Epstein-Barr virus-induced posttransplant lymphoproliferative disorders. ASTS/ASTP EBV-PTLD Task Force and The Mayo Clinic Organized International Consensus Development Meeting

Differences between xenotransplantation and allogeneic kidney transplantation: the current situation and future challenges in Japan

Kidney transplantation is the only curative option for patients with chronic renal failure, significantly improving their survival and quality of life. However, this treatment remains limited by the shortage of organ donors. The shortage of kidney donors remains a serious problem all over the world, and is particularly severe in Japan. While advancements in immunosuppressive therapies and histocompatibility testing have improved outcomes in allogeneic kidney transplantation, the rising number of dialysis patients has worsened the gap between the demand for and supply of suitable donor organs. In response to this pressing need, xenotransplantation has gained attention as a promising alternative solution. Recent progress driven by gene-editing technologies, including CRISPR-Cas9, has facilitated the development of genetically modified pigs suitable for potential human transplantation. This review provides an overview of the key differences in immune response and infection risks between xenogeneic and allogeneic kidney transplants. In addition, it comprehensively examines the challenges and potential of xenogeneic kidney transplantation from multiple perspectives, including differences in immunosuppressive therapies between allogeneic and xenogeneic transplantation. We also discuss the feasibility of xenogeneic kidney transplantation as a solution to the organ shortage in Japan and present directions for addressing challenges toward clinical application. We hope this review will provide valuable insights into the potential of xenogeneic kidney transplantation as a new treatment option for chronic renal failure and contribute to efforts to address the donor shortage problem in Japan.

Frontiers and Controversies in De Novo Gastrointestinal Tumors After Organ Transplantation: Current Progress and Future Directions

The increasing success of organ transplantation has significantly improved survival for patients with end-stage diseases, yet it introduces a complex dilemma: the elevated risk for the development of de novo gastrointestinal (GI) tumors. The sustained immunosuppression required to maintain graft function paradoxically undermines the body's natural defenses against cancer, leading to a higher incidence, aggressive progression, and atypical presentations of GI tumors among transplant recipients compared with the general population. This presents a pressing challenge: balancing the dual imperatives of preventing graft rejection and effectively managing malignancies. Current treatment paradigms, including surgical approaches, chemotherapy, radiation therapy, and the emerging role of immunotherapy, are fraught with complexities due to the altered immune landscape in these patients. This review underscores the critical need to understand the multifaceted relationship between post-transplantation immunosuppression and tumorigenesis, providing a comprehensive exploration of epidemiologic shifts, pathophysiologic insights, and the intricacies of the tumor microenvironment in this unique patient population. Understanding and managing GI tumors in transplant recipients is not only a clinical challenge, but also a necessary frontier in transplant oncology, promising to refine therapeutic strategies and improve the longevity and quality of life for this growing patient cohort.

Predictors of Posttransplant Lymphoproliferative Disease in Pediatric Patients

OBJECTIVE

Posttransplant lymphoproliferative disorder (PTLD) is a complication of pediatric solid organ transplantation. Benign adenotonsillar lymphoid hyperplasia confounds the ability to diagnose PTLD. Our aim was to identify factors that predict the presence of PTLD to inform decision-making regarding adenotonsillectomy.

METHODS

The electronic medical records at a quaternary children's hospital were queried over a 23-year period (2000-2023) for solid organ transplant patients that underwent tonsillectomy and/or adenoidectomy. Demographics, clinical presentation, and EBV serologies were analyzed to determine factors associated with presence of PTLD on final pathology.

RESULTS

A total of 114 patients met inclusion criteria for analysis. Thirty-two of the 114 patients (28.1%) who underwent tonsillectomy and/or adenoidectomy had PTLD. Age at transplant, age at biopsy, sex, race, and type of organ transplanted were not found to be associated with development of PTLD. Patients with PTLD were more likely to have smaller tonsils, sore throat, fever, and tonsillar exudate; they were less likely to experience sleep disordered breathing. The immunosuppression agent used for induction and the number of maintenance immunosuppressive medications were not associated with the development of PTLD. Increased Epstein-Barr Virus (EBV) PCR copy number correlated to increased risk of developing PTLD (p < 0.003).

CONCLUSION

Tonsillar hypertrophy and sleep disordered breathing are not necessarily indicative of the presence of PTLD. Suspicion for adenotonsillar PTLD should be based on symptomatology, clinical exam, EBV serologies, and degree of EBV PCR positivity. Sore throat, fever, tonsillar exudates, and significant elevation in EBV PCR copy number are particularly concerning for PTLD.

LEVEL OF EVIDENCE

3 Laryngoscope, 2025.

Mechanistic Understanding of EBV+Lymphoproliferative Disease Development After Transplantation

Posttransplant lymphoproliferative disorders (PTLDs) are among the most common malignant complications after transplantation, leading to a drastic reduction in patient survival rates. The majority of PTLDs are tightly linked to Epstein-Barr virus (EBV+PTLDs) and are the result of an uncontrolled proliferation of EBV-infected cells. However, although EBV infections are a common finding in transplant recipients, most patients with high EBV loads will never develop EBV+PTLD. Natural killer cells and EBV-specific CD8+ T lymphocytes are critical for controlling EBV-infected cells, and the impairment of these cytotoxic immune responses facilitates the unfettered proliferation of EBV-infected cells. Recent years have seen a considerable increase in available literature aiming to describe novel risk factors associated with the development of EBV+PTLD, which may critically relate to the strength of EBV-specific natural killer cell and EBV-CD8+ T lymphocyte responses. The accumulation of risk factors and the increased risk of developing EBV+PTLD go hand in hand. On the one hand, most of these risk factors, such as the level of immunosuppression or the EBV donor and recipient serologic mismatch, and distinct genetic risk factors are host related and affect cytotoxic EBV-specific immune responses. On the other hand, there is growing evidence that distinct EBV variants may have an increased malignant potential and are thus more likely to induce EBV+PTLD. Here, we aim to review, from a mechanistic point of view, the risk factors for EBV+PTLD in the host and the infecting EBV variants that may explain why only a minority of transplant recipients develop EBV+PTLD.

Cytokine Storm Syndromes Associated with Epstein-Barr Virus

Epstein-Barr virus (EBV) is a ubiquitous and predominantly B cell tropic virus. One of the most common viruses to infect humans, EBV, is best known as the causative agent of infectious mononucleosis (IM). Although most people experience asymptomatic infection, EBV is a potent immune stimulus and as such it elicits robust proliferation and activation of the B-lymphocytes it infects as well as the immune cells that respond to infection. In certain individuals, such as those with inherited or acquired defects affecting the immune system, failure to properly control EBV leads to the accumulation of EBV-infected B cells and EBV-reactive immune cells, which together contribute to the development of often life-threatening cytokine storm syndromes (CSS). Here, we review the normal immune response to EBV and discuss several CSS associated with EBV, such as chronic active EBV infection, hemophagocytic lymphohistiocytosis, and post-transplant lymphoproliferative disorder. Given the critical role for cytokines in driving inflammation and contributing to disease pathogenesis, we also discuss how targeting specific cytokines provides a rational and potentially less toxic treatment for EBV-driven CSS.

Influence of De Novo Malignancies on Long-Term Survival after Lung Transplantation

(1) Background: Malignancies are an important cause of mortality after solid organ transplantation. The purpose of this study was to analyze the incidence of malignancies in patients receiving lung transplants (LT) and their influence on patients' survival. (2) Methods: Review of consecutive LT from 1994 to 2021. Patients with and without malignancies were compared by univariable and multivariable analyses. Survival was compared with Kaplan-Meier and Cox regression analysis. (3) Results: There were 731 LT malignancies developed in 91 patients (12.4%) with related mortality of 47% (n = 43). Native lung cancer, digestive and hematological malignancies were associated with higher lethality. Malignancies were more frequent in males (81%; p = 0.005), transplanted for emphysema (55%; p = 0.003), with cyclosporine-based immunosuppression (58%; p < 0.001), and receiving single LT (65%; p = 0.011). Survival was worse in patients with malignancies (overall) and with native lung cancer. Risk factors for mortality were cyclosporine-based immunosuppression (OR 1.8; 95%CI: 1.3-2.4; p < 0.001) and de novo lung cancer (OR 2.6; 95%CI: 1.5-4.4; p < 0.001). (4) Conclusions: Malignancies are an important source of morbidity and mortality following lung transplantation that should not be neglected. Patients undergoing single LT for emphysema are especially at higher risk of mortality due to lung cancer in the native lung.

Lymphoproliferative disorders after renal transplantation along 2 decades: a large longitudinal study of 21.546 recipients

INTRODUCTION

Post transplant lymphoproliferative disorders (PTLD) are heterogeneous lymphoid proliferations in recipients of solid organs which seem to be related to Epstein Barr Virus (EBV). The use of antilymphocyte antibodies, EBV seronegativity in the recipient,acute rejection and CMV infection have been identified as classical risk factors.

MATERIAL Y METHODS

We have studied in a retrospective observational study, the incidence of PTLD in a period of 22 years, its relationship with EBV, presence of classical risk factors and outcome in 21546 simple adult renal transplant recipients from cadaveric and living donors, transplanted in 21 hospitals from 1990 to 2009.

RESULTS

A total of 275 recipients developed PTLD (1,2%),195 males (70,9%), 80 females (29,1%) aged 59.2 (p25 44.7 p75 68)years. Two hundred forty-five (89.0%) were 1st transplant recipients and 269 (97,8%) from cadaveric donors. EBV in the tissue was reported in 94 out of the 155 studied recipients (60.6%) and 86.0% of the proliferations were due to B lymphocytes. PTLD median appearance after transplant were 42.months (p25, 75, 12, 77, 5). One hundred eighty-eight recipients out of 275 patients (68.3%) had any classical risk factor and the use of antilymphocyte antibodies was the most frequent. During the follow-up, 172 patients died (62,5%) and 103 (37,5%) had a complete remission. The main cause of death was PTLD progression (n = 91, 52,9%), followed by sepsis (n = 24, 13,9%). The follow-up period post-transplant of the recipients was between 3 and 22 years. The incidence was 0,14% during the first year post-trasplant and 0.98% the cumulative incidence at 10 years. Patient survival after diagnosis was 51%, 44% and 39% after 1, 2 and 5 years, respectively. Finally, overall graft survival was 48%, 39% and 33% at the same periods.

CONCLUSION

PTLD has a low incidence in renal transplant recipients. Most of the proliferations are due to B lymphocytes and seem to have a close relationship with EBV. PTLD can develop in the absence of classical risk factors. The prognosis is poor, mainly due to PTLD progression, but the survivors can even maintain their grafts.

Impact of Epstein-Barr virus infection in patients with inflammatory bowel disease

A high prevalence of Epstein-Barr virus (EBV) infection in patients with inflammatory bowel disease (IBD) has been reported in many case reports and studies; thus, the association between EBV and IBD has gained increasing attention. Patients with IBD are at an increased risk of opportunistic EBV infection owing to the common use of immunomodulators. EBV infection in IBD patients can cause various complications, including superimposed viral colitis, which is associated with chronicity, exacerbation, and poor prognosis of refractory IBD, and can induce progression to lymphoproliferative disorders, such as EBV-positive mucocutaneous ulcer (EBVMCU), lymphomatoid granulomatosis (LYG), hemophagocytic lymphohistiocytosis (HLH) and diffuse large B-cell lymphoma (DLBCL). It has been suggested to screen for EBV before initiating immunosuppressive therapy and monitor the status of EBV infection in patients with IBD, especially those who are EBV-seronegative and have a risk of primary EBV infection. Clinicians should also be careful of misdiagnosing IBD and EBV-associated lymphoproliferative diseases due to similarities in both clinical symptoms and endoscopic manifestations. Withdrawal of immunosuppressants has been shown to be an effective strategy to achieve remission of disease at the time of EBV diagnosis, but antiviral therapy remains controversial. The present review aims to describe the characteristics of the complications caused by EBV infection and generalize the recent research progress on and challenges caused by EBV infection in IBD patients. The literature for writing this review was collected from 'PubMed' research engine. The keywords 'inflammatory bowel disease and Epstein-Barr virus' or 'ulcerative colitis and Epstein-Barr virus' or 'Crohn's disease and Epstein-Barr virus' were used to collect the literature and relevant papers were collected to help writing this review.

Epstein-Barr virus perpetuates B cell germinal center dynamics and generation of autoimmune-associated phenotypes in vitro

Human B cells encompass functionally diverse lineages and phenotypic states that contribute to protective as well as pathogenic responses. Epstein-Barr virus (EBV) provides a unique lens for studying heterogeneous B cell responses, given its adaptation to manipulate intrinsic cell programming. EBV promotes the activation, proliferation, and eventual outgrowth of host B cells as immortalized lymphoblastoid cell lines (LCLs) in vitro, which provide a foundational model of viral latency and lymphomagenesis. Although cellular responses and outcomes of infection can vary significantly within populations, investigations that capture genome-wide perspectives of this variation at single-cell resolution are in nascent stages. We have recently used single-cell approaches to identify EBV-mediated B cell heterogeneity in de novo infection and within LCLs, underscoring the dynamic and complex qualities of latent infection rather than a singular, static infection state. Here, we expand upon these findings with functional characterizations of EBV-induced dynamic phenotypes that mimic B cell immune responses. We found that distinct subpopulations isolated from LCLs could completely reconstitute the full phenotypic spectrum of their parental lines. In conjunction with conserved patterns of cell state diversity identified within scRNA-seq data, these data support a model in which EBV continuously drives recurrent B cell entry, progression through, and egress from the Germinal Center (GC) reaction. This "perpetual GC" also generates tangent cell fate trajectories including terminal plasmablast differentiation, which constitutes a replicative cul-de-sac for EBV from which lytic reactivation provides escape. Furthermore, we found that both established EBV latency and de novo infection support the development of cells with features of atypical memory B cells, which have been broadly associated with autoimmune disorders. Treatment of LCLs with TLR7 agonist or IL-21 was sufficient to generate an increased frequency of IgD-/CD27-/CD23-/CD38+/CD138+ plasmablasts. Separately, de novo EBV infection led to the development of CXCR3+/CD11c+/FCRL4+ B cells within days, providing evidence for possible T cell-independent origins of a recently described EBV-associated neuroinvasive CXCR3+ B cell subset in patients with multiple sclerosis. Collectively, this work reveals unexpected virus-driven complexity across infected cell populations and highlights potential roles of EBV in mediating or priming foundational aspects of virus-associated immune cell dysfunction in disease.

CD30+ Lymphoproliferative Disorders as Potential Candidates for CD30-Targeted Therapies

CONTEXT.—

In the early 1980s, a monoclonal antibody termed Ki-1 was developed against a cell line derived from a patient with Hodgkin lymphoma. This antibody detected a limited number of benign activated lymphocytes in lymphoid tissue, whereas in Hodgkin lymphoma it appeared to be nearly specific for Reed-Sternberg cells and their mononuclear variants. Subsequent studies showed that Ki-1 expression defined a new type of lymphoma that was later designated anaplastic large cell lymphoma with or without anaplastic large cell kinase expression/translocation. In the past 30 years, numerous new lymphoma entities have been defined, many of which are variably positive for CD30. Many virally transformed lymphoproliferative disorders are also frequently positive for CD30.

OBJECTIVE.—

To illustrate the broad spectrum of CD30+ hematologic malignancies and to provide an update of CD30-targeted therapies.

DATA SOURCES.—

Personal experiences and published works in PubMed.

CONCLUSIONS.—

Because of its low expression in normal tissue, CD30 was studied as a therapeutic target for many years. However, the first functional humanized antibody against CD30 was developed only about 10 years ago. Brentuximab vedotin is a humanized anti-CD30 antibody linked to a cytotoxin, and was approved by the US Food and Drug Administration in 2012 for treating refractory Hodgkin lymphoma and anaplastic large cell lymphoma. Since then, the list of Food and Drug Administration-approved CD30-targeted hematologic malignancies has grown. Recently, the therapies using tumor antigen-specific chimeric antigen receptor T cells targeting CD30 have incited a great deal of enthusiasm and are studied in clinical trials.

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.

Post-transplant lymphoproliferative disease after pediatric kidney transplant

Post-transplant lymphoproliferative disease (PTLD) is the most common malignancy complicating solid organ transplantation (SOT) in adults and children. PTLD encompasses a spectrum of histopathologic features and organ involvement, ranging from benign lymphoproliferation and infectious-mononucleosis like presentation to invasive neoplastic processes such as classical Hodgkin lymphoma. The predominant risk factors for PTLD are Epstein-Barr virus (EBV) serostatus at the time of transplant and the intensity of immunosuppression following transplantation; with EBV-negative recipients of EBV-positive donor organs at the highest risk. In children, PTLD commonly presents in the first two years after transplant, with 80% of cases in the first year, and over 90% of cases associated with EBV-positive B-cell proliferation. Though pediatric kidney transplant recipients are at lower risk (1-3%) for PTLD compared to their other SOT counterparts, there is still a significant risk of morbidity, allograft failure, and an estimated 5-year mortality rate of up to 50%. In spite of this, there is no consensus for monitoring of at-risk patients or optimal management strategies for pediatric patients with PTLD. Here we review pathogenesis and risk factors for the development of PTLD, with current practices for prevention, diagnosis, and management of PTLD in pediatric kidney transplant recipients. We also highlight emerging concepts, current research gaps and potential future developments to improve clinical outcomes and longevity in these patients.

Cancer After Pediatric Kidney Transplantation: A Long-term Single-center Experience in Japan

Background

The cancer incidence, types, and risk factors after pediatric kidney transplantation (KT) have been reported in the United States, Canada, Europe, Australia, and New Zealand. However, no information is available about cancer in pediatric KT recipients in Asian countries.

Methods

Children aged <20 y who underwent initial KT from 1983 to 2016 were analyzed. We compared the cancer incidence with that in the general Japanese population using standardized incidence ratio and examined posttransplant cancer risk using Cox proportional hazards models.

Results

A total of 356 children (median age, 11.7 y; interquartile range, 5.0-17.6) received KT with a follow-up period of 4466 person-years. The median age of cancer onset was 18.5 y (interquartile range, 8.0-32.3), and 13 cancers occurred in 12 patients (3.4%). Two patients died from cancer. The most common cancers were posttransplant lymphoproliferative disorders (PTLDs) (38.5%). The median time to PTLD and non-PTLD diagnosis after KT was 0.6 and 16.4 y, respectively. There was no occurrence of skin cancer. The posttransplant cancer incidence was 9.9 times higher than that in the general age-matched population (standardized incidence ratio = 9.9; 95% confidence interval, 4.80-18.39). The cumulative cancer incidence was 5.3% in 20 y after KT, which is lower than that reported in previous studies. We could not identify any risk factors for all cancer after KT in all patients, whereas subgroup analysis in 264 patients with available data of recipient Epstein-Barr virus serological status showed that recipient Epstein-Barr virus-negative serology was an independent risk factor for cancer development.

Conclusions

The incidence of cancer is higher in Japanese pediatric KT recipients than in the general population. The cumulative incidence of cancer after KT was lower in our population than that previously reported. This may be because there was no skin cancer observed in the Japanese pediatric KT recipients in our study.

Dysregulation of miRNAs in DLBCL: Causative Factor for Pathogenesis, Diagnosis and Prognosis

MicroRNA is a small non-coding RNA (sncRNA) involved in gene silencing and regulating post-transcriptional gene expression. miRNAs play an essential role in the pathogenesis of numerous diseases, including diabetes, cardiovascular diseases, viral diseases and cancer. Diffuse large B-cell lymphoma (DLBCL) is an aggressive non-Hodgkin's lymphoma (NHL), arising from different stages of B-cell differentiation whose pathogenesis involves miRNAs. Various viral and non-viral vectors are used as a delivery vehicle for introducing specific miRNA inside the cell. Adenoviruses are linear, double-stranded DNA viruses with 35 kb genome size and are extensively used in gene therapy. Meanwhile, Adeno-associated viruses accommodate up to 4.8 kb foreign genetic material and are favorable for transferring miRNA due to small size of miRNA. The genetic material is integrated into the DNA of the host cell by retroviruses so that only dividing cells are infected and stable expression of miRNA is achieved. Over the years, remarkable progress was made to understand DLBCL biology using advanced genomics and epigenomics technologies enabling oncologists to uncover multiple genetic mutations in DLBCL patients. These genetic mutations are involved in epigenetic modification, ability to escape immunosurveillance, impaired BCL6 and NF-κβ signaling pathways and blocking terminal differentiation. These pathways have since been identified and used as therapeutic targets for the treatment of DLBCL. Recently miRNAs were also identified to act either as oncogenes or tumor suppressors in DLBCL pathology by altering the expression levels of some of the known DLBCL related oncogenes. i.e., miR-155, miR-17-92 and miR-21 act as oncogenes by altering the expression levels of MYC, SHIP and FOXO1, respectively, conversely; miR-34a, mir-144 and miR-181a act as tumor suppressors by altering the expression levels of SIRT1, BCL6 and CARD11, respectively. Hundreds of miRNAs have already been identified as biomarkers in the prognosis and diagnosis of DLBCL because of their significant roles in DLBCL pathogenesis. In conclusion, miRNAs in addition to their role as biomarkers of prognosis and diagnosis could also serve as potential therapeutic targets for treating DLBCL.

Posttransplant Lymphoproliferative Disorder Status Post-Solid Organ Transplant Presenting to the Emergency Department: Single Institute Experience

OBJECTIVE

The objective of this study was to evaluate the clinical, laboratory, imaging, and pathology findings associated with emergency department presentations of posttransplant lymphoproliferative disorder (PTLD) after solid organ transplant (SOT).

METHODS

Fifteen patients presenting to a single tertiary care center between 2004 and 2019 with PTLD after SOT were identified from a pathology database. Twelve patients presenting through the emergency department were included in the study. Demographic, clinical, imaging, pathology, treatment, and outcome data were reviewed.

RESULTS

Among this 12 patient cohort (7 men; mean age, 44.2 years), transplant history included 4 combined kidney/pancreas, 4 kidney, 2 liver, 1 cardiac, and 1 lung. Mean time from transplant to diagnosis was 7.6 years. Posttransplant lymphoproliferative disorder was identified on initial computed tomography scans in 10 of 12 patients. The most common sites for PTLD development were the gastrointestinal tract (4/12) and liver (3/12). Outcomes included resolution of PTLD in 9 of 12 patients, with 3 patients dying within 6 months of diagnosis.

CONCLUSIONS

Posttransplant lymphoproliferative disorder is a serious consequence of solid organ transplantation that can present in various locations and with varied symptomatology in the emergency setting. Other posttransplant complications may present similarly including chronic rejection and infection. Posttransplant lymphoproliferative disorder should be considered in SOT patients presenting with worsening abdominal pain or constitutional symptoms, even with normal laboratory workup.

Treatment of post-transplant lymphoproliferative disorder (PTLD) in a heart transplant recipient with chimeric antigen receptor T-cell therapy

Post-transplant lymphoproliferative disorders (PTLD) are a group of lesions that can complicate solid organ or hematopoietic stem cell transplantation and are often associated with Epstein-Barr virus (EBV). The treatment of PTLD is dependent on the type of lesion and includes a wide range of therapies, but chimeric antigen receptor (CAR) T-cell therapy has not previously been reported as a treatment option for PTLD. We present a patient who developed refractory PTLD in her right retroperitoneum, right inguinal and iliac chains, and right axillary region shortly after heart transplantation and was treated with CAR T-cell therapy. She could not tolerate complete discontinuation of immunosuppression due to the risk of rejection of a life-supporting graft. The patient's PTLD responded to CAR T-cell therapy, and her heart was monitored throughout the treatment course without any signs of rejection or ventricular dysfunction. CAR T-cell therapy may be a viable treatment option in patients who develop PTLD after a solid organ transplant.

Oral diseases after liver transplantation: a systematic review and meta-analysis

Objective To conduct a systematic review and meta-analysis to evaluate the impact of liver transplantation on the occurrence and frequency of oral diseases in humans.Data sources The study query was performed on Medline/PubMed, Ovid, Cochrane Library and Embase databases, including the grey literature.Data selection Observational studies comparing the frequency of oral manifestations in post-liver transplantation patients versus reference population were eligible for inclusion.Data extraction and analysis The article selection, data extraction and quality assessment were executed by three independent investigators. A random-effects meta-analysis was carried out for computation of relative risks of oral malignancies (standardised incidence ratio [SIR] and 95% confidence interval [CI]).Data synthesis Among 248 studies identified, 11 met the eligibility criteria and six were included in the meta-analysis. Opportunistic fungal infections (Candida spp.) and lesions with malignant potential were reported to be more frequently prevalent after liver transplantation. Calculations indicated that after liver transplantation, the patients have a fivefold increased risk for oral cancer occurrence compared to the general population (SIR = 5.006; 95% CI 2.803 to 8.94; p <0.001).Conclusions The findings suggest that liver transplantation increases the risk of oral malignancies and the frequency of other mucosal lesions.

Heterogeneous Manifestations of Posttransplant Lymphoma in Renal Transplant Recipients: A Case Series

Posttransplant lymphoproliferative disorder (PTLD) occurs in 1% to 3% of adult renal transplant recipients (RTRs). PTLD has a heterogeneous presentation and is often associated with Epstein-Barr virus (EBV) and immunosuppression. We present a descriptive case series of 16 RTRs who demonstrate a variety of PTLD manifestations. Fifty-six percent received rabbit antithymocyte globulin induction, and 37.5% received basiliximab. Maintenance immunosuppression included glucocorticoids, tacrolimus, and mycophenolate mofetil. Median time from transplantation to PTLD diagnosis was 96.5 months. PTLD involved a single site in 44% of RTRs and multiple sites in 56%. PTLD was localized to the gastrointestinal tract in 9 RTRs, in lymph nodes in 9, central nervous system in 4, bone marrow in 3, skin in 3, lungs in 2, perinephric space in 2, mediastinum in 1, and native kidney in 1. PTLD was EBV positive in 8 RTRs, monomorphic/monoclonal in 14, and of B-cell lineage in 13. Three RTRs had T-cell PTLD. Immunosuppressive agents, except glucocorticoids, were discontinued at diagnosis. Treatment was chemotherapy either alone (in 14 RTRs) or in combination with radiation. Complete remission was achieved in 62.5% of RTRs. Renal dysfunction developed in 62.5% of RTRs, and 4 received dialysis. The overall mortality rate was 62.5%, with median time of death 6.5 months after diagnosis. PTLD that was EBV negative and had T-cell involvement presented with aggressive disease and a higher mortality. Clinicians should be aware of the various PTLD manifestations. Early diagnosis and a multidisciplinary approach to treatment is crucial for improved patient outcomes.

Reduction of immunosuppression combined with whole-brain radiotherapy and concurrent systemic rituximab is an effective yet toxic treatment of primary central nervous system post-transplant lymphoproliferative disorder (pCNS-PTLD): 14 cases from the prospective German PTLD registry

Post-transplant lymphoproliferative disorders (PTLD) exclusively affecting the central nervous system-primary CNS-PTLD (pCNS-PTLD)-are rare. There is no standard therapy, and previous case series have included heterogeneous treatment approaches. We performed a retrospective, multi-centre analysis of 14 patients with pCNS-PTLD after solid organ transplantation (SOT) treated in the prospective German PTLD registry with reduction of immunosuppression (RI), whole-brain radiotherapy (WBRT), and concurrent systemic rituximab between 2001 and 2018. Twelve of fourteen patients were kidney transplant recipients and median age at diagnosis was 65 years. Thirteen of fourteen cases (93%) were monomorphic PTLD of the diffuse large B-cell lymphoma type, and 12/13 were EBV-associated. The median dose of WBRT administered was 40 Gy with a median fraction of 2 Gy. The median number of administered doses of rituximab (375 mg/m²) IV was four. All ten patients evaluated responded to treatment (100%). Median OS was 2.5 years with a 2-year Kaplan-Meier estimate of 63% (95% confidence interval 30-83%) without any recorded relapses after a median follow-up of 2.6 years. Seven of fourteen patients (50%) suffered grade III/IV infections under therapy (fatal in two cases, 14%). During follow-up, imaging demonstrated grey matter changes interpreted as radiation toxicity in 7/10 evaluated patients (70%). The combination of RI, WBRT, and rituximab was an effective yet toxic treatment of pCNS-PTLD in this series of 14 patients. Future treatment approaches in pCNS-PTLD should take into account the significant risk of infections as well as radiation-induced neurotoxicity.

The time-dependent effects of early-onset Epstein-Barr viremia on adult acute leukemia patients following allo-HSCT with ATG-containing MAC regimen

Epstein-Barr virus (EBV) viremia is a common complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The purpose of this study was to evaluate the impacts of early-onset EBV viremia in acute leukemia (AL) patients who underwent allo-HSCT with anti-thymocyte globulin (ATG)-containing myeloablative conditioning (MAC) regimen. Two hundred and ninety-six patients were included between January 2013 and December 2015. In 126 patients (42.6%) who developed early-onset EBV viremia, with a median time of 48 (range 18~99) days after allo-HSCT. The cumulative incidence of EBV viremia at 30 and 90 days after allo-HSCT were 4.1 and 39.9%, respectively. Prognostic analysis showed that the adjusted overall survival in early-EBV^pos group was significantly lower than early-EBV^neg group within the first 26.7 months after allo-HSCT [hazard ratio (HR), 1.63, P = 0.012], but significantly higher than those afterward (after 26.7 months: HR 0.11, P = 0.035); for the adjusted event-free survival, early-EBV^pos group was significantly inferior in early-EBV^pos group within the first 10.8 months after transplantation (HR: 1.55, P = 0.042), and this adverse effect was not detected any more after 10.8 months (HR: 0.58, P = 0.107). Compared with early-EBV^neg group after adjusting by aGVHD and CMV viremia, HR for death from transplant-related mortality was 2.78-fold higher in patients with early-EBV viremia in piecewise constant Cox analysis (P = 0.006), and this adverse effect was not detected any more after the cut-point time (HR: 0.67, P = 0.361). No differences in terms of relapse and relapse mortality were observed between early-EBV^pos and early-EBV^neg group (P > 0.05). In conclusion, the impacts on transplant outcomes of early-EBV viremia were time-dependent, which may help to optimize management strategies for early-EBV viremia after allo-HSCT, especially in AL patients with ATG-containing MAC regimen.

18F-FDG PET/CT for Evaluation of Post-Transplant Lymphoproliferative Disorder (PTLD)

Post-transplant lymphoproliferative disorders (PTLD) are a spectrum of heterogeneous lymphoproliferative conditions that are serious and possibly fatal complications after solid organ or allogenic hematopoietic stem cell transplantation. Most PTLD are attributed to Epstein-Barr virus reactivation in B-cells in the setting of immunosuppression after transplantation. Early diagnosis, accurate staging, and timely treatment are of vital importance to reduce morbidity and mortality. Given the often nonspecific clinical presentation and disease heterogeneity of PTLD, tissue biopsy and histopathological analysis are essential to establish diagnosis and most importantly, determine the subtype of PTLD, which guides treatment options. Advanced imaging modalities such as ¹⁸F-FDG PET/CT have played an increasingly important role and have shown high sensitivity and specificity in detection, staging, and assessing treatment response in multiple clinical studies over the last two decades. However, larger multicenter prospective validation is still needed to further establish the clinical utility of PET imaging in the management of PTLD. Significantly, new hybrid imaging modalities such as PET/MR may help reduce radiation exposure, which is especially important in pediatric transplant patients.

Post-renal transplant malignancies: Opportunities for prevention and early screening

GOAL OF THE REVIEW

While transplant recipients are aware of increased malignancy risk, there is little consensus on the preventative measures. The goal of this review is to bring available preventative measures to light and prompt more research to be done with ultimate goal of developing an individualized prevention plan for each patient based on risk factors and available screening tools.

INTRODUCTION

Transplant surgery offers patients with end-stage renal disease a longer life expectancy with help of immunosuppressive therapies. Nonetheless, life-long immunosuppression comes at a cost of post-renal transplant malignancies, which have become the leading cause of morbidity in this patient group.

DISCUSSION

Post-renal transplant cancers can develop through either de novo, by donor-related transmission, or recurrence of recipient's pre-transplant cancer. While immunosuppressive therapy is considered to be the leading cause, weakened immunosurveillance of neoplastic cells and inadequate immune response against oncogenic viruses also plays an important role. The most common cancers seen in renal transplant patients are skin cancers and post-transplant lymphoproliferative disorder (PTLD). Risk factors for skin cancers have are ultraviolet light, human papilloma virus infection, and use of cyclosporin and azathioprine. Numerous viral infections have been associated with transplant-related malignancies post-transplant.

CONCLUSION

While lowering of immunosuppressive therapy remains the treatment of choice, it may lead to graft failure. Given some of the presented malignancies have modifiable risk factors and options for screening, clinical outcomes can be improved. Limiting skin exposure, dermatologic screening, and prophylactic retinoids can help lower the incidence rate of skin malignancy. Endoscopic screening for renal transplant patients can help identify gastric adenocarcinoma early and improve survival rates. Some of the post-transplant malignancies have been responsive to anti-viral treatment.

A multicenter survey on post-transplant lymphoproliferative disorders in pediatric heart transplant recipients: A case for development of consensus guidelines for screening, surveillance, and treatment?

Post-transplant lymphoproliferative disorders (PTLD) are the main malignancy seen after pediatric heart transplant and are a significant cause of morbidity and mortality. Prior to the development of detailed guidelines, we sought to identify trends in screening, diagnosis, and treatment of pediatric PTLD. All Pediatric Heart Transplant Society (PHTS) institutions were surveyed. No identifiable patient information was shared. From 56 PHTS centers, 22 responses were received (39.3%). 100% agree PTLD cannot be diagnosed solely based on elevated Epstein-Barr virus (EBV) load. All respondents routinely screen for EBV by blood PCR, but frequency of screening varies. There was intermediate consensus regarding the use of computed tomography (CT) and/or positron emission tomography (PET) in surveillance management for PTLD. Most centers require a diagnostic biopsy before initiating new treatment for PTLD (14 of 18, 77.8%), but many reduce immune suppression based on elevated EBV without pathologic PTLD (16 of 22, 72.7%). Beyond immune modulation, rituximab is most commonly used (9 of 13, 69.2%). Consultation with oncology is common (17 of 17, 100%), but timing varies widely. Our survey highlights significant elements of agreement and significant practice variation among PHTS institutions regarding pediatric PTLD. Reduction of immune suppression prior to pathologic diagnosis of PTLD is a common management strategy. When this fails, rituximab is used, but is most often reserved until after confirmation of the diagnosis. Oncology subspecialists are commonly involved in these cases. Our findings highlight the need to develop improved guidelines for evaluation and treatment of pediatric PTLD.

Posttransplant Lymphoproliferative Disorder in Pediatric Patients: Characteristics of Disease in EBV-seropositive Recipients

BACKGROUND

Patients at greatest risk of posttransplant lymphoproliferative disorder (PTLD) are those who acquire primary Epstein-Barr virus (EBV) infection after solid organ transplantation. The incidence of PTLD among patients who are EBV-seropositive before transplant is lower, and little is known about the differences in presentation and outcome of this population. We describe the characteristics of EBV-seropositive transplant recipients (R+) who developed PTLD and compare survival outcomes with EBV-seronegative recipients (R-).

METHODS

A hospital-based registry was used to identify all patients with biopsy-proven PTLD for the period 2000-2014. Characteristics and outcomes were compared between R+ and R- patients with PTLD.

RESULTS

Sixty-nine patients were included, among which 20 (29.0%) were R+ and 49 (71.0%) were R-. Multiorgan transplant patients accounted for 25% of PTLD cases in R+ patients, while accounting for only 2.1% of all transplants during the study period. There was no difference in PTLD site between R+ and R- patients. PTLD among R+ individuals occurred during the second year after transplant (median: 1.92; range: 0.35-3.09 y) compared with during the first year for R- individuals (median: 0.95; range: 0.48-2.92 y; P = 0.380). There was a trend for a higher overall mortality among R+ individuals (log rank: 0.09). PTLD-related mortality did not differ between R+ and R- individuals (log rank: 0.17).

CONCLUSIONS

PTLD among R+ individuals was more likely to occur among multiorgan recipients, and there was a tendency for poorer outcomes at 1 and 5 years after the diagnosis of PTLD.

Biological Difference Between Epstein-Barr Virus Positive and Negative Post-transplant Lymphoproliferative Disorders and Their Clinical Impact

Epstein–Barr virus (EBV) infection is correlated with several lymphoproliferative disorders, including Hodgkin disease, Burkitt lymphoma, diffuse large B-cell lymphoma (DLBCL), and post-transplant lymphoproliferative disorder (PTLD). The oncogenic EBV is present in 80% of PTLD. EBV infection influences immune response and has a causative role in the oncogenic transformation of lymphocytes. The development of PTLD is the consequence of an imbalance between immunosurveillance and immunosuppression. Different approaches have been proposed to treat this disorder, including suppression of the EBV viral load, reduction of immune suppression, and malignant clone destruction. In some cases, upfront chemotherapy offers better and durable clinical responses. In this work, we elucidate the clinicopathological and molecular-genetic characteristics of PTLD to clarify the biological differences of EBV(+) and EBV(–) PTLD. Gene expression profiling, next-generation sequencing, and microRNA profiles have recently provided many data that explore PTLD pathogenic mechanisms and identify potential therapeutic targets. This article aims to explore new insights into clinical behavior and pathogenesis of EBV(–)/(+) PTLD with the hope to support future therapeutic studies.

Limited Utility of Serology and Heterophile Test in the Early Diagnosis of Epstein-Barr Virus Mononucleosis in a Child after Renal Transplantation

Background: Epstein-Barr virus (EBV) infection is associated with significant morbidity and mortality in renal transplant (RT) recipients. The spectrum of illness ranges from infectious mononucleosis (IM) to post-transplant lymphoproliferative disorder (PTLD). In association with clinical signs and symptoms, virus-specific serology and heterophile antibody tests are widely used in confirming the diagnosis of IM in the general population. However, these tests may have a limited role in immunosuppressed RT recipients from seropositive donor, especially in children who were EBV-seronegative prior to the transplant. The aim of this study is to evaluate the utility of these tests in the early diagnosis of IM in this subset of patients. Methods: This is a case study with a review of literature. Results: Here, we present a 14-year-old male with hemophilia B who presented with fever, fatigue, sore throat, palatal petechial rash, exudative tonsillitis and cervical lymphadenopathy 3 months post-RT. He was EBV seronegative prior to RT and received a deceased donor kidney transplant from a seropositive donor. Induction was done with Thymoglobulin and maintenance immunosuppression consisted of tacrolimus and mycophenolate. Initial heterophile antibody test (monospot) was negative, but became positive at 5 months and remained positive at 9 months follow-up post-RT. EBV viral capsid antigens (VCA) IgM and IgG, early antigen (EA) and nuclear antigen (EBNA) were all negative at the time of presentation. VCA IgM and IgG both became positive at 5 months and peaked at 9 months follow-up, however the EA and EBNA remained negative. EBV viral load as measured by polymerase chain reaction (PCR) was negative for the first 3 months post-RT but became positive at presentation, peaked at 6 months and started declining thereafter. Peripheral blood smear examination showed no absolute and atypical lymphocytosis. Cytomegalovirus PCR in the blood and throat culture for streptococcus were negative. There was no splenomegaly. He was managed conservatively with intravenous fluids, bed rest, antipyretics and reduction of immunosuppression. Conclusions: EBV serological markers have a limited role in the early diagnosis of EBV-IM following RT in prior seronegative children. Initial heterophile antibody test may also be negative, and hence a repeat test may be necessary. Once becoming positive, the VCA IgM may remain persistently elevated for prolonged duration. In addition to the suppressed cellular immunity secondary to immunosuppression, humoral response to viral infections is also delayed in transplant recipients, especially in the early transplant period. Hence, routine monitoring with PCR is superior to serology in diagnosing IM early and monitoring the EBV infection post-RT for timely evaluation and management.

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.

Immunosuppression Is Associated With Clinical Features and Relapse Risk of B Cell Posttransplant Lymphoproliferative Disorder: A Retrospective Analysis Based on the Prospective, International, Multicenter PTLD-1 Trials

BACKGROUND

Current guideline recommendations for immunosuppression reduction after diagnosis of posttransplant lymphoproliferative disorder (PTLD) include stopping antimetabolites, reducing calcineurin inhibitors, and maintaining corticosteroids. However, the effect of immunosuppression on PTLD relapse risk after up-to-date therapy is unclear.

METHODS

This is a retrospective analysis of immunosuppression, patient baseline characteristics, and relapse risk measured as landmark time to progression (TTP) starting 1 year after start of therapy in 159 patients with B cell PTLD after solid organ transplantation treated in the prospective, international, multicenter PTLD-1 trials with either sequential treatment (rituximab followed by cyclophosphamide (CHOP-21 chemotherapy) 750 mg/m intravenously [IV] day (d) 1, doxorubicin 50 mg/m IV d1, vincristine 1.4 mg/m (maximum, 2 mg) IV d1, and prednisone 50 mg/m PO d1-5, every 21 days) or risk-stratified sequential treatment (rituximab followed by rituximab or rituximab (R-CHOP-21 immunochemotherapy) 375 mg/m IV day (d) 1, cyclophosphamide 750 mg/m IV d1, doxorubicin 50 mg/m IV d1, vincristine 1.4 mg/m (max. 2 mg) IV d1, and prednisone 50 mg/m PO d1-5, every 21 days).

RESULTS

Patient baseline characteristics at diagnosis of PTLD differed significantly depending on immunosuppression before diagnosis. Compared with immunosuppression before diagnosis, significantly fewer patients received an antimetabolite or a calcineurin inhibitor (CNI) after diagnosis of PTLD. Relapse risk measured as landmark TTP was significantly higher for patients on corticosteroids compared to all others (P = 0.010) as well as for patients on ciclosporin compared with those on tacrolimus (P = 0.002), but similar for those on antimetabolites compared with all others (P = 0.912). In a Cox regression analysis of landmark TTP, corticosteroid-containing immunosuppression after diagnosis of PTLD (P = 0.002; hazard ratio, 11.195) and age (P = 0.001; hazard ratio, 1.076/year) were identified as independent, significant risk factors for PTLD relapse.

CONCLUSIONS

In the prospective PTLD-1 trials, corticosteroid use after diagnosis of PTLD is associated with an increased risk of relapse, whereas the use of antimetabolites is not. These findings require prospective validation.

Renal transplantation and predisposition to opportunistic infections

PURPOSE OF REVIEW

Infections represent a significant source of morbidity and mortality after kidney transplantation in children. We review recent advances in epidemiology, assessment, prevention and treatment for several different infections.

RECENT FINDINGS

Infections, such as bacterial urinary tract infection or opportunistic viral infection remain common, may be increasing and represent a large proportion of hospitalization. Extended antiviral agent use reduces the incidence of cytomegalovirus disease but its efficacy to reduce Epstein-Barr virus disease remains controversial. Human herpesvirus-6 and hepatitis E virus represent new infections to keep in mind. Ureteral stenting increases the rate of early UTI. Several new vaccines are now available, but rates of complete vaccination pretransplant are low.

SUMMARY

Infections remain a critical posttransplant issue associated with significant medical burdens. Emerging data on associated risk factors, assessment of and treatment for infections provide clinicians with new knowledge.

Incidence of Neoplasia in Pigs and Its Relevance to Clinical Organ Xenotransplantation

As clinical pig organ xenotransplantation draws closer, more attention is being paid to diseases that affect pigs and those that provide a potential risk to human recipients of pig organs. Neoplasia arising from the pig organ graft is one such concern. Various tumors and other neoplastic diseases are well known to show increased incidence in organ allotransplant recipients receiving immunosuppressive therapy. Whether this effect will prove to be the case after xenotransplantation has not yet been established. Malignant tumors in young pigs are rare, with lymphosarcoma, nephroblastoma, and melanoma being the most common. The combination of noninvasive techniques and intraoperative examination of the pig organ likely will readily confirm that a pig organ graft is tumor-free before xenotransplantation. Posttransplantion lymphoproliferative disorder (PTLD) is a concern after allotransplantation, but the incidence after solid organ allotransplantation is low when compared with hematopoietic cell allotransplantation (for example, bone marrow transplantation), unless immunosuppressive therapy is particularly intensive. Organ-source pigs used for clinical xenotransplantation will be bred and housed under designated pathogen-free conditions and will be free of the γ-herpesvirus that is a key factor in the development of PTLD in pigs. Therefore if a recipient of a pig xenograft develops PTLD, it will almost certainly be of recipient origin. The increasing availability of organs from pigs genetically-engineered to protect them from the human immune response likely will diminish the need for intensive immunosuppressive therapy. Considering the low incidence of malignant disease in young pigs, donor-derived malignancy is likely to be rare in patients who receive pig organ grafts. However, if the graft remains viable for many years, the incidence of graft malignancy may increase.

Opportunities to Target the Life Cycle of Epstein-Barr Virus (EBV) in EBV-Associated Lymphoproliferative Disorders

Many lymphoproliferative disorders (LPDs) are considered "EBV associated" based on detection of the virus in tumor tissue. EBV drives proliferation of LPDs via expression of the viral latent genes and many pre-clinical and clinical studies have shown EBV-associated LPDs can be treated by exploiting the viral life cycle. After a brief review of EBV virology and the natural life cycle within a host we will discuss the importance of the viral gene programs expressed during specific viral phases, as well as within immunocompetent vs. immunocompromised hosts and corresponding EBV-associated LPDs. We will then review established and emerging treatment approaches for EBV-associated LPDs based on EBV gene expression programs. Patients with EBV-associated LPDs can have a poor performance status, multiple comorbidities, and/or are immunocompromised from organ transplantation, autoimmune disease, or other congenital or acquired immunodeficiency making them poor candidates to receive intensive cytotoxic chemotherapy. With the emergence of EBV-directed therapy there is hope that we can devise more effective therapies that confer milder toxicity.

Will donor-derived neoplasia be problematic after clinical pig organ or cell xenotransplantation?

There is an increased incidence of certain tumors and other neoplastic disease in organ allotransplant recipients receiving immunosuppressive therapy. Following clinical pig organ xenotransplantation, will there be a risk of the development of neoplasia in the pig graft or in other tissues transplanted with it, eg, lymph nodes? The incidence of neoplasia in young slaughterhouse pigs is very low (<0.005%), but in older pigs is largely unknown (as most pigs are killed within the first six months of life). However, lymphosarcoma, nephroblastoma, and melanoma have been reported in pigs. These tumors should be readily identified by ultrasound or direct inspection and palpation before an organ is excised for clinical xenotransplantation, and so transfer to the human recipient should be unlikely. Post-transplant lymphoproliferative disorder (PTLD) has been reported in pigs receiving intensive immunomodulatory therapy, particularly if this includes whole body irradiation, in an effort to induce mixed hematopoietic chimerism and immunological tolerance. However, the pigs used as sources of organs in xenotransplantation should be free of the porcine lymphotropic herpesvirus that is a key causative factor for PTLD in pigs, and so donor-derived PTLD should not occur. We conclude that the risk of a malignant tumor developing in a transplanted organ from a young pig is small.

Infection in Kidney Transplant Recipients

In organ transplant recipients, impaired inflammatory responses suppress the clinical and radiologic findings of infection. The possible etiologies of infection are diverse, ranging from common bacterial and viral pathogens that affect the entire community to opportunistic pathogens that cause invasive disease only in immunocompromised hosts. Antimicrobial therapies required to treat established infection are often complex, with accompanying risks for drug toxicities and drug interactions with the immunosuppressive agents used to maintain graft function. Rapid and specific diagnosis is essential for successful therapy. The risk of serious infections in the organ transplant patient is largely determined by the interaction between two factors: the patient’s epidemiologic exposures and the patient’s net state of immunosuppression. The epidemiology of infection includes environmental exposures and nosocomial infections, organisms derived from donor tissues, and latent infections from the recipient activated with immunosuppression. The net state of immune suppression is a conceptual framework that measures those factors contributing to risk for infection: the dose, duration, and temporal sequence of immunosuppressive drugs; the presence of foreign bodies or injuries to mucocutaneous barriers; neutropenia; metabolic abnormalities including diabetes; devitalized tissues, hematomas, or effusions postsurgery; and infection with immunomodulating viruses. Multiple factors are present in each host. A timeline exists to aid in the development of a differential diagnosis for infection. The timeline for each patient is altered by changes in prophylaxis and immunosuppressive drugs. For common infections, new microbiologic assays, often nucleic acid based, are useful in the diagnosis and management of opportunistic infections.

Prise en charge du transplanté rénal en réanimation

La transplantation rénale est la thérapeutique de choix de l’insuffisance rénale chronique au stade ultime, son usage est de plus en plus large. Les progrès réalisés dans les traitements immunosuppresseurs ont permis une amélioration de la durée de vie du greffon, mais au prix d’une augmentation des complications cardiovasculaires et infectieuses. Environ 5 % des transplantés rénaux présentent des complications sévères qui nécessitent une prise en charge intensive. Elles sont principalement de cause infectieuse et dominées par la défaillance respiratoire aiguë. L’insuffisance rénale aiguë est commune, elle affecte la fonction du greffon à court et long termes. La prise en charge en réanimation de ces complications doit prendre en compte le terrain particulier du transplanté rénal et les effets délétères de l’immunosuppression, condition nécessaire à une amélioration de la mortalité qui reste à plus de 30 %.

Posttransplant Lymphoproliferative Disorder: Experience from a Pediatric Nephrology Unit in North India

Posttransplant lymphoproliferative disorder (PTLD) is reported in 1%–3% among pediatric renal allograft recipients. We report the experience of PTLD among pediatric renal allograft recipients at a pediatric nephrology center in North India. Four cases of PTLD were identified from among records of 95 pediatric renal allograft recipients over a period of 21 years. Constitutional and localizing symptoms were present in three patients each. The diagnosis was suggested on positron emission tomography in three patients and confirmed by histopathology in all. Sites affected included tonsils, cervical lymph nodes, duodenum, and para-aortic lymph nodes in one patient each. The lymphocytic infiltrate was polymorphic in three patients and monomorphic in one. Immunostaining suggested B-cell origin in all patients. There was evidence of Epstein–Barr virus infection in only one patient. The patients were successfully managed with reduction of immunosuppression (in all), rituximab (in 3), and excision of affected tissue (in 1). Over a follow-up period of 30–88 months, there were no episodes of disease recurrence or allograft rejection, and renal function was preserved.

Diagnostic Performance and Comparative Evaluation of the Architect, Liaison, and Platelia Epstein-Barr Virus Antibody Assays

BACKGROUND

Epstein-Barr Virus (EBV) is one of the most prevalent causes of viral infection in humans. EBV infection stage (acute, past, or absent infection) is typically determined using a combination of assays that detect EBV-specific markers, such as IgG and IgM antibodies against the EBV viral capsid antigen (VCA) and IgG antibodies against the EBV nuclear antigen (EBNA). We compared the diagnostic performance and agreement of results between three commercial EBV antibody assays using an EBV performance panel (SeraCare Life Science, Milford, MA, USA) as a reference.

METHODS

EBV antibody tests of EBV VCA IgM, VCA IgG, and EBNA IgG antibodies were performed by the Architect (Abbott Diagnostics, Wiesbaden, Germany), Liaison (DiaSorin, Saluggia, Italy), and Platelia (Bio-Rad, Marnes-la-Coquette, France) assays. Agreement between the three assays was evaluated using 279 clinical samples, and EBV DNA and antibody test results were compared.

RESULTS

The three EBV antibody assays showed good diagnostic performance with good and excellent agreement with the performance panel (kappa coefficient, >0.6). The overall VCA IgM positivity rate was higher in EBV DNA-positive samples than in EBV DNA-negative samples for all three EBV antibody assays (P=0.02). The three EBV antibody assays exhibited good agreement in results for the clinical samples.

CONCLUSIONS

The diagnostic performance of the three EBV antibody assays was acceptable, and they showed comparable agreement in results for the clinical samples.

Etiology of increased cancer incidence after solid organ transplantation

Over the past decades, there has been an encouraging increase in survival after solid organ transplantation. However, with longer life spans, more transplant recipients are at risk of dying with functioning grafts from illnesses such as cancer and cardiovascular conditions. Malignancy has emerged as an important cause of death in transplant recipients and is expected to become the leading cause of death in transplanted patients within the next decade. While it is known that solid organ transplant recipients have a three to five-fold increased risk of developing cancer compared with the general population, the mechanisms that lead to the observed excess risk in transplant recipients are less clear. This review explores the etiology of the increased cancer incidence in solid organ transplant including the effect of immunosuppressants on immunosurveillance and activation of oncogenic viruses, and carcinogenic effects of these medications; the role of chronic stimulation of the immune system on the development of cancer; and the impact of pre-existing cancer risk factors and factors related to end-stage organ disease on the cancer excess incidence in solid organ transplant recipients.

Primary Central Nervous System Post-transplant Lymphoproliferative Disorder Diagnosed by Peripheral Facial Nerve Palsy

Although primary central nervous system post-transplant lymphoproliferative disorder (PCNS-PTLD) causes various symptoms depending on the tumor region, there has been no previous report of PCNS-PTLD in the cerebellopontine angle that was diagnosed due to peripheral facial nerve palsy. We herein report a case involving a 62-year-old man with PCNS-PTLD in the cerebellopontine angle who was diagnosed due to peripheral facial nerve palsy. The reduction of immunosuppressive therapy, whole-brain radiotherapy, intrathecal chemotherapy, and rituximab were effective in treating this patient. Physicians should therefore be mindful that PCNS-PTLD can cause peripheral facial nerve palsy in renal transplant recipients.

EBV-Associated Lymphoproliferative Disorder and Hemophagocytic Lymphohistiocytosis in a Patient with Severe Celiac Disease

Background

Epstein-Barr virus- (EBV-) associated lymphoproliferative disease (LPD) is a rare condition, usually occurring in immunocompromised patients. We report a case of EBV-associated LPD in a patient with severe celiac disease, the first report to describe this syndrome in a patient with this diagnosis.

Case Summary

A 69-year-old Caucasian woman with recent diagnosis of celiac sprue presented to our hospital with persistent diarrhea, abdominal pain, weight loss, and fatigue despite adherence to gluten-free diet for a number of weeks prior to presentation. She underwent evaluation for occult malignancy and was found to have diffuse intra-abdominal mesenteric lymphadenopathy on CT scan. Biopsy of mesenteric nodes revealed an EBV positive, CD20 positive mixed lymphoproliferative process with T-cell predominance, but without a monoclonal cell population felt to be consistent with EBV-associated LPD. Bone marrow biopsy revealed hemophagocytic lymphohistiocytosis, complicating her course. She was treated with steroids and rituximab but continued to decline, eventually developing MSSA bacteremia and succumbing to her disease.

Conclusion

To our knowledge, this is the first report of the constellation of celiac sprue, EBV-associated LPD, and hemophagocytic lymphohistiocytosis. Providers caring for patients with severe, uncontrolled celiac disease and adenopathy should consider EBV-associated LPD.

A rare cause of gastrointestinal bleeding in the post-transplant setting

Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication noted after solid organ transplantation and is frequently related to Epstein-Barr virus infection. The present case highlights an unusual presentation of PTLD - gastrointestinal bleeding - in the absence of systemic symptoms.

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.