Features of Epstein-Barr virus reactivation after allogeneic hematopoietic cell transplantation in Korean children living in an area of high seroprevalence against Epstein-Barr virus

Who is the patient at risk for EBV reactivation and disease: expert opinion focused on post-transplant lymphoproliferative disorders following hematopoietic stem cell transplantation

INTRODUCTION

Post-transplant lymphoproliferative disorders (PTLD) represent a diverse group of diseases. They develop as a consequence of uncontrolled proliferation of lymphoid or plasmacytic cells resulting from T-cell immunosuppression after transplantation of either hematopoietic cells (HCT) or solid organs (SOT), caused mainly by latent Epstein-Barr virus (EBV). The risk for EBV recurrence is dependent on the level of incompetency of the immune system, presented as an impairment of T-cell immunity.

AREAS COVERED

This review summarizes the data on incidence and risk factors of EBV infection in patients after HCT. The median rate of EBV infection in HCT recipients was estimated at 30% after allogeneic and<1% after autologous transplant; 5% in non-transplant hematological malignancies; 30% in SOT recipients. The median rate of PTLD after HCT is estimated at 3%. The most frequently reported risk factors for EBV infection and disease include: donor EBV-seropositivity, use of T-cell depletion, especially with ATG; reduced-intensity conditioning; mismatched family or unrelated donor transplants; and acute or chronic graft-versus-host-disease.

EXPERT OPINION

The major risk factors for EBV infection and EBV-PTLD can be easily identified: EBV-seropositive donor, depletion of T-cells, and the use of immunosuppressive therapy. Strategies for avoiding risk factors include elimination EBV from the graft and improving T-cell function.

Outcomes of haploidentical bone marrow transplantation in patients with severe aplastic anemia-II that progressed from non-severe acquired aplastic anemia

Severe aplastic anemia II (SAA-II) progresses from non-severe aplastic anemia (NSAA). The unavailability of efficacious treatment has prompted the need for haploidentical bone marrow transplantation (haplo-BMT) in patients lacking a human leukocyte antigen (HLA)-matched donor. This study aimed to investigate the efficacy of haplo-BMT for patients with SAA-II. Twenty-two patients were included and followed up, and FLU/BU/CY/ATG was used as conditioning regimen. Among these patients, 21 were successfully engrafted, 19 of whom survived after haplo-BMT. Four patients experienced grade II-IV aGvHD, including two with grade III-IV aGvHD. Six patients experienced chronic GvHD, among whom four were mild and two were moderate. Twelve patients experienced infections during BMT. One was diagnosed with post-transplant lymphoproliferative disorder and one with probable EBV disease, and both recovered after rituximab infusion. Haplo-BMT achieved 3-year overall survival and disease-free survival rate of 86.4% ± 0.73% after a median follow-up of 42 months, indicating its effectiveness as a salvage therapy. These promising outcomes may support haplo-BMT as an alternative treatment strategy for patients with SAA-II lacking HLA-matched donors.

Factors Associated with Post-Transplant Active Epstein-Barr Virus Infection and Lymphoproliferative Disease in Hematopoietic Stem Cell Transplant Recipients: A Systematic Review and Meta-Analysis

This systematic review was undertaken to identify risk factors associated with post-transplant Epstein–Barr virus (EBV) active infection and post-transplant lymphoproliferative disease (PTLD) in pediatric and adult recipients of hematopoietic stem cell transplants (HSCT). A literature search was conducted in PubMed and EMBASE to identify studies published until 30 June 2020. Descriptive information was extracted for each individual study, and data were compiled for individual risk factors, including, when possible, relative risks with 95% confidence intervals and/or p-values. Meta-analyses were planned when possible. The methodological quality and potential for bias of included studies were also evaluated. Of the 3362 titles retrieved, 77 were included (62 for EBV infection and 22 for PTLD). The overall quality of the studies was strong. Several risk factors were explored in these studies, but few statistically significant associations were identified. The use of anti-thymocyte globulin (ATG) was identified as the most important risk factor positively associated with post-transplant active EBV infection and with PTLD. The pooled relative risks obtained using the random-effect model were 5.26 (95% CI: 2.92–9.45) and 4.17 (95% CI: 2.61–6.68) for the association between ATG and post-transplant EBV infection and PTLD, respectively. Other risk factors for EBV and PTLD were found in the included studies, such as graft-versus-host disease, type of conditioning regimen or type of donor, but results are conflicting. In conclusion, the results of this systematic review indicate that ATG increases the risk of EBV infection and PTLD, but the link with all other factors is either nonexistent or much less convincing.

Epstein-Barr virus reactivation after allogeneic hematopoietic stem cell transplantation: multifactorial impact on transplant outcomes

Epstein-Barr virus (EBV) reactivation after allogeneic hematopoietic cell transplantation (allo-HCT) is one of the major concerns that may lead to fatal EBV diseases. However, updated data are needed because of the remarkable evolution of the HCT protocol and donor selection. We conducted a retrospective study that enrolled 890 allo-HCT recipients. Independent risk factors for EBV reactivation were use of antithymocyte globulin, haploidentical donor, and the presence of chronic graft-versus-host disease. The cumulative incidence of EBV reactivation was 2.9%, 11.7%, 27.3%, and 41.9% for patients with 0, 1, 2, and 3 risk factors, respectively (P < 0.001). Posttransplant lymphoproliferative disorders (PTLDs) occurred in seven patients. EBV reactivation was associated with inferior survival in recipients who survived more than 2 years post-HCT (P < 0.001) but might time-dependently benefit those patients with malignancies by decreasing relapse incidence (P = 0.046). A decreased relapse incidence was observed 1 year after HCT for recipients at first or second remission (P = 0.042) and in the first year post-HCT for recipients with advanced diseases (P = 0.032). We concluded that with current management, PTLDs were efficiently controlled, but EBV reactivation still had a multifactorial impact on transplant outcomes. Multicenter prospective studies are warranted to validate these findings.

Rationale for assessing the therapeutic potential of resveratrol in hematological malignancies

Promising results from pre-clinical studies on the naturally-occurring polyphenol resveratrol have generated considerable interest and somewhat excessive expectations regarding the therapeutic potential of this compound for treating or preventing various diseases, including cardiovascular and neurodegenerative disorders and cancer. Resveratrol has potent inhibitory activity in vitro against various tumor types, including cell lines derived from virtually all blood malignancies. Pharmacological studies have shown that resveratrol is safe for humans but has poor bioavailability, due to its extensive hepatic metabolism. Curiously, a substantial proportion of the orally administered resveratrol can reach the bone marrow compartment. Notably, various pathways dysregulated in blood cancers are known to be molecular targets of resveratrol, thus substantiating the potential utility of this agent in blood malignancies. In this review, we primarily focus on the scientific evidence that supports the potential utility of resveratrol for the management of select hematological malignancies. In addition, potential clinical trials with resveratrol are suggested.

Management of Epstein-Barr Virus infections and post-transplant lymphoproliferative disorders in patients after allogeneic hematopoietic stem cell transplantation: Sixth European Conference on Infections in Leukemia (ECIL-6) guidelines

Epstein-Barr virus-related post-transplant lymphoproliferative disorders are recognized as a significant cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation. To better define current understanding of post-transplant lymphoproliferative disorders in stem cell transplant patients, and to improve its diagnosis and management, a working group of the Sixth European Conference on Infections in Leukemia 2015 reviewed the literature, graded the available quality of evidence, and developed evidence-based recommendations for diagnosis, prevention, prophylaxis and therapy of post-transplant lymphoproliferative disorders exclusively in the stem cell transplant setting. The key elements in diagnosis include non-invasive and invasive methods. The former are based on quantitative viral load measurement and imaging with positron emission tomography; the latter with tissue biopsy for histopathology and detection of Epstein-Barr virus. The diagnosis of post-transplant lymphoproliferative disorder can be established on a proven or probable level. Therapeutic strategies include prophylaxis, preemptive therapy and targeted therapy. Rituximab, reduction of immunosuppression and Epstein-Barr virus-specific cytotoxic T-cell therapy are recommended as first-line therapy, whilst unselected donor lymphocyte infusions or chemotherapy are options as second-line therapy; other methods including antiviral drugs are discouraged.

Varicella zoster virus infection after allogeneic hematopoietic cell transplantation in children using a relatively short duration of acyclovir prophylaxis: A retrospective study

Although acyclovir prophylaxis against varicella zoster virus (VZV) infection for ≥1 year is recommended after allogeneic hematopoietic cell transplantation (HCT), the emergence of acyclovir-resistant viruses and adverse drug effects cannot be ignored. We investigated the cumulative incidence of VZV infection after allogeneic HCT in children receiving a shorter duration of acyclovir prophylaxis than recommended and evaluated the appropriateness of the short duration of acyclovir prophylaxis.Medical records of 217 children who received allogeneic HCT were retrospectively reviewed until a median of 25 months (range = 1-59 months) after HCT. Acyclovir prophylaxis was given for a median of 9 weeks (range = 3-24 weeks) after HCT.VZV infection was diagnosed in 33 (15.2%) children at a median time of 5 months (range = 2-41 months) after HCT. The 1-year and 2-year cumulative incidences of VZV infection after allogeneic HCT were 11.2% and 15.5%, respectively. These incidences were between the previously reported 1-year incidence of 25% to 30% in patients not receiving prophylaxis and 1-year incidence of 4% to 5% in patients receiving ≥1 year duration of prophylaxis. Male sex and older age were significantly associated with VZV infection after allogeneic HCT. Only 1 chickenpox patient experienced severe complications because of VZV infection, and there were no deaths attributable to VZV infection.In conclusion, a shorter duration of acyclovir prophylaxis may be appropriate for children receiving allogeneic HCT, based on the rare occurrence of severe complications because of VZV infection and the expected discomfort because of daily oral medication for a long time.

Epstein-Barr Virus-related Posttransplant Lymphoproliferative Disorder in Children: A Single-institution Experience

We report 4 pediatric cases of biopsy-proven posttransplant lymphoproliferative disorder (PTLD) in the context of allogeneic hematopoietic stem cell transplantation (HSCT). All cases showed diffuse staining with latent membrane protein-1 in immunohistochemistry. The median age at transplant of 4 patients with PTLD was 10.1 years (range, 2.2 to 13.2 y). The median interval between HSCT and the diagnosis of PTLD was 5.5 months (range, 4 to 8 mo). All patients were treated with rituximab at dosage of 375 mg/m at weekly intervals. Reduction of immunosuppression was warranted in all cases. All patients survived with median follow-up duration of 27 months. Although PTLD has been rare following allogeneic HSCT, reduction of immunosuppression combined with rituximab yielded significant response rates in patients with this infrequent but potentially lethal complication. The preliminary finding of this study demonstrated that severe aplastic anemia is closely associated with the development of PTLD in children.