Complete Recovery After Immunosuppressive Treatment Change in a Patient With Posttransplant Lymphoproliferative Disorder

Posttransplant lymphoproliferative diseases are a rare but important cause of morbidity and mortality secondary to immunosuppression after solid-organ or bone marrow transplant. Generally, posttransplant lymphoproliferative diseases develop in the first 2 years after transplant, when immunosuppressive therapy is the most intense. Change or reduction in immunosup - pressive treatment is an option for treatment of posttransplant lymphoproliferative diseases. We evaluated the treatment of a patient with posttransplant lymphoproliferative disease after liver transplant. A 64-year-old man underwent liver transplant from a living donor (the patient's son) in 2011 to treat hepatocellular cancer secondary to chronic hepatitis B. Tacrolimus and mycophenolate mofetil were used for immunosuppression through 9 years after liver transplant. In the abdominal computed tomography performed in response to abdominal pain during follow-up in March 2019, multiple solid lesions were observed. A liver biopsy revealed posttransplant lymphoproliferative disease with diffuse large B-cell lymphoma. Fluorine-18 positron emission tomography/computed tomography imaging of the patient showed no pathology in favor of primary lymphoproliferative disease. Mycophenolate mofetil and tacrolimus treatment was changed to everolimus. In the follow-up dynamic magnetic resonance imaging examination that was performed at 3 months after treatment change, we observed that the lesion at liver segment 6 had regressed to 30 mm and several lesions with similar features were observed in the right lobe of the liver. Additional liver biopsy results were compatible with complete remission. The patient's clinical symptoms had fully regressed at 18 months after the diagnosis of PTLD, at the time of this writing. Ongoing radiological and clinical follow-up has shown complete remission. Change from calcineurin treatment to treatment with an inhibitor of the mechanistic target of rapamycin may be an essential and new option for treatment of posttransplant lymphoproliferative disease after liver transplant.

The clinical efficacy of Rituximab administration in autoimmunity disorders, primary immunodeficiency diseases and malignancies

Rituximab (RTX), as a monoclonal antibody-based immunotherapeutic intervention targeting CD20 on B cells, has proven efficacy in the treatment of patients with some immune-mediated diseases. In the present review, we provided information on the immunobiological mechanisms of signaling for RTX and its clinical applications, according to the immune-pathophysiology involved in the microenvironment of multiple diseases. We highlighted combination therapy, dose schedules, and laboratory monitoring, as well as the associated common and rare side effects to avoid. We also discussed the efficacy and safety of RTX-based therapeutic strategies and whether RTX therapy can be used as a promising treatment regimen for autoimmune diseases, primary immunodeficiency diseases, and malignancies. Our review highlights and supports the importance of collaboration between basic medical researchers and clinical specialists when considering the use of RTX in the treatment of various immune-mediated disorders.

The BCL-2 family protein inhibitor ABT-737 as an additional tool for the treatment of EBV-associated post-transplant lymphoproliferative disorders

Post‐transplant lymphoproliferative disorders (PTLD) and Burkitt's lymphoma (BL) are B‐cell malignancies strongly associated with Epstein–Barr virus (EBV) infection. In these lymphoproliferative disorders, EBV infection induces an increase in the expression of the anti‐apoptotic protein BCL‐2. Given its chemoprotective effect, BCL‐2 constitutes an attractive target for new therapeutic strategies for EBV‐positive B‐cell malignancies. Here, we show that ABT‐737, a small inhibitor of BCL‐2, BCL‐X(L), and BCL‐w, strongly induced apoptosis in vitro in EBV‐positive lymphoblastoid cell lines (which is a model for PTLD), whereas BL was less sensitive. ABT‐737 reduced tumor growth and increased the overall survival of mice in a xenograft model of PTLD but had no effect on BL xenograft mice. ABT‐737 combined with a low dose of cyclophosphamide, a major component of the conventional CHOP chemotherapy regimen for BL patients, reduced tumor growth during treatment but failed to improve the overall survival of BL xenograft mice. By contrast, the combination of ABT‐737 and rituximab, one of the main options for the treatment of PTLD, was highly efficient and induced approximately 70% remission in PTLD xenograft mice. These results suggest that the use of agents targeting BCL‐2, either alone or in combination with other conventional drugs, represents a novel promising approach for post‐transplant EBV‐positive B lymphoproliferative disorders.

Identification of multiple potent neutralizing and non-neutralizing antibodies against Epstein-Barr virus gp350 protein with potential for clinical application and as reagents for mapping immunodominant epitopes

Prevention of Epstein-Barr virus (EBV) infection has focused on generating neutralizing antibodies (nAbs) targeting the major envelope glycoprotein gp350/220 (gp350). In this study, we generated 23 hybridomas producing gp350-specific antibodies. We compared the candidate gp350-specific antibodies to the well-characterized nAb 72A1 by: (1) testing their ability to detect gp350 using enzyme-linked immunosorbent assay, flow cytometry, and immunoblot; (2) sequencing their heavy and light chain complementarity-determining regions (CDRs); (3) measuring the ability of each monoclonal antibody (mAb) to neutralize EBV infection in vitro; and (4) mapping the gp350 amino acids bound by the mAbs using competitive cell and linear peptide binding assays. We performed sequence analysis to identify 15 mAbs with CDR regions unique from those of murine 72A1 (m72A1). We observed antigen binding competition between biotinylated m72A1, serially diluted unlabeled gp350 nAbs (HB1, HB5, HB11, HB20), and our recently humanized 72A1, but not gp350 non-nAb (HB17) or anti-KSHV gH/gL antibody.

Progressive Multifocal Leukoencephalopathy Following Combined Rituximab-Based Immune-Chemotherapy for Post-transplant Lymphoproliferative Disorder in a Renal Transplant Recipient: A Case Report

BACKGROUND

Transplant recipients are at risk of developing progressive multifocal leukoencephalopathy (PML), an opportunistic infection due to reactivation of JC virus. Post-transplant lymphoproliferative disorders (PTLDs) represent a common malignancy in this population, and antiCD20-therapy has become an established component of its treatment.

CASE PRESENTATION

We describe the first case of a renal allograft transplant recipient with PTLD who received rituximab-based immune-chemotherapy and developed PML shortly thereafter. Despite early suspicion and diagnosis, the disease ran a relentlessly progressive course, and the patient succumbed to his illness shortly thereafter.

CONCLUSION

PML should be strongly suspected whenever unusual neurologic symptoms appear in the context of immunosuppression. Clinicians and patients should be aware of the potential for PML after rituximab therapy.

Clinical-grade generation of peptide-stimulated CMV/EBV-specific T cells from G-CSF mobilized stem cell grafts

Background

A major complication after allogeneic hematopoietic stem cell transplantation (aSCT) is the reactivation of herpesviruses such as cytomegalovirus (CMV) and Epstein–Barr virus (EBV). Both viruses cause significant mortality and compromise quality of life after aSCT. Preventive transfer of virus-specific T cells can suppress reactivation by re-establishing functional antiviral immune responses in immunocompromised hosts.

Methods

We have developed a good manufacturing practice protocol to generate CMV/EBV-peptide-stimulated T cells from leukapheresis products of G-CSF mobilized and non-mobilized donors. Our procedure selectively expands virus-specific CD8+ und CD4+ T cells over 9 days using a generic pool of 34 CMV and EBV peptides that represent well-defined dominant T-cell epitopes with various HLA restrictions. For HLA class I, this set of peptides covers at least 80% of the European population.

Results

CMV/EBV-specific T cells were successfully expanded from leukapheresis material of both G-CSF mobilized and non-mobilized donors. The protocol allows administration shortly after stem cell transplantation (d30+), storage over liquid nitrogen for iterated applications, and protection of the stem cell donor by avoiding a second leukapheresis.

Conclusion

Our protocol allows for rapid and cost-efficient production of T cells for early transfusion after aSCT as a preventive approach. It is currently evaluated in a phase I/IIa clinical trial.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1498-3) contains supplementary material, which is available to authorized users.

Impact of the posttransplant lymphoproliferative disorder subtype on survival

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication of solid organ transplantation. Histologic heterogeneity and a lack of treatment standards have made evaluating clinical outcomes in specific patient populations difficult. This systematic literature review investigated the impact of the PTLD histologic subtype on survival in a large data set.

METHODS

Case series were identified on PubMed with the search terms post-transplant lymphoproliferative disorder/disease, PTLD, and solid organ transplantation, with additional publications identified through reference lists. The patient characteristics, immunosuppressive regimen, treatment, survival, and follow-up time for 306 cases were extracted from 94 articles, and these cases were combined with 11 cases from Emory University Hospital. Patients with a recorded subtype were included in a Kaplan-Meier survival analysis (n = 234). Cox proportional hazards regression analyses identified predictors of overall survival (OS) for each subtype and B-cell subgroup.

RESULTS

OS differed significantly between monomorphic T-cell neoplasms (median, 9 months) and polymorphic, monomorphic B-cell, and Hodgkin-type neoplasms, for which the median OS was not reached (P = .0001). Significant differences in OS among B subgroups were not detected, but there was a trend toward decreased survival for patients with Burkitt-type PTLD. Kidney transplantation and a reduction of immunosuppression were associated with increased OS for patients with B-cell neoplasms in a multivariate analysis. Immunosuppression with azathioprine was associated with decreased OS for patients with T-cell neoplasms, whereas radiotherapy was associated with improved OS for patients with that subtype.

CONCLUSIONS

The histologic subtype represents an important prognostic factor in PTLD, with patients with T-cell neoplasms exhibiting very poor OS. Possibly lower survival for certain subsets of patients with B-cell PTLD should be explored further and suggests the need for subtype-specific therapies to improve outcomes. Cancer 2018;124:2327-36. © 2018 American Cancer Society.

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.

Primary Intestinal Hodgkin Lymphoma Mimicking Intraabdominal Abscess in a Renal Transplant Recipient: A Case Report

INTRODUCTION

Post-transplant lymphoproliferative disease (PTLD) comprises a variety of lymphoid and plasma cell disorders arising in patients with a solid organ transplant. Monomorphic lymphomas represent the most significant part of this wide spectrum, with the overall risk rising with the aggressiveness of lymphoid proliferation in comparison to the general population. The development of Hodgkin lymphoma is very rare in transplant recipients, comprising less than 6% of all monomorphic PTLD, while cases of primary intestinal Hodgkin lymphoma in these circumstances are anecdotal.

CASE REPORT

We describe an exceptional case of intestinal Hodgkin lymphoma mimicking an intra-abdominal abscess that developed in a transplant recipient 19 years after kidney transplantation. By presenting this case, we wish to emphasize the importance of suitable diagnostic pathways in transplant recipients experiencing prolonged fever episodes or masses of unknown origin, thus raising the awareness of possible PTLD development in such patients.

CONCLUSION

The lack of information about transplant recipients with Hodgkin PTLD regarding the site of involvement and type of treatment suggests the necessity of conducting larger international studies aimed at providing further insight into this particular group of patients.

Posttransplant Viral Syndromes in Pediatric Patients: A Review

The success of pediatric solid organ transplantation has been largely due to advancements in surgical techniques, technology, and preoperative and postoperative care. Potent immunosuppression continues to reduce the incidence and severity of rejection, and improve long-term survival. However, there is growing awareness of the role immunosuppression plays in contributing to the incidence of cytomegalovirus, Epstein-Barr virus, and Epstein-Barr virus–associated posttransplant lymphoproliferative disease. Herpes viruses such as these present as primary or recurrent disease and continue to be a significant source of morbidity and mortality in transplant recipients. This paper reviews the predictors of disease, clinical features, diagnosis, and methods of treatment of these major posttransplant viral syndromes. As part of the human herpes virus family, varicella-zoster virus will also be discussed. A case study shows the delicate balance of treating concomitant varicella infection at the time of transplantation.

Remission of late-onset post-heart transplantation lymphoproliferative disorder following treatment with rituximab and modified mini-CHOP chemotherapy: A case report

Post-transplant lymphoproliferative disorder (PTLD) is one of the most frequent secondary malignancies that can follow immunosuppressive therapy for solid organ transplantation, and may result in severe morbidities and even mortality. A middle-aged Han Chinese patient, prescribed with immunosuppressive cyclosporine and prednisone, developed PTLD that manifested as a painless cervical lymph node enlargement, 12 years following heart transplantation. Histology revealed monomorphic B-cell PTLD (diffuse large-cell lymphoma); as a result the immunosuppressive regimen of the patient was changed to tacrolimus and mycophenolate mofetil. In addition, the patient was changed to 6-cycle rituximab with a modified mini-CHOP (R-mini-CHOP) regimen for induction, and 8-cycle quarterly rituximab treatment and maintenance therapy. R-mini-CHOP therapy was well tolerated, and no allograft rejection occurred. The patient exhibited clinical remission as demonstrated by the results of the positron emission tomography-computed tomography at the 5-year follow-up visit following R-mini-CHOP therapy. In conclusion, R-mini-CHOP therapy following reduced immunosuppression is effective and safe for the treatment of late-onset PTLD following heart transplantation.

B-Cell-Rich T-Cell Lymphoma Associated with Epstein-Barr Virus-Reactivation and T-Cell Suppression Following Antithymocyte Globulin Therapy in a Patient with Severe Aplastic Anemia

B-cell lymphoproliferative disorder (B-LPD) is generally characterized by the proliferation of Epstein-Barr virus (EBV)-infected B lymphocytes. We here report the development of EBV-negative B-LPD associated with EBV-reactivation following antithymocyte globulin (ATG) therapy in a patient with aplastic anemia. The molecular autopsy study showed the sparse EBV-infected clonal T cells could be critically involved in the pathogenesis of EBV-negative oligoclonal B-LPD through cytokine amplification and escape from T-cell surveillances attributable to ATG-based immunosuppressive therapy, leading to an extremely rare B-cell-rich T-cell lymphoma. This report helps in elucidating the complex pathophysiology of intractable B-LPD refractory to rituximab.

Posttransplantation lymphoproliferative disease: proposed imaging classification

Posttransplantation lymphoproliferative disease (PTLD) is the second most common tumor in adult transplant recipients. Most cases of PTLD are attributed to Epstein-Barr virus. Decreased levels of immunosurveillance against this tumor virus as a result of immunosuppressive regimens are thought to account for most cases of PTLD. Histologically, PTLD ranges from relatively benign lymphoid hyperplasia to poorly differentiated lymphoma, and tissue sampling is required to establish the subtype. The frequency of PTLD varies depending on the type of allograft and immunosuppressive regimen. PTLD has a bimodal manifestation, with most cases occurring within the first year after transplantation and a second peak occurring 4-5 years after transplantation. Patients are often asymptomatic or present with nonspecific symptoms, and a mass visible at imaging may be the first clue to the diagnosis. Imaging plays an important role in identifying the presence of disease, guiding tissue sampling, and evaluating response to treatment. The appearance of PTLD at imaging can vary. It may be nodal or extranodal. Extranodal disease may involve the gastrointestinal tract, solid organs, or central nervous system. Solid organ lesions may be solitary or multiple, infiltrate beyond the organ margins, and obstruct organ outflow. Suggestive imaging findings should prompt tissue sampling, because knowledge of the PTLD subtype is imperative for appropriate treatment. Treatment options include reducing immunosuppression, chemotherapy, radiation therapy, and surgical resection of isolated lesions.

Post-transplant lymphoproliferative disease (PTLD): risk factors, diagnosis, and current treatment strategies

Post-transplant lymphoproliferative diseases (PTLD) are heterogeneous lymphoid disorders ranging from indolent polyclonal proliferations to aggressive lymphomas that complicate solid organ or hematopoietic transplantation. Risk factors for PTLD include viral infections, degree of immunosuppression, recipient age and race, allograft type, and host genetic variations. Clinically, extra-nodal disease is common including 10-15 % presenting with central nervous system (CNS) disease. Most PTLD cases are B cell (5-10 % T/NK cell or Hodgkin lymphoma), while over one-third are EBV-negative. World Health Organization (WHO) diagnostic categories are: early lesions, polymorphic, and monomorphic PTLD; although in practice, a clear separation is not always possible. Therapeutically, reduction in immunosuppression remains a mainstay, and recent data has documented the importance of rituximab +/- combination chemotherapy. Therapy for primary CNS PTLD should be managed according to immunocompetent CNS paradigms. Finally, novel treatment strategies for PTLD have emerged, including adoptive immunotherapy and rational targeted therapeutics (e.g., anti-CD30 based therapy and downstream signaling pathways of latent membrane protein-2A).

Diagnosis and treatment of viral diseases in recipients of allogeneic hematopoietic stem cell transplantation

Viral infections are important causes of morbidity and mortality after allogeneic stem cell hematopoietic transplantation (allo-HSCT). Although most viral infections present with asymptomatic or subclinical manifestations, viruses may result in fatal complications in severe immunocompromised recipients. Reactivation of latent viruses, such as herpesviruses, is frequent during the immunosuppression that occurs with allo-HSCT. Viruses acquired from community, such as the respiratory and gastrointestinal viruses, are also important pathogens of post-transplant viral diseases. Currently, molecular diagnostic methods have replaced or supplemented traditional methods, such as viral culture and antigen detection, in diagnosis of viral infections. The utilization of polymerase chain reaction facilitates the early diagnosis. In view of lacking efficacious agents for treatment of viral diseases, prevention of viral infections is extremely valuable. Application of prophylactic strategies including preemptive therapy reduces viral infections and diseases. Adoptive cellular therapy for restoring virus-specific immunity is a promising method in the treatment of viral diseases.

A case of EBV driven haemophagocytic lymphohistiocytosis complicating a teenage Crohn's disease patient on azathioprine, successfully treated with rituximab

We report a case of Epstein-Barr virus infection with the subsequent development of haemophagocytic lymphohistiocytosis in a teenage Crohn's disease patient treated with azathioprine. We found that the early introduction of the anti-B cell monoclonal antibody rituximab precipitated a rapid fall in circulating B-cells and EBV viral load, resulting in a prompt and sustained recovery from what is a potentially fatal complication of azathioprine therapy in Crohn's disease patients.

Epstein-Barr virus infection and posttransplant lymphoproliferative disorder

Epstein-Barr virus (EBV) is an important pathogen in recipients of solid organ transplants (SOT). Infection with EBV manifests as a spectrum of diseases/malignancies ranging from asymptomatic viremia through infectious mononucleosis to posttransplant lymphoproliferative disorder (PTLD). EBV disease and its associated PTLD is more frequently seen when primary EBV infection occurs after transplant, a common scenario in pediatric SOT recipients. Intensity of immunosuppressive therapies also influences the risk for PTLD. The use of EBV viral load monitoring facilitates the diagnosis and management of EBV/PTLD as well as being used to inform preemptive therapy with reduction of immunosuppression, the most effective intervention for prevention of and treatment for PTLD. Other therapies, including the rituximab (anti-CD20 monoclonal antibody) and traditional chemotherapy, are also useful in the treatment of established PTLD. The future development of standards for management based on EBV viral load and routine monitoring of EBV-specific CTL responses promise further improvement in outcomes with EBV and PTLD.

Monitoring of nonsteroidal immunosuppressive drugs in patients with lung disease and lung transplant recipients: American College of Chest Physicians evidence-based clinical practice guidelines

OBJECTIVES

Immunosuppressive pharmacologic agents prescribed to patients with diffuse interstitial and inflammatory lung disease and lung transplant recipients are associated with potential risks for adverse reactions. Strategies for minimizing such risks include administering these drugs according to established, safe protocols; monitoring to detect manifestations of toxicity; and patient education. Hence, an evidence-based guideline for physicians can improve safety and optimize the likelihood of a successful outcome. To maximize the likelihood that these agents will be used safely, the American College of Chest Physicians established a committee to examine the clinical evidence for the administration and monitoring of immunosuppressive drugs (with the exception of corticosteroids) to identify associated toxicities associated with each drug and appropriate protocols for monitoring these agents.

METHODS

Committee members developed and refined a series of questions about toxicities of immunosuppressives and current approaches to administration and monitoring. A systematic review was carried out by the American College of Chest Physicians. Committee members were supplied with this information and created this evidence-based guideline.

CONCLUSIONS

It is hoped that these guidelines will improve patient safety when immunosuppressive drugs are given to lung transplant recipients and to patients with diffuse interstitial lung disease.

Detection of the Epstein-Barr virus in blood and bone marrow mononuclear cells of patients with aggressive B-cell non-Hodgkin's lymphoma is not associated with prognosis

The Epstein-Barr virus (EBV) is associated with a large spectrum of lymphoproliferative diseases. Traditional methods of EBV detection include the immunohistochemical identification of viral proteins and DNA probes to the viral genome in tumoral tissue. The present study explored the detection of the EBV genome, using the BALF5 gene, in the bone marrow or blood mononuclear cells of patients with diffuse large B-cell lymphomas (DLBCL) and related its presence to the clinical variables and risk factors. The results show that EBV detection in 21.5% of patients is not associated with age, gender, staging, B symptoms, international prognostic index scores or any analytical parameters, including lactate dehydrogenase (LDH) or β-2 microglobulin (B2M). The majority of patients were treated with R-CHOP-like (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone or an equivalent combination) and some with CHOP-like chemotherapy. Response rates [complete response (CR) + partial response (PR)] were not significantly different between EBV-negative and -positive cases, with 93.2 and 88.9%, respectively. The survival rate was also similar in the two groups, with 5-year overall survival (OS) rates of 64.3 and 76.7%, respectively. However, when analyzing the treatment groups separately there was a trend in EBV-positive patients for a worse prognosis in patients treated with CHOP-like regimens that was not identified in patients treated with R-CHOP-like regimens. We conclude that EBV detection in the bone marrow and blood mononuclear cells of DLBC patients has the same frequency of EBV detection on tumoral lymphoma tissue but is not associated with the risk factors, response rate and survival in patients treated mainly with immunochemotherapy plus rituximab. These results also suggest that the addition of rituximab to chemotherapy improves the prognosis associated with EBV detection in DLBCL.

Acute or chronic life-threatening diseases associated with Epstein-Barr virus infection

Infectious mononucleosis (IM) is one of the representative, usually benign, acute diseases associated with primary Epstein-Barr virus (EBV) infection. IM is generally self-limiting and is characterized mostly by transient fever, lymphadenopathy and hepatosplenomegaly. However, very rarely primary EBV infection results in severe or fatal conditions such as hemophagocytic lymphohistiocytosis together with fulminant hepatitis designated as severe or fatal IM or EBV-associated hemophagocytic lymphohistiocytosis alone. In addition, chronic EBV-associated diseases include Burkitt's lymphoma, undifferentiated nasopharyngeal carcinoma, Hodgkin lymphoma, T-cell lymphoproliferative disorder (LPD)/lymphoma, natural killer-cell LPD including leukemia or lymphoma, gastric carcinoma, pyothorax-associated lymphoma and senile B-cell LPD as well as chronic active EBV infection and LPD/lymphoma in patients with immunodeficiency. The number of chronic life-threatening diseases linked to the EBV infection is increasingly reported and many of these diseases have a poor prognosis. This review will focus on the historical, pathogenetic, diagnostic, therapeutic and prophylactic issues of EBV-associated life-threatening diseases.

Cardiac antibody-mediated rejection

Many factors limit short- and long-term survival after pediatric heart transplantation. Historically, attention had been directed toward T-cell responses and acute cellular rejection. Presence of pretransplant antibodies against HLA is associated with increased donor wait times and poor post-transplant outcomes. Therapies aimed to mitigate circulating antibodies include plasmapheresis, protein A immunoadsorption columns, intravenous immune globulin, rituximab, and bortezomib. The negative effects of B cells, HLA antibodies, and AMR and potential interventions are the focus of this review article.

Nonsurgical care of intestinal and multivisceral transplant recipients: a review for the intensivist

Intestinal and multivisceral transplantation has evolved from an experimental procedure to the treatment of choice for patients with irreversible intestinal failure and serious complications related to long-term parenteral nutrition. Increased numbers of transplant recipients and improved survival rates have led to an increased prevalence of this patient population in intensive care units. Management of intestinal and multivisceral transplant recipients is uniquely challenging because of complications arising from the high incidence of transplant rejection and its treatment. Long-term comorbidities, such as diabetes, hypertension, chronic kidney failure, and neurological sequelae, also develop in this patient population as survival improves. This article is intended for intensivists who provide care to critically ill recipients of intestinal and multivisceral transplants. As perioperative care of intestinal/multivisceral transplant recipients has been described elsewhere, this review focuses on common nonsurgical complications with which one should be familiar in order to provide optimal care. The article is both a review of the current literature on multivisceral and isolated intestinal transplantation as well as a reflection of our own experience at the University of Miami.

Epstein-Barr virus-associated B-cell lymphomas: pathogenesis and clinical outcomes

Epstein-Barr virus (EBV) is a ubiquitous human γ-herpesvirus that establishes a life-long asymptomatic infection in immunocompetent hosts. It is also found to be frequently associated with a broad spectrum of B-cell lymphomas predominantly seen in immunodeficient patients. Despite many resemblances, these EBV-linked lymphoproliferative disorders display heterogeneity at the clinical and the molecular level. Moreover, EBV-associated lymphoproliferative diseases differ in their differential expression patterns of the EBV-encoded latent antigens, which are directly related to their interactions with the host. EBV-driven primary B-cell immortalization is linked to the cooperative functions of these latent proteins, which are critical for perturbing many important cell-signaling pathways maintaining B-cell proliferation. Additionally, it is used as a surrogate model to explore the underlying mechanisms involved in the development of B-cell neoplasms. Recent discoveries have revealed that a number of sophisticated mechanisms are exploited by EBV during cancer progression. This finding will be instrumental in the design of novel approaches for therapeutic interventions against EBV-associated B-cell lymphomas. This review limits the discussion to the biology and pathogenesis of EBV-associated B-cell lymphomas and the related clinical implications.

High incidence of post transplant lymphoproliferative disorder after antithymocyte globulin-based conditioning and ineffective prediction by day 28 EBV-specific T lymphocyte counts

The largest study on post-allogeneic hematopoietic cell transplant lymphoproliferative disorder (PTLD) epidemiology showed a cumulative incidence of 1.7% in patients receiving antithymocyte globulin (ATG). We had noted an apparently higher incidence in our transplant recipients whose conditioning included ATG. Therefore, we formally determined the incidence of PTLD through chart review. We also evaluated whether counts of EBV-specific T lymphocytes measured by cytokine flow cytometry could identify patients at risk of developing PTLD. Among 307 allogeneic transplant recipients, 25 (8.1%) developed PTLD. This was biopsy proven in 11 patients, and was fatal in seven patients. Patient age, EBV serostatus, donor type/match or GVHD did not influence PTLD risk significantly. Median onset of PTLD was 55 (range, 28-770) days post transplant. Day 28 EBV-specific T lymphocyte counts were not significantly different in 11 patients who developed PTLD and 31 non-PTLD patients matched for published risk factors for PTLD. In summary, when using conditioning with thymoglobulin 4.5 mg/kg, the incidence of PTLD is relatively high and cannot be predicted by day 28 cytokine flow cytometry-determined EBV-specific T lymphocyte counts. Thus, in this scenario PTLD prevention may be warranted, for example, using EBV DNAemia monitoring with preemptive therapy.

The role of rituximab in autologous and allogeneic hematopoietic stem cell transplantation for non-Hodgkin's lymphoma

The addition of rituximab to chemotherapy has substantially changed the treatment strategies for patients with B-cell lymphomas. Rituximab, combined with standard chemotherapy regimens, shows consistently improved results compared with chemotherapy alone and has been extensively employed in both newly diagnosed and relapsed patients with B-cell lymphoma. Because of its low toxicity profile and its potent antilymphoma activity mediated through direct apoptotic and indirect effector mechanisms, rituximab also has been actively incorporated into stem cell transplantation (SCT) protocols to attain a state of minimal disease, provide a safe and effective method for in vivo purging prior to autologous SCT, and promote graft-versus-lymphoma effects in allogeneic SCT. This review compiles the still immature but rapidly growing data on this combined modality.

Hematopoietic stem cell transplantation after posttransplant lymphoproliferative disorder

A 16-yr-old girl received liver transplantation for fulminant hepatitis. Aplastic anemia developed, and she received hematopoietic stem cell transplantation (HSCT). Eleven months after liver transplantation, abdominal lymph node enlargement and colon ulcers were observed, and colon biopsy showed posttransplant lymphoproliferative disorder (PTLD). Immunosuppression reduction was attempted, but it produced no therapeutic effect. Fourteen months after liver transplantation, she received a second HSCT due to engraftment failure, and PTLD resolved completely. The second HSCT can serve as cellular therapy for PTLD.

Management of post-transplant lymphoproliferative disorder in adult solid organ transplant recipients - BCSH and BTS Guidelines

A joint working group established by the Haemato-oncology subgroup of the British Committee for Standards in Haematology (BCSH) and the British Transplantation Society (BTS) has reviewed the available literature and made recommendations for the diagnosis and management of post-transplant lymphoproliferative disorder in adult recipients of solid organ transplants. This review details the therapeutic options recommended including reduction in immunosuppression (RIS), transplant organ resection, radiotherapy and chemotherapy. Effective therapy should be instituted before progressive disease results in declining performance status and multi-organ dysfunction. The goal of treatment should be a durable complete remission with retention of transplanted organ function with minimal toxicity.

Emerging role of CD20 blockade in allogeneic hematopoietic cell transplantation

There is growing evidence incriminating B lymphocytes in the pathogenesis of graft-versus-host disease (GVHD). Better understanding of the role of B lymphocytes has uncovered new therapeutic approaches, such as CD20 blockade, which appear to be improving outcomes in allogeneic hematopoietic cell transplant recipients. Administration of the chimeric murine/human anti-CD20 monoclonal antibody, rituximab, prior to hematopoietic cell allografting or as part of preparative regimens appears to reduce treatment-related mortality and to improve posttransplant outcomes mainly by decreasing the incidence and severity of acute GVHD. This beneficial effect of rituximab has not had an impact, to the same extent on the incidence of chronic GVHD, which remains a significant cause of morbidity and mortality following hematopoietic cell allografting. Alternatively, rituximab has been shown to be effective for treatment of cGVHD, but data is limited because of the lack of randomized controlled clinical trials and the small sample size in most of the published series. Incorporation of rituximab into the therapeutic armamentarium of Epstein-Barr virus-associated posttransplant lymphoproliferative disorder has clearly improved the overall prognosis of this dreadful disease. This review highlights the evolving role of CD20 blockade in allogeneic hematopoietic cell transplantation and the need to continue to refine B cell depletion strategies in this setting.

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.

Single agent efficacy of rituximab in childhood immunosuppression related lymphoproliferative disease: a United Kingdom Children's Cancer Study Group (UKCCSG) retrospective review

Survival in childhood lymphoproliferative disease (LPD) remains poor, particularly in non-transplant patients. The anti-CD20 antibody rituximab shows promise but data in children is scant. A retrospective study of 22 (aged 11 months to 18 years) children treated with rituximab is presented. Two had primary immunodeficiency, two had prolonged immunosuppression and 18 had post-transplant LPD (eight bone marrow, five liver, four heart, one kidney). Nine patients had multi-organ involvement and 13 single site disease. Seventeen out of 22 had rituximab alone. In 16, a dose of 375 mg/m2 i.v. weekly was used (less in one patient due to renal dysfunction). Twelve patients received four courses and ten patients received one to three courses. Fever was the main side-effect in four. Eight (47%) had single agent response; four complete and four partial. All had other treatment prior to rituximab. Median follow-up was 35 months (range 22 - 47 months). In childhood LPD unresponsive to standard treatment, rituximab showed single agent response and requires further evaluation.

Increased Ig-null B lymphocytes in the peripheral blood of pediatric solid organ transplant recipients with elevated Epstein-Barr viral loads

In this study, the characteristics of Ig-null B cells in high viral load carriers were examined by four-color flow cytometry. The frequency of Ig-null B cells in patients with high, low or undetectable virus loads was found that while patients with a high load had more Ig-null cells, these cells were also present in the low and undetectable load groups. As Ig-null cells from patients with no viral load were EBV-negative, EBV infection was not absolutely required for the generation or survival of Ig-null cells. Ig-null cells were CD19(+), sIg(-), CD5(-), CD10(-), CD27(-), CD23(-), CD38(-), and CD69(-) with variable surface expression of CD20 and CD40. Ig-null cells did not have a proliferating cell phenotype (Ki67(-)) and a high proportion were HLA class I(-) and class II(-). Virus copy number in CD19(+) Ig-null cell populations may be much higher than in CD19(+) Ig(+) cell populations. EBV infected Ig-null cells were common in blood specimens from pediatric solid organ transplant recipients and infected Ig-null cells may pose potential problems for immunotherapies that target infected B cells directly.

Oncolytic rat parvovirus H-1PV, a candidate for the treatment of human lymphoma: In vitro and in vivo studies

The incidence of lymphomas developing in both immunocompetent and immunosuppressed patients continues to steadily increase worldwide. Current chemotherapy and immunotherapy approaches have several limitations, such as severe side toxicity and selection of resistant cell variants. Autonomous parvoviruses (PVs), in particular the rat parvovirus H-1PV, have emerged as promising anticancer agents. Although it is apathogenic in humans, H-1PV has been shown to infect and suppress various rat and human tumors in animal models. In this study, we demonstrate the capacity of H-1PV for efficiently killing, through necrosis, cell cultures originating from Burkitt's lymphoma (BL), while sparing normal B lymphocytes. The cytotoxic effect was generally accompanied by a productive H-1PV infection. Remarkably, parvovirus-based monotherapy efficiently suppressed established BL at an advanced stage in a severe combined immunodeficient (SCID) mouse model of the disease. The data show for the first time that an oncolytic parvovirus deserves further consideration as a potential tool for the treatment of some non-Hodgkin B-cell lymphomas, including those resistant to apoptosis induction by rituximab.

EBV-related lymphoproliferative disease complicating therapy with the anti-CD2 monoclonal antibody, siplizumab, in patients with T-cell malignancies

PURPOSE

We report an increased incidence of EBV-induced B-cell lymphoproliferative disease (LPD) in patients treated with siplizumab, an anti-CD2 antibody. The development of EBV-LPD has been associated with the use of immunosuppressive agents used in solid organ, bone marrow, and stem cell transplantation and in certain congenital immunodeficiencies.

EXPERIMENTAL DESIGN

We conducted a single-institution phase I dose-escalation trial of siplizumab, a humanized monoclonal antibody to CD2, in 29 patients with T-cell malignancies.

RESULTS

Although initial responses were encouraging, 4 (13.7%) patients developed EBV-LPD and the trial was stopped. Reductions in CD4(+) and CD8(+) cell count numbers in response to therapy were seen in all patients, but in those patients developing EBV-LPD a significantly greater reduction in natural killer (NK) cell number and CD2 expression on T cells was seen. These findings highlight the importance of NK-cell depletion and CD2 expression in addition to T-cell depletion in the etiology of EBV-LPD.

CONCLUSIONS

The emergence of EBV-LPD may be associated with the ability of siplizumab to deplete both T and NK cells without affecting B cells. Agents that deplete T- and NK-cell populations without affecting B cell number should be screened for this potentially serious adverse event.

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

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

EBV-associated lymphoproliferative disorders: classification and treatment

Since its discovery as the first human tumor virus, Epstein-Barr virus (EBV) has been implicated in the development of a wide range of B-cell lymphoproliferative disorders, including Burkitt's lymphoma, classic Hodgkin's lymphoma, and lymphomas arising in immunocompromised individuals (post-transplant and HIV-associated lymphoproliferative disorders). T-cell lymphoproliferative disorders that have been reported to be EBV associated include a subset of peripheral T-cell lymphomas, angioimmunoblastic T-cell lymphoma, extranodal nasal type natural killer/T-cell lymphoma, and other rare histotypes. EBV encodes a series of products interacting with or exhibiting homology to a wide variety of antiapoptotic molecules, cytokines, and signal transducers, hence promoting EBV infection, immortalization, and transformation. However, the exact mechanism by which EBV promotes oncogenesis is an area of active debate. The focus of this review is on the pathology, diagnosis, classification, and pathogenesis of EBV-associated lymphomas. Recent advances in EBV cell-based immunotherapy, which is beginning to show promise in the treatment of EBV-related disorders, are discussed.

Poor outcome in post transplant lymphoproliferative disorder with pulmonary involvement after allogeneic hematopoietic SCT: 13 years' experience in a single institute

EBV-induced post transplant lymphoproliferative disorder (PTLD) continues to be a major complication after transplantation. Between January 1993 and April 2006, 12 cases of B-cell lymphoproliferative disorder were identified among 577 patients after allogeneic hematopoietic SCT (HSCT) with an overall incidence of 2.51% at 1 year. Grades II-IV acute GVHD, CMV antigenemia and the use of antithymocyte globulin (ATG) were independent risk factors for PTLD. At diagnosis, all of the tumors were CD20-positive and 11 (92%) were EBV-encoded RNA (EBER)-positive. Of the 12 patients with B-cell lymphoproliferative disorder, 8 had pulmonary involvement and 10 had extranodal involvement. Eleven patients received weekly rituximab therapy at a dose of 375 mg/m(2); the median interval between the onset of symptoms and rituximab therapy was 6 days. The overall mortality rate was 92% and seven (64%) of the deaths were directly attributable to disseminated PTLD within days or weeks of presentation. In our series, pulmonary PTLD followed an extremely aggressive course and poor response to current therapy, even though rituximab was included in the therapeutic regimens.

Prospective study of sequential reduction in immunosuppression, interferon alpha-2B, and chemotherapy for posttransplantation lymphoproliferative disorder

BACKGROUND

Several interventions can cure posttransplant lymphoproliferative disease (PTLD); a sequential approach is usual, starting with reduction in immunosuppressives (RI). The efficacy of RI remains poorly defined, particularly in adults. We assessed an algorithm starting with a defined course of RI in all patients, escalating to interferon (IFN) alpha2b, and finally to chemotherapy, in a prospective multicenter phase II study of adult solid organ transplant recipients. The design predated rituximab.

METHODS

Reduction in immunosuppressives: cyclosporine or tacrolimus reduction by 50% for 2 weeks; a further 50% reduction for 1 week if not in complete remission (CR). Intravenous acyclovir was given for the duration of all RI. Patients with less than CR, or any rejection, resumed immunosuppressives and proceeded to IFN 3 MIU/m(2)/day for up to 3 months; if less than CR, ProMACE-CytaBOM chemotherapy.

RESULTS

Twenty patients were registered over 60 months; 16 patients with biopsy-proven PTLD were eligible (13 heart, 3 kidney recipients). Median age was 47 (24-75) years. Reduction in immunosuppressives resulted in only 1 of 16 partial responses (12.5%), no CR. Progressive disease occurred in 8 of 16 (50%) and 6 of 16 (38%) experienced rejection. Only 1 of 13 (7%) patients achieved durable CR with IFN. Seven eligible patients received ProMACE-CytaBOM chemotherapy, five of seven (67%) achieving CR, four of five durable beyond 2 years.

CONCLUSIONS

Reduction in immunosuppressives produced no CR, progressive disease and rejection were frequent; response to IFN was rare. A strong case can be made for adding rituximab to RI as initial therapy. Chemotherapy resulted in 57% durable CR, data that are relevant for the up to two thirds of PTLD patients who are refractory to rituximab.

A national conference to determine research priorities in pediatric solid organ transplantation

The need for evidence-based practice guidelines requires high quality, carefully controlled clinical research trials. This multidisciplinary conference attempted to: identify urgent clinical and research issues, identify obstacles to performing clinical trials, develop concepts for organ-specific and all-organ research and generate a report that would serve as a blueprint for future research initiatives. A few themes became evident. First, young children present a unique immunologic environment which may lead to tolerance, therefore, including young children in immunosuppression withdrawal and tolerance trials may increase the potential benefits of these studies. Second, adolescence poses significant barriers to successful transplantation. Non-adherence may be insufficient to explain poorer outcomes. More studies focused on identification and prevention of non-adherence, and the potential effects of puberty are required. Third, the relatively naive immune system of the child presents a unique opportunity to study primary infections and alloimmune responses. Finally, relatively small numbers of transplants performed in pediatric centers mandate multicenter collaboration. Investment in registries, tissue and DNA repositories will enhance productivity. The past decade has proven that outcomes after pediatric transplantation can be comparable to adults. The pediatric community now has the opportunity to design and complete studies that enhance outcomes for all transplant recipients.