Adapted treatment of Epstein-Barr virus infection to prevent posttransplant lymphoproliferative disorder after heart transplantation

Epidemiology and Management of Infections in Liver Transplant Recipients

Background: Improvements in liver transplant (LT) outcomes are attributed to advances in surgical techniques, use of potent immunosuppressants, and rigorous pre-LT testing. Despite these improvements, post-LT infections remain the most common complication in this population. Bacteria constitute the most common infectious agents, while fungal and viral infections are also frequently encountered. Multi-drug-resistant bacterial infections develop because of polymicrobial overuse and prolonged hospital stays. Immediate post-LT infections are commonly caused by viruses. Conclusions: Appropriate vaccination, screening of both donor and recipients before LT and antiviral prophylaxis in high-risk individuals are recommended. Antimicrobial drug resistance is common in high-risk LT and associated with poor outcomes; epidemiology and management of these cases is discussed. Additionally, we also discuss the effect of coronavirus disease 2019 (COVID-19) infection and monkeypox in the LT population.

The IPTA Nashville consensus conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: II-consensus guidelines for prevention

The International Pediatric Transplant Association (IPTA) convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorder after solid organ transplantation in children. In this report from the Prevention Working Group, we reviewed the existing literature regarding immunoprophylaxis and chemoprophylaxis, and pre-emptive strategies. While the group made a strong recommendation for pre-emptive reduction of immunosuppression at the time of EBV DNAemia (low to moderate evidence), no recommendations for use could be made for any prophylactic strategy or alternate pre-emptive strategy, largely due to insufficient or conflicting evidence. Current gaps and future research priorities are highlighted.

Prevention of Oncogenic Gammaherpesvirinae (EBV and HHV8) Associated Disease in Solid Organ Transplant Recipients

Long-term risk for malignancy is higher among solid organ transplant (SOT) recipients compared to the general population. Four non-hepatitis viruses have been recognized as oncogenic in SOT recipients-EBV, cause of EBV-associated lymphoproliferative diseases; human herpes virus 8 (HHV8), cause of Kaposi sarcoma, primary effusion lymphoma and multicentric Castleman disease; human papilloma virus, cause of squamous cell skin cancers, and Merkel cell polyomavirus, cause of Merkel cell carcinoma. Two of these viruses (EBV and HHV8) belong to the human herpes virus family. In this review, we will discuss key aspects regarding the clinical presentation, diagnosis, treatment, and prevention of diseases in SOT recipients associated with the two herpesviruses.

A quick algorithmic review on management of viral infectious diseases in pediatric solid organ transplant recipients

Pediatric solid organ transplant is a life-saving procedure for children with end-stage organ failure. Viral infections are a common complication following pediatric solid organ transplantation (SOT), which can lead to increased morbidity and mortality. Pediatric solid organ transplant recipients are at an increased risk of viral infections due to their immunosuppressed state. The most commonly encountered viruses include cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), varicella-zoster virus (VZV), adenoviruses, and BK polyomavirus. Prevention strategies include vaccination prior to transplantation, post-transplant prophylaxis with antiviral agents, and preemptive therapy. Treatment options vary depending on the virus and may include antiviral therapy and sometimes immunosuppression modification. This review provides a Quick Algorithmic overview of prevention and treatment strategies for viral infectious diseases in pediatric solid organ transplant recipient.

Cytomegalovirus and Epstein-Barr virus infection during daratumumab treatment in patients with multiple myeloma

ABSTRACTSWe explored the incidence of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections in 131 patients with multiple myeloma (MM), 53 of whom received daratumumab (Dara) treatments. The Dara group had more RRMM patients than the group without Dara. CMV infection was significantly more common in patients treated with Dara (16.98%) than in patients treated with regimens without Dara (2.56%). During Dara treatments, 24.53% of patients developed CMV and/or EBV infections. Patients who developed infections had significantly lower levels of albumin and lymphocytes in their peripheral blood. The median time from the first Dara infusion to infection was 27 days. We observed NK cell depletion and T cell expansion during Dara-treatment. Patients with CMV and/or EBV infections had significantly lower numbers of NK cells, total T cells, and CD8 + T cells at 1 month, and lower numbers of CD8 + T cells at 2 months after the first Dara infusion than those without infections.

Molecular Monitoring of Lymphomas

Molecular monitoring of tumor-derived alterations has an established role in the surveillance of leukemias, and emerging nucleic acid sequencing technologies are likely to similarly transform the clinical management of lymphomas. Lymphomas are well suited for molecular surveillance due to relatively high cell-free DNA and circulating tumor DNA concentrations, high somatic mutational burden, and the existence of stereotyped variants enabling focused interrogation of recurrently altered regions. Here, we review the clinical scenarios and key technologies applicable for the molecular monitoring of lymphomas, summarizing current evidence in the literature regarding molecular subtyping and classification, evaluation of treatment response, the surveillance of active cellular therapies, and emerging clinical trial strategies.

Reinforcement of cell-mediated immunity driven by tumor-associated Epstein-Barr virus (EBV)-specific T cells during targeted B-cell therapy with rituximab

Introduction

In immunocompromised patients, Epstein-Barr virus (EBV) infection or reactivation is associated with increased morbidity and mortality, including the development of B-cell lymphomas. The first-line treatment consists of reduction of immunosuppression and administration of rituximab (anti-CD20 antibody). Furthermore, the presence of EBV-specific T cells against latent EBV proteins is crucial for the control of EBV-associated diseases. Therefore, in addition to effective treatment strategies, appropriate monitoring of T cells of high-risk patients is of great importance for improving clinical outcome. In this study, we hypothesized that rituximab-mediated lysis of malignant EBV-infected B cells leads to the release and presentation of EBV-associated antigens and results in an augmentation of EBV-specific effector memory T-cell responses.

Methods

EBV-infected B lymphoblastoid cell lines (B-LCLs) were used as a model for EBV-associated lymphomas, which are capable of expressing latency stage II and III EBV proteins present in all known EBV-positive malignant cells. Rituximab was administered to obtain cell lysates containing EBV antigens (AC^EBV). Efficiency of cross-presentation of EBV-antigen by B-LCLs compared to cross-presentation by professional antigen presenting cells (APCs) such as dendritic cells (DCs) and B cells was investigated by in vitro T-cell immunoassays. Deep T-cell profiling of the tumor-reactive EBV-specific T cells in terms of activation, exhaustion, target cell killing, and cytokine profile was performed, assessing the expression of T-cell differentiation and activation markers as well as regulatory and cytotoxic molecules by interferon-γ (IFN-γ) EliSpot assay, multicolor flow cytometry, and multiplex analyses.

Results

By inhibiting parts of the cross-presentation pathway, B-LCLs were shown to cross-present obtained exogenous AC^EBV-derived antigens mainly through major histocompatibility complex (MHC) class I molecules. This mechanism is comparable to that for DCs and B cells and resulted in a strong EBV-specific CD8⁺ cytotoxic T-cell response. Stimulation with AC^EBV-loaded APCs also led to the activation of CD4⁺ T helper cells, suggesting that longer peptide fragments are processed via the classical MHC class II pathway. In addition, B-LCLs were also found to be able to take up exogenous antigens from surrounding cells by endocytosis leading to induction of EBV-specific T-cell responses although to a much lesser extent than cross-presentation of AC^EBV-derived antigens. Increased expression of activation markers CD25, CD71 and CD137 were detected on EBV-specific T cells stimulated with AC^EBV-loaded APCs, which showed high proliferative and cytotoxic capacity as indicated by enhanced EBV-specific frequencies and increased secretion levels of cytotoxic effector molecules (e.g. IFN-γ, granzyme B, perforin, and granulysin). Expression of the regulatory proteins PD-1 and Tim-3 was induced but had no negative impact on effector T-cell functions.

Conclusion

In this study, we showed for the first time that rituximab-mediated lysis of EBV-infected tumor cells can efficiently boost EBV-specific endogenous effector memory T-cell responses through cross-presentation of EBV-derived antigens. This promotes the restoration of antiviral cellular immunity and presents an efficient mechanism to improve the treatment of CD20⁺ EBV-associated malignancies. This effect is also conceivable for other therapeutic antibodies or even for therapeutically applied unmodified or genetically modified T cells, which lead to the release of tumor antigens after specific cell lysis.

Recent Advances in Adult Post-Transplant Lymphoproliferative Disorder

PTLD is a rare but severe complication of hematopoietic or solid organ transplant recipients, with variable incidence and timing of occurrence depending on different patient-, therapy-, and transplant-related factors. The pathogenesis of PTLD is complex, with most cases of early PLTD having a strong association with Epstein-Barr virus (EBV) infection and the iatrogenic, immunosuppression-related decrease in T-cell immune surveillance. Without appropriate T-cell response, EBV-infected B cells persist and proliferate, resulting in malignant transformation. Classification is based on the histologic subtype and ranges from nondestructive hyperplasias to monoclonal aggressive lymphomas, with the most common subtype being diffuse large B-cell lymphoma-like PTLD. Management focuses on prevention of PTLD development, as well as therapy for active disease. Treatment is largely based on the histologic subtype. However, given lack of clinical trials providing evidence-based data on PLTD therapy-related outcomes, there are no specific management guidelines. In this review, we discuss the pathogenesis, histologic classification, and risk factors of PTLD. We further focus on common preventive and frontline treatment modalities, as well as describe the application of novel therapies for PLTD and elaborate on potential challenges in therapy.

Post-transplant Lymphoproliferative Disorder Following Cardiac Transplantation

Post-transplant lymphoproliferative disorder (PTLD) is a spectrum of lymphoid conditions frequently associated with the Epstein Barr Virus (EBV) and the use of potent immunosuppressive drugs after solid organ transplantation. PTLD remains a major cause of long-term morbidity and mortality following heart transplantation (HT). Epstein-Barr virus (EBV) is a key pathogenic driver in many PTLD cases. In the majority of PTLD cases, the proliferating immune cell is the B-cell, and the impaired T-cell immune surveillance against infected B cells in immunosuppressed transplant patients plays a key role in the pathogenesis of EBV-positive PTLD. Preventive screening strategies have been attempted for PTLD including limiting patient exposure to aggressive immunosuppressive regimens by tailoring or minimizing immunosuppression while preserving graft function, anti-viral prophylaxis, routine EBV monitoring, and avoidance of EBV seromismatch. Our group has also demonstrated that conversion from calcineurin inhibitor to the mammalian target of rapamycin (mTOR) inhibitor, sirolimus, as a primary immunosuppression was associated with a decreased risk of PTLD following HT. The main therapeutic measures consist of immunosuppression reduction, treatment with rituximab and use of immunochemotherapy regimens. The purpose of this article is to review the potential mechanisms underlying PTLD pathogenesis, discuss recent advances, and review potential therapeutic targets to decrease the burden of PTLD after HT.

Viral infections in lung transplantation

Viral infections account for up to 30% of all infectious complications in lung transplant recipients, remaining a significant cause of morbidity and even mortality. Impact of viral infections is not only due to the direct effects of viral replication, but also to immunologically-mediated lung injury that may lead to acute rejection and chronic lung allograft dysfunction. This has particularly been seen in infections caused by herpesviruses and respiratory viruses. The implementation of universal preventive measures against cytomegalovirus (CMV) and influenza (by means of antiviral prophylaxis and vaccination, respectively) and administration of early antiviral treatment have reduced the burden of these diseases and potentially their role in affecting allograft outcomes. New antivirals against CMV for prophylaxis and for treatment of antiviral-resistant CMV infection are currently being evaluated in transplant recipients, and may continue to improve the management of CMV in lung transplant recipients. However, new therapeutic and preventive strategies are highly needed for other viruses such as respiratory syncytial virus (RSV) or parainfluenza virus (PIV), including new antivirals and vaccines. This is particularly important in the advent of the COVID-19 pandemic, for which several unanswered questions remain, in particular on the best antiviral and immunomodulatory regimen for decreasing mortality specifically in lung transplant recipients. In conclusion, the appropriate management of viral complications after transplantation remain an essential step to continue improving survival and quality of life of lung transplant recipients.

Characteristics, management, and outcome of pediatric patients with post-transplant lymphoproliferative disease-A 20 years' experience from Austria

BACKGROUND

Management of pediatric post-transplantation lymphoproliferative disorder (PTLD) after hematopoietic stem cell (HSCT) and solid organ transplantation (SOT) is challenging.

AIM

This study of 34 PTLD patients up to 19-years old diagnosed in Austria from 2000 to 2018 aimed at assessing initial characteristics, therapy, response, and outcome as well as prognostic markers of this rare pediatric disease.

METHODS AND RESULTS

A retrospective data analysis was performed. Types of allografts were kidney (n = 12), liver (n = 7), heart (n = 5), hematopoietic stem cells (n = 4), lungs (n = 2), multi-visceral (n = 2), small intestine (n = 1), and vessels (n = 1). Eighteen/34 were classified as monomorphic PTLD, with DLBCL accounting for 15 cases. Polymorphic disease occurred in nine, and non-destructive lesions in six cases. One patient had a non-classifiable PTLD. Thirteen/34 patients are surviving event-free in first remission (non-destructive, n = 4/6; polymorphic, n = 4/9; monomorphic, n = 6/18). Fourteen/34 patients lacked complete response to first-line therapy, of whom seven died. Four/34 patients relapsed, of whom two died. In 3/34 patients, death occurred as a first event. The 5-year overall and event-free survival rates were 64% ± 9% and 35% ± 9% for the whole cohort. Among all parameters analyzed, only malignant disease as the indication for transplantation had a significantly poor influence on survival.

CONCLUSIONS

This study shows PTLD still to be a major cause of mortality following SOT or HSCT in children. A continued understanding of the molecular biology of the disease shall allow to decrease treatment intensity for lower risk patients and to identify patients who may benefit from newer therapy approaches to improve outcome and decrease morbidity.

Distinct immunopathological mechanisms of EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013-2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4⁺ <300 cells/mm³ , p <  .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm³ ) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.

Current Practices on Diagnosis, Prevention and Treatment of Post-Transplant Lymphoproliferative Disorder in Pediatric Patients after Solid Organ Transplantation: Results of ERN TransplantChild Healthcare Working Group Survey

(1) Background: Post-transplant lymphoproliferative disease (PTLD) is a significant complication of solid organ transplantation (SOT). However, there is lack of consensus in PTLD management. Our aim was to establish a present benchmark for comparison between international centers and between various organ transplant systems and modalities; (2) Methods: A cross-sectional questionnaire of relevant PTLD practices in pediatric transplantation was sent to multidisciplinary teams from 17 European center members of ERN TransplantChild to evaluate the centers’ approach strategies for diagnosis and treatment and how current practices impact a cross-sectional series of PTLD cases; (3) Results: A total of 34 SOT programs from 13 European centers participated. The decision to start preemptive treatment and its guidance was based on both EBV viremia monitoring plus additional laboratory methods and clinical assessment (61%). Among treatment modalities the most common initial practice at diagnosis was to reduce the immunosuppression (61%). A total of 126 PTLD cases were reported during the period 2012–2016. According to their histopathological classification, monomorphic lesions were the most frequent (46%). Graft rejection after PTLD remission was 33%. Of the total cases diagnosed with PTLD, 88% survived; (4) Conclusions: There is still no consensus on prevention and treatment of PTLD, which implies the need to generate evidence. This might successively allow the development of clinical guidelines.

Association of antiviral prophylaxis and rituximab use with posttransplant lymphoproliferative disorders (PTLDs): A nationwide cohort study

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation (SOT). Most PTLD cases are associated with Epstein-Barr virus (EBV) infection. The role of antiviral prophylaxis or rituximab therapy for prevention of PTLD in SOT recipients is controversial. In a nationwide cohort, we assessed the incidence, presentation, and outcome of histologically proven PTLD. We included 4765 patients with a follow-up duration of 23 807 person-years (py). Fifty-seven PTLD cases were identified; 39 (68%) were EBV positive (EBV+ PTLD). Incidence rates for EBV+ PTLD at 1, 2, and 3 years posttransplant were 3.51, 2.24, and 1.75/1000 py and 0.44, 0.25, and 0.29/1000 py for EBV- PTLD. We did not find an effect of antiviral prophylaxis on early and late EBV+ PTLD occurrence (early EBV+ PTLD: SHR 0.535 [95% CI 0.199-1.436], p = .264; late EBV+ PTLD: SHR 2.213, [95% CI 0.751-6.521], p = .150). However, none of the patients (0/191) who received a rituximab-containing induction treatment experienced PTLD, but 57 of 4574 patients without rituximab induction developed PTLD. In an adjusted restricted mean survival time model, PTLD-free survival was significantly longer (0.104 years [95% CI 0.077-0.131]) in patients receiving rituximab as induction treatment. This study provides novel data on the association of rituximab induction and reduced risk for PTLD.

Expanded utilization of rituximab in paediatric cardiac transplant patients

WHAT IS KNOWN AND OBJECTIVE

Epstein-Barr virus (EBV) viraemia and autoimmune cytopenias (AICs) are significant complications that occur following paediatric solid organ transplantation. A variety of treatment methods have been investigated but limited research has focused on the utilization of rituximab in paediatric cardiac transplant recipients for these indications. Rituximab is a monoclonal antibody that binds the CD20 antigen on the surface of B-type lymphocytes resulting in B-cell cytotoxicity. It is considered a second-line therapy for treatment of autoimmune cytopenias and EBV viraemia following adult solid organ transplant (SOT) and haematopoietic stem cell transplant (HSCT). However, data for its use in the paediatric population for treatment of autoimmune cytopenias are lacking. Dosing is based on adult studies, and the frequency and length of therapy associated with resolution of EVB viraemia and AICs in paediatric cardiac transplant recipients is unknown. The objective of this retrospective study was to describe the dosing and length of therapy of expanded off-label use of rituximab for the management of refractory EBV viraemia and AICs, specifically in paediatric cardiac transplant patients.

METHODS

A retrospective chart review was conducted evaluating children <18 years of age who underwent cardiac transplantation, were diagnosed with EBV viraemia or autoimmune cytopenia, and subsequently received treatment with rituximab between June 1995 and October 2018. Data were analysed descriptively.

RESULTS AND DISCUSSION

Of all (n = 188) paediatric cardiac transplant recipients since 1995, 10 patients met the inclusion/exclusion criteria. Primary diagnoses were EBV viraemia (n = 6), immune haemolytic anaemia (n = 3) and immune thrombocytopenic purpura (n = 1). Complete responses were observed in 83.3% and 100% of patients with EVB viraemia and AICs treated with rituximab, respectively. All patients (n = 10) received rituximab 325 mg/m² at weekly intervals. The number of total doses associated with complete resolution was 4-6 doses for EBV viraemia and 2-4 doses for AICs. The most common adverse events reported were neutropenia (n = 3), thrombocytopenia (n = 4), infusion reactions (n = 1) and significant anaemia (n = 2).

WHAT IS NEW AND CONCLUSION

Although the efficacy of rituximab for treatment of EBV viraemia and autoimmune cytopenia in the paediatric cardiac transplant population remains unclear, our study supported the benefit of rituximab when added to therapy for treatment of EBV viraemia and ACIs.

High-intensity interval training in allogeneic adoptive T-cell immunotherapy - a big HIT?

Background

Adoptive transfer of virus-specific T cells (VSTs) represents a prophylactic and curative approach for opportunistic viral infections and reactivations after transplantation. However, inadequate frequencies of circulating memory VSTs in the T-cell donor’s peripheral blood often result in insufficient enrichment efficiency and purity of the final T-cell product, limiting the effectiveness of this approach.

Methods

This pilot study was designed as a cross-over trial and compared the effect of a single bout (30 min) of high-intensity interval training (HIT) with that of 30 min of continuous exercise (CONT) on the frequency and function of circulating donor VSTs. To this end, we used established immunoassays to examine the donors’ cellular immune status, in particular, with respect to the frequency and specific characteristics of VSTs restricted against Cytomegalovirus (CMV)-, Epstein–Barr-Virus (EBV)- and Adenovirus (AdV)-derived antigens. T-cell function, phenotype, activation and proliferation were examined at different time points before and after exercise to identify the most suitable time for T-cell donation. The clinical applicability was determined by small-scale T-cell enrichment using interferon- (IFN-) γ cytokine secretion assay and virus-derived overlapping peptide pools.

Results

HIT proved to be the most effective exercise program with up to fivefold higher VST response. In general, donors with a moderate fitness level had higher starting and post-exercise frequencies of VSTs than highly fit donors, who showed significantly lower post-exercise increases in VST frequencies. Both exercise programs boosted the number of VSTs against less immunodominant antigens, specifically CMV (IE-1), EBV (EBNA-1) and AdV (Hexon, Penton), compared to VSTs against immunodominant antigens with higher memory T-cell frequencies.

Conclusion

This study demonstrates that exercise before T-cell donation has a beneficial effect on the donor’s cellular immunity with respect to the proportion of circulating functionally active VSTs. We conclude that a single bout of HIT exercise 24 h before T-cell donation can significantly improve manufacturing of clinically applicable VSTs. This simple and economical adjuvant treatment proved to be especially efficient in enhancing virus-specific memory T cells with low precursor frequencies.

Malignancy after lung transplantation

Lung transplantation is an established therapeutic option for selected patients with advanced lung diseases. As early outcomes after lung transplantation have improved, chronic medical illnesses have emerged as significant obstacles to long-term survival. Among them is post-transplant malignancy, currently representing the 2^nd most common cause of death 5–10 years after transplantation. Chronic immunosuppressive therapy and resulting impairment of anti-tumor immune surveillance is thought to have a central role in cancer development after solid organ transplantation (SOT). Lung transplant recipients receive more immunosuppression than other SOT populations, likely contributing to even higher risk of cancer among this group. The most common cancers in lung transplant recipients are non-melanoma skin cancers, followed by lung cancer and post-transplant lymphoproliferative disorder (PTLD). The purpose of this review is to outline the common malignancies following lung transplant, their risk factors, prognosis and current means for both prevention and treatment.

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.

Immunoglobulin abnormalities in 1677 solid organ transplant recipients. Implications for posttransplantation follow-up

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a severe complication of solid organ transplantation (SOT). However, there is no consensus on PTLD screening methods. Gammopathies (GP), which occur in 10-25% of SOT recipients, have been linked to subsequent development of PTLD. Therefore, GP detection methods, such as serum protein electrophoresis (SPE), serum protein immunofixation (SIFE), urine protein immunofixation (UIFE) and the quantitative measurement of serum free light chains (SFLC) are candidate methods for PTLD screening.

OBJECTIVE

We aimed to assess the frequency of PTLD and GP, association of GP with subsequent PTLD, allograft loss or death and the diagnostic performance of SPE/SIFE in PTLD screening. The main objective was to explore, whether GP detection methods can be used to enhance the efficiency of PTLD screening and to formulate a concise algorithm for posttransplantation (post-Tx) follow-up.

METHODS

We performed a cohort study on 1677 SOT recipients with SPE/SIFE data who underwent kidney, liver, heart, pancreas, Langerhans islets or multiple organ transplantation at the Institute of Clinical and Experimental Medicine between 1966 and 2015. The median (IQR) of follow-up time was 8.0 (4.0-12.0) years.

RESULTS

The frequencies of PTLD and GP in SOT recipients were 2.8% and 6.4%, respectively. The frequencies of transient GP, GP of undetermined significance and malignant GP were 33%, 63% and 4% respectively. The median time between SOT and GP detection was 2.0 (interquartile range 1.0-7.0) years. GP was associated with a significantly higher risk of PTLD, allograft loss and death, with hazard ratios (95% confidence intervals) of a 6.06 (2.51-14.64), 2.61 (1.49-4.6) and 1.99 (1.2-3.3), respectively. Additionally, GP was associated with 2.98-fold increased risk of allograft loss in kidney transplant patients. SPE diagnostic sensitivity and specificity for PTLD were 14.8% and 93.9%, respectively. PTLD was diagnosed more often and earlier if SPE/SIFE was included in the post-Tx follow-up.

CONCLUSIONS

GP after SOT is associated with a high risk of PTLD, allograft loss and poor survival. The combination of SPE, SIFE, SFLC and UIFE is optimal for GP detection. These methods aid in identifying patients who are at risk for PTLD or allograft damage and should be included in regular post-Tx follow-up.

Post-transplant lymphoproliferative disorders, Epstein-Barr virus infection, and disease in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

PTLD with the response-dependent sequential use of RIS, rituximab, and cytotoxic chemotherapy is recommended. Evidence gaps requiring future research and alternate treatment strategies including immunotherapy are highlighted.

Incidence, risk factors, and clinical significance of Epstein-Barr virus reactivation in myelodysplastic syndrome after allogeneic haematopoietic stem cell transplantation

Epstein-Barr virus (EBV) reactivation is a life-threatening complication after allogeneic haematopoietic stem cell transplantation (allo-HSCT). In this study, we investigated the characteristics of EBV reactivation in 186 consecutive myelodysplastic (MDS) patients who underwent allo-HSCT in our centre. In 35 patients (18.8%) who experienced EBV reactivation after allo-HSCT, the median onset was 53 days (range 4-381 days). The cumulative incidence of EBV reactivation at the first, sixth, and twelfth month after allo-HSCT was 10.7%, 15.1%, and 17.9%, respectively. Twenty-five patients (71.4%) received pre-emptive rituximab therapy, and no patients developed post-transplant lymphoproliferative disorders. Stem cell source was proven to be a risk factor correlated with EBV reactivation. The cumulative incidence of relapse in the EBV-positive group was 11.4%, 25.2%, and 31.0% at the first, second, and third year after transplantation, respectively, being significantly higher than the corresponding 6.8%, 10.2%, and 10.2%, in the EBV-negative group (P = 0.014). Prognostic analysis showed that EBV reactivation was an independent risk factor for relapse-free survival (RFS). Patients in the EBV-positive group showed obviously shorter RFS than those in the EBV-negative group, with 3-year RFS of 62% and 85%, respectively (P = 0.017).

Spanish Lymphoma Group (GELTAMO) guidelines for the diagnosis, staging, treatment, and follow-up of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) accounts for approximately 30% of non-Hodgkin lymphoma (NHL) cases in adult series. DLBCL is characterized by marked clinical and biological heterogeneity, encompassing up to 16 distinct clinicopathological entities. While current treatments are effective in 60% to 70% of patients, those who are resistant to treatment continue to die from this disease. An expert panel performed a systematic review of all data on the diagnosis, prognosis, and treatment of DLBCL published in PubMed, EMBASE and MEDLINE up to December 2017. Recommendations were classified in accordance with the Grading of Recommendations Assessment Development and Evaluation (GRADE) framework, and the proposed recommendations incorporated into practical algorithms. Initial discussions between experts began in March 2016, and a final consensus was reached in November 2017. The final document was reviewed by all authors in February 2018 and by the Scientific Committee of the Spanish Lymphoma Group GELTAMO.

Comprehensive review of post-organ transplant hematologic cancers

A higher risk for a variety of cancers is among the major complications of posttransplantation immunosuppression. In this part of a continuing series on cancers posttransplantation, this review focuses on the hematologic cancers after solid organ transplantation. Posttransplantation lymphoproliferative disorders (PTLDs), which comprise the great majority of hematologic cancers, represent a spectrum of conditions that include, but are not limited to, the Hodgkin and non-Hodgkin lymphomas. The oncogenic Epstein-Barr virus is a key pathogenic driver in many PTLD cases, through known and unknown mechanisms. The other hematologic cancers include leukemias and plasma cell neoplasms (multiple myeloma and plasmacytoma). Clinical features vary across malignancies and location. Preventive screening strategies have been attempted mainly for PTLDs. Treatments include the chemotherapy regimens for the specific cancers, but also include reduction of immunosuppression, rituximab, and other therapies.

Personalized adoptive immunotherapy for patients with EBV-associated tumors and complications: Evaluation of novel naturally processed and presented EBV-derived T-cell epitopes

Morbidity and mortality of immunocompromised patients are increased by primary infection with or reactivation of Epstein-Barr virus (EBV), possibly triggering EBV⁺ post-transplant lymphoproliferative disease (PTLD). Adoptive transfer of EBV-specific cytotoxic T cells (EBV-CTLs) promises a non-toxic immunotherapy to effectively prevent or treat these complications. To improve immunotherapy and immunomonitoring this study aimed at identifying and evaluating naturally processed and presented HLA-A*03:01-restricted EBV-CTL epitopes as immunodominant targets. More than 15000 peptides were sequenced from EBV-immortalized B cells transduced with soluble HLA-A*03:01, sorted using different epitope prediction tools and eleven candidates were preselected. T2 and Flex-T peptide-binding and dissociation assays confirmed the stability of peptide-MHC complexes. Their immunogenicity and clinical relevance were evaluated by assessing the frequencies and functionality of EBV-CTLs in healthy donors (n > 10) and EBV⁺ PTLD-patients (n = 5) by multimer staining, Eli- and FluoroSpot assays. All eleven peptides elicited EBV-CTL responses in the donors. Their clinical applicability was determined by small-scale T-cell enrichment using Cytokine Secretion Assay and immunophenotyping. Mixtures of these peptides when added to the EBV Consensus pool revealed enhanced stimulation and enrichment efficacy. These EBV-specific epitopes broadening the repertoire of known targets will improve manufacturing of clinically applicable EBV-CTLs and monitoring of EBV-specific T-cell responses in patients.

Posttransplant Lymphoproliferative Disease Presenting as an Extracranial Mass

Posttransplant lymphoproliferative disease is a serious complication following stem cell and solid organ transplantation. Early recognition of the disease is important in facilitating timely therapy and improving long-term outcomes. We report a renal transplant recipient presenting with an extracranial frontoparietal soft tissue mass that was subsequently diagnosed as a B-cell lymphoma. The patient was treated successfully with immunosuppression reduction, anti-CD20 monoclonal antibody therapy, and cytotoxic chemotherapy. Our case highlights the importance of recognizing soft tissue masses in the head and neck as a potential clinical manifestation of PTLD in solid organ transplant recipients.

A French Cohort Study of Kidney Retransplantation after Post-Transplant Lymphoproliferative Disorders

BACKGROUND AND OBJECTIVES

Post-transplant lymphoproliferative disorders arising after kidney transplantation portend an increased risk of morbidity and mortality. Retransplantation of patients who had developed post-transplant lymphoproliferative disorder remains questionable owing to the potential risks of recurrence when immunosuppression is reintroduced. Here, we investigated the feasibility of kidney retransplantation after the development of post-transplant lymphoproliferative disorder.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We reviewed the data from all patients who underwent kidney retransplantation after post-transplant lymphoproliferative disorder in all adult kidney transplantation centers in France between 1998 and 2015.

RESULTS

We identified a total of 52 patients with kidney transplants who underwent 55 retransplantations after post-transplant lymphoproliferative disorder. The delay from post-transplant lymphoproliferative disorder to retransplantation was 100±44 months (28-224); 98% of patients were Epstein-Barr virus seropositive at the time of retransplantation. Induction therapy for retransplantation was used in 48 patients (i.e., 17 [31%] patients received thymoglobulin, and 31 [57%] patients received IL-2 receptor antagonists). Six patients were also treated with rituximab, and 53% of the patients received an antiviral drug. The association of calcineurin inhibitors, mycophenolate mofetil, and steroids was the most common maintenance immunosuppression regimen. Nine patients were switched from a calcineurin inhibitor to a mammalian target of rapamycin inhibitor. One patient developed post-transplant lymphoproliferative disorder recurrence at 24 months after retransplantation, whereas post-transplant lymphoproliferative disorder did not recur in 51 patients.

CONCLUSIONS

The recurrence of post-transplant lymphoproliferative disorder among patients who underwent retransplantation in France is a rare event.

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.

Daunting but Worthy Goal: Reducing the De Novo Cancer Incidence After Transplantation

Solid-organ transplant recipients are at increased risk of developing de novo malignancies compared with the general population, and malignancies become a major limitation in achieving optimal outcomes. The prevention and the management of posttransplant malignancies must be considered as a main goal in our transplant programs. For these patients, immunosuppression plays a major role in oncogenesis by both impairement of immunosurveillance, enhancement of chronic viral infection, and by direct prooncogenic effects. It is essential to manage the recipient with a long-term adapted screening program beginning before transplantation to use a prophylaxis to decrease infection-related cancer, to propose a viral monitoring, and to modulate the immunosuppression toward lower doses especially for calcineurin inhibitors. Indeed, strategies to induce tolerance or to allow a dramatic reduction of the immunosuppression burden are the more promising approaches for the reduction of the posttransplant malignancies.

Increased risk of PTLD in lung transplant recipients with cystic fibrosis

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is an important cause of morbidity and mortality following lung transplantation. Recipients with cystic fibrosis (CF) may have an increased risk of PTLD although the literature is limited to single center cohorts. Our primary aim is to examine PTLD in an adult lung transplant population by utilizing the International Society for Heart and Lung Transplantation Registry.

METHODS

We studied 30,598 adult recipients of lung transplants performed between 1999 and 2011. The primary outcome was development of and time to PTLD. In addition to indication for transplant, other predictors examined included Epstein-Barr virus (EBV) and cytomegalovirus (CMV) serostatus, gender, and age. Outcomes were assessed with univariable and multivariable Cox proportional hazard models to obtain hazard ratios (HR).

RESULTS

17% of the cohort had a diagnosis of CF. PTLD developed in 2% of CF recipients compared to 1% for non-CF recipients (p<0.001). Compared to non-CF recipients, CF recipients had higher prevalence of EBV and CMV seronegativity and higher prevalences of high risk EBV and CMV mismatch (D+/R-). There is a significant association between CF and the development of PTLD [HR 1.66 (95% CI 1.30-2.12)]. Stratified multivariable analysis controlling for age revealed EBV negative non-CF recipients have an almost 2 fold increased risk of developing PTLD, whereas EBV negative CF recipients had an almost 6.5 fold increased risk.

CONCLUSIONS

CF recipients have a higher risk for PTLD compared to non-CF recipients. Further studies are needed to account for additional risk factors and management in this population post-transplant.

The Epstein-Barr virus DNA load in the peripheral blood of transplant recipients does not accurately reflect the burden of infected cells

Transplant recipients frequently exhibit an increased Epstein-Barr virus (EBV) load in the peripheral blood. Here, we quantitated the EBV-infected cells in the peripheral blood of these patients and defined the mode of viral infection, latent or lytic. These data indicated that there is no strong correlation between the number of infected cells and the EBV load (EBVL). This can be explained by a highly variable number of EBV copies per infected cell and by lytic replication in some cells. The plasma of these patients did not contain any free infectious viruses, but contained nevertheless EBV DNA, sometimes in large amounts, that probably originates from cell debris and contributed to the total EBVL. Some of the investigated samples carried a highly variable number of infected cells in active latency, characterized by an expression of the Epstein-Barr nuclear antigens (EBNA2) protein. However, a third of the samples expressed neither EBNA2 nor lytic proteins. Patients with an increased EBVL represent a heterogeneous group of patients whose infection cannot be characterized by this method alone. Precise characterization of the origin of an increased EBVL, in particular, in terms of the number of EBV-infected cells, requires additional investigations including the number of EBV-encoded small RNA-positive cells.

Post-transplant lymphoproliferative disorders

Post-transplant lymphoproliferative disorders (PTLDs) are a group of conditions that involve uncontrolled proliferation of lymphoid cells as a consequence of extrinsic immunosuppression after organ or haematopoietic stem cell transplant. PTLDs show some similarities to classic lymphomas in the non-immunosuppressed general population. The oncogenic Epstein-Barr virus (EBV) is a key pathogenic driver in many early-onset cases, through multiple mechanisms. The incidence of PTLD varies with the type of transplant; a clear distinction should therefore be made between the conditions after solid organ transplant and after haematopoietic stem cell transplant. Recipient EBV seronegativity and the intensity of immunosuppression are among key risk factors. Symptoms and signs depend on the localization of the lymphoid masses. Diagnosis requires histopathology, although imaging techniques can provide additional supportive evidence. Pre-emptive intervention based on monitoring EBV levels in blood has emerged as the preferred strategy for PTLD prevention. Treatment of established disease includes reduction of immunosuppression and/or administration of rituximab (a B cell-specific antibody against CD20), chemotherapy and EBV-specific cytotoxic T cells. Despite these strategies, the mortality and morbidity remains considerable. Patient outcome is influenced by the severity of presentation, treatment-related complications and risk of allograft loss. New innovative treatment options hold promise for changing the outlook in the future.

Post-transplant lymphoproliferative disorder in adult renal transplant recipients: survival and prognosis

Post-transplant lymphoproliferative disorder (PTLD) is a rare, serious complication following solid organ transplantation, with an incidence of 2.6 cases per 1000 patient years. Optimal treatment strategies and risk stratifications specific to kidney transplantation are lacking and PTLD mortality remains high. This study investigated survival and prognosis in 89 cases of PTLD presenting over 44 years at Manchester Royal Infirmary. Patient survival following diagnosis was 72% at 6 months, 67% at 1 year and 54% at 3 years. In multivariate analysis, a poorer 3 year survival was associated with acute kidney injury at diagnosis (p = 0.0001), impaired renal function (p = 0.04), early onset (p = 0.02), T cell disease (p = 0.02) and previous treatment with anti-thymocyte globulin (p = 0.04). The inclusion of graft function adds prognostic value to risk stratification and should be explored further. Strategies to improve survival should include timing and choice of immuno-chemotherapy, preparation for dialysis and aggressive surveillance for sepsis and treatment toxicity.

Current Management Concepts: Primary Central Nervous System Lymphoma, Natural Killer T-Cell Lymphoma Nasal Type, and Post-transplant Lymphoproliferative Disorder

Primary central nervous system lymphoma, natural killer T-cell lymphoma nasal type, and post-transplant lymphoproliferative disorder are uncommon and complex lymphoproliferative disorders. These disorders present with different risk factors, have complex tumor characteristics, and require unique therapeutic interventions. These diseases require a multidisciplinary complex team approach. This article will update current management approaches and concepts.

Epstein-Barr Virus-Positive Posttransplant Lymphoproliferative Disease After Solid Organ Transplantation: Pathogenesis, Clinical Manifestations, Diagnosis, and Management

Posttransplant lymphoproliferative disease (PTLD) is a potentially fatal complication after (solid organ) transplantation, which is highly associated with Epstein-Barr virus (EBV). The EBV-specific cytotoxic T cell response that is essential in controlling the virus in healthy individuals is suppressed in transplant recipients using immunosuppressive drugs. A primary EBV infection in EBV-seronegative patients receiving an EBV-seropositive donor organ or a reactivation in those who are already latently infected pretransplantation can lead to uninhibited growth of EBV-infected B cells and subsequently to PTLD. Effective preventive strategies, such as vaccines and antiviral agents, are lacking. Because not every transplant recipient with increasing EBV viral load develops PTLD, it is hard to decide how intensively these patients should be monitored and how and when a preemptive intervention should take place. There is a need for other tools to help predict the development of PTLD in patients at risk to make timing and strategy of preemptive intervention easier and more reliable.

The cornerstone of the treatment of patients with PTLD is restoring the host's immunity by reduction of immunosuppressive drug therapy. American and British guidelines recommend to add rituximab monotherapy or rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisolone, depending on histology and clinical characteristics. Although response to these therapies is good, toxicity is a problem, and PTLD still has a relatively high mortality rate. An evolving therapy, especially in PTLD occurring in allogeneic stem cell transplantation, is restoring the host's immune response with infusion of EBV-specific cytotoxic T cells. This may also play a role in the future in both prevention and treatment of PTLD in SOT.

How I treat posttransplant lymphoproliferative disorders

Posttransplant lymphoproliferative disorder (PTLD) is a potentially fatal disorder arising after solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT). Iatrogenically impaired immune surveillance and Epstein-Barr virus (EBV) primary infection/reactivation are key factors in the pathogenesis. However, current knowledge on all aspects of PTLD is limited due to its rarity, morphologic heterogeneity, and the lack of prospective trials. Furthermore, the broad spectrum of underlying immune disorders and the type of graft represent important confounding factors. Despite these limitations, several reviews have been written aimed at offering a guide for pathologists and clinicians in diagnosing and treating PTLD. Rather than providing another classical review on PTLD, this "How I Treat" article, based on 2 case reports, focuses on specific challenges, different perspectives, and novel insights regarding the pathogenesis, diagnosis, and treatment of PTLD. These challenges include the wide variety of PTLD presentation (making treatment optimization difficult), the impact of EBV on pathogenesis and clinical behavior, and the controversial treatment of Burkitt lymphoma (BL)-PTLD.

Current preventive strategies and management of Epstein-Barr virus-related post-transplant lymphoproliferative disease in solid organ transplantation in Europe. Results of the ESGICH Questionnaire-based Cross-sectional Survey

There is limited clinical evidence on the utility of the monitoring of Epstein-Barr virus (EBV) DNAemia in the pre-emptive management of post-transplant lymphoproliferative disease (PTLD) in solid organ transplant (SOT) recipients. We investigated current preventive measures against EBV-related PTLD through a web-based questionnaire sent to 669 SOT programmes in 35 European countries. This study was performed on behalf of the ESGICH study group from the European Society of Clinical Microbiology and Infectious Diseases. A total of 71 SOT programmes from 15 European countries participated in the study. EBV serostatus of the recipient is routinely obtained in 69/71 centres (97%) and 64 (90%) have access to EBV DNAemia assays. EBV monitoring is routinely used in 85.9% of the programmes and 77.4% reported performing pre-emptive treatment for patients with significant EBV DNAemia levels. Pre-emptive treatment for EBV DNAemia included reduction of immunosuppression in 50.9%, switch to mammalian target of rapamycin inhibitors in 30.9%, and use of rituximab in 14.5% of programmes. Imaging by whole-body 18-fluoro-deoxyglucose positron emission tomography (FDG-PET) is used in 60.9% of centres to rule out PTLD and complemented computer tomography is used in 50%. In 10.9% of centres, FDG-PET is included in the first-line diagnostic workup in patients with high-risk EBV DNAemia. Despite the lack of definitive evidence, EBV load measurements are frequently used in Europe to guide diagnostic workup and pre-emptive reduction of immunosuppression. We need prospective and controlled studies to define the impact of EBV monitoring in reducing the risk of PTLD in SOT recipients.

Post-transplant lymphoproliferative disorders

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