify recipient risk thereby more appropriately distributing deceased donor grafts. A persistent shortage of appropriate donors continues to contribute to patient mortality. The consequences of long-term immunosuppression have become increasingly apparent such that health care providers need to be aware of the side effects of chronic immunosuppression. New strategies need to be defined to minimize the need of continuous immunosuppression. The continued success of pediatric liver transplantation will require multi-disciplinary health care teams comprised of general pediatricians, pediatric hepatologists, transplant surgeons, and transplant coordinators who focus on the complex needs of the transplant recipient.

Epstein-Barr virus-associated Hodgkin's disease following renal transplantation

Post-transplant lymphoproliferative disorders (PTLD) have been recognized as a complication of immunosuppression and occur with a reported incidence of 1 to 8% of recipients receiving solid organ transplantation. PTLD are classified into two major categories, polymorphic and monomorphic PTLD. The majority of the monomorphic PTLD cases are non-Hodgkin's lymphoma of B-cell origin. Hodgkin's disease is not part of the typical spectrum of PTLD; however, it has been rarely reported. We describe a case of Hodgkin's disease following renal transplantation. A 41-year-old man developed right cervical lymphadenopathy following renal transplantation 116 months previously for chronic renal failure of unknown origin. He had been taking cyclosporine, mycophenolate mofetil and prednisone. A lymph node biopsy revealed mixed cellularity Hodgkin's disease. Immunohistochemical staining was positive for CD30 and EBV-latent membrane protein-1. No other site of disease was identified. The immunosuppressive agents were reduced (mycophenolate mofetil was discontinued, cyclosporine dose reduced from 200 mg to 150 mg and prednisone continued at 5 mg). After 2 cycles of ABVD followed by radiation therapy (3600 cGy), he achieved complete remission.

Otolaryngological manifestations of posttransplant lymphoproliferative disorder in pediatric thoracic transplant patients

OBJECTIVE

To identify the otolaryngological manifestations of posttransplant lymphoproliferative disorder (PTLD) in pediatric heart and lung transplant recipients.

METHODS

A 14-year retrospective case series review (1990-2003) of children less than 18 years of age presenting with PTLD after receiving orthotopic heart and lung transplants at St. Louis Children's hospital (St. Louis, MO, USA).

RESULTS

One hundred ninety seven cardiac and 246 pulmonary transplant patients were included in this review. Thirteen heart transplant patients developed PTLD with 39% (5/13) presenting in the head and neck. Thirty-two lung transplant patients developed PTLD with 25% (8/32) presenting in the head and neck. PTLD in cardiac transplants most often presented as adenotonsillar hypertrophy or cervical lymphadenopathy. The sinonasal cavity was the most common site of head and neck PTLD in pulmonary transplants patients.

CONCLUSIONS

This study suggests that head and neck involvement is more common than currently reported in the literature. As thoracic organ transplants become more frequent in children, otolaryngologists caring for this population should maintain a high index of suspicion for any suggestive findings. Evaluation must include tissue biopsy, as histopathologic examination is required for diagnosis.

Managing Breast Cancer in the Renal Transplant Patient: A Unique Dilemma

Improvements in immunosuppression have increased patient and graft survival in transplant recipients. As a result, there is greater risk of neoplastic processes such as breast cancer. Treatment in this population is complicated by the necessary immunosuppression, vascular accesses, and transplant grafts. General surgeons may expect to encounter more of these complex patients in the community setting. We sought to evaluate the surgical treatment of breast cancer in patients with renal transplants. Hospital and private physician records were queried to identify patients who developed breast cancer after a renal or pancreatic/renal transplantation. These charts were reviewed for demographics, type of breast cancer and treatment, location of dialysis access, and complications. From June 1, 1994, to May 31, 2004, 14 patients were identified. Eight patients had functioning transplants. All patients underwent operative interventions. Ten patients underwent adjuvant treatment. Three had functioning transplants and chose not to risk the graft with cessation of immunotherapy. However, no patient with functioning transplants who underwent chemotherapy developed organ failure. Breast cancer after transplantation poses a unique dilemma. The threat of transplanted organ failure is a major concern to these patients and often supersedes adjuvant therapies.

Pediatric liver transplantation

In the past two decades, pediatric liver transplantation has become the state-of-the-art operation with anticipated success and limited mortality. The future success of pediatric liver transplantation will require thoughtful solutions to the delicate balance of risk to donors and recipients, the complex needs of the acute postoperative patient, and the long-term challenges of chronic immunosuppression in these previously unsalvageable patients.

Epstein-Barr viremia levels after pediatric liver transplantation as measured by real-time polymerase chain reaction

Effective immunosuppression has improved the results following liver transplantation, but also increased the risk for opportunistic infections. Epstein-Barr virus (EBV) infection in transplant patients can cause various symptoms including the life-threatening premalignant condition, post-transplantation lymphoproliferative disorder (PTLD). Serum specimens from 24 consecutive children (mean 7.6 specimens/patient), who had undergone liver transplantation in Göteborg from January 1995 to May 2002, were analyzed retrospectively for EBV DNA by real-time TaqMan polymerase chain reaction (PCR). The results were related to clinical picture, immunosuppression, graft rejection and infections with other agents. Eleven patients (46%) developed primary EBV infection at a mean time of 4.8 months after transplantation, and six (25%) reactivated EBV infection at a mean of 4.0 months after transplantation. Four of the 11 patients with primary infection had symptomatic EBV infection: two had PTLD and two hepatitis. One patient in the group with reactivated infection developed PTLD. EBV DNA levels were significantly higher in the group with primary symptomatic infection compared with the patients with primary asymptomatic infection (mean 65 500 copies/mL; range 14 200-194 300 vs. 3700 copies/mL; range 100-9780). In patients with symptomatic infection EBV DNA levels did not differ between PTLD and hepatitis patients. The data suggest that quantitative analysis of EBV DNA in serum by real-time PCR is useful for identification of EBV-related disease.

Post-transplant lymphoproliferative disorders (PTLD) after solid organ transplantation

Post-transplant lymphoproliferative disorders (PTLD) are a well-recognised and potentially fatal complication after solid organ transplantation. They include a spectrum of disorders ranging from benign hyperplasia to invasive malignant lymphoma. The majority of cases are associated with Epstein Barr virus (EBV)-driven tumour formation in B cells and are a consequence of the detrimental effect of immunosuppressive agents on the immune-control of EBV. This review provides an update on the pathogenesis and clinical features of PTLD after solid organ transplantation and discusses recent progress in management. Reduction in immunosuppressive therapy remains a key component of therapy for EBV-positive PTLD and may lead to remission in early disease. Chemotherapy is used when reduced immunosuppression fails to control early disease and as initial therapy for many cases of late disease. Unfortunately, the mortality for PTLD that fails to respond to a reduction in immunosuppression remains high. Newer treatments include manipulation of the cytokine environment, B lymphocyte depleting antibodies and adoptive T cell immunotherapy using allogeneic or autologous EBV-specific cytotoxic T lymphocytes. Although early results appear promising, well-designed clinical trials are needed to assess the efficacy of these novel approaches. EBV vaccination may in the future prove an effective prophylaxis against EBV-driven PTLD but until then, avoiding excessive immunosuppressive therapy may help minimise the risk of PTLD.

Liver transplantation in children: part 1--peri-operative issues

This two-part review provides a comprehensive summary of clinical and research literature on paediatric liver transplantation. Part 1 outlines the peri-operative issues of liver transplantation, covers a brief history, discusses the indications and methods of transplantation and outlines the physical complications which can occur either as a result of the surgery or the subsequent immunosuppressive therapy required to maintain graft integrity. Post-liver transplantation care may require prolonged admission in hospital due to the complications that can occur during surgery and as a result of immunosuppression. This can have a further impact on the emotional status of the child and family. Health care professionals in all settings require greater knowledge about paediatric liver transplantation, its associated complications and long-term health implications.

Sirolimus-induced ulceration of the small bowel in islet transplant recipients: report of two cases

Sirolimus (SRL) has been used for most islet recipients over the past 5 years. It provides balanced immunosuppression in combination with low-dose calcineurin inhibitors, while avoiding corticosteroids. This regimen decreases the risk of nephrotoxicity, neurotoxicity and diabetogenicity. SRL has also been used selectively in clinical liver and kidney transplantation. A number of common side effects including anemia, leucopenia, thrombocytopenia, hypercholesterolemia, mouth ulceration, joint pain, extremity edema and impaired wound healing have been associated with the use of SRL. As SRL is used more frequently, evidence has been gathered on its rare but severe side effects. We report 2 patients who underwent islet transplantation and developed symptomatic small bowel ulceration that resolved after complete withdrawal of SRL. Although small bowel ulceration is rare, it can potentially progress to more serious complications if not treated adequately. Our experience highlights an uncommon but potentially serious adverse effect of high-dose SRL in islet recipients.

Cardiovascular Emergencies in the Pediatric Patient

Children who have heart disease may present to the emergency department (ED) in many stages of life with a range of cardiovascular manifestions, from minimally irritating palpitations to the life-threatening derangements of shock or lethal dysrhythmia. They can present with congenital heart disease, after a temporizing procedure has been performed or after their definitive repair. Children can also present with fever, weakness, dyspnea, syncope, or chest pain; alternatively, children may present to the ED with active dysrhythmia, pulmonary edema, or cardiogenic shock . These symptoms and presentations may result from Kawasaki disease,hypertrophic cardiomyopathy, or arrhythmia; therefore, emergency physicians must also be comfortable with the most common types of heart disease associated with these symptoms and presentations. The purpose of this article is to describe the physiology and presentation of undiagnosed congenital heart disease, to describe the complications that can occur after a staged or definitive repair,and to discuss acquired heart disease in children.

Induction of pre-transplant Epstein-Barr virus (EBV) infection by donor blood transfusion in EBV-seronegative recipients may reduce risk of post-transplant lymphoproliferative disease in adolescent renal transplant patients: report of two cases

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is a life-threatening complication following organ transplantation. The greatest risk is seen in Epstein-Barr virus (EBV)-seronegative patients receiving allografts from EBV-seropositive donors. We demonstrate a new approach of pre-transplant prophylaxis of EBV-related PTLD, suggesting that, prior to living-related renal transplantation, blood transfusion from an EBV-seropositive donor to an EBV-seronegative recipient could induce primary EBV infection in the recipient, developing EBV immunity and decreasing risk of PTLD.

METHODS

Recipients underwent weekly donor-specific blood transfusion (3 x 100 mL) before transplantation. EBV-mRNA expression, viral load, serological tests, and clinical signs of EBV infection were assessed following blood transfusion.

RESULTS

We explored a new approach in 2 young EBV-seronegative renal allograft recipients. Both patients developed primary EBV infection following blood transfusion before transplantation and showed symptom-free seroconversion post-transplantation without persistent EBV activation. There were no signs of PTLD during 5-year follow-up.

CONCLUSIONS

A new effective and inexpensive approach is suggested for development of EBV immunity and probably for prophylaxis of EBV-associated PTLD.

High fatality rate of Epstein-Barr virus-associated lymphoproliferative disorder occurring after bone marrow transplantation with rabbit antithymocyte globulin conditioning regimens

Epstein-Barr virus (EBV)-associated lymphoproliferative disorder (EBV-LPD) following bone marrow transplantation can be fatal. The major risk factors for the development of EBV-LPD are ex vivo T-cell depletion or in vivo T-cell depletion with either antithymocyte globulin (ATG) or monoclonal anti-T-cell antibodies. Between March 1999 and January 2001, a total of 23 transplants with ATG of equine source (20 transplants) and ATG of rabbit source (3 transplants) used as part of the preparatory regimen were performed at the Barbara Ann Karmanos Cancer Institute in Detroit, Mich. The three patients who received rabbit ATG developed EBV-LPD between 60 and 90 days following bone marrow transplantation. However, there were no cases of EBV-LPD in the equine group. Treatment given in these cases consisted of tapering immunosuppression, antiviral therapy, unprocessed donor lymphocyte infusion, mobilized peripheral blood progenitor cell rescue infusion (one patient), and chemotherapy (one patient). All three patients died of complications from EBV-LPD. The association of rabbit ATG with the development of EBV-LPD suggests that patients receiving rabbit ATG as part of their preparatory regimens require close monitoring of the EBV viral load and possible early intervention with antiviral therapy.

Monitoring of Epstein-Barr viral load in pediatric heart and lung transplant recipients by real-time polymerase chain reaction

BACKGROUND

Elevation in Epstein-Barr virus (EBV) load measured in peripheral blood has been proposed as a marker for development of post-transplant lymphoproliferative disease (PTLD), but there are few published data examining this relationship. We report the longitudinal surveillance of EBV for all recipients of heart (HTx), heart-lung (HLTx) and lung (LTx) transplants at our institution.

METHODS

The study population included all patients transplanted between January 2003 and July 2004. EBV load was serially measured in peripheral blood by real-time polymerase chain reaction (PCR). Results were correlated with recipient pre-transplant EBV status and development of PTLD.

RESULTS

Forty-four transplant operations were performed, including 33 HTx, 6 HLTx and 5 LTx. Thirty-two (73%) of the patients were EBV seropositive pre-transplant. Nineteen (44%) pediatric recipients developed EB viremia, including 17 HTx, 1 HLTx and 1 LTx. Eleven (58%) of these patients were EBV seropositive pre-transplant. EBV was first detected at a median of 30.5 days (range 2 to 81) post-transplant. The median peak EBV load in that group was 10,099 copies/ml (range 5,935 to 255,466) whole blood. One patient with cystic fibrosis post-LTx developed PTLD localized in the colon. This patient was EBV seronegative pre-transplant; peak EBV load was 14,513 copies/ml. Acute infectious mononucleosis was seen in 1 case. Positive pre-transplant EBV status did not predict post-transplant EB viremia (positive predictive value 0.03).

CONCLUSIONS

Contrary to earlier reports, our data demonstrate that a high EBV load does not lead to PTLD early post-transplant. These results do not support the practice of pre-emptively reducing immunosuppression in patients with raised EBV load.

Epstein-Barr virus-associated B-cell lymphoma in the setting of iatrogenic immune dysregulation presenting initially in the skin

BACKGROUND

Epstein-Barr virus (EBV) has been implicated in B-cell lymphoma associated with iatrogenic immune dysregulation, primarily in the context of extracutaneous lymphoma.

METHODS

We describe six patients, five transplant recipients receiving cyclosporine and one patient with rheumatoid arthritis receiving methotrexate, who developed cutaneous presentations of EBV-associated B-cell lymphoma. Human herpesvirus 8 (HHV8) and EBV thymidine kinase (vTK) expression were also explored.

RESULTS

The cases comprised plasmablastic lymphoma (one case), plasmacytic marginal zone lymphoma (two cases), and diffuse large B-cell lymphoma (three cases). There was a monoclonal gammopathy in one and concurrent extracutaneous disease in two of the six patients. EBV-associated latent small nuclear RNA was detected in all cases with coexpression of HHV8 in one of the five cases and of vTK in three of the six cases. Three patients responded to a reduction in the immunosuppressive regimen and antiviral therapy. Recurrent disease developed in two, with one patient succumbing to multiorgan dissemination.

CONCLUSIONS

EBV-associated cutaneous B-cell lymphoma is characterized by a long interval between the initiation of immunosuppression and the development of lymphoma. Although previous reports have reported an indolent clinical course, an aggressive clinical course may occur. HHV8 and lytic phase EBV antigens are detected in some cases, possibly suggesting a pathogenetic role.

Successful laser ablation of diffuse laryngeal swelling in posttransplant lymphoproliferative disorder: the Japanese first case

Posttransplant lymphoproliferative disorder (PTLD) is a well-known complication of pediatric organ transplantation. The first symptoms are often in the ear, nose, or throat (ENT) area. We report the first Japanese case of an airway obstruction in PTLD. A 7-year-old boy who had a liver transplant at the age of 2 years presented with progressive stridor. Fiberoptic examination revealed enlarged epiglottis and swelling arytenoids. Highly suspicious of early-PTLD, he was treated with reduction of immunosuppression, but no improvement on his larynx was observed. Laser ablation of swelling arytenoids worked. Surgical debulking is effective to ease an airway obstruction in cases of PTLD.

Analysis of factors that influence survival with post-transplant lymphoproliferative disorder in renal transplant recipients: the Israel Penn International Transplant Tumor Registry experience

Significant mortality is associated with post-transplant lymphoproliferative disorder (PTLD) in kidney transplant recipients (KTX). Univariate/multivariate risk factor survival analysis of US PTLD KTX reported to Israel Penn International Transplant Tumor Registry from November 1968 to January 2000 was performed. PTLD presented 18 (median) (range 1-310) months in 402 KTX. Death rates were greater for those diagnosed within 6 months (64%) versus beyond 6 months (54%, p = 0.04). No differences in death risk for gender, race, immunosuppression, EBV, B or T cell positivity were identified. Death risk increased for multiple versus single sites (73% vs. 53%, hazards ratio (HR) 1.4). A 1-year increase in age increased HR for death by 2%. Surgery was associated with increased survival (55% vs. 0% without surgery) (p < 0.0001). Patients with allograft involvement, treated with transplant nephrectomy alone (n = 20), had 80% survival versus 53% without allograft removal (n = 15) (p < 0.001). Overall survival was 69% for allograft involvement alone versus 36% for other organ involvement plus allograft (n = 19 alive) (p < 0.0001). Death risk was greater for multiple site PTLD and increasing age, and risks were additive. Univariate analysis identified increased death risk for those not receiving surgery, particularly allograft involvement alone.

Epstein-Barr virus- and human herpesvirus 8-associated primary cutaneous plasmablastic lymphoma in the setting of renal transplantation

BACKGROUND

Plasmablastic lymphoma (PBL) is a recently recognized entity most often reported in the oral cavity, mainly in the setting of underlying human immunodeficiency viral infection whereby a role for Epstein-Barr virus (EBV) and more recently human herpesvirus 8 (HHV8) has been described. Although EBV has been implicated in a variety of lymphoproliferative lesions, until recently HHV8 has only been associated with primary effusion lymphoma, multicentric Castleman's disease, and Kaposi's sarcoma. We describe a case of PBL occurring in the setting of renal transplantation.

METHODS

We encountered a case of PBL occurring in the setting of renal transplantation. We characterized the tumor by routine immunohistochemistry and evaluated for the presence of immunoglobulin light chain restriction and EBV RNA by in situ hybridization. We assessed for the presence of HHV8 RNA by reverse transcriptase in situ hybridization.

RESULTS

The tumor showed a histomorphology compatible with a PBL. In addition, there was strong RNA expression in the neoplastic cells for EBER-1, EBER-2, and HHV8.

CONCLUSION

This case suggests a possible role of both viruses in the pathogenesis of PBL in sites other than the oral cavity and expands the spectrum of post-transplantation lymphoproliferative disease to include PBL.

Long-term follow-up of Epstein-Barr virus viremia in pediatric recipients of renal transplants

The common observation of Epstein-Barr virus (EBV) viremia in pediatric recipients of renal transplants and the occurrence of an EBV-related pulmonary leiomyoma prompted us to intensify the follow-up of EBV infections from 1995 to October 2000. Follow-up included serology and detection of viral DNA in blood using a semi-quantitative nested polymerase chain reaction (PCR) and later a real-time PCR with higher sensitivity. The aim of this study was the early detection of primary infections or reactivations. We obtained 250 samples from 32 patients. EBV DNA detection was consistently negative in 14 patients. There were 5 patients that were considered at risk for post-transplant lymphoproliferative disease, as they were EBV seronegative and were given a kidney from a positive donor. Of these, 4 had at least one episode of high-level EBV viremia. During these episodes, an absence of noticeable symptoms that could be related to EBV was noted for all but 1 patient. This child presented with severe neutropenia 1 month after grafting and, 28 months later, several nodules of pulmonary leiomyoma, which were found to be EBV related. Four episodes of high-level viremia were observed before the discovery of the leiomyoma. Viral DNA detection is important for the follow-up of such patients that are especially at risk of serious complications of EBV infections.

Effect of combined T- and B-cell depletion of allogeneic HLA-mismatched bone marrow graft on the magnitude and kinetics of Epstein-Barr virus load in the peripheral blood of bone marrow transplant recipients

Recipients of T-cell-depleted bone marrow (BM) transplants (BMT) frequently develop Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) preceded by a rapid and prominent increase of EBV load in the peripheral blood. The level of this increase positively correlates with the incidence of PTLD. Using a semiquantitative PCR assay we compared the blood levels of EBV-DNA in patients transplanted with either T-cell or T- and B-cell-depleted human leukocyte antigen (HLA)-mismatched BM grafts. Combined T- and B-cell depletion correlated with significantly lower maximal levels of EBV load, which were reached with slower kinetics. These data indicate that B-cell depletion of BM can be used for prophylaxis of PTLD in BM transplant recipients and can affect the long-term balance between EBV and its host.

Viral interactions with the Notch pathway

The Notch signaling pathway influences cell fate decisions, proliferation versus differentiation and cell survival. Viruses both utilize and manipulate the differentiation state of infected cells, promote or block cell cycling and employ a variety of mechanisms to evade innate cellular anti-viral responses and promote cell survival. In light of these commonalities, it is perhaps not surprising that several viruses have tapped into the Notch pathway to advance their own life cycles. This first became apparent from studies showing targeting of Epstein-Barr virus proteins to the nuclear effector of Notch signaling CSL (CBF1/RBPJk). More recently the Kaposi's sarcoma-associated herpesvirus RTA protein has been found to bind CSL. Notch pathway interactions have also been described for adenovirus SV40 and human papilloma virus. This review focuses on the herpesvirus protein interactions with the Notch pathway and the insights that these interactions have provided.

Developmental outcomes with early orthotopic liver transplantation for infants with neonatal-onset urea cycle defects and a female patient with late-onset ornithine transcarbamylase deficiency

Urea cycle defects (UCDs) typically present with hyperammonemia, the duration and peak levels of which are directly related to the neurologic outcome. Liver transplantation can cure the underlying defect for some conditions, but the preexisting neurologic status is a major factor in the final outcome. Multicenter data indicate that most of the children who receive transplants remain significantly neurologically impaired. We wanted to determine whether aggressive metabolic management of ammonia levels after early referral/transfer to a metabolism center and early liver transplantation would result in better neurologic outcomes. We report on 5 children with UCDs, ie, 2 male patients with X-linked ornithine transcarbamylase deficiency and 2 male patients with carbamoyl phosphate synthase deficiency, all of whom had neonatal presentations and underwent orthotopic liver transplantation before 1 year of age, and 1 female patient with partial X-linked ornithine transcarbamylase deficiency that was intractable to medical therapy, who underwent transplantation at 35 months of age. Developmental testing with the Griffiths scale was performed on 3 occasions each, 12 months apart, up to 45 months after transplantation. Full-scale indices for 3 children who underwent early transplantation showed average developmental quotients of 67. All 5 children had metabolic cures. There were no deaths (30-month survival rate: 100%). One child is currently listed for repeat transplantation because of bile duct stenosis and cirrhosis. We conclude that early liver transplantation and aggressive metabolic management improve early neurologic outcomes for children with UCDs, but longer follow-up monitoring is needed.

Epstein-Barr virus and cancer

EBV was the first human virus to be directly implicated in carcinogenesis. It infects >90% of the world's population. Although most humans coexist with the virus without serious sequelae, a small proportion will develop tumors. Normal host populations can have vastly different susceptibility to EBV-related tumors as demonstrated by geographical and immunological variations in the prevalence of these cancers. EBV has been implicated in the pathogenesis of Burkitt's lymphoma, Hodgkin's disease, non-Hodgkin's lymphoma, nasopharyngeal carcinoma, and lymphomas, as well as leiomyosarcomas arising in immunocompromised individuals. The presence of this virus has also been associated with epithelial malignancies arising in the gastric region and the breast, although some of this work remains in dispute. EBV uses its viral proteins, the actions of which mimic several growth factors, transcription factors, and antiapoptotic factors, to usurp control of the cellular pathways that regulate diverse homeostatic cellular functions. Recent advances in antiviral therapeutics, application of monoclonal antibodies, and generation of EBV-specific CTLs are beginning to show promise in the treatment of EBV-related disorders.

An overview of paediatric lung transplantation

Paediatric lung transplantation is indicated in selected children with end-stage lung disease that is not amenable to conventional medical or surgical therapy. The indications and complications differ from adult lung transplant patients. Due to the long waiting times for suitable cadaveric lungs, other types of lung transplantation, such as living donor lobar and split-lung procedures, have been utilised in paediatric patients. Unlike adult candidates, cystic fibrosis and primary pulmonary hypertension are the primary indications. Most recipients are in the adolescent age group. Complications that occur with greater frequency in paediatric lung recipients include somatic growth and graft function, post-transplant lymphoproliferative disease and medical non-adherence. While long-term outcome remains similar between adult and paediatric lung transplant recipients, there is a lower risk of bronchiolitis obliterans in very young recipients and in those who receive living donor lobar lung transplantation. Research into these clinical problems is hampered by the fact that only a small number of paediatric transplants are performed at each centre. Hence, improvement in outcome for these children will be dependent on developing methods to produce better tolerance, understanding the mechanisms/treatment of bronchiolitis obliterans and multi-centre studies that focus on the problems that primarily affect the paediatric lung transplant recipient.

Post-transplant lymphoproliferative disorder limited to the skin

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a condition affecting immunosuppressed transplant patients and has a variety of clinical presentations. It is rarely found in the skin, and cases of PTLD in the skin are usually linked with lymph node or other organ involvement.

METHODS

We report a case of plasmacytoid PTLD that is limited to the skin. A 63-year-old man with a history of cardiac transplant presented with exophytic tumors involving the lower extremity. The diagnosis and classification of the various forms of PTLD are discussed.

RESULTS

Histology, immunohistochemical stains, and in situ hybridization revealed an aggressive plasmacytoid tumor that was Epstein-Barr virus positive. The patient's tumors resolved with decreased immunosuppression and localized radiation.

CONCLUSION

This case is unusual for several reasons including involvement limited to the skin, presentation 15 years following transplant, and plasmacytoid phenotype of the tumor. This disorder will likely be seen by dermatologists and dermatopathologists with the increasing use of immunosuppressive medications in the dermatologist's patient population.

Complete immunosuppressive withdrawal as a uniform approach to post-transplant lymphoproliferative disease in pediatric liver transplantation

Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) in pediatric liver transplant recipients is associated with a high mortality (up to 60%) and the younger age groups, who are predominantly EBV-naïve, are at highest risk for development of this disease. The aim of this study is to assess, in this high-risk group, patient outcome and graft loss to rejection when complete withdrawal of immunosuppressive agents (IMS) is instituted as the mainstay of treatment in addition to the use of standard therapy. A retrospective analysis of 335 pediatric patients whose liver transplants were performed by our team between September 1988 and September 2002, was carried out through review of computer records, database and patient charts. Fifty patients developed either EBV or PTLD; 80% were < or =2 yr of age. Of these 50 patients, 19 had a positive tissue diagnosis for PTLD and 31 were diagnosed with EBV infection, 14 of whom had positive tissue for EBV. Fifty-eight percent of patients who developed PTLD and 51.6% of patients with EBV received antibody for induction or treatment of rejection prior to onset of disease. Forty-six patients (92%) received post-transplant antiviral prophylaxis with ganciclovir or acyclovir. Antiviral treatment included ganciclovir in 76%, acyclovir in 20% and Cytogam (in addition to one of the former agents) in 44%. In those with PTLD, treatment included chemotherapy (n = 1), Rituximab (n = 2), and ocular radiation (n = 1). IMS was stopped in all patients with PTLD and in 19 with EBV infection and was held as long as there was no allograft rejection. Eight patients have remained off IMS for a mean of 1535.5 +/- 623 days. Of the 21 patients who were restarted on IMS for acute rejection, 18 responded to steroids and/or reinstitution of low-dose calcineurin inhibitors. The mean time to rejection while off IMS in this group was 107.43 +/- 140 days (range: 7-476). Two patients were re-transplanted for chronic rejection; one had chronic rejection that existed prior to discontinuing IMS. The mortality rate in our series was 31.6% in those with PTLD and 6% in those with EBV disease. The cause of death was related to PTLD or sepsis in all cases; no deaths were due to graft loss from acute or chronic rejection. PTLD is associated with high mortality in the pediatric population. Based on this report, we advocate aggressive management of PTLD that is composed of early cessation of IMS, the use of antiviral therapy, and chemotherapy when indicated. Episodes of rejection that occur after stopping IMS can be successfully treated with standard therapy without graft loss to acute rejection.

The post-transplant lymphoproliferative disorder-a literature review

The Epstein-Barr virus (EBV)-induced post-transplant lymphoproliferative disorder (PTLD) affects 1%-10% of all paediatric renal transplant recipients. This is a heterogeneous group of conditions characterised by EBV-driven proliferation of B-lymphocytes in the face of impaired T-cell immune surveillance. The risk factors predisposing to PTLD are becoming better understood, but its pathogenesis and myriad of clinical and histological features remain poorly defined. While new treatment modalities are being tried with variable success, regular EBV surveillance and carefully monitored reduction of immunosuppression remain the mainstay of treatment. In this review, we have presented the current knowledge of this increasingly common complication in renal transplant recipients.

Inhibition of Epstein-Barr virus-induced growth proliferation by a nuclear antigen EBNA2-TAT peptide

Epstein-Barr virus (EBV) causes infectious mononucleosis and is associated with cancers in immunocompromised populations. Antiviral drugs targeted against lytic viral replication have limited efficacy in these disease settings. EBV infection of peripheral blood mononuclear cells induces growth proliferation and the EBV latency Epstein-Barr virus-encoded nuclear antigen (EBNA)2 transcriptional transactivator (TAT) is essential for this response. EBNA2 targets the cellular DNA-binding protein CBF1 to mimic activated Notch signaling. A 10-aa peptide from the CBF1 interaction domain of EBNA2 was synthesized as a fusion with the protein transduction domain of HIV-1 TAT. The EBNA2-TAT peptide blocked EBNA2-CBF1 interaction in an in vitro GST affinity assay and labeling with fluorescein confirmed that the EBNA2-TAT peptide efficiently entered cultured B cells. Neither EBNA2-TAT, nor a mutant peptide with a 2-aa substitution that was unable to block the EBNA2-CBF1 interaction, significantly affected the growth of non-EBNA2-expressing EBV(-) B cells or Burkitt's lymphoma Akata cells. However, treatment of an EBV-immortalized lymphoblastoid cell line with the EBNA2-TAT peptide stopped cell growth and reduced cell viability. RT-PCR analyses of gene expression in the peptide-treated lymphoblastoid cell line cultures revealed that EBNA2-TAT treatment down-regulated the EBNA2-responsive viral LMP1 and LMP2 genes and cellular CD23, intercellular adhesion molecule 1, BATF, and Cdk1 genes while up-regulating expression of the cyclin-dependent kinase inhibitor p21. EBV-induced outgrowth of B cells from cultured peripheral blood mononuclear cells was also blocked in a dose-responsive manner by the EBNA2-TAT peptide. This study suggests that cell-permeable EBNA2 peptides may have potential as novel anti-EBV therapeutics.

Epstein-Barr virus viral load in Crohn's disease: effect of immunosuppressive therapy

BACKGROUND

More than 80% of non-Hodgkin lymphomas (NHLs) occurring in transplant recipients on immunosuppressive therapy are associated with Epstein-Barr virus (EBV) infection. EBV viral load (EBV-VL) is predictive of NHL occurrence in this setting. The aim of this work was to determine EBV-VL in patients with Crohn's disease (CD), both according to disease activity and use of immunosuppressive therapy, including infliximab.

METHODS

Between December 1999 and July 2001, EBV-VL was determined 212 times by quantitative polymerase chain reaction (PCR) assay in 138 patients with CD and in 24 EBV-seropositive controls free of CD.

RESULTS

EBV-VL did not differ significantly between the controls and the patients with CD and was not influenced by CD activity or by immunosuppressive therapy, including recent infliximab infusion. High EBV-VL values were observed in two patients with severe uncontrolled CD, but returned to normal once the flare-up had been controlled (by immunosuppressive drugs in one case and by surgery in the other case).

CONCLUSIONS

EBV viral load is on the whole similar in patients with Crohn's disease and in EBV-seropositive controls. Infliximab infusion does not seem to increase significantly EBV-VL in the short-term. However, some patients with Crohn's disease have transient, very high EBV-VL values that are compatible with an increased risk of NHL in the transplant setting. The long-term clinical outcome of these patients must be determined.

Hodgkin's lymphoma after post-transplant lymphoproliferative disease in a renal transplant recipient

Lymphoid malignancies such as post-transplant lymphoproliferative disease (PTLD) are a major complication of solid organ transplantation. Hodgkin's lymphoma (HL) is not part of the typical spectrum of PTLD, but has rarely been reported as a separate complication. We report a case of HL occurring after previous PTLD in a renal transplant recipient. A 9-yr-old girl with end-stage autosomal recessive polycystic kidney disease received a cadaveric renal transplant at 1 yr of age. She developed polymorphic PTLD localized to the bone marrow at 6 yr post-transplant. She was treated with reduction of immunosuppression and alpha-interferon. No chemotherapy or anti-B cell antibody was administered. The PTLD resolved and kidney graft function remained stable. At 9 yr post-transplant, she presented again with fever of 2 wk duration, associated with enlarged lymph nodes at multiple sites. A lymph node biopsy revealed the presence of classic Reed Sternberg cells positive for CD15, CD30 and EB RNA. She was treated with standard combination chemotherapy for HL with COPP/ABV. All immunosuppressive agents were discontinued except for low dose prednisone. The patient had an excellent response, with resolution of her lymphadenopathy and maintenance of stable graft function. RS like cells have been reported in the setting of PTLD, but these cells possess an activated B cell phenotype, are EBV negative and CD15 negative. True HL following PTLD has been reported in only three previous cases, with good response to standard chemotherapy in each.

Immunosuppression and the risk of post-transplant malignancy among cadaveric first kidney transplant recipients

The success of renal transplantation may be counterbalanced by serious adverse medical events. The effect of immunosuppression on the incidence of de novo neoplasms among kidney recipients should be monitored continuously. Using data from the Scientific Registry of Transplant Recipients, we studied the association of induction therapy by immunosuppression with antilymphocyte antibodies, with the development of de novo neoplasms. The study population included more than 41 000 recipients who received a cadaveric first kidney transplant after December 31, 1995, and were followed through February 28, 2002. Using Cox regression models, we estimated time to development of two types of malignancy: de novo solid tumors and post-transplant lymphoproliferative disorder (PTLD). We made adjustments for several patient demographic factors and comorbidities. Induction therapy was significantly associated with a higher relative risk (RR) of PTLD (RR = 1.78, p < 0.001), but not with a greater likelihood of de novo tumors (RR = 1.07, p = 0.42). Treatment with maintenance tacrolimus vs. cyclosporine showed a significantly different RR of developing de novo tumors for recipients with induction than for those not receiving induction (p = 0.024). These new estimates of the magnitude of malignancy risk associated with induction therapy may be useful for clinical practice.

Limitations of EBV-PCR monitoring to detect EBV associated post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) represents a significant threat to the survival of pediatric transplant recipients. Epstein-Barr (EBV) viral load monitoring using polymerase chain reaction (PCR) has been reported to have a variable sensitively with relatively higher specificity as in an indicator of the development of PTLD. We report two cases of pathologically confirmed PTLD in children who failed to develop sustained increases in their EBV-PCR determined viral loads. We suggest that clinicians should be aware of the potential for false-negative results of EBV-PCR in pediatric transplant recipients.