Chemotherapy for posttransplant lymphoproliferative disorder: the Israel Penn International Transplant Tumor Registry experience

Post-transplant lymphoproliferative disease in children, adolescents, and young adults

Post-transplant lymphoproliferative disease (PTLD) remains a major complication of transplantation. PTLD is a rare entity and very heterogenous making consensus on diagnosis and treatment very challenging. The majority are Epstein-Barr virus (EBV) driven, CD20+ B-cell proliferations. PTLD does occur following hematopoietic stem cell transplant (HSCT), but due to the relative short risk period and efficacy of pre-emptive therapy, PTLD following HSCT will not be discussed in this review. This review will focus on the epidemiology, role of EBV, clinical presentation, diagnosis and evaluation and the current and emerging treatment strategies for pediatric PTLD following solid organ transplantation.

Epstein-Barr virus-associated posttransplant lymphoproliferative disorders: new insights in pathogenesis, classification and treatment

PURPOSE OF REVIEW

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication following transplantation from an allogeneic donor. Epstein-Barr Virus (EBV) is involved in a substantial number of cases. In this review, we aim to summarize recent knowledge on pathogenesis, classification and treatment of EBV + PTLD.

RECENT FINDINGS

New insights in the complex oncogenic properties of EBV antigens noncoding Ribonucleic acids (RNAs), especially EBV MicroRNA (miRNAs), have increased our knowledge of the pathogenesis of EBV + PTLD. In addition the potential influence of EBV on the tumor microenvironment is becoming clearer, paving the way for new types of immunotherapy. Currently PTLD is classified according to the World Health Organization classification together with other lymphoproliferative disorders, based on the specific immunosuppression. However, a new framework integrating all types of lymphoproliferative disorders in all different settings of immune deficiency and dysregulation is needed. Although treatment of EBV + and EBV - PTLD was largely similar in the past, EBV-directed therapies are currently increasingly used.

SUMMARY

The use of EBV-directed therapies and new agents, based on better understanding of pathogenesis and classification of PTLD, will change the treatment landscape of EBV + PTLD in the next era.

Treatment of posttransplant lymphoproliferative disorder with poor prognostic features in children and young adults: Short-course EPOCH regimens are safe and effective

No guidelines exist for which intensive chemotherapy regimen is best in pediatric or young adult patients with high-risk posttransplant lymphoproliferative disorder (PTLD). We retrospectively reviewed patients with PTLD who received interval-compressed short-course etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin (SC-EPOCH) regimens at our institution. Eight patients were included with median age of 12 years. All patients achieved a complete response with a manageable toxicity profile. Two patients developed second, clonally unrelated, EBV-positive PTLD and one patient had recurrence at 6 months off therapy. No graft rejection occurred during therapy. All eight patients are alive with median follow-up of 29 months.

Post-transplantation lymphoproliferative disorders: Current concepts and future therapeutic approaches

Transplant recipients are vulnerable to a higher risk of malignancy after solid organ transplantation and allogeneic hematopoietic stem-cell transplant. Post-transplant lymphoproliferative disorders (PTLD) include a wide spectrum of diseases ranging from benign proliferation of lymphoid tissues to frank malignancy with aggressive behavior. Two main risk factors of PTLD are: Firstly, the cumulative immunosuppressive burden, and secondly, the oncogenic impact of the Epstein-Barr virus. The latter is a key pathognomonic driver of PTLD evolution. Over the last two decades, a considerable progress has been made in diagnosis and therapy of PTLD. The treatment of PTLD includes reduction of immunosuppression, rituximab therapy, either isolated or in combination with other chemotherapeutic agents, adoptive therapy, surgical intervention, antiviral therapy and radiotherapy. In this review we shall discuss the prevalence, clinical clues, prophylactic measures as well as the current and future therapeutic strategies of this devastating disorder.

Post-transplant lymphoproliferative disorder after solid-organ transplant in children

The post-transplant lymphoproliferative disorders (PTLD) are a diverse group of potentially life-threatening conditions affecting organ transplant recipients. PTLD arises in the setting of an attenuated host immunologic system that is manipulated to allow a foreign graft but then fails to provide adequate immune surveillance of transformed malignant or premalignant lymphocytes. The diversity of biological behavior and clinical presentation makes for a challenging clinical situation for those involved in the care of children with PTLD occurring after solid-organ transplantation. This review details a large transplant center's multidisciplinary approach to monitoring for PTLD and systematic approach to intervention, which has been essential for early recognition and successful treatment.

Role of Chemotherapy and Rituximab for Treatment of Posttransplant Lymphoproliferative Disorder in Solid Organ Transplantation

Objective:

To evaluate the role of chemotherapy and/or rituximab for treatment of posttransplant lymphoproliferative disorder (PTLD) in solid organ transplantation.

Data Sources:

A MEDLINE search (1966–May 2007) was conducted using the key words posttransplant lymphoproliferative disorder, solid organ transplantation, chemotherapy, and rituximab. References of relevant articles and abstracts from recent hematology, oncology, and transplantation scientific meetings (2004–May 2007) were also reviewed.

Study Selection and Data Extraction:

Prospective and retrospective studies identified from the data sources were evaluated, and all information deemed relevant was included for this review.

Data Synthesis:

Overall response rates ranged from 53% to 68%, 25% to 83%, and 74% to 100% for rituximab monotherapy, chemotherapy, and chemotherapy plus rituximab, respectively. Positive response to treatment was influenced by prognostic factors, including presence of Epstein-Barr virus in tumor cells, normal lactate dehydrogenase levels, good performance status, early disease onset after transplantation, and early disease stages. These factors in study patients likely contribute to the variability in response rates seen between treatment options. Severe adverse effects, ranging from grade 3 neutropenia to infection resulting in death, occurred more frequently in patients receiving chemotherapy than in patients receiving only rituximab.

Conclusions:

Although reduction in immunosuppressive medications remains the first-line therapy for PTLD treatment, many cases do not respond to this treatment alone, especially monomorphic or more aggressive cases of lymphoma. Therefore, it is reasonable to begin active treatment including rituximab and/or chemotherapy initially, along with reduction in immunosuppression in many cases. Further prospective, comparative studies are urgently needed to confirm the efficacy of these treatment strategies as well as to clarify which subset of patients may benefit most from them.

Risk-adapted Treatment for Severe B-Lineage Posttransplant Lymphoproliferative Disease After Solid Organ Transplantation in Children

BACKGROUND

Optimal management of posttransplant lymphoproliferative disease (PTLD) remains to be defined due to heterogeneity of this condition and lack of predictors of the outcome. Here we report our experience with pediatric PTLD nonresponsive to immunosuppression (IS) withdrawal, managed after stratification into high and low risk according to the presenting features.

METHODS

This is a single-center retrospective review of prospectively enrolled patients. From 2001 to 2011, 17 children were diagnosed with severe B-lineage, CD20+, PTLD after a median of 37 months (range, 5-93) from liver (12), heart (4), or multiorgan (1) transplantation. Treatment was tailored on 2 risk groups: (1) standard-risk (SR) patients received IS reduction and rituximab; (2) high-risk (HR) patients received IS discontinuation, rituximab and polychemotherapy.

RESULTS

The cumulative incidence of rejection at 1 and 5 years after the diagnosis of PTLD was 35% (95% confidence interval [95% CI], 18-69%) and 53% (33-85%), respectively, whereas the disease-free survival at 1 and 5 years was 94% (95% CI, 65-99%) and 75% (45-90%), respectively. Three children died, PTLD-free, from different transplant-related complications: primary nonfunction after retransplantation (liver), cytomegalovirus disease 21 months after PTLD treatment (liver), graft dysfunction 25 months after PTLD (heart).

CONCLUSIONS

Severe B-lineage PTLD after solid organ transplantation may be classified as SR or HR and treated accordingly with a tailored protocol obtaining a satisfactory long-term outcome. This approach accomplishes the control of lymphoproliferation in severe forms as well as the minimization of toxicity in milder PTLDs.

Late-onset post-transplantation lymphoproliferative disorders after kidney transplantation: a monocentric study over three decades

BACKGROUND

Late-onset post-transplantation lymphoproliferative disorders (PTLDs) occur 1 year after transplantation and are associated with poor prognosis. Initial treatment usually involves a reduction in immunosuppressive treatment. While early-onset PTLDs have a good prognosis following RI, this approach is generally inadequate for late-onset PTLDs. We assessed the specific outcome of late-onset PTLDs after kidney transplantation during the past three decades.

METHODS

We reviewed the clinical and biological data of 52 kidney transplant recipients who developed late-onset PTLDs at our centre between 1980 and 2010. We compared clinical features, long-term outcome and renal prognosis of late-onset PTLDs both before and after the era of rituximab.

RESULTS

Before 2000, 38% of the patients underwent surgery and 76% received chemotherapy either immediately or after surgery. After 2000, rituximab was administrated to 70% of the patients either alone (23%) or in combination with chemotherapy (77%). Chemotherapy alone was administrated in 26% of the cases. Before and after 2000, complete remission was achieved in 38 and 87% of the cases, respectively (P = 0.0005). The 5-year overall survival (OS) was 33.3 and 69% (P = 0.003), and 5-year disease-free survival was 37.5 and 80%, respectively (P = 0.19). Renal function was preserved in 70% of the cases at the end of the follow-up.

CONCLUSIONS

This study shows an increase in OS and low graft loss for patients with late-onset PTLDs during the last decade, which may be attributed to multiple changes in clinical practice, including a more standardized treatment and the use of rituximab in combination with chemotherapy.

Burden of de novo malignancy in the liver transplant recipient

Recipients of liver transplantation (LT) have a higher overall risk (2-3 times on average) of developing de novo malignancies than the general population, with standardized incidence ratios ranging from 1.0 for breast and prostate cancers to 3-4 for colon cancer and up to 12 for esophageal and oropharyngeal cancers. Aside from immunosuppression, other identified risk factors for de novo malignancies include the patient's age, a history of alcoholic liver disease or primary sclerosing cholangitis, smoking, and viral infections with oncogenic potential. Despite outcome studies showing that de novo malignancies are major causes of mortality and morbidity after LT, there are no guidelines for cancer surveillance protocols or immunosuppression protocols to lower the incidence of de novo cancers. Patient education, particularly for smoking cessation and excess sun avoidance, and regular clinical follow-up remain the standard of care. Further research in epidemiology, risk factors, and the effectiveness of screening and management protocols is needed to develop evidence-based guidelines for the prevention and treatment of de novo malignancies.

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.

Post-transplant lymphoproliferative disorder after lung transplantation: a review of 35 cases

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a complication of organ transplantation. The risk of developing PTLD varies depending on a number of factors, including the organ transplanted and the degree of immunosuppression used.

METHODS

We report a retrospective analysis of 35 patients with PTLD treated at our center after lung transplantation. Of 705 patients who received allografts, 34 (4.8%) developed PTLD. One patient underwent transplantation elsewhere and was treated at our center.

RESULTS

PTLD involved the allograft in 49% of our patients and the gastrointestinal (GI) tract lumen in 23%. Histologically, 39% of tumors were monomorphic and 48% polymorphic. The time to presentation defined the location and histology of disease. Of 17 patients diagnosed within 11 months of transplantation, PTLD involved the allograft in 12 (71%) and the GI tract in 1 (p = 0.01). This "early" PTLD was 85% polymorphic (p = 0.006). Conversely, of the 18 patients diagnosed more than 11 months after transplant, the lung was involved in 5 (28%) and the GI tract in 7 (39%; p = 0.01). "Late" PTLD was 71% monomorphic (p = 0.006). Median overall survival after diagnosis was 18.57 months. Overall survival did not differ between all lung transplant recipients and those who developed PTLD.

CONCLUSIONS

PTLD is an uncommon complication after lung transplantation, and its incidence declined remarkably in the era of modern immunosuppression. We report several factors that are important for predisposition toward, progression of, and treatment of PTLD after lung transplantation.

Malignancies following lung transplantation

Malignancy is an important complication of thoracic organ transplantation and is associated with significant morbidity and mortality. Lung transplant recipients are at greater risk for cancer than immunocompetent persons, with cancer-specific incidence rates up to 60-fold higher than the general population. The increased risk for cancer is attributed to neoplastic properties of immunosuppressive medications, oncogenic viruses, and cancer-specific risk factors. This article addresses the epidemiology, presentation, and treatment of the most common malignancies after lung transplantation, including skin cancer, posttransplant lymphoproliferative disorder, and bronchogenic carcinoma.

Management of posttransplant lymphoproliferative disorders following solid organ transplant: an update

Development of secondary malignancies is a well-known complication of solid organ transplant, with skin cancer and lymphoproliferative disorders being most frequently observed. Posttransplant lymphoproliferative disorders, caused by diminished immune surveillance, represent a broad spectrum of pathological and clinical disorders, ranging from benign conditions to very aggressive lymphomas. Here we review treatment options for adult patients experiencing posttransplant lymphoproliferative disorders following solid organ transplant.

Treatment advances in posttransplant lymphoproliferative disease

PURPOSE OF REVIEW

Epstein-Barr virus-associated posttransplant lymphoproliferative disease (PTLD) is a life-threatening complication of organ transplantation. As we continue to observe improved outcomes of patients living after solid or hematopoietic stem cell transplantation, we can expect to see a parallel increase in the incidence of PTLD. Several innovative therapeutic approaches are currently under development to add to our arsenal of treatment strategies in this devastating disease.

RECENT FINDINGS

The past decade has witnessed significant progress in the understanding and treatment of PTLD. The tolerability and effectiveness of standard treatment regimens, such as a reduction in immunosuppression, rituximab, and chemotherapy, have been confirmed and improved upon. Newer options for treatment demonstrating significant promise include antiviral therapy with arginine butyrate, as well as Epstein-Barr virus-specific cytotoxic T-cell therapy.

SUMMARY

Both the heterogeneous PTLD population and the lack of standardized and evidence-based treatment approaches make treatment a difficult decision for the clinician. This article reviews and updates the evidence behind accepted strategies such as reduction in immunosuppression, rituximab, and chemotherapy, as well as explores novel and effective therapeutic modalities including antiviral therapy with arginine butyrate and adoptive allogeneic T-cell therapy.

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.

Predictors of outcome in post-transplant lymphoproliferative disorder: an evaluation of tumor infiltrating lymphocytes in the context of clinical factors

We hypothesized that the number of tumor infiltrating cytotoxic T-cells (CTCs) and regulatory T-cells (Tregs), shown to have prognostic value in other lymphoproliferative disorders, could predict survival in post-transplant lymphoproliferative disorder (PTLD). Sixty-two patients were diagnosed with PTLD between 1987 and 2007, with 44 cases representing monomorphic B-cell PTLDs with diffuse aggressive morphologic features. Of these 44 cases, 31 had sufficient tissue for further study. On univariate analysis, high tumor infiltrating CD3(+) T-cell (> or =550/10 hpf) and TIA-1(+) CTC (> or =300/10 hpf) counts were associated with favorable overall survival (OS), PTLD-specific survival (PTLD-SS), and progression-free survival (PFS) while Treg counts were not predictive of outcome. However, on multivariate analysis, clinical factors were the most powerful predictor of PTLD outcome (performance status and CHOP as first line therapy for OS; performance status and number of extranodal sites for both PTLD-SS and PFS).

Post cardiac transplantation lymphoproliferative disorder presenting as t(8;14) Burkitt leukaemia/lymphoma treated with low intensity chemotherapy and rituximab

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) occasionally presents as Burkitt lymphoma/L3 leukaemia (BLL).

PROCEDURE

We reviewed records of cases of PTLD post-cardiac transplantation (1990-2007) occurring in our unit.

RESULTS

There were 15 episodes in 13 patients including four cases of EBV-driven Burkitt-type disease with t(8;14) translocations presenting with advanced stage disease. The first case was treated with a variety of low dose chemotherapy combinations. Despite problems during therapy he obtained complete remission, but died from complications of pre-existing cardiac allograft vasculopathy 7 months later. The subsequent three cases were treated with a UKCCSG low stage lymphoma protocol, NHL 9001 and Rituximab. They remain in complete remission.

CONCLUSIONS

In the context of PTLD the prognostic significance of advanced stage EBV-driven BLL with the t(8;14) translocation may be different to that in immunocompetent children.

Late donor cardiectomy after paediatric heterotopic cardiac transplantation

BACKGROUND

Cardiac transplantation is a life-saving procedure in infants and children with advanced cardiomyopathy. However, it is greatly limited by shortage of paediatric donors and the complications of long-term immunosuppression, including post-transplant lymphoproliferative disorder (PTLD). We report the management of an infant who had heterotopic cardiac transplantation for advanced cardiomyopathy with secondary pulmonary hypertension who developed seemingly incurable PTLD.

METHODS

An 8-month-old girl presented in 1994 with signs of severe heart failure, secondary to dilated cardiomyopathy. At age 11 months, the patient underwent a heterotopic cardiac transplantation.

FINDINGS

The patient developed many episodes of PTLD associated with Epstein-Barr virus infection that were resistant to several therapies, including reduction of immunosuppression. Native heart recovery enabled removal of the donor heart 10.5 years after the original operation to allow complete cessation of immunosuppression. Her postoperative course was uncomplicated and the outcome was excellent. 3.5 years after surgery, the patient remains well, in complete remission from her PTLD, and has normal cardiac function.

INTERPRETATION

This case shows several issues relating to the use of heterotopic cardiac transplantation in infants and the capacity of the heart to recover. It also provides new insights into the interaction between the immune system with several aspects of modern management of post-transplantation PTLD.

FUNDING

None.

The management of posttransplant lymphoproliferative disorder

Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication of allogeneic hematopoietic stem cell and solid organ transplantation. Most cases are EBV-positive B-cell neoplasms, which occur in the setting of pharmacologically impaired cellular immunity. Several different treatment strategies including cytotoxic antitumor therapy, anti-B-cell monoclonal antibody therapy, antiviral therapy, and modalities aimed at restoration of EBV-specific cellular immunity have been employed. In addition, efforts to identify patients at high risk for PTLD have resulted in attempts at prophylactic and preemptive therapies. In this review we discuss the available literature on differing approaches to PTLD management, identify areas in need of further investigation, and, when possible, make general recommendations. Reduction of immunosuppression remains the mainstay of first-line treatment. Accumulating evidence supports the role of rituximab as second-line therapy with cytotoxic chemotherapy reserved for specific circumstances. Further investigations are needed to better define the role of more novel and less widely available therapies such as the adoptive transfer of EBV-specific T cells and optimization of antiviral therapies.

Successful prolonged rituximab treatment for post-transplant lymphoproliferative disorder following living donor liver transplantation in a child

PTLD is a serious complication of immunosuppression in solid organ transplant recipients. The incidence of PTLD is significantly higher in pediatric recipients than in adult because children are often EBV-seronegative and they may develop primary EBV infection after transplantation. We herein describe a case of GI-PTLD who achieved a complete remission by prolonged rituximab, a chimeric monoclonal antibody against CD20, mono-therapy. A one-yr-old female underwent a LDLT for liver failure after having previously undergone the Kasai procedure for biliary atresia. At sixty days following the transplantation, GI-PTLD developed. Withdrawal of immunosuppression and a surgical resection were thus performed. A histopathological examination of tumor revealed atypical medium to large cell lymphoid proliferation with strong CD20 immunopositivity indicating their B-cell origin. Polymorphic PTLD was diagnosed. Rituximab was administered at a dose of 375 mg/m2 once a week, and the monotherapy resulted in a complete remission after 34 administrations. Based on this case, rituximab appears to be beneficial as a first-line therapy for PTLD.

Severe cold agglutinin disease caused by recurrent monomorphic Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorder (PTLD), clonally related to an EBV-negative plasmacytic hyperplasia in a pediatric multivisceral organ transplant recipient

PTLD represent major post-transplant complications. The major etiologic factor is EBV. Association with cold agglutinin disease has not been described so far. We report a three-yr-old girl who developed oligoclonal EBV-negative plasmacytic hyperplasia as well as Coombs test-positive anemia one yr after multivisceral organ transplantation, performed after subtotal bowel resection for colointestinal aganglionosis and liver cirrhosis resulting from long-term parenteral nutrition. The patient was treated for plasmacytic hyperplasia with cyclophosphamide and prednisolone and achieved clinical remission. One yr later PTLD progressed possibly driven by EBV to DLBCL. The migration patterns of the amplified Ig heavy chain genes demonstrated a probable clonal relationship of the DLBCL to a clone almost present in the plasmacytic hyperplasia. This progression was accompanied by a rapid rise of cold agglutinin titers with symptoms of severe cold agglutinin disease, leading to right femoral and extern iliac vein thromboses requiring partial leg amputation. After four cycles of rituximab, cyclophosphamide, and prednisolone, the patient achieved complete PTLD remission and the cold agglutinins disappeared. Summarizing, PTLD may be accompanied by cold agglutinin disease, and both may be successfully treated by immuno-chemotherapy. The appearance of cold agglutinins in transplant patients may indicate PTLD development.

Rituximab in the management of post-transplantation lymphoproliferative disorder after solid organ transplantation: proceed with caution

The introduction of single-agent rituximab has markedly changed the approach to therapy of patients with post-transplantation lymphoproliferative disorder (PTLD), but response to treatment varies substantially between patients. In the current report, we analyze long-term efficacy of single-agent rituximab in 60 patients and present factors predictive of progression-free and overall survival. Twelve months after completing first-line treatment, 34 of 60 patients (57%) had progressive disease, resulting in a median progression-free survival of 6.0 months at a median follow-up of 16.3 months. Using multivariate Cox regression analysis, the following factors were identified as significantly predictive of overall survival: age at diagnosis, performance status, lactate dehydrogenase (LDH), and time from transplantation to PTLD. Stage of disease and Epstein-Barr virus association of PTLD did not influence overall survival. LDH and time from transplantation to PTLD were also predictive of progression-free survival. The international prognostic index was shown to be of limited predictive value in these patients, but a PTLD-specific prognostic index separated low-, intermediate-, and high-risk patients with high significance: 2-year overall survival rates after first-line treatment with single-agent rituximab were 88, 50, and 0%, respectively. Thus, prognostic indices can be useful tools for prediction of treatment outcome and for the development of risk-adapted treatment strategies in patients with PTLD and may also provide the basis for interstudy comparisons.

Salvage Chemotherapy for Refractory and Relapsed Posttransplant Lymphoproliferative Disorders (PTLD) After Treatment With Single-Agent Rituximab

BACKGROUND

Single-agent rituximab has demonstrated encouraging efficacy and tolerability in posttransplant lymphoproliferative disorders (PTLDs) failing to respond to immunosuppression reduction (IR). This retrospective analysis was undertaken to determine the efficacy and safety of salvage therapy in recipients of solid organ transplants with progression of PTLD after rituximab first-line therapy.

METHODS

Eleven patients who had received IR and single-agent rituximab were analyzed. Of these, 10 had received CHOP salvage chemotherapy. One patient with limited disease received tumor irradiation and further IR. Most patients (73%) had late PTLD (median onset of disease 145 months posttransplant), and most (83%) had monomorphic histology; 36% had EBV-association.

RESULTS

IR and irradiation therapy re-induced complete remission (CR) and allowed long-term disease control in a patient with polymorphic PTLD relapse. CHOP therapy achieved CR in five (50%) and partial remission (PR) in two (20%) patients. Four of five (80%) patients achieving CR remained in CR at a median follow-up of 44.2 months. Of the patients achieving PR, one is currently alive, and the second died from transplant rejection after converting to CR after consolidative chemotherapy. Patients with stable disease (two) and progressive disease (one) have died from PTLD. There was one possible CHOP-associated death (acute cardiac event) and two patients had to be switched to less-toxic monotherapies. Median overall survival was 46.5 months (95% confidence interval: 23.6-49.1 months).

CONCLUSIONS

CHOP salvage therapy achieved a favorable overall response rate of 70% in this setting, indicating that PTLD generally remains chemotherapy-sensitive after progression following first-line rituximab.

Malignancy in pediatric transplant recipients

Malignancy is a well defined complication of chronic immunosuppression. Post transplant malignancies appear to be related to cumulative doses of immunosuppression, and in pediatric patients, acute infection of previously naive patients. The most commonly encountered malignancy in this age population is Post Transplant Lymphoproliferative Disorder (PTLD). PTLD is not a single entity but rather represents a continuum of disease. Treatment of PTLD should be initiated with immunosuppression reduction. Standard dose chemotherapy leads to significant morbidity. With the introduction of anti-CD20 antibody treatment with rituximab, chemotherapy has become second line therapy. The occurrence of solid malignancy appears to be associated with chronic immunosuppression. These cancers include those of skin, gynecologic organs, and the rectum, all of which appear to have the strongest association with viral mediators. Several strategies have been postulated to minimize the occurrence of malignancy. These include ganciclovir prophylaxis for the prevention of PTLD and the use of mychophenolic acid and TOR inhibitor maintenance to diminish the incidence of PTLD and solid malignancies. This leaves transplant physicians with several new and novel immunosuppressive agents with uncertain oncologic potentials that will need to be examined over the next decade.

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

Post-transplant lymphoproliferative disorder (PTLD) following solid organ transplantation is an important form of post-transplant malignancy. PTLD is typically associated with Epstein-Barr virus (EBV) and occurs in the setting of profound immunosuppression resulting in a deficiency of EBV-specific cytotoxic T lymphocytes (CTL). Predisposing factors include EBV mismatch between donor and recipient, use of immunosuppression especially T-cell depletive therapies and genetic predisposition of recipients. The standard approach has been to reduce immunosuppression but is often insufficient to induce tumour regression. Further understanding of the immunobiology of PTLD has resulted in improved monitoring techniques (including EBV viral load determined by polymerase chain reaction) and newer treatment options. Recent work has highlighted a potential role for dendritic cells in both the pathogenesis and treatment of PTLD. Current treatment modalities include adoptive immunotherapy using ex vivo generated autologous EBV-specific CTL or allogeneic CTL, cytokine therapies, antiviral agents, and more recently, rituximab and dendritic-cell based therapies. This review focuses on the developments and progress in the pathogenesis, diagnosis and treatment of PTLD.

Hodgkin disease-like posttransplantation lymphoproliferative disorder of donor origin in a renal allograft recipient

Posttransplantation lymphoproliferative disorder (PTLD) develops in 1.6% of renal allograft recipients. More than 90% are of recipient origin. There are only a few reports of Hodgkin disease-like PTLD in allograft patients. We report the case of a Hodgkin disease-like PTLD of donor origin in a 16-year-old renal allograft recipient. Fourteen months after transplantation, an increasing inhomogeneous structure in the hilar region of the transplanted kidney became apparent and was excised. Histological examination showed Hodgkin- and Sternberg-Reed-like cells. Immunostaining showed CD20-positive and CD15-negative cells and Epstein-Barr virus (EBV) involvement (EBV-encoded small nonpolyadenylated RNA and EBV-determined nuclear antigen 2). DNA fingerprinting analysis proved the lymphoma to be of donor origin. Treatment consisted of nephrectomy, discontinuation of immunosuppression therapy, and local radiation. Three years after lymphoma removal, the patient was still without relapse and underwent retransplantation with stable function of the second allograft for more than 2 years now.

Management of patients with post-transplant lymphoproliferative disorder: the role of rituximab

Post-transplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ and bone marrow transplantations. Rituximab (Rituxan, Mabthera), a chimeric monoclonal antibody to the CD20 antigen on the surface of B-cell lymphocytes, has been used increasingly in the treatment of PTLD. Rituximab was initially approved for the treatment of low-grade non-Hodgkin lymphomas, but multiple case studies, retrospective analyses, and phase II trials demonstrate the benefit of rituximab in PTLD. This paper reviews the current data on rituximab and its promising role in the management of PTLD.

Low-Dose Chemotherapy for Epstein-Barr Virus–Positive Post-Transplantation Lymphoproliferative Disease in Children After Solid Organ Transplantation

Purpose

To evaluate the efficacy of a low-dose chemotherapy regimen in children with Epstein-Barr virus (EBV) –positive, post-transplantation lymphoproliferative disease (PTLD) after organ transplantation who have experienced failure with front-line therapy for PTLD.

Patients and Methods

Eligible patients received cyclophosphamide (600 mg/m2 intravenous for 1 day) and prednisone (2 mg/kg orally for 5 days) every 3 weeks for six cycles.

Results

Thirty-six patients treated on study were assessable for analyses. Front-line therapies for PTLD before study entry included immune suppression reduction or withdrawal (n = 36), antiviral therapy (n = 33), surgical resection (n = 8), rituximab (n = 2), and interferon alfa (n = 1). Reasons for failure of front-line therapy included progressive disease (PD; n = 33) and persistent disease with concurrent allograft rejection (n = 3). Thirty patients (83%) had stage III to IV disease, 92% had extranodal disease, and 75% had ≥ three sites of disease. The overall response rate was 83% (75% complete response + 8% partial response). The relapse rate was 19%, with only one of five relapsed patients alive and disease-free. Four patients presented with fulminant, disseminated PTLD; only one of these four patients achieved a response, and all four died of PD. Two patients died of treatment-related toxicity. Three patients (8%) experienced allograft loss, but two of the three patients are alive and disease-free after a second transplantation. The 2-year overall, relapse-free, and failure-free (without PTLD and with functioning original allograft) survival rates were 73%, 69%, and 67%, respectively.

Conclusion

This low-dose chemotherapy regimen is effective for children with EBV-positive, nonfulminant PTLD who have experienced treatment failure with front-line therapy, and this study represents the largest series of PTLD patients treated prospectively with a uniform chemotherapy regimen.