Who is at risk for post-transplant lymphoproliferative disorders (PTLD) after liver transplantation?

Cancer risk associated with cytomegalovirus infection among solid organ transplant recipients in the United States

BACKGROUND

Cytomegalovirus (CMV) is among the most common viral infections after solid organ transplantation (SOT). Associations of CMV with cancer risk among SOT recipients have been incompletely evaluated.

METHODS

The authors used linked data from the US SOT registry and 32 cancer registries. Poisson regression was used to compare cancer incidence across CMV risk groups based on donor (D) and recipient (R) immunoglobulin G (IgG) serostatus: high risk (R-negative/D-positive), moderate risk (R-positive), and low risk (R-negative/D-negative).

RESULTS

In total, 247,318 SOT recipients were evaluated during 2000-2017 (R-negative/D-positive, 20.3%; R-positive, 62.9%; R-negative/D-negative, 16.8%). CMV-seropositive recipients were older, more racially/ethnically diverse, and had lower socioeconomic status than CMV-seronegative recipients. Compared with R-negative/D-negative recipients, recipients in the R-negative/D-positive and R-positive groups had a lower incidence of diffuse large B-cell lymphoma (DLBCL; R-negative/D-positive: adjusted incidence rate ratio [aIRR], 0.74; 95% confidence interval [CI], 0.59-0.91; R-positive: aIRR, 0.83; 95% CI, 0.69-1.00). CMV serostatus modified the association between Epstein-Barr virus (EBV) status and DLBCL (p = .0006): DLBCL incidence was increased for EBV R-negative/D-positive recipients (aIRR, 3.46; 95% CI, 1.50-7.95) among CMV R-negative/D-negative recipients but not among the other CMV risk groups. Compared with recipients who were CMV R-negative/D-negative, those who were R-negative/D-positive had a lower incidence of small intestine cancer (aIRR, 0.23; 95% CI, 0.09-0.63), and R-positive recipients had a higher incidence of lung cancer (aIRR, 1.24; 95% CI, 1.05-1.46). CMV status was not associated with risk for other cancers.

CONCLUSIONS

CMV status was not associated with risk for most cancers among SOT recipients. The inverse association with DLBCL may reflect the protective effects of CMV prophylaxis or treatment with off-target efficacy against EBV infection (the major cause of lymphoma in SOT recipients).

Medical care of liver transplant patients

INTRODUCTION

Liver transplantation is a life-changing event for patients and survival following transplantation has improved significantly since the first transplantation in 1967. Following liver transplantation, patients face a unique set of healthcare management decisions including transplantation-specific complications, recurrence of primary liver disease, as well as metabolic and malignancy concerns related to immunosuppression. As more patients with liver disease receive transplantation and live longer, understanding and managing these patients will require not only transplant specialist but also local subspecialist and primary care physicians.

AREAS COVERED

This review covers common issues related to the management of patients following liver transplantation including immunosuppression, liver allograft dysfunction, metabolic complications, as well as routine health maintenance such as immunizations and cancer screening.

EXPERT OPINION

Optimizing medical care for patients following liver transplant will benefit from ensuring all providers, not just transplant specialist, have a basic understanding of the common issues encountered in the post-transplant patient. This review provides an overview of common healthcare concerns and management options for patients following liver transplantation.

De novo malignancies after liver transplantation: The effect of immunosuppression-personal data and review of literature

BACKGROUND

Immunosuppression has undoubtedly raised the overall positive outcomes in the post-operative management of solid organ transplantation. However, long-term exposure to immunosuppression is associated with critical systemic morbidities. De novo malignancies following orthotopic liver transplants (OLTs) are a serious threat in pediatric and adult transplant individuals. Data from different experiences were reported and compared to assess the connection between immunosuppression and de novo malignancies in liver transplant patients.

AIM

To study the role of immunosuppression on the incidence of de novo malignancies in liver transplant recipients.

METHODS

A systematic literature examination about de novo malignancies and immunosuppression weaning in adult and pediatric OLT recipients was described in the present review. Worldwide data were collected from highly qualified institutions performing OLTs. Patient follow-up, immunosuppression discontinuation and incidence of de novo malignancies were reported. Likewise, the review assesses the differences in adult and pediatric recipients by describing the adopted immunosuppression regimens and the different type of diagnosed solid and blood malignancy.

RESULTS

Emerging evidence suggests that the liver is an immunologically privileged organ able to support immunosuppression discontinuation in carefully selected recipients. Malignancies are often detected in liver transplant patients undergoing daily immunosuppression regimens. Post-transplant lymphoproliferative diseases and skin tumors are the most detected de novo malignancies in the pediatric and adult OLT population, respectively. To date, immunosuppression withdrawal has been achieved in up to 40% and 60% of well-selected adult and pediatric recipients, respectively. In both populations, a clear benefit of immunosuppression weaning protocols on de novo malignancies is difficult to ascertain because data have not been specified in most of the clinical experiences.

CONCLUSION

The selected populations of tolerant pediatric and adult liver transplant recipients greatly benefit from immunosuppression weaning. There is still no strong clinical evidence on the usefulness of immunosuppression withdrawal in OLT recipients on malignancies. An interesting focus is represented by the complete reconstitution of the immunological pathways that could help in decreasing the incidence of de novo malignancies and may also help in treating liver transplant patients suffering from cancer.

De Novo Malignancies After Transplantation: Risk and Surveillance Strategies

De novo malignancies are one of the leading causes of late mortality after liver and kidney transplantation. Nonmelanoma skin cancer is the most common malignancy, followed by posttransplant lymphoproliferative disorder and solid organ tumors. Immunosuppression is a key factor for cancer development, although many other transplant-related and traditional risk factors also play a role. In this review, the authors summarize risk factors and outcomes of frequently encountered de novo malignancies after liver and kidney transplantation to stratify recipients at highest risk. Future efforts in prospectively validated, cost-effective surveillance strategies that improve survival of these complex patients are greatly needed.

A population-based study of 135 lymphomas after solid organ transplantation: The role of Epstein-Barr virus, hepatitis C and diffuse large B-cell lymphoma subtype in clinical presentation and survival

BACKGROUND

Epstein-Barr virus (EBV) plays a major role in the development of post-transplant lymphoproliferative disorder (PTLD), but there is an increasing awareness of EBV-negative PTLD. The clinical presentation of EBV-negative PTLD has not been as well characterised as EBV-positive cases. Further, there is limited knowledge on the clinical importance of diffuse large B-cell lymphoma (DLBCL) cell of origin subtype post-transplant.

MATERIALS AND METHODS

We studied the role of EBV, hepatitis C (HCV) and DLBCL subtype in clinical presentation and survival in 135 post-transplant lymphomas diagnosed 1980-2006 in a population-based cohort of 10 010 Swedish solid organ transplant recipients. The lymphomas were re-evaluated according to WHO 2008, examined for EBV, and clinical data were collected from medical records.

RESULTS

Lymphoma incidence rate was 159/100 000 person-years and is also reported by lymphoma subtype. EBV-negative lymphomas constituted 48% and were associated with HCV infection (p = 0.02), bone marrow involvement (p < 0.001), and T-cell phenotype (p = 0.002). Among DLBCL, 78% were of non-germinal centre subtype, which was associated with EBV-positivity (69%, p = 0.001), early occurrence (p = 0.03), heart/liver/lung/pancreas recipients (p = 0.02), anti-T-cell globulin (p = 0.001), and tacrolimus treatment (p = 0.02). DLBCL subtypes had similar overall survival. Five-year overall survival was 42% in all treated patients. Independent poor prognostic factors were older age, B symptoms, ECOG 2-4, kidney/pancreas/heart recipients, T-cell lymphoma, and HCV-infection.

CONCLUSIONS

With long follow-up, a large part of PTLD is EBV-negative, due to a high proportion of T-cell lymphomas and low of polymorphic PTLD. EBV-negative PTLD have a different clinical presentation. HCV may play an aetiological role in late-onset PTLD and was revealed as a new prognostic factor for inferior survival that needs to be confirmed in larger studies. The heavier immunosuppression in non-kidney transplantations seems to play a role in the development of non-germinal centre DLBCL. DLBCL cell of origin subtype lacks prognostic importance in the transplant setting.

Post-transplant lymphoproliferative disorders in liver transplant recipients: a clinicopathological study

BACKGROUND AND AIMS

Complications after liver transplantation are major factors that determine the prognosis of patients. In this study, we aimed at investigating an important though less frequently occurring complication, post-transplant lymphoproliferative disorders (PTLD), in a single institution after liver transplantation.

METHODS

15 cases with a diagnosis of PTLD in post-liver transplant patients were retrieved from our archive and the clinicopathological features reviewed.

RESULTS

The overall incidence of PTLD was 2.3% (n=15/658), and the incidence was much higher in the paediatric than the adult age groups, being 11.1% (9/81) and 1% (6/577), respectively. The median time of presentation was 16 months after transplantation (occurrence time ranging from 2 to 87 months after transplantation). Lymph nodes, gastrointestinal tract and graft liver were the commonest sites of involvement. 11 cases were classified as monomorphic PTLD according to WHO classification and the majority (n=10/11) of them were of B cell differentiation. 12 of the total 15 PTLD cases showed a positive result for Epstein-Barr virus-encoded RNAs with in situ hybridisation. Eight patients were alive at the time of review, and two of them suffered from recurrence of the PTLD. Among the seven patients who died, six succumbed within 1 year from the diagnosis of PTLD.

CONCLUSIONS

Despite its relative rarity as a complication for liver transplantation, PTLD imposes significant effects on the morbidity, mortality and treatment implications in postliver transplant patients. The clinicopathological data would hopefully provide better insight into the surveillance and management for susceptible patients.

Long-term outcome after liver transplantation

Liver transplantation is a life-saving therapy for patients with end-stage liver disease, acute liver failure, and liver tumors. Over the past 4 decades, improvements in surgical techniques, peritransplant intensive care, and immunosuppressive regimens have resulted in significant improvements in short-term survival. Focus has now shifted to addressing long-term complications and improving quality of life in liver recipients. These include adverse effects of immunosuppression; recurrence of the primary liver disease; and management of diabetes, hypertension, dyslipidemia, obesity, metabolic syndrome, cardiovascular disease, renal dysfunction, osteoporosis, and de novo malignancy. Issues such as posttransplant depression, employment, sexual function, fertility, and pregnancy must not be overlooked, as they have a direct impact on the liver recipient's quality of life. This review summarizes the latest data in long-term outcome after liver transplantation.

Long-term medical management of the liver transplant recipient: what the primary care physician needs to know

Recognition, management, and prevention of medical complications and comorbidities after liver transplant is the key to improved long-term outcomes. Beyond allograft-related complications, metabolic syndrome, cardiovascular disease, renal dysfunction, and malignancies are leading causes of morbidity and mortality in this patient population. Primary care physicians have an important role in improving outcomes of liver transplant recipients and are increasingly relied on for managing these complex patients. This review serves to assist the primary care physician in the long-term management issues of liver transplant recipients.

Immunosuppression induction with rabbit anti-thymocyte globulin with or without rituximab in 1000 liver transplant patients with long-term follow-up

Rabbit anti-thymocyte globulin (rATG)-based immunosuppression induction is being increasingly used in liver transplantation (LT) in conjunction with steroid-free protocols to delay the initiation of calcineurin inhibitors. This study reports a single-center comparison of transplant outcomes and complications in 3 immunosuppression eras. Data were obtained retrospectively from a center research database, and the analysis included LT patients from 2001 to 2008. The immunosuppression consisted of rATG induction in 3 doses (6 mg/kg in all): (1) the first dose was administered perioperatively [the rabbit anti-thymocyte globulin in the operating room (rATG-OR) era]; (2) the first dose was delayed until 48 hours after transplantation [the rabbit anti-thymocyte globulin after a delay (rATG-D) era]; or (3) the first dose was delayed until 48 hours after transplantation, and a single dose of rituximab was added 72 hours after transplantation [the rabbit anti-thymocyte globulin after a delay plus rituximab (rATG-D-Ritux) era]. The initial maintenance immunosuppression was tacrolimus monotherapy, which was started on postoperative day 2. There were 166 patients (16%) in the rATG-OR era, 259 patients (26%) in the rATG-D era, and 588 patients (58%) in the rATG-D-Ritux era (1013 patients in all). Demographically, the latter eras were characterized by higher recipient and donor ages; greater percentages of liver-kidney transplants, hepatocellular carcinoma (HCC), donation after cardiac death (DCD), and imported organs; and shorter graft ischemia times. There were no significant differences between the 3 immunosuppression groups in unadjusted patient survival 3 and 5 years after transplantation (80% and 75% for the rATG-OR era, 75% and 67% for the rATG-D era, and 79% and 71% for the rATG-D-Ritux era, P = 0.15). The 5-year survival rates for patients with hepatitis C virus (HCV) and HCC were 65% and 68%, respectively. The factors included in the Cox regression model for patient death included the Model for End-Stage Liver Disease score [hazard ratio (HR) = 1.03, P = 0.001], HCV (HR = 1.28, P = 0.04), donor age (HR = 1.01, P = 0.001), recipient age (HR = 1.01, P = 0.05), and DCD (HR = 1.55, P = 0.11). rATG-based induction immunosuppression can be safely used in adult LT recipients with excellent survival and low rejection rates and without increases in immunosuppression-related side effects.

Screening of de novo tumors after liver transplantation

De novo malignancies are frequent complications after liver transplantation. They are one of the leading causes of late death. Some authors have reported promising results following implementation of extensive cancer surveillance programs. Screening protocols might benefit patients by providing a diagnosis at an earlier stage when tumors may be cured. These protocols should be based on the specific risk factors of every patient. Unfortunately, the scientific evidence supporting screening protocols is still very weak both in the general population and in the transplant patients. On this basis, there is not enough evidence to recommend routine screening for all liver transplant recipients, apart from the recommendations accepted for the general population. Multicenter studies in selected groups of patients at high risk for malignancy may be the only way of defining the potential benefit of screening programs post-transplantation.

Hepatitis C virus infection can affect lymphoproliferative disorders only as a cofactor for Epstein-Barr virus in liver transplant recipients: PTLD.Int survey

OBJECTIVES

Hepatitis C virus infection has a 10.5% frequency in liver transplant posttransplant lymphoproliferative disorders. Studies have suggested that hepatitis C virus infection plays a role in developing posttransplant lymphoproliferative disorders. Pooling data of posttransplant lymphoproliferative disorders developing in liver recipients from the literature, we analyzed and compared characteristics, behavior, and prognoses of posttransplant lymphoproliferative disorders arising in hepatitis C virus-positive versus negative liver graft recipients.

MATERIALS AND METHODS

We conducted a search for the available data though PubMed and Google Scholar for reports of posttransplant lymphoproliferative disorders and hepatitis C virus infection in liver transplant recipients. Overall, 29 studies were found and their data are included in the analyses.

RESULTS

Overall, data of 212 liver transplant patients were included. Sixty-three percent were male. No difference was found between hepatitis C virus-positive liver transplant patients with posttransplant lymphoproliferative disorders compared to their hepatitis C virus-negative counterparts regarding sex, time from transplant to lymphoma development, lymphoma cell type, remission, mortality rate, multiorgan involvement, disseminated posttransplant lymphoproliferative disorders, and histopathologic evaluations (P > .1 for all). Hepatitis C virus-positive liver transplant recipients representing posttransplant lymphoproliferative disorders who were concomitantly positive for Epstein-Barr virus were significantly more likely to develop lymphomas in the early posttransplant period (26 [67%] vs 16 [40%]; P = .024) and to complicate liver (19 [63%] vs 8 [30%]; P = .017) than hepatitis C virus-/Epstein-Barr virus+ patients.

CONCLUSIONS

Hepatitis C virus infection alone has no significant effect on lymphoproliferative disorders after liver transplant; but when combined with Epstein-Barr virus infection, it represents some significant different presentations of the disease. However, no survival effect was found for hepatitis C virus with or without simultaneous Epstein-Barr virus infection, in the posttransplant lymphoproliferative disorders setting. Future prospective studies are needed for confirming our results.

Long-term management of the liver transplant recipient: pearls for the practicing gastroenterologist

Liver transplantation is becoming more common and patients are surviving longer after transplantation. Special care must be paid to the long-term management of these patients because they are at increased risk for medical problems, malignancies, and adverse effects from immunosuppression. A stable and continuing relationship must be developed between the physician and the patient to optimize the long-term outcomes for these individuals.

Risk factors and incidence of de novo malignancy in liver transplant recipients: a systematic review

Orthotopic liver transplant (OLT) is an established life saving procedure for both acute and chronic liver failure, but incidences and risk factors for development of these malignancies are yet to be established. To determine the incidences and risk factors associated with de novo malignancy after OLT. We performed a systematic review of relevant epidemiological studies available on MEDLINE, which provided information on the incidences and risk factors for the development malignancies in adult OLT recipients published from 1983 to 2009. All data was compiled from retrospective studies. Independent risk factors for the development of de novo malignancy in adult OLT recipients were identified to be statistically significant including immunosuppression, hepatitis C virus infection, smoking, alcoholic cirrhosis and sun exposure. OLT recipients with smoking and alcohol history are of particular risk for head and neck and lung cancers. Primary sclerosing cholangitis and inflammatory bowel disease were found to be independent risk factors for colon cancer. Adult OLT recipients are at increased risk for the development of post-transplant malignancies and obviates the need for surveillance protocols that are safe and cost-effective. OLT recipients should be advised on taking proper precautions in the sun, smoking cessation, and eliminating alcohol consumption. Given the emergence of alcoholic cirrhosis as a leading indication for liver transplantation, the early detection of lung and head and neck cancers is of particular importance.

Liver transplanted patients with preoperative autoimmune hepatitis and immunological disorders are at increased risk for Post-Transplant Lymphoproliferative Disease (PTLD)

BACKGROUND

Long term immunosuppression and therapy of acute rejections result in a 20-120-fold increased risk to develop Non Hodgkin lymphoma (NHL). Since immunosuppressive therapy and immunological disorders are major risk factors for the development of NHL in the non-transplant population we aimed to analyze risk factors for PTLD in our cohort of liver transplanted (LT) patients.

METHODS

We analyzed retrospectively 431 patients liver transplanted between 1998 and 2008.

RESULTS

PTLD was diagnosed in eleven of 431 patients (2.6%). PTLD, especially late PTLD, was significantly more frequent in patients who received steroids before LT (Kaplan-Meier: p<0.001). Moreover PTLD in immunocompromised patients with preoperative steroid treatment occurred at a significantly younger age (49.5+/-4.7 years) compared to patients without steroids (60.6+/-5.1 years; p=0.006). Multivariate analysis revealed pretransplant steroid treatment and liver transplantation for autoimmune hepatitis as main risk factors for the development of PTLD after liver transplantation (p<0.001).

CONCLUSION

Liver transplanted patients who received steroids before LT due to immunological disorders and patients with autoimmune hepatitis seem to be at particular high risk to develop PTLD. Prospective cohort studies including immunoepidemiologic investigations of abnormalities of cellular, humoral and innate immunity should be carried out to identify predictive factors and patients at risk.

Posttransplant lymphoproliferative diseases

The risk of developing cancer after solid organ transplantation (SOT) is about 5- to 10-fold greater than that of the general population. The cumulative risk of cancer rises to more than 50% at 20 years after transplant and increases with age, and so children receiving transplants are at high risk of developing a malignancy. Posttransplant lymphoproliferative disease (PTLD) is the most common cancer observed in children following SOT, accounting for half of all such malignancies. PTLD is a heterogeneous group of disorders with a wide spectrum of pathologic and clinical manifestations and is a major contributor to long-term morbidity and mortality in this population. Among children, most cases are associated with Epstein-Barr virus infection. This article reviews the pathology, immunobiology, epidemiology, and clinical aspects of PTLD, underscoring the need for ongoing systematic study of complex biologic and therapeutic questions.

Hepatitis B virus reactivation is a risk factor for development of post-transplant lymphoproliferative disease after liver transplantation

Post-transplant lymphoproliferative disease (PTLD) is believed to be associated with immunosuppressive regimens, underlying diseases and lymphotropic viral infections after organ transplantation. Hepatitis B virus (HBV) has been identified as a risk factor for non-Hodgkin's lymphoma, but no association between HBV and PTLD has been shown. In this study, we reviewed a series of 203 consecutive patients who underwent liver transplantation (LTx) for benign liver disease in our center. The patients comprised 144 patients with hepatitis B and 59 contemporary patients without hepatitis B. After LTx, 36 of the 144 patients with hepatitis B experienced HBV reactivation, while the remaining 108 patients did not. There was no difference in the incidences of PTLD between patients with and without hepatitis B (p = 0.497). Overall, four patients (11.1%) with HBV reactivation developed PTLD, compared to only one patient (0.9%) without HBV reactivation (p = 0.007). The relative odds for developing PTLD in patients with HBV reactivation were 17.5. No differences were observed for the follow-up periods, immunosuppressive regimens and rejection episodes (p > 0.05 for all). These data suggest that PTLD may be more prevalent in patients who experience HBV reactivation after liver transplantation. HBV reactivation may be a risk factor for development of PTLD.

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.

Orthotopic liver transplantation and what to do during follow-up: recommendations for the practitioner

Improvements in surgical technique and the introduction of several new immunosuppressive medications mean that outcome after orthotopic liver transplantation (OLT) has improved continuously over the past 15 years. Given the increasing longevity of patients after OLT, the recognition and prevention of long-term complications after transplantation have become ever more important. With respect to graft function, physicians responsible for the everyday care of patients following transplantation should be particularly aware of the risk of late and chronic rejection episodes and of recurrence of the underlying liver disease. The major challenge of post-transplant care is, however, how best to prevent and manage the long-term adverse effects caused by the immunosuppressive medications prescribed. Screening investigations for early diagnosis of malignancy, strict control of cardiovascular risk factors, preservation of renal function, and prevention of infections are, therefore, fundamental. This Review suggests guidelines for the management of OLT recipients to improve long-term survival, overall outcome and health-related quality of life.

Intrahepatic cholestasis after liver transplantation

Biochemical cholestasis after liver transplantation is common and often has no clinical significance if biliary anastomosis strictures and leaks have been excluded. There is no agreed upon definition for severe cholestasis, but it is associated with a worse mortality. There has been little evaluation on risk factors, but these include cryoprecipitate and platelet transfusion intraoperatively, nonidentical blood group, suboptimal graft appearance, inpatient status before transplant, and bacteremia within the first month. Associated causes considered as early (<6 months) include ischemia-reperfusion injury, primary nonfunction, small-for-size graft syndrome, infection, drugs and acute cellular rejection. Late causes include hepatic artery thrombosis, chronic rejection, biliary complications, recurrent viral and cholestatic disease, and posttransplant lymphoproliferative disorder.

Posttransplant Lymphoproliferative Disorders After Liver Transplantation: Analysis of Early and Late Cases in a 255 Patient Series

We reviewed the incidence and the impact of posttransplant lymphoproliferative disorders (PTLDs) on patient survival among a consecutive series of 255 patients. Five cases of PTLD were observed in adults: two cases were early (less than 1 year) and three cases, late lymphomas. The EBV positivity and the degree of immunosuppression were the main risk factors. We labeled cases as early or late according to whether the time elapsed from the transplant to the first clinical evidence of PTLD was less than 12 months. The median time from transplant to diagnosis of PTLD was 8 (early) and 108 (late) months. All cases were treated by reduction in immunosuppressive therapy with conventional chemotherapy and rituximab. The early cases with lymphoma located at the hepatic hilum died due to local complications (biliary sepsis and hemobilia), after an initial partial response to chemotherapy. The three patients with late cases are in remission after a mean follow-up of 23 months.

Tonsil enlargement after liver transplantation in adults--reason enough for tonsillectomy? Two cases of tonsillar posttransplantation lymphoproliferative disease

Posttransplantation lymphoproliferative disease (PTLD) is a well-known complication of solid organ and bone marrow transplantation. It is agreed that the main causes of PTLD are chronic infection with Epstein-Barr virus (EBV); the intensity, rather then the type, of immunosuppression used; and underlying recipient disease. Hepatitis C virus (HCV) and cytomegalovirus, as cofactors of EBV infection, have been suggested to increase the risk of PTLD. Use of calcineurin inhibitors, anti-CD3 monoclonal antibody (OKT3), and antithymocyte globulin may increase the risk of PTLD. On the other hand, mycophenolate mofetil, sirolimus, and the anti-interleukin-2 receptor monoclonal antibodies Daclizumab and basiliximab have not been demonstrated to increase the risk of PTLD. The incidence of PTLD after liver transplantation (LT) is estimated to be 1.5-3%, but a tonsillar location is extremely rare in adults. Thus, little is known about the best diagnostic tools for and treatment by LT recipients with tonsillar PTLD. Here, we report 2 cases of adult LT recipients with tonsillar PTLD. Tonsillectomy was used as a diagnostic tool and treatment option and resulted in complete remission for >2 years. Considering the high mortality and diagnostic difficulties of PTLD, together with the relatively low risks of tonsillectomy, we recommend tonsillectomy for treating tonsil enlargement of unknown cause and suspected PTLD in LT recipients. A larger series of patients and prospective studies comparing different treatment options will be needed to substantiate our recommendation.

Posttransplantation lymphoproliferative disorder--the great mimic in liver transplantation: appraisal of the clinicopathologic spectrum and the role of Epstein-Barr virus

Case series describing posttransplantation lymphoproliferative disorder (PTLD) after liver transplantation (LTx) have been limited in number because of the rarity of the disorder. The prevalence of Epstein-Barr virus (EBV) infection and its detection, the clinical and histological diversity of disease, and survival have varied. The aim of this study is to define the clinical and pathological spectrum of PTLD after LTx, and evaluate EBV prevalence, impact of infection, and patient survival. A retrospective analysis of all LTx recipients at our institution diagnosed with PTLD from January 1990 until May 2005, recording clinical presentations, times of presentation after transplantation, histological findings, results of EBV assessment, and survival, as well as the interrelationship of these variables. Among 621 LTx recipients were 22 cases of PTLD in 21 patients, of whom 5 were children and 16 were adults. Extranodal disease was present in 17 of 22 cases (77%) involving a wide variety of organ systems, while 5/22 (23%) had lymphadenopathy. The spectrum of PTLD histopathology was equally varied. In situ hybridization for EBV showed negativity in 8 of 13 (62%) and positivity in 5 of 13 (38%) cases tested. Neither time interval from transplantation to presentation (median 33 months) nor mortality (average 32%) was influenced by EBV status. In conclusion, PTLD in LTx recipients is predominantly extranodal and can involve a wide variety of organ systems, which may confound initial diagnosis. The lymphoproliferative histological spectrum is also diverse. Nowadays, PTLD is frequently EBV-negative, and EBV status does not appear to influence clinical or pathological presentation, or survival.