The ABC of Epstein-Barr Virus Infections

Awakening the sleeping giant: Epstein-Barr virus reactivation by biological agents

Epstein-Barr virus (EBV) may cause harm in immunocompromised conditions or on stress stimuli. Various chemical agents have been utilized to induce the lytic cycle in EBV-infected cells. However, apart from chemical agents and external stress stimuli, certain infectious agents may reactivate the EBV. In addition, the acute infection of other pathogens may provide suitable conditions for EBV to thrive more and planting the roots for EBV-associated pathologies. Various bacteria such as periodontal pathogens like Aggregatibacter, Helicobacter pylori, etc. have shown to induce EBV reactivation either by triggering host cells directly or indirectly. Viruses such as Human simplex virus-1 (HSV) induce EBV reactivation by HSV US3 kinase while other viruses such as HIV, hepatitis virus, and even novel SARS-CoV-2 have also been reported to cause EBV reactivation. The eukaryotic pathogens such as Plasmodium falciparum and Aspergillus flavus can also reactivate EBV either by surface protein interaction or as an impact of aflatoxin, respectively. To highlight the underexplored niche of EBV reactivation by biological agents, we have comprehensively presented the related information in this review. This may help to shedding the light on the research gaps as well as to unveil yet unexplored mechanisms of EBV reactivation.

Children Are Not Small Adults: Similarities and Differences in Renal Transplantation Between Adults and Pediatrics

Kidney transplantation is the treatment of choice for all patients with end-stage kidney disease, including pediatric patients. Graft survival in pediatrics was lagging behind adults, but now is comparable with the adult cohort. Although many of the protocols have been adopted from adults, there are issues unique to pediatrics that one should be aware of to take care of this population. These issues include recipient size consideration, increased incidence of viral infections, problems related to growth, common occurrence of underlying urological issues, and psychosocial issues. This article addresses the similarities and differences in renal transplantation, from preparing a patient for transplant, the transplant process, to post-transplant complications.

Considerations and controversies of pharmacologic management of the pediatric kidney transplant recipient

Pediatric kidney transplantation has experienced considerable growth and improvement in patient and allograft outcomes over the past 20 years, in part due to advancements in immunosuppressive regimens and management. Despite this progress, care for this unique population can be challenging due to limited pediatric transplant data and trials, intricacies related to differences in children and adolescents compared with their adult counterparts, and limitations to long-term survival facing all solid organ transplant populations. Immunosuppression and infection prevention practices vary from one pediatric transplant center to another and clinical controversies exist surrounding treatment and dosing. This review aims to summarize key aspects of pharmacologic management in this population and present pertinent data that describe the influence of practice to serve as a resource for practitioners caring for this unique specialty patient population. Additionally, this review highlights select controversies that exist within pediatric kidney transplantation.

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

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

Donor-derived Viral Infections in Liver Transplantation

Donor-derived infections are defined as any infection present in the donor that is transmitted to 1 or more recipients. Donor-derived infections can be categorized into 2 groups: "expected" and "unexpected" infections. Expected transmissions occur when the donor is known to have an infection, such as positive serology for cytomegalovirus, Epstein Barr virus, or hepatitis B core antibody, at the time of donation. Unexpected transmissions occur when a donor has no known infection before donation, but 1 or more transplant recipients develop an infection derived from the common donor. Unexpected infections are estimated to occur in far less than 1% of solid organ transplant recipients. We will review the epidemiology, risk factors, and approaches to prevention and management of donor-derived viral infectious disease transmission in liver transplantation.

Management of post-transplant lymphoproliferative disorders

PURPOSE OF REVIEW

Post-transplant lymphoproliferative disease (PTLD) is a major complication of hematopoietic stem cell and solid organ transplantation. The incidence of transplantation in childhood has been steadily rising, making PTLD the most common form of lymphoproliferation in childhood. The purpose of this review is to summarize the role of the Epstein-Barr virus (EBV) in the pathophysiology and discuss the management of PTLD.

RECENT FINDINGS

More than 90% of pediatric PTLD is EBV-positive. In immunocompetent hosts, the virus is controlled by cytotoxic T-cells, the cells targeted by immunosuppression to avoid graft-versus-host disease and/or organ rejection in transplant patients. The majority of pediatric transplant candidates are EBV-negative prior to transplant increasing the risk of EBV-induced lymphoproliferation upon seroconversion after transplant. Treatment options include reduction of immunosuppression, anti-CD20 monoclonal antibodies, and/or chemotherapy. Advanced understanding of the importance of cellular immunity in controlling lymphoproliferation has led to the development of cellular therapies targeting virus-specific antigens.

SUMMARY

PTLD is the most common form of lymphoproliferation in childhood due to the rising incidence of transplantation. EBV plays a pivotal role in the pathophysiology. Cellular therapies targeting viral antigens may replace chemotherapy in the treatment of PTLD in the near future.

Post-transplant lymphoproliferative disorder of the pediatric airway: Presentation and management

OBJECTIVE

Post-transplant lymphoproliferative disorder (PTLD) is a rare complication of immunosuppression with little consensus on its evaluation and management. The purpose of this contemporary review is to describe a pediatric patient with PTLD of the airway and review the literature to provide multidisciplinary recommendations regarding management.

DATA SOURCES

Retrospective chart and literature review.

REVIEW METHODS

A pediatric patient with PTLD of the airway is described. An extensive literature search to review the existing data on pediatric PTLD of the upper airway was also performed.

RESULTS

A pediatric patient with mixed fetal/embryonal hepatoblastoma developed laryngo-tracheal PTLD following liver transplantation. Diagnostic positron emission tomography (PET) scan demonstrated multiple sites of abnormal fluorodeoxyglucose (FDG) uptake within the larynx, distal esophagus, cervical lymph nodes, and abdomen concerning for PTLD. Laryngeal biopsy demonstrated Epstein-Barr virus (EBV) positive cells confirming the diagnosis. Rituximab therapy and reduction of immunosuppression resulted in resolution of his laryngeal disease in 3 months. An extensive literature search to review the existing data on pediatric PTLD of the larynx and trachea revealed 14 reported cases.

CONCLUSIONS

PTLD of the pediatric airway is an EBV-associated disease that requires a high index of suspicion as patients can often present with non-specific signs and symptoms but progress to have significant airway compromise. Evaluation consists of peripheral blood polymerase chain reaction (PCR) assays, biopsy, and PET/CT imaging. Management options include reduction of immunosuppression and/or systemic therapies.

Post-transplant lymphoproliferative disease in pediatric solid organ transplant recipients

Post-transplant lymphoproliferative disease (PTLD) in solid organ transplant (SOT) recipients has become one of the most common forms of lymphoproliferation in childhood and is a serious complication of SOT. More than 90% of cases are of B-cell origin, Epstein Barr virus (EBV) positive and are mostly occurring in the early post-transplant period. Pathologically and clinically it is a heterogenous disease ranging from being responsive to reduced immunosuppression without further intervention to rapidly progressive fulminant PTLD requiring prompt initiation of therapy. Prognosis overall is favorable. Current treatment strategies as well new promising targeted immune-based therapies such as rituximab and EBV-specific cytotoxic T-lymphocytes are being discussed.

Infections caused by herpes viruses other than cytomegalovirus in solid organ transplant recipients

Despite great advances in solid organ transplantation (SOT) in recent decades, infection remains a major cause of morbidity and mortality among SOT recipients. Members of the herpesvirus family are the most common viral pathogens causing disease in this patient population. Herpes viruses are large enveloped DNA viruses that commonly reactivate during periods of severe immunosuppression. Currently, infections caused by herpes viruses continue to complicate clinical management of transplant patients. Although cytomegalovirus (CMV) is the most important virus of this family and is the subject of active research, herpes simplex virus (HSV) and varicella-zoster virus (VZV) can also lead to severe disease. Epstein-Barr virus (EBV) associated with post-transplant lymphoproliferative disease is increasingly recognized as a major complication of SOT. There is less information available on the role and impact of other viruses of the herpesvirus family, such as the human herpes virus 6 (HHV-6), human herpes virus 7 (HHV-7) and human herpes virus 8 (HHV-8). This review summarizes current knowledge regarding epidemiology, clinical manifestations, diagnosis, treatment and prevention of infections caused by herpes viruses other than CMV in SOT recipients.