Evaluation of Epstein-Barr Virus (EBV) Antibody Screening of Organ Donors for Allocation of Organs to EBV Serostatus Matched Recipients

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.

Fecal Microbiota Transplantation Donor Screening Updates and Research Gaps for Solid Organ Transplant Recipients

In this review, we discuss stool donor screening considerations to mitigate potential risks of pathogen transmission through fecal microbiota transplant (FMT) in solid organ transplant (SOT) recipients. SOT recipients have a higher risk for Clostridioides difficile infection (CDI) and are more likely to have severe CDI. FMT has been shown to be a valuable tool in the treatment of recurrent CDI (RCDI); however, guidelines for screening for opportunistic infections transmitted through FMT are underdeveloped. We review reported adverse effects of FMT as they pertain to an immunocompromised population and discuss the current understanding and recommendations for screening found in the literature while noting gaps in research. We conclude that while FMT is being performed in the SOT population, typically with positive results, there remain many unanswered questions which may have major safety implications and warrant further study.

Predictors of Epstein-Barr virus serostatus and implications for vaccine policy: A systematic review of the literature

BACKGROUND

Epstein-Barr virus (EBV) is an important human pathogen; it infects >90% people globally and is linked to infectious mononucleosis and several types of cancer. Vaccines against EBV are in development. In this study we present the first systematic review of the literature on risk factors for EBV infection, and discuss how they differ between settings, in order to improve our understanding of EBV epidemiology and aid the design of effective vaccination strategies.

METHODS

MEDLINE, Embase, and Web of Science were searched on 6th March 2017 for observational studies of risk factors for EBV infection. Studies were excluded if they were published before 2008 to ensure relevance to the modern day, given the importance of influencing future vaccination policies. There were no language restrictions. After title, abstract and full text screening, followed by checking the reference lists of included studies to identify further studies, data were extracted into standardised spreadsheets and quality assessed. A narrative synthesis was undertaken.

RESULTS

Seventy-seven papers met our inclusion criteria, including data from 31 countries. There was consistent evidence that EBV seroprevalence was associated with age, increasing throughout childhood and adolescence and remaining constant thereafter. EBV was generally acquired at younger ages in Asia than Europe/North America. There was also compelling evidence for an association between cytomegalovirus infection and EBV. Additional factors associated with EBV seroprevalence, albeit with less consistent evidence, included ethnicity, socioeconomic status, other chronic viral infections, and genetic variants of HLA and immune response genes.

CONCLUSIONS

Our study is the first systematic review to draw together the global literature on the risk factors for EBV infection and includes an evaluation of the quality of the published evidence. Across the literature, the factors examined are diverse. In Asia, early vaccination of infants would be required to prevent EBV infection. In contrast, in Western countries a vaccine could be deployed later, particularly if it has only a short duration of protection and the intention was to protect against infectious mononucleosis. There is a lack of high-quality data on the prevalence and age of EBV infection outside of Europe, North America and South-East Asia, which are essential for informing effective vaccination policies in these settings.

Predictors of Epstein-Barr virus serostatus in young people in England

BACKGROUND

Epstein-Barr virus (EBV) is an important human pathogen which causes lifelong infection of > 90% people globally and is linked to infectious mononucleosis (arising from infection in the later teenage years) and several types of cancer. Vaccines against EBV are in development. In order to determine the most cost-effective public health strategy for vaccine deployment, setting-specific data on the age at EBV acquisition and risk factors for early infection are required. Such data are also important to inform mathematical models of EBV transmission that can determine the required target product profile of vaccine characteristics. We thus aimed to examine risk factors for EBV infection in young people in England, in order to improve our understanding of EBV epidemiology and guide future vaccination strategies.

METHODS

The Health Survey for England (HSE) is an annual, cross-sectional representative survey of households in England during which data are collected via questionnaires and blood samples. We randomly selected individuals who participated in the HSE 2002, aiming for 25 participants of each sex in each single year age group from 11 to 24 years. Stored samples were tested for EBV and cytomegalovirus (CMV) antibodies. We undertook descriptive and regression analyses of EBV seroprevalence and risk factors for infection.

RESULTS

Demographic data and serostatus were available for 732 individuals. EBV seroprevalence was strongly associated with age, increasing from 60.4% in 11-14 year olds throughout adolescence (68.6% in 15-18 year olds) and stabilising by early adulthood (93.0% in those aged 22-24 years). In univariable and multivariable logistic regression models, ethnicity was associated with serostatus (adjusted odds ratio for seropositivity among individuals of other ethnicity versus white individuals 2.33 [95% confidence interval 1.13-4.78]). Smoking was less strongly associated with EBV seropositivity.

CONCLUSIONS

By the age of 11 years, EBV infection is present in over half the population, although age is not the only factor associated with serostatus. Knowledge of the distribution of infection in the UK population is critical for determining future vaccination policies, e.g. comparing general versus selectively targeted vaccination strategies.

Prevalence and molecular profiling of Epstein Barr virus (EBV) among healthy blood donors from different nationalities in Qatar

BACKGROUND

The Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis. EBV is highly prevalent lymphotropic herpesvirus and has been linked to several malignancies. Transmission is generally by oral secretions, but can be through blood transfusions and organ transplantations. This study aimed to determine the seroprevalence, viremia rates, and circulating genotypes of EBV in healthy blood donors in Qatar.

METHODS

Blood samples from 673 blood donors of different nationalities residing in Qatar (mainly Qatar, Egypt, Syria, Jordan, Pakistan, and India) were collected and tested for anti-EBV capsid (VCA; IgG & IgM), nuclear (EBNA; IgG), and early (EA-D; IgG) antigens. Avidity testing was determined when active infection was suspected. DNA was extracted from the buffy coat and subjected to EBV-DNA quantification using qRT-PCR. Genotyping was performed using nested-PCR targeting EBV-EBNA2 gene, and phylogeny by sequence analysis of the LMP-1 gene.

RESULTS

97.9% (673/659) of the samples were seropositive as indicated by the presence VCA-IgG, while 52.6% (354/673) had detectible EBV-DNA. EBV seroprevalence and viremia rates increased significantly with age. Genotyping of 51 randomly selected samples showed predominance of Genotype 1 (72.5%, 37/51) as compared to genotype 2 (3.5%), and mixed infections were detected in 4% of the samples. Sub-genotyping for these samples revealed that the Mediterranean strain was predominant (65.3%), followed by B95.8 prototype and North Carolina strains (12.2% each), and China1 strain (6%).

CONCLUSION

As a first study to evaluate EBV infection in highly diverse population in Qatar, where expatriates represent more than 85% of the population, our results indicated high seroprevalence and viremia rate of EBV in different nationalities, with genotype 1 and Mediterranean strain being predominant. Clinical significance of these finding have not been investigated and shall be evaluated in future studies.

Posttransplant lymphoproliferative disease after lung transplantation

Posttransplant lymphoproliferative disease (PTLD) after lung transplantation occurs due to immunosuppressant therapy which limits antiviral host immunity and permits Epstein-Barr viral (EBV) replication and transformation of B cells. Mechanistically, EBV survives due to latency, escape from cytotoxic T cell responses, and downregulation of host immunity to EBV. Clinical presentation of EBV may occur within the lung allograft early posttransplantation or later onset which is more likely to be disseminated. Improvements in monitoring through EBV viral load have provided a means of earlier detection; yet, sensitivity and specificity of EBV load monitoring after lung transplantation may require further optimization. Once PTLD develops, staging and tissue diagnosis are essential to appropriate histopathological classification, prognosis, and guidance for therapy. The overall paradigm to treat PTLD has evolved over the past several years and depends upon assessment of risk such as EBV-naïve status, clinical presentation, and stage and sites of disease. In general, clinical practice involves reduction in immunosuppression, anti-CD20 biologic therapy, and/or use of plasma cell inhibition, followed by chemotherapy for refractory PTLD. This paper focuses upon the immunobiology of EBV and PTLD, as well as the clinical presentation, diagnosis, prognosis, and emerging treatments for PTLD after lung transplantation.

[Evaluation of the potential organ donor with special regards to heart donation]

Angesichts der auch in Österreich vorherrschenden Knappheit an verfügbaren Organspendern für Herztransplantationen erscheint es dringlich notwendig, eine Optimierung von Spenderevaluierung und Management zu diskutieren. In der vorliegenden Arbeit werden allgemeine Spenderkriterien und herzspezifische Parameter detailliert diskutiert und im Zusammenhang mit der internationalen Literatur dargestellt. Es wird der "marginale" und im Gegensatz dazu der "optimale" Organspender definiert. Das Spendermanagement wird besprochen, wobei neben der hämodynamischen Optimierung auch auf zusätzliche intensivmedizinische Aspekte eingegangen wird. Erst die exakte Evaluierung erlaubt die individuelle Zuteilung des Organs zum passenden Empfänger und stellt somit insbesondere bei marginalen Spendern die Grundlage eines Therapieerfolgs dar.

Posttransplant lymphoproliferative diseases

The risk of developing cancer after solid organ transplantation (SOT) is about 5- to 10-fold greater than that of the general population. The cumulative risk of cancer rises to more than 50% at 20 years after transplant and increases with age, and so children receiving transplants are at high risk of developing a malignancy. Posttransplant lymphoproliferative disease (PTLD) is the most common cancer observed in children following SOT, accounting for half of all such malignancies. PTLD is a heterogeneous group of disorders with a wide spectrum of pathologic and clinical manifestations and is a major contributor to long-term morbidity and mortality in this population. Among children, most cases are associated with Epstein-Barr virus infection. This article reviews the pathology, immunobiology, epidemiology, and clinical aspects of PTLD, underscoring the need for ongoing systematic study of complex biologic and therapeutic questions.

Tonsil enlargement after liver transplantation in adults--reason enough for tonsillectomy? Two cases of tonsillar posttransplantation lymphoproliferative disease

Posttransplantation lymphoproliferative disease (PTLD) is a well-known complication of solid organ and bone marrow transplantation. It is agreed that the main causes of PTLD are chronic infection with Epstein-Barr virus (EBV); the intensity, rather then the type, of immunosuppression used; and underlying recipient disease. Hepatitis C virus (HCV) and cytomegalovirus, as cofactors of EBV infection, have been suggested to increase the risk of PTLD. Use of calcineurin inhibitors, anti-CD3 monoclonal antibody (OKT3), and antithymocyte globulin may increase the risk of PTLD. On the other hand, mycophenolate mofetil, sirolimus, and the anti-interleukin-2 receptor monoclonal antibodies Daclizumab and basiliximab have not been demonstrated to increase the risk of PTLD. The incidence of PTLD after liver transplantation (LT) is estimated to be 1.5-3%, but a tonsillar location is extremely rare in adults. Thus, little is known about the best diagnostic tools for and treatment by LT recipients with tonsillar PTLD. Here, we report 2 cases of adult LT recipients with tonsillar PTLD. Tonsillectomy was used as a diagnostic tool and treatment option and resulted in complete remission for >2 years. Considering the high mortality and diagnostic difficulties of PTLD, together with the relatively low risks of tonsillectomy, we recommend tonsillectomy for treating tonsil enlargement of unknown cause and suspected PTLD in LT recipients. A larger series of patients and prospective studies comparing different treatment options will be needed to substantiate our recommendation.