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

Rare Case of Pediatric Post-transplant Lymphoproliferative Disorder Presenting With Pleural Masses Complicated by Pleural Effusions

Post-transplant lymphoproliferative disorder is a complication in organ transplant recipients characterized by uncontrolled proliferation of B-lymphocytes, occurring in 6% of pediatric patients, with risk factors including primary Epstein-Barr virus infection, intensity of immunosuppression, and cytomegalovirus infection. The clinical symptoms are often nonspecific, and it is associated with a high mortality rate if left untreated. We describe a rare case of post-transplant lymphoproliferative disorder who presented with pleural-based masses resulting in pleural effusions.

Evaluation of a Quantitative Dual-Target EBV DNA Test on a Fully Automated Molecular Testing System

The measurement of Epstein-Barr virus (EBV) deoxyribonucleic acid (DNA) is key to diagnosing and managing EBV-associated complications in transplant recipients. The performance of the new Conformité Européenne (CE) and Food and Drug Administration (FDA)-cleared quantitative Roche cobas EBV real-time PCR assay was determined by using EDTA-plasma dilution panels and clinical samples that were spiked with either the World Health Organization's EBV international standard or high-titer EBV lambda stock. Correlation with the Abbott Realtime EBV assay was assessed in clinical specimens and conducted at two independent laboratories. An in silico analysis revealed that the dual-target test (EBNA1 and BMRF2) was 100% inclusive for the known diversity of EBV. The overall limit of detection (LoD) was 16.6 IU/mL for genotype 1 (GT1). GT2 LoD was verified at 18.8 IU/mL. The linear ranges were from 1.40 × 101 to 2.30 × 108 IU/mL and from 2.97 × 101 to 9.90 × 107 IU/mL for GT1 and GT2, respectively. Accuracy was confirmed across the linear range (mean difference not exceeding ±0.18 log10). Precision was not influenced by the factors analyzed (standard deviation of 0.02 to 0.17 log10), including the presence of potentially interfering endogenous or exogenous substances. Plasma samples were stable under several conditions (variable time points, storage, and freeze/thaw cycles). In clinical EBV DNA-positive samples, correlation between the cobas EBV test and the comparator was high (n = 126 valid results; R2 = 0.96) with a 0.1 mean log10 titer difference. The cobas EBV test is an accurate, sensitive, specific, and reproducible assay for the detection of EBV DNAemia in plasma. In general, high levels of automation and calibration to the international standard will lead to improvements in the harmonization of quantitative EBV DNA test results across laboratories.

Current Perspectives on the Management of Herpesvirus Infections in Solid Organ Transplant Recipients

Solid organ transplant recipients (SOTRs) are at high risk of human herpesvirus (HHV)-related morbidity and mortality due to the use of immunosuppressive therapy. We aim to increase awareness and understanding of HHV disease burden in SOTRs by providing an overview of current prevention and management strategies as described in the literature and guidelines. We discuss challenges in both prevention and treatment as well as future perspectives.

An Effective Combination Therapy for the Treatment of Pediatric Monomorphic Post-transplant Lymphoproliferative Disorder With Plasmacytic Differentiation

Post-transplant lymphoproliferative disorder (PTLD) is a complication of immunosuppressive therapy following solid organ or hematopoietic cell transplantation. Initial treatment typically includes a reduction of immunosuppression with or without rituximab. However, the optimal therapy for PTLD with plasmacytic differentiation is unclear. We present 3 cases of pediatric patients with plasmacytic PTLD. Two patients received a standard rituximab-based approach and relapsed, prompting additional chemotherapy. The third patient was treated with a novel regimen of bortezomib, dexamethasone, and daratumumab. This regimen was safe, well-tolerated, and resulted in a 2-year remission. Larger studies are needed to further explore this regimen.

Minimizing the Risk of Donor-Derived Events and Maximizing Organ Utilization Through Education and Policy Development

Herein, we review the current knowledge of donor-derived disease and current US Organ Procurement and Transplantation Network policies to minimize the risk. During the process, we also consider actions to further mitigate the risk of donor-derived disease. The overarching goal is to provide an infectious disease perspective on the complex decision of organ acceptance for transplant programs and candidates.

Early Detection of Epstein-Barr Virus as a Risk Factor for Chronic High Epstein-Barr Viral Load Carriage at a Living-donor-dominant Pediatric Liver Transplantation Center

BACKGROUND

Epstein-Barr virus (EBV) infection and posttransplant lymphoproliferative disorders (PTLDs) after pediatric liver transplantation (LT) account for significant morbidity and mortality. Knowledge of EBV kinetics, epidemiology, and outcomes among pediatric living-donor LT cases is largely lacking. This study aims to provide clinical information related to EBV infection, chronic high EBV load (CHL) carriage, and PTLD at a living-donor-dominant pediatric LT center.

METHODS

A total of 5827 EBV load measurements from 394 LT recipients fulfilling inclusion criteria and their clinical data were analyzed. EBV loads >1000 copies/μg DNA (742 IU/μg DNA) were considered "high," and CHL was defined by persistence >6 mo.

RESULTS

The highlighted results were as follows: (1) 94% of recipients underwent living-donor LT; (2) 80% of EBV seronegative recipients developed first EBV infection <2 y post-LT, and their EBV loads were consistently higher than those of seropositive recipients within <3 y post-LT but did not differ thereafter; (3) 61 (15%) recipients met CHL criteria, but none developed PTLD; (4) age <5 y, cytomegalovirus seronegative donors, and early development of EBV DNAemia <6 mo post-LT were independent risk factors for CHL; (5) the incidence of rejections after 1-y post-LT was comparably low among CHL carriers whose immunosuppression was minimized.

CONCLUSIONS

Early detection of EBV following LT and CMV seronegative donors would facilitate risk stratification to prevent PTLD while titrating immunosuppression among pediatric LT recipients.

Future Comorbidities in an Aging Cystic Fibrosis Population

Cystic fibrosis (CF) is an autosomal recessive disease due to mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. With the advent of highly effective modulator therapy targeting the abnormal CFTR protein, people with CF (PwCF) are living more than 40 years longer than the pre-modulator therapy era. As a result, PwCF are facing new challenges of managing similar comorbidities affecting the average aging population. While CF is notoriously identified as a chronic respiratory disease, the multisystem presence of the CFTR gene can contribute to other organ-related complications acutely, but also heighten the likelihood of chronic conditions not routinely encountered in this cohort. In this overview, we will focus on risk factors and epidemiology for PwCF as they relate to cardiovascular disease, dyslipidemia, CF-related diabetes, pulmonary hypertension, obstructive sleep apnea, CF-liver disease, bone health and malignancy. With increased awareness of diseases affecting a newly aging CF population, a focus on primary and secondary prevention will be imperative to implementing a comprehensive care plan to improve long-term morbidity and mortality.

Hepatic Manifestations of Systemic Diseases

In addition to being the primary target of infections such as viral hepatitis, the liver may also be affected by systemic disease. These include bacterial, mycotic, and viral infections, as well as autoimmune and infiltrative diseases. These conditions generally manifest as abnormal liver biochemistries, often with a cholestatic profile, and may present with additional signs/symptoms such as jaundice and fever. A high index of suspicion and familiarity with potential causal entities is necessary to guide appropriate testing, diagnosis, and treatment.

Post-transplant Lymphoproliferative Disorder (PTLD) in the US Population: Demographics, Treatment Characteristics, and Survival Analysis

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a lymphoplasmacytic proliferative disorder in the setting of hematopoietic stem cells and solid organ transplants. PTLD is divided into nondestructive, polymorphic, monomorphic, and classical Hodgkin lymphoma subtypes. Most cases of PTLDs are Epstein-Barr virus (EBV) related (two third of the cases), and most are of B cell (80-85%) origin. The polymorphic PTLD subtype can be locally destructive and show malignant features. Treatment for PTLD includes a reduction in immunosuppression, surgery, cytotoxic chemotherapy and/or immunotherapy, anti-viral agents, and/or radiation. The aim of this study was to examine the demographic factors and treatment modalities that influence survival in patients with polymorphic PTLD.

METHODS

About 332 cases of polymorphic PTLD were identified from 2000 to 2018 using the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

The median age of the patients was found to be 44 years. The most common age groups were between the ages of 1-19 years (n=100. 30.1%) and 60-69 years (n=70. 21.1%). The majority of cases in this cohort underwent systemic (cytotoxic chemo and/or immuno) therapy only (n=137, 41.3%), while 129 (38.9%) cases did not undergo any treatment. The overall five-year observed survival was 54.6% (95% confidence interval (CI), 51.1 - 58.1). One-year and five-year survival with systemic therapy was 63.8% (95% CI, 59.6 - 68.0) and 52.5% (95% CI, 47.7 - 57.3), respectively. The one-year and five-year survival with surgery was 87.3% (95% CI, 81.2-93.4) and 60.8% (95% CI., 42.2 - 79.4), respectively. The one-year and five-year without therapy were 67.6% (95% CI, 63.2-72.0) and 49.6% (95% CI, 43.5-55.7), respectively. Univariate analysis revealed that surgery alone (hazard ratio (HR) 0.386 (0.170-0.879), p = 0.023) was a positive predictor of survival. Race and sex were not predictors of survival, although age >55 years was a negative predictor for survival (HR 1.128 (1.139-1.346), p <0.001).

CONCLUSION

Polymorphic PTLD is a destructive complication of organ transplantation that is usually associated with EBV positivity. We found that it most often presents in the pediatric age group, and its occurrence in those older than 55 years was associated with a worse prognosis. Treatment with surgery alone is associated with improved outcomes and should be considered in addition to a reduction in immunosuppression in cases of polymorphic PTLD.

Outcome of Brain Lymphoma in a High Epstein-Barr Virus-Prevalence Country After Kidney Transplantation

BACKGROUND

The incidence of post-transplant lymphoproliferative disorder (PTLD) in adult kidney transplant (KTx) recipients is less common in Taiwan. In our institute, we observed that brain lymphoma was the most notorious type.

METHODS

The study describes the clinical, histologic, and radiological features of primary central nervous lymphoma (PCNSL) and the outcomes and associations with Epstein-Barr virus (EBV) infection in our center.

RESULTS

Among 1470 KTx recipients, 5 patients had tissue-proven brain lymphoma (0.34%). The brain pathology disclosed diffuse large B-cell lymphoma in all patients. EBV was detected through in situ hybridization for Epstein-Barr encoding region (EBER) to disclose the EBV inclusion in the nuclei of lymphoma cells. The first treatment step was the reduction of immunosuppressants; 4 patients received whole-brain radiotherapy after complete resection of PCNSL, and 1 received concurrent chemoradiotherapy. Only one patient had poor performance status at the time of diagnosis and had a poor response to treatment with steroids. Four patients survived (mean 36.5 months, range 8.6 to 57.6 months), but one died after rapid neurologic deterioration.

CONCLUSION

Epstein-Barr virus inclusion was found in PCNSL in our patients; however, the role of EBV in PCNSL remains to be clarified. Post-transplant lymphoproliferative disorder is a rare malignancy after KTx with a predilection of brain involvement in Taiwan. We report a successful care experience in a patient with primary CNS lymphoma with better survival.

Infections after organ transplantation and immune response

Organ transplantation has provided another chance of survival for end-stage organ failure patients. Yet, transplant rejection is still a main challenging factor. Immunosuppressive drugs have been used to avoid rejection and suppress the immune response against allografts. Thus, immunosuppressants increase the risk of infection in immunocompromised organ transplant recipients. The infection risk reflects the relationship between the nature and severity of immunosuppression and infectious diseases. Furthermore, immunosuppressants show an immunological impact on the genetics of innate and adaptive immune responses. This effect usually reactivates the post-transplant infection in the donor and recipient tissues since T-cell activation has a substantial role in allograft rejection. Meanwhile, different infections have been found to activate the T-cells into CD₄⁺ helper T-cell subset and CD₈⁺ cytotoxic T-lymphocyte that affect the infection and the allograft. Therefore, the best management and preventive strategies of immunosuppression, antimicrobial prophylaxis, and intensive medical care are required for successful organ transplantation. This review addresses the activation of immune responses against different infections in immunocompromised individuals after organ transplantation.

Evaluation of host cellular responses to Epstein-Barr virus (EBV) in adult lung transplant patients with EBV-associated diseases

Epstein-Barr virus (EBV) reactivation is commonly observed in lung transplant recipients (LTRs). However, cellular immune responses to EBV in adult LTRs have not been well described. We aimed to study CD4/CD8 ratio, EBV-specific T cells polyfunctional responses and phenotypic changes in natural killer (NK) cells in adult LTRs presenting with EBV-associated diseases. The CD4/CD8 ratio was significantly decreased in LTRs with EBV DNAemia compared with LTRs without EBV DNAemia and healthy controls (HCs). Stimulation with EBV lytic antigen BZLF1 peptide pools induced significant individual and polyfunctional responses from CD8+ CD69+ T cells. Frequencies of CD8+ CD69+ T cells expressing CD107a were significantly higher in LTRs without EBV DNAemia than in LTRs with DNAemia. Frequencies of CD8+ CD69+ T cells concurrently expressing CD107a, IFN-γ, and TNF-α were significantly greater in LTRs with and without EBV DNAemia than in HCs. Finally, BZLF1 induced significantly higher frequencies of CD8+ CD69+ T cells expressing CD107a and IFN-γ in LTRs without EBV DNAemia when compared with EBNA3B. Frequency of more differentiated CD56dim CD16pos NK cells was significantly decreased in LTRs with EBV DNAemia and PTLD compared with HCs. In conclusion, we noted the presence of significant changes in circulating cellular immune responses to EBV in adult LTRs.

Post-transplant lymphoproliferative disorder: Update on treatment and novel therapies

Post-transplant lymphoproliferative disorder (PTLD) is rare and heterogeneous lymphoid proliferations that occur as a result of immunosuppression following solid organ transplant (SOT) and haematopoietic stem cell transplant (HSCT) with the majority being driven by EBV. Although some histologies are similar to lymphoid neoplasms seen in immunocompetent patients, treatment of PTLD may be different due to difference in pathobiology and higher risk of treatment complications. The most common treatment approach in SOT PTLD after failing immunosuppression reduction (RIS) takes into consideration a risk-stratified sequential algorithm with rituximab +/- chemotherapy based on phase 2 studies. In HSCT PTLD, RIS alone and chemotherapy are usually ineffective making rituximab +/- RIS as the gold standard of frontline treatment. In this review, we give an update on the treatment of PTLD beyond RIS. We highlight the most recent studies that attempted to incorporate more aggressive chemotherapy regimens and novel treatments into the traditional risk-stratified sequential approach. We also discuss the role of EBV-cytotoxic T lymphocytes in treatment of EBV-driven PTLD. Other novel agents with potential role in PTLD will be discussed in addition to the challenges that could arise with chimeric antigen receptor T-cell therapy and immune checkpoint inhibitors in this population.

Expert Consensus on the Characteristics of Patients with Epstein-Barr Virus-Positive Post-Transplant Lymphoproliferative Disease (EBV+ PTLD) for Whom Standard-Dose Chemotherapy May be Inappropriate: A Modified Delphi Study

INTRODUCTION

Following hematopoietic stem cell transplantation or solid organ transplantation, patients are at risk of developing Epstein-Barr virus-positive post-transplant lymphoproliferative disease (EBV⁺ PTLD), which is an ultra-rare and potentially lethal hematologic malignancy. Common treatments for EBV⁺ PTLD include rituximab alone or combined with chemotherapy. Given specific considerations for this population, including severity of the underlying condition requiring transplant, the rigors of the transplant procedure, as well as risks to the transplanted organ, there is a group of patients with EBV⁺ PTLD for whom chemotherapy may be inappropriate; however, there is limited information characterizing these patients. This study aimed to reach expert consensus on the key characteristics of patients for whom chemotherapy may be inappropriate in a real-world setting.

METHODS

A two-round modified Delphi study was conducted to reach consensus among clinicians with expertise treating EBV⁺ PTLD. Articles identified in a targeted literature review guided the development of round 1 and 2 topics and related statements. The consensus threshold for round 1 statements was 75.0%. If consensus was achieved in round 1, the statement was not discussed further in round 2. The consensus thresholds for round 2 were moderate (62.5-75.0%), strong (87.5%), or complete (100.0%).

RESULTS

The panel was composed of a total of eight clinicians (seven hematologists/hemato-oncologists) from six European countries. The panel generated a final list of 43 consensus recommendations on the following topics: terminology used to describe patients for whom chemotherapy may be inappropriate; demographic characteristics; organ transplant characteristics; comorbidities that preclude the use of chemotherapy; EBV⁺ PTLD characteristics; and factors related to treatment-related mortality and morbidity.

CONCLUSIONS

This modified Delphi panel successfully achieved consensus on key topics and statements that characterized patients with EBV⁺ PTLD for whom chemotherapy may be inappropriate. These recommendations will inform clinicians and aid in the treatment of EBV⁺ PTLD.

Multicenter study of pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders

BACKGROUND

Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorder [EBV(-)M-PTLD] comprises approximately 10% of M-PTLD. No large multi-institutional pediatric-specific reports on treatment and outcome are available.

METHODS

A multi-institutional retrospective review of solid organ recipients diagnosed with EBV(-)M-PTLD aged ≤21 years between 2001 and 2020 in 12 centers in the United States and United Kingdom was performed, including demographics, staging, treatment, and outcomes data.

RESULTS

Thirty-six patients were identified with EBV(-)M-PTLD. Twenty-three (63.9%) were male. Median age (range) at transplantation, diagnosis of EBV(-)M-PTLD, and interval from transplant to PTLD were 2.2 years (0.1-17), 14 years (3.0-20), and 8.5 years (0.6-18.3), respectively. Kidney (n = 17 [47.2%]) and heart (n = 13 [36.1%]) were the most commonly transplanted organs. Most were Murphy stage III (n = 25 [69.4%]). Lactate dehydrogenase was elevated in 22/34 (64.7%) and ≥2 times upper limit of normal in 11/34 (32.4%). Pathological diagnoses included diffuse large B-cell lymphoma (n = 31 [86.1%]) and B-non-Hodgkin lymphoma (B-NHL) not otherwise specified (NOS) (n = 5 [13.9%]). Of nine different regimens used, the most common were: pediatric mature B-NHL-specific regimen (n = 13 [36.1%]) and low-dose cyclophosphamide, prednisone, and rituximab (n = 9 [25%]). Median follow-up from diagnosis was 3.0 years (0.3-11.0 years). Three-year event-free survival (EFS) and overall survival (OS) were 64.8% and 79.9%, respectively. Of the seven deaths, six were from progressive disease.

CONCLUSIONS

EFS and OS were comparable to pediatric EBV(+) PTLD, but inferior to mature B-NHL in immunocompetent pediatric patients. The wide range of therapeutic regimens used directs our work toward developing an active multi-institutional registry to design prospective studies.

PLAIN LANGUAGE SUMMARY

Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders (EBV(-)M-PTLD) have comparable outcomes to EBV(+) PTLD, but are inferior to diffuse large B-cell lymphoma in immunocompetent pediatric patients. The variety of treatment regimens used highlights the need to develop a pediatric PTLD registry to prospectively evaluate outcomes. The impact of treatment regimen on relapse risk could not be assessed because of small numbers. In the intensive pediatric B-non-Hodgkin lymphoma chemoimmunotherapy group, 11 of 13 patients remain alive in complete remission after 0.6 to 11 years.

Analytical evaluation of the cobas® 6800 system for the detection and quantification of BK Virus (BKV) and Epstein Barr Virus (EBV) at a US solid organ and hematopoietic stem cell transplant center

The cobas® EBV and BKV assays are the first FDA-approved, quantitative assays for monitoring posttransplant reactivation of these viruses. In this study, we assessed performance of the fully-automated cobas® assays, compared with Diasorin Molecular ASR, our laboratory developed test, and demonstrated a strong interassay correlation for BK and EBV monitoring.

Virological Markers in Epstein–Barr Virus-Associated Diseases

Epstein–Barr virus (EBV) is an oncogenic virus infecting more than 95% of the world’s population. After primary infection—responsible for infectious mononucleosis in young adults—the virus persists lifelong in the infected host, especially in memory B cells. Viral persistence is usually without clinical consequences, although it can lead to EBV-associated cancers such as lymphoma or carcinoma. Recent reports also suggest a link between EBV infection and multiple sclerosis. In the absence of vaccines, research efforts have focused on virological markers applicable in clinical practice for the management of patients with EBV-associated diseases. Nasopharyngeal carcinoma is an EBV-associated malignancy for which serological and molecular markers are widely used in clinical practice. Measuring blood EBV DNA load is additionally, useful for preventing lymphoproliferative disorders in transplant patients, with this marker also being explored in various other EBV-associated lymphomas. New technologies based on next-generation sequencing offer the opportunity to explore other biomarkers such as the EBV DNA methylome, strain diversity, or viral miRNA. Here, we review the clinical utility of different virological markers in EBV-associated diseases. Indeed, evaluating existing or new markers in EBV-associated malignancies or immune-mediated inflammatory diseases triggered by EBV infection continues to be a challenge.

A lesion-selective albumin-CTLA4Ig as a safe and effective treatment for collagen-induced arthritis

BACKGROUND

CTLA4Ig is a dimeric fusion protein of the extracellular domain of cytotoxic T-lymphocyte protein 4 (CTLA4) and an Fc (Ig) fragment of human IgG₁ that is approved for treating rheumatoid arthritis. However, CTLA4Ig may induce adverse effects. Developing a lesion-selective variant of CTLA4Ig may improve safety while maintaining the efficacy of the treatment.

METHODS

We linked albumin to the N-terminus of CTLA4Ig (termed Alb-CTLA4Ig) via a substrate sequence of matrix metalloproteinase (MMP). The binding activities and the biological activities of Alb-CTLA4Ig before and after MMP digestion were analyzed by a cell-based ELISA and an in vitro Jurkat T cell activation assay. The efficacy and safety of Alb-CTLA4Ig in treating joint inflammation were tested in mouse collagen-induced arthritis.

RESULTS

Alb-CTLA4Ig is stable and inactive under physiological conditions but can be fully activated by MMPs. The binding activity of nondigested Alb-CTLA4Ig was at least 10,000-fold weaker than that of MMP-digested Alb-CTLA4Ig. Nondigested Alb-CTLA4Ig was unable to inhibit Jurkat T cell activation, whereas MMP-digested Alb-CTLA4Ig was as potent as conventional CTLA4Ig in inhibiting the T cells. Alb-CTLA4Ig was converted to CTLA4Ig in the inflamed joints to treat mouse collagen-induced arthritis, showing similar efficacy to that of conventional CTLA4Ig. In contrast to conventional CTLA4Ig, Alb-CTLA4Ig did not inhibit the antimicrobial responses in the spleens of the treated mice.

CONCLUSIONS

Our study indicates that Alb-CTLA4Ig can be activated by MMPs to suppress tissue inflammation in situ. Thus, Alb-CTLA4Ig is a safe and effective treatment for collagen-induced arthritis in mice.

Comparison of four commercial EBV DNA quantitative tests to a new test at an early stage of development

BACKGROUND

Regular screening for Epstein-Barr virus (EBV) DNA using quantitative RT-PCR is recommended for early intervention in at-risk patients. Harmonization of quantitative RT-PCR assays is critical to avoid misinterpretation of results. Here, we compare quantitative results of the cobas® EBV assay to four commercial RT-qPCR assays.

METHODS

The cobas EBV, EBV R-Gene, artus EBV RG PCR, RealStar EBV PCR kit 2.0 and Abbott EBV RealTime assays were compared for analytic performance using a 10-fold dilution series of EBV reference material, normalized to the WHO standard. For clinical performance, their quantitative results were compared using anonymized, leftover EBV-DNA-positive EDTA plasma samples.

RESULTS

For analytic accuracy, the cobas EBV deviated -0.0097 log₁₀ from target values. The other tests showed deviations between 0.0037 and -0.12 log₁₀. For clinical performance, accuracy and linearity of cobas EBV data from both study sites were excellent. Bland-Altman bias and Deming regression analyses showed statistical correlation for cobas EBV to both EBV R-Gene and Abbott RealTime assays but an offset of cobas EBV to artus EBV RG PCR and RealStar EBV PCR kit 2.0.

CONCLUSION

The cobas EBV showed the closest correlation to the reference material, followed closely by EBV R-Gene and Abbott EBV RealTime. Values obtained are stated in IU/mL, facilitating comparison across testing sites and potentially improving utilization of guidelines for diagnosis, monitoring, and treatment of patients.

Late airway complications following pediatric liver transplantation: A case series

BACKGROUND

Late airway complications, as consequence of immunosuppression following pediatric liver transplantation are uncommonly reported.

METHODS

In this retrospective case series, we describe two young children presenting with symptoms of airway obstruction, secondary to differing pathologies in the supraglottic airway, as a result of immunosuppression following liver transplantation.

RESULTS

Case 1, a 2-year-old girl who presented with stridor 12-months following liver transplantation, was found to have a proliferative soft tissue mass involving the supraglottic larynx. Biopsies were consistent with infiltrative eosinophilic laryngitis and associated eosinophilic esophagitis. Case 2, a 12-month-old female who presented with stridor 5-months following liver transplantation, was found to have an exophytic soft tissue mass involving the supraglottis and hypopharynx. Biopsies revealed polymorphic Epstein-Barr virus (EBV) driven post-transplant lymphoproliferative disease (PTLD). Case 1 was managed with local resection and high dose oral corticosteroids. Case 2 responded to debulking of the necrotic supraglottic mass, reduction of immunosuppression and rituximab.

CONCLUSION

A high index of suspicion needs to be maintained for complications of immunosuppression for appropriate diagnosis of airway presentations following pediatric liver transplantation. Further research is necessary to improve early detection and consolidate management strategies for these airway lesions.

New concepts in EBV-associated B, T, and NK cell lymphoproliferative disorders

EBV-associated lymphoproliferative disorders (LPD) include conditions of B, T, and NK cell derivation with a wide clinicopathological spectrum ranging from indolent, self-limiting, and localized conditions to highly aggressive lymphomas. Since the 2016 World Health Organization (WHO) lymphoma classification, progress has been made in understanding the biology of the EBV-associated LPDs. The diagnostic criteria of EBV+ mucocutaneous ulcer and lymphomatoid granulomatosis have been refined, and a new category of EBV-positive polymorphic B cell LPD was introduced to encompass the full spectrum of EBV-driven B cell disorders. The differential diagnosis of these conditions is challenging. This report will present criteria to assist the pathologist in diagnosis. Within the group of EBV-associated T and NK cell lymphomas, a new provisional entity is recognized, namely, primary nodal EBV+ T or NK cell lymphoma. The EBV + T and NK cell LPDs in children have undergone major revisions. In contrast to the 2016 WHO classification, now four major distinct groups are recognized: hydroa vacciniforme (HV) LPD, severe mosquito bite allergy, chronic active EBV (CAEBV) disease, and systemic EBV-positive T cell lymphoma of childhood. Two forms of HV LPD are recognized: the classic and the systemic forms with different epidemiology, clinical presentation, and prognosis. The subclassification of PTLD, not all of which are EBV-positive, remains unaltered from the 2016 WHO classification. This review article summarizes the conclusions and the recommendations of the Clinical Advisory Committee (CAC), which are summarized in the International Consensus Classification of Mature Lymphoid Neoplasms.

Performance Evaluation of the Fully Automated NeuMoDx RT-PCR Platform for the Quantification of CMV and EBV DNA in EDTA Plasma: Implications for Clinical Management and Establishment of a Conversion Formula

The NeuMoDx96 platform is a fully automated real-time PCR (RT-PCR) system. To provide continued testing quality with the introduction of new assays, the primary aim of this study was to evaluate the analytical and clinical performance of the NeuMoDx platform for the detection and quantification of CMV and EBV DNA in EDTA plasma. As no conversion from log₁₀ international units per milliliter to copies per milliliter was provided, the secondary aim was to calculate and establish a conversion factor for the output of results in copies per milliliter for CMV and EBV. Archived ETDA plasma samples (cytomegalovirus [CMV], n = 290; Ebstein-Barr virus [EBV], n = 254) were used to evaluate the analytical performance of the NeuMoDx96 platform against the routine real-time quantitative PCR (qPCR) assays. Additionally, the first WHO international standards (WHO-IS) for CMV (n = 70) and EBV (n = 72) were used for the calculation of the intra- and interassay variation. WHO-IS qualitative agreement between the assays was 100%. Intra-assay variability was low for both CMV assays (coefficient of variation [CV], phosphate-buffered saline [PBS], 3 log₁₀ IU/mL NeuMoDx, 3.67%; Abbott RealTime, CMV, 3.35%) and NeuMoDx EBV assay (CV, PBS, 3 log₁₀ IU/mL, 3.05%) but high for the Altona EBV assay (CV, PBS, 3 log₁₀ IU/mL, 26.13%). The overall qualitative concordance in clinical samples was 96.8% (270/279) for CMV and 96.7% (237/245) for EBV. The mean difference between the assays was -0.2 log₁₀ IU/mL (CMV) and -0.18 log₁₀ IU/mL (EBV). High qualitative concordance and a significant correlation of quantitative values for both assays make NeuMoDx CMV and EBV assays suitable for routine diagnostic testing. The new RT-PCR system and conversion formulas to report results in copies per milliliter are now applied in clinical routine testing. IMPORTANCE Clinical management of solid organ transplant (SOT) patients requires the careful monitoring of immunosuppression and viral infection or reactivation. qPCR is the gold standard for the detection and quantification of very small amounts of viral DNA and allows for an early assessment of viral load kinetics. The tested NeuMoDx 96 platform provides faster results than the previously used RT-PCR workflows for CMV (Abbott m2000 and RealTime CMV assay) and EBV (LightCycler 480 II, Roche high pure extraction, and Altona RealStar EBV assay) DNA detection. The implemented conversion formulas allow the continued reporting in clinically established copies per milliliter, important for long-term care of SOT patients.

Post-Transplant Lymphoproliferative Disease (PTLD) after Allogeneic Hematopoietic Stem Cell Transplantation: Biology and Treatment Options

Post-transplant lymphoproliferative disease (PTLD) is a serious complication occurring as a consequence of immunosuppression in the setting of allogeneic hematopoietic stem cell transplantation (alloHSCT) or solid organ transplantation (SOT). The majority of PTLD arises from B-cells, and Epstein-Barr virus (EBV) infection is present in 60-80% of the cases, revealing the central role played by the latent infection in the pathogenesis of the disease. Therefore, EBV serological status is considered the most important risk factor associated with PTLDs, together with the depth of T-cell immunosuppression pre- and post-transplant. However, despite the advances in pathogenesis understanding and the introduction of novel treatment options, PTLD arising after alloHSCT remains a particularly challenging disease, and there is a need for consensus on how to treat rituximab-refractory cases. This review aims to explore the pathogenesis, risk factors, and treatment options of PTLD in the alloHSCT setting, finally focusing on adoptive immunotherapy options, namely EBV-specific cytotoxic T-lymphocytes (EBV-CTL) and chimeric antigen receptor T-cells (CAR T).

Characteristics and Outcome of Post-Transplant Lymphoproliferative Disorders After Solid Organ Transplantation: A Single Center Experience of 196 Patients Over 30 Years

Post-transplant lymphoproliferative disorder (PTLD) is a rare but life-threatening complication after transplantation. In this retrospective, monocentric study we aimed to collect real life data regarding PTLD and determine the role of Epstein Barr Virus (EBV) status and year of diagnosis on prognosis. We identified 196 biopsy-proven PTLD after solid organ transplantation (SOT) diagnosed at the University Hospitals Leuven (Belgium) from 1989 to 2019. EBV status was positive in 61% of PTLD. The median overall survival (OS) was 5.7 years (95% CI: 2.99-11.1). Although EBV positivity was not significantly correlated with OS in multivariate analyses (HR: 1.44 (95% CI: 0.93-2.24); p = 0.10), subgroup analysis showed a significantly better median OS for EBV negative post-transplant diffuse large B-cell lymphoma (DLBCL) compared to EBV positive post-transplant DLBCL (8.8 versus 2.5 years respectively; p = 0.0365). There was a significant relation between year of PTLD diagnosis and OS: the more recent the PTLD diagnosis, the lower the risk for death (adjusted HR: 0.962 (95% CI: 0.931-0.933); p = 0.017). In conclusion, the prognosis of PTLD after SOT has improved in the past decades. Our analysis shows a significant relation between EBV status and OS in post-transplant DLBCL.

In vitro and in vivo evidence that the switch from calcineurin to mTOR inhibitors may be a strategy for immunosuppression in Epstein-Barr virus-associated post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder is a life-threatening complication of immunosuppression following transplantation mediated by failure of T cells to control Epstein-Barr virus (EBV)-infected and transformed B cells. Typically, a modification or reduction of immunosuppression is recommended, but insufficiently defined thus far. In order to help delineate this, we characterized EBV-antigen-specific T cells and lymphoblastoid cell lines from healthy donors and in patients with a kidney transplant in the absence or presence of the standard immunosuppressants tacrolimus, cyclosporin A, prednisolone, rapamycin, and mycophenolic acid. Phenotypes of lymphoblastoid cell-lines and T cells, T cell-receptor-repertoire diversity, and T-cell reactivity upon co-culture with autologous lymphoblastoid cell lines were analyzed. Rapamycin and mycophenolic acid inhibited lymphoblastoid cell-line proliferation. T cells treated with prednisolone and rapamycin showed nearly normal cytokine production. Proliferation and the viability of T cells were decreased by mycophenolic acid, while tacrolimus and cyclosporin A were strong suppressors of T-cell function including their killing activity. Overall, our study provides a basis for the clinical decision for the modification and reduction of immunosuppression and adds information to the complex balance of maintaining anti-viral immunity while preventing acute rejection. Thus, an immunosuppressive regime based on mTOR inhibition and reduced or withdrawn calcineurin inhibitors could be a promising strategy for patients with increased risk of or manifested EBV-associated post-transplant lymphoproliferative disorder.

Neutropenia in pediatric solid organ transplant

Neutropenia is generally defined as an absolute neutrophil count in the circulation of less than 1500/mm³ and occurs in up to 25%-30% of pediatric solid organ transplant recipients (SOT) within the first year after transplantation. In the SOT population, neutropenia is most often a result of drug-induced bone marrow suppression but can also be secondary to viral infection, nutritional deficiencies, lymphoproliferative infiltrate, and inherited causes. Outcomes for patients with neutropenia vary by degree of neutropenia and type of solid organ transplant. Management of neutropenia should begin by addressing the underlying cause, including reducing or removing medications when appropriate, treating infections, and addressing nutrient deficiencies; however, consultation with an experienced pediatric hematologist and use of granulocyte colony-stimulating factor (G-CSF) may be helpful in some cases. Overall, data on clinical outcomes for G-CSF use remain limited, but observational studies may support its use in patients with infections or severe neutropenia.

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.

Combined assessment of Epstein-Barr virus viral capsid antigen and Epstein-Barr virus nuclear antigen-1 serology for post-transplant lymphoproliferative disorder risk stratification in adult solid organ transplant recipients

BACKGROUND

Epstein-Barr virus (EBV) seronegative solid organ transplant recipients (SOTRs) are at increased risk for post-transplant lymphoproliferative disorder (PTLD). Assays for EBV serostatus assess antibody to both EBV viral capsid antigen (VCA) and Epstein-Barr nuclear antigen-1 (EBNA-1), but PTLD risk among SOT recipients with discordant VCA and EBNA-1 results is unknown.

METHODS

We performed a retrospective, single-center cohort study to determine the risk of PTLD among adult (≥ 18 years) SOTRs with discordant pre-transplant VCA and EBNA-1 IgG compared to that of SOTRs with concordantly negative or concordantly positive serology using univariable and multivariable Cox-proportional hazards models.

RESULTS

Of 4106 SOTRs, the number (%) who were concordantly positive, concordantly negative, and discordant was 3787 (92.2%), 149 (3.6%), and 170 (4.2%), respectively. The adjusted hazard of PTLD was significantly higher among discordant SOTRs compared to concordantly positive SOTRs (aHR 2.6, 95% CI 1.04-6.6, p =.04) and lower compared to concordantly negative SOTRs (aHR 0.27, 95% CI 0.10-0.76, p <.001). The adjusted hazard of EBV+ PTLD among those with discordant serology was also significantly higher compared to the concordantly positive cohort (aHR 3.53, 95% CI 1.04-12.0, p =.04) and significantly lower compared to the concordantly negative cohort (aHR 0.23, 95% CI 0.06-0.82, p =.02).

CONCLUSIONS

Risk of PTLD among SOTRs with discordant VCA and EBNA-1 may be intermediate between those with concordantly positive and negative serology. If confirmed in future studies, revision of national EBV serology reporting to include both VCA and EBNA results may be needed to optimize PTLD risk stratification.

Gastrointestinal symptoms and endoscopy findings after pediatric solid organ transplantation: A case series

BACKGROUND

Gastrointestinal symptoms are common among solid organ transplant (SOT) recipients. Information about colonoscopy findings after pediatric SOT is limited. This retrospective study reports endoscopy findings in a nationwide pediatric transplant recipient cohort.

METHODS

All pediatric recipients (kidney, liver, or heart) transplanted between 2010 and 2020 at our institution (n = 193) who had undergone ileocolonoscopy and upper gastrointestinal endoscopy after SOT were enrolled. Sixteen patients were identified. A meticulous search on clinical data including transplantation, gastrointestinal symptoms, endoscopy findings, and follow-up data was performed.

RESULTS

Endoscopy was performed at a median of 2.6 years (0.4-13.3) after the first transplantation (median age at SOT 1.2 years). Gastrointestinal symptoms leading to endoscopy did not differ between the different transplant groups. The leading endoscopy indications were prolonged diarrhea and anemia. PTLD was found in 8 (50%) patients. Five were histologically early PTLD lesions and three were monomorphic large B-cell PTLDs (two EBV-positive and one EBV-negative), one having previously been diagnosed with autoimmune enteropathy. One patient had EBV enteritis. De novo inflammatory bowel disease was found in one patient, eosinophilic gastroenteritis in another, and in one patient with several episodes of watery diarrhea, the histological finding was mild non-specific colitis. In four patients, the endoscopy finding remained unclear and the symptoms were suspected to be caused by infectious agents or mycophenolate.

CONCLUSIONS

PTDL with various stages is a common finding after pediatric SOT in patients with gastrointestinal symptoms. Endoscopy should be considered in transplant recipients with prolonged diarrhea, anemia, and/or abdominal pain.

Epstein-Barr Virus DNAemia and post-transplant lymphoproliferative disorder in pediatric solid organ transplant recipients

BACKGROUND

Pediatric solid organ transplant (SOT) recipients commonly have Epstein-Barr virus (EBV) DNAemia and are at risk of developing post-transplant lymphoproliferative disorder (PTLD). EBV DNAemia has not been analyzed on a continuous scale in this population.

METHODS

All children ≤ 18 years of age who underwent SOT at a single center between January 1, 2007 and July 31, 2018 were included in this retrospective study. Transplant episodes in which PTLD occurred were compared to transplant episodes without PTLD. Multivariable logistic regression was used to identify factors associated with the development of EBV DNAemia and maximum height of EBV DNAemia. A Cox proportional hazards model was used to calculate hazard ratios for time to PTLD.

RESULTS

Of 275 total transplant recipients and 294 transplant episodes, there were 14 episodes of PTLD. Intestinal and multivisceral transplant were strongly associated with PTLD (p = 0.002). Risk factors for the development of EBV DNAemia include donor and recipient positive EBV serologies (p = 0.001) and older age (p = 0.001). Maximum level of EBV DNAemia was significantly associated with development of PTLD (p<0.0001). Every one log (log10) increase in the maximum level of EBV DNAemia was associated with a more than doubling of the hazard on developing PTLD (HR: 2.18, 95% CI 1.19-3.99).

CONCLUSIONS

Transplant type was strongly associated with development of PTLD in pediatric SOT recipients. EBV serologies and age were associated with the development of EBV DNAemia and height of DNAemia. High levels of EBV DNAemia were strongly associated with an increased hazard for PTLD.

Herpesvirus-Associated Encephalitis: an Update

Purpose of Review

Recent Findings

Summary

Gastrointestinal manifestations, risk factors, and management in patients with post-transplant lymphoproliferative disorder: A systematic review

BACKGROUND

Patients with a history of solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT) are at an increased risk of developing post-transplant lymphoproliferative disorder (PTLD). The gastrointestinal (GI) tract is commonly affected as it has an abundance of B and T cells.

AIM

To determine typical GI-manifestations, risk factors for developing PTLD, and management.

METHODS

Major databases were searched until November 2021.

RESULTS

Non-case report studies that described GI manifestations of PTLD, risk factors for developing PTLD, and management of PTLD were included. Nine articles written within the last 20 years were included in the review. All articles found that patients with a history of SOT, regardless of transplanted organ, have a propensity to develop GI-PTLD.

CONCLUSION

GI tract manifestations may be nonspecific; therefore, consideration of risk factors is crucial for identifying GI-PTLD. Like other lymphoma variants, PTLD is very aggressive making early diagnosis key to prognosis. Initial treatment is reduction of immunosuppression which is effective in more than 50% of cases; however, additional therapy including rituximab, chemotherapy, and surgery may also be required.

Non-Hodgkin lymphoma after pediatric kidney transplantation

Non-Hodgkin lymphoma (NHL) that develops after kidney transplantation belongs to post-transplant lymphoproliferative disorders (PTLD) occurring with an incidence of 2-3%. Most pediatric cases are related to primary infection with Epstein-Barr virus (EBV), able to transform and immortalize B cells and widely proliferate due to the lack of relevant control of cytotoxic T cells in patients receiving post-transplant immunosuppression. NHL may develop as a systemic disease or as a localized lesion. The clinical pattern is variable, from non-symptomatic to fulminating disease. Young age of transplant recipient, seronegative EBV status at transplantation, and EBV mismatch between donor and recipient (D+/R-) are regarded as risk factors. Immunosuppression impacts the development of both early and late NHLs. Specific surveillance protocols, including monitoring of EBV viral load, are used in patients at risk; however, detailed histopathology diagnosis and evaluation of malignancy staging is crucial for therapeutic decisions. Minimizing of immunosuppression is a primary management, followed by the use of rituximab in B-cell NHLs. Specific chemotherapeutic protocols, adjusted to lymphoma classification and staging, are used in advanced NHLs. Radiotherapy and/or surgical removal of malignant lesions is limited to the most severe cases. Outcome is variable, depending on risk factors and timing of diagnosis, however is positive in pediatric patients in terms of graft function and patient survival. Kidney re-transplantation is possible in survivors who lost the primary graft due to chronic rejection, however may be performed after at least 2-3 years of waiting time, careful verification of malignancy-free status, and gaining immunity against EBV.

Overview of pediatric kidney transplantation

Kidney transplantation is the treatment of choice for pediatric patients with end-stage kidney disease. Unlike adult recipients undergoing transplantation, special considerations must be taken when transplanting children based on the underlying etiology of kidney disease, previous surgical procedures, anatomical limitations and necessary technical adjustments. Additionally, the choice of donor must be measured to ensure optimal graft survival given a longer post-transplant life expectancy. Those topics as well as frequently encountered postoperative complications are also discussed in this publication.

Seropositivity for cytomegalovirus and PCR-EBV monitoring: Protective factors for posttransplant lymphoproliferative disorder in pediatric liver transplant

BACKGROUND

PTLD is a clinical condition with high mortality. Monitoring EBV replication can be a useful tool to avoid the development of PTLD.

MATERIALS AND METHODS

This was a retrospective analysis of 428 pediatric patients who underwent liver transplantation between 1989 and 2016. The patients were divided into 2 groups (transplanted before 2006, when PCR-EBV was not monitored, and after 2006, when PCR-EBV monitoring was started). Patients with continuous PCR measurements for EBV were evaluated for the impact of a reduction in immunosuppression or a change in immunosuppressants on the number of viral copies. A logistic regression model was applied to evaluate factors related to PTLD.

RESULTS

The prevalence of PTLD was 4.2%. After monitoring patients with PCR for EBV levels, a predominance of the most severe, monomorphic form of lymphoproliferative disorder was observed (p = .009). The PTLD mortality was 5%. There was a change in the PCR level after tacrolimus reduction (p = .002) and after tacrolimus exchange for mTOR (p = .008). The number of EBV copies was significantly higher (p = .029) in patients who developed PTLD. In the multiple regression model, seropositivity for CMV was an independent protective factor for lymphoproliferative disorder (OR=0.09; 95% CI 0.02-0.42), reducing the chance of having PTLD adjusted by serology for EBV by 91%.

CONCLUSIONS

Monitoring the EBV viral load by PCR seems to prevent the emergence of milder forms of lymphoproliferative disorder. Pretransplant seropositivity for CMV is a protective factor for PTLD.

Nondestructive versus advanced post-transplant lymphoproliferative disorder in a single-center pediatric kidney transplant population

BACKGROUND

Pediatric kidney transplant recipients are at risk for the development of post-transplant lymphoproliferative disorders (PTLD), a group of potentially devastating diseases that present on a spectrum of severity ranging from nondestructive PTLD to more histologically destructive lesions. Currently, there is inadequate evidence to guide evaluation and management of nondestructive PTLD.

METHODS

This is a single-center case series of pediatric kidney transplant recipients between January 1, 2008 and December 31, 2019, who were diagnosed with PTLD. The aim was to describe clinical characteristics, presentation, and management of nondestructive versus advanced PTLD.

RESULTS

Eighteen patients were diagnosed with nondestructive PTLD and seven with more advanced PTLD histopathology. The majority (66.7%) of nondestructive PTLD patients (n = 16) presented with tonsillar hypertrophy and/or snoring and were managed conservatively, with minimal reduction in tacrolimus dose and no further evaluation. No patient progressed to more advanced PTLD. Advanced PTLD patients (n = 7) were more likely to present with fever, elevated creatinine, a new mass of gastrointestinal symptoms. They received workup with imaging and oncology consultation, and were managed with chemotherapy.

CONCLUSIONS

Patients with nondestructive PTLD often present with symptoms of sleep-disordered breathing and can be managed conservatively with excellent clinical outcomes. More study is needed to guide care of this under-researched population.

A Fatal Complication of Liver Transplant: Posttransplant Lymphoproliferative Disease

Immunosuppressive therapy is a double-edged sword and causes a risk for some complications, such as opportunistic infections and posttransplant lymphoproliferative disease. The most likely risk factors for posttransplant lymphoproliferative disease are Epstein-Barr virus serology mismatch, prolonged and high viral load for Epstein-Barr virus, higher doses of immunosuppressive therapy, and cytomegalovirus infection. Transplant recipients who are seropositive for Epstein-Barr virus show a lower risk for posttransplant lymphoproliferative disease than seronegative recipients. Here, we present a 3.5-year-old boy who was seropositive for Epstein-Barr virus and developed posttransplant lymphoproliferative disease 18 months after liver transplant with a previous history of cytomegalovirus- related pneumatosis intestinalis.

Spleen-Restricted Posttransplant Lymphoproliferative Disorder in the First Year After Kidney Transplant - A Case Report

Posttransplant lymphoproliferative disorders (PTLDs) are a feared complication after transplant. They are mostly of B cell origin and are frequently Epstein-Barr virus (EBV)-positive, particularly in early onset PTLD. Later on, non-B and EBV-negative PTLD are increasingly reported. EBV seronegative receptors (particularly when paired with an EBV seropositive donor) together with the net degree of immunosuppression-a concept often difficult to quantify-are the most consistently described risk factors for the development of PTLD. Conversely, its association with a particular immunosuppressive agent or other virus, namely cytomegalovirus (CMV) infection or disease, has been inconsistently reported. We present a challenging case where an EBV negative monomorphic peripheric T-cell lymphoma was diagnosed in the first year after kidney transplant in a patient with a recent history of CMV disease from a resistant strain.

Bacterial and Viral Infection and Sepsis in Kidney Transplanted Patients

Kidney transplanted patients are a unique population with intrinsic susceptibility to viral and bacterial infections, mainly (but not exclusively) due to continuous immunosuppression. In this setting, infectious episodes remain among the most important causes of death, with different risks according to the degree of immunosuppression, time after transplantation, type of infection, and patient conditions. Prevention, early diagnosis, and appropriate therapy are the goals of infective management, taking into account that some specific characteristics of transplanted patients may cause a delay (the absence of fever or inflammatory symptoms, the negativity of serological tests commonly adopted for the general population, or the atypical anatomical presentation depending on the surgical site and graft implantation). This review considers the recent available findings of the most common viral and bacterial infection in kidney transplanted patients and explores risk factors and outcomes in septic evolution.

Transplant Onconephrology in Patients With Kidney Transplants

Cancer is a leading cause of death in patients with kidney transplantation. Patients with kidney transplants are 10- to 200-times more likely to develop cancers after transplant than the general population, depending on the cancer type. Recent advances in cancer therapies have dramatically improved survival outcomes; however, patients with kidney transplants face unique challenges of immunosuppression management, cancer screening, and recurrence of cancer after transplant. Patients with a history of cancer tend to be excluded from transplant candidacy or are required to have long cancer-free wait time before wait-listing. The strategy of pretransplant wait time management may need to be revisited as cancer therapies improve, which is most applicable to patients with a history of multiple myeloma. In this review, we discuss several important topics in transplant onconephrology: the current recommendations for pretransplant wait times for transplant candidates with cancer histories, cancer screening post-transplant, post-transplant lymphoproliferative disorder, strategies for transplant patients with a history of multiple myeloma, and novel therapies for patients with post-transplant malignancies. With emerging novel cancer treatments, it is critical to have multidisciplinary discussions involving patients, caregivers, transplant nephrologists, and oncologists to achieve patient-oriented goals.

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.