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

Post-transplant indolent T cell lymphoproliferative disorder in living donor liver transplantation: a case report

Background

Post-transplant lymphoproliferative disorder (PTLD) of T cell type has been rarely reported. Accurate diagnosis of this life-threatening rare form of PTLD is important for the treatment strategy.

Case presentation

A 7-year-old boy had severe diarrhea and weight loss progressively at 7 years post-living donor liver transplantation (LDLT) for biliary atresia. Endoscopy in the gastrointestinal (GI) tract revealed multiple erosions and ulcer lesions with prominent intraepithelial lymphocytosis in the duodenum and terminal ileum. Immunohistochemical examination demonstrated that these accumulated lymphocytes mainly comprised small- to medium-sized T cells expressing CD3, CD4, CD5, CD7, and CD103, but lacking CD8, CD56, and Epstein-Barr virus-encoded small RNAs. In addition, T cell receptor β gene rearrangement was detected by polymerase chain reaction analysis. Comprehensively, the lesions were best interpreted as post-transplant indolent T cell lymphoproliferative disorder (LPD) of the intestine. Clinical remission was achieved by reducing the immunosuppressant.

Conclusion

A rarely reported indolent type of T cell LPD in post-LDLT was diagnosed by direct inspection and histological investigation. Although the histological classification and therapeutic strategy for post-transplant indolent T cell LPD have not been established, reducing immunosuppression allowed complete remission in our case. To prevent the incidence of PTLD and de novo malignancy, developing a methodology to set a proper dose of immunosuppressant is required.

Noninfectious pulmonary complications of haematopoietic stem cell transplantation

Haematopoietic stem cell transplantation (HSCT) is an established treatment for a variety of malignant and nonmalignant conditions. Pulmonary complications, both infectious and noninfectious, are a major cause of morbidity and mortality in patients who undergo HSCT. Recent advances in prophylaxis and treatment of infectious complications has increased the significance of noninfectious pulmonary conditions. Acute lung injury associated with idiopathic pneumonia syndrome remains a major acute complication with high morbidity and mortality. On the other hand, bronchiolitis obliterans syndrome is the most challenging chronic pulmonary complication facing clinicians who are taking care of allogeneic HSCT recipients. Other noninfectious pulmonary complications following HSCT are less frequent. This review provides a clinical update of the incidence, risk factors, pathogenesis, clinical characteristics and management of the main noninfectious pulmonary complications following HSCT.

Noninfectious pulmonary complications following haematopoietic stem cell transplantation is a major cause of morbidity and mortality in this patient population. There are recent advances in the diagnosis and management of these conditions.http://bit.ly/2FgsIYG

Epstein-Barr virus infections are strongly dependent on activating and inhibitory KIR-HLA pairs after T-cell replate unrelated hematopoietic stem cell transplantation, the principles, and method of pairing analysis

Viral infections are the main cause of increased morbidity and mortality among recipients in allogeneic hematopoietic stem cell transplantation (HSCT). Natural killer (NK) cells fight virally infected cells provided directional activation of cytotoxicity. In this study, we analyzed the role of receptor-ligand pairs that include inhibitory or activating killer cell immunoglobulin-like receptors (KIRs) with their HLA class I ligands in the course of viral infections. The paper also presents an algorithm that allows performing automated inhibitory (i) KIR:HLA pairing and rechecking in the clinical setting. The obtained results indicate a significant adverse roles of reduced number of iKIR:HLA pairs (40% vs 9%; odds ratio [OR] = 6.67; P = .0057; 95% confidence interval [CI] 1.74-25.62) and the presence of activating KIR:HLA pairs (15% vs 5%, OR = 3.58, P = .028, 95% CI 1.19-10.73) in EBV infections post HSCT.

Relationship between rabbit anti-thymocyte globulin and development of PTLD and its aggressive form in renal transplant population

Introduction

The aim of our study is to explore the relationship of rabbit anti-thymocyte globulin (R-ATG) on development of post-transplant lymphoproliferative disease (PTLD) and its aggressive forms (monomorphic PTLD and Hodgkin lymphoma) in renal transplant recipients.

Methodology

All patients diagnosed with PTLD post-renal transplant in the United States’ Organ Procurement and Transplantation Network from 2003 till 2013 and followed up till 2017 were retrospectively reviewed. Multi-variable logistic regression analysis assessed association of R-ATG to development of PTLD and its aggressive form.

Results

Risk of developing PTLD post renal transplant is 1.35%. In comparison to interleukin-2 blocker induction therapy, R-ATG is associated with increased risk of development of PTLD (Odds Ratio = 1.48, confidence interval ranges from 1.04 to 2.11, p = .02) and is associated with higher risk of development of aggressive PTLD (Odds Ratio = 1.83, confidence interval ranges from 1.001 to 3.34, p = .04).

Conclusion

We conclude that R-ATG induction is associated with a higher risk of PTLD and its aggressive form (monomorphic PTLD and Hodgkin lymphoma). Careful monitoring for development of PTLD in renal transplant recipients receiving R-ATG induction therapy is advised.

Uniform graft-versus-host disease prophylaxis with posttransplant cyclophosphamide, sirolimus, and mycophenolate mofetil following hematopoietic stem cell transplantation from haploidentical, matched sibling and unrelated donors

Following the success of posttransplant cyclophosphamide (PT-CY) as graft-versus-host disease (GVHD) prophylaxis in haploidentical transplantation, this prevention strategy has progressively been used for allogeneic hematopoietic stem cell transplantation (allo-HSCT) from HLA-matched sibling (MSD) and unrelated donor (MUD). We have introduced PT-CY plus sirolimus and micophenolate mofetil (PT-CY-Sir-MMF) as GVHD prophylaxis in allo-HSCT, irrespective of donor type. This study reports on the safety and efficacy of PT-CY-Sir-MMF in 158 consecutive allo-HSCT from MSD (n = 52), MUD (n = 64), and haploidentical (n = 42) donor. Median age was 53 years and 66% had acute leukemia or myelodysplastic syndrome. Cumulative incidences of acute GHVD grade II-IV, III-IV and moderate to severe cGVHD were 27%, 9% and 27%, respectively. The incidence of hepatic sinusoidal obstruction syndrome was 9.5%. The 1-year cumulative incidence of non-relapse mortality, relapse and event-free survival were 14%, 12% and 75%, respectively. Compared with MSD and MUD, haploidentical transplantation had a higher incidence of CMV DNAemia requiring therapy (34% vs 35% and 52%, respectively, p = 0.04) and was a risk factor for grade III-IV acute GVHD (RR 2.8, p = 0.05). Our study shows that PT-CY-Sir-MMF is not only feasible and effective in preventing GVHD after haploidentical HSCT, but also in allo-HSCT from MSD and MUD.

Management of Epstein-Barr virus-related post-transplant lymphoproliferative disorder after allogeneic hematopoietic stem cell transplantation

Epstein–Barr virus-related post-transplant lymphoproliferative disorder (EBV-PTLD) is a rare but life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). T-cell immunodeficiency after transplantation and EBV primary infection/reactivation play major roles in the pathogenesis. Unspecific clinical manifestations make the diagnosis difficult and time consuming. Moreover, this fatal disease usually progresses rapidly, and leads to multiple organ dysfunction or death if not treated promptly. Early diagnosis of EBV-DNAemia or EBV-PTLD generally increases the chances of successful treatment by focusing on regular monitoring of EBV-DNA and detection of symptomatic patients as early as possible. Rituximab ± reduction of immunosuppression (RI) is currently the first-line choice in preemptive intervention and targeted treatment. Unless patients are suffering from severe graft versus host disease (GvHD), it is better to combine rituximab with RI. Once a probable diagnosis is made, the first-line treatment should be initiated rapidly, along with, or ahead of, biopsy, although histopathologic confirmation is requisite. In addition, EBV-specific cytotoxic T lymphocytes (EBV-CTLs) or donor lymphocyte infusion (DLI) has shown promise in cases of suboptimal response. Chemotherapy ± rituximab might lend more opportunities to refractory/relapsed patients, who might also benefit from ongoing clinical trials. Herein, we discuss our clinical experience in detail based on the current literature and our five cases.

Adoptive cell therapies for posttransplant infections

PURPOSE OF REVIEW

Viral and fungal infections cause significant morbidity and mortality following hematopoietic stem-cell transplantation (HSCT), primarily due to the prolonged and complex immunodeficient state that results from conditioning chemo-radiotherapy and subsequent prophylaxis of graft vs. host disease. Although currently available antimicrobial pharmacotherapies have demonstrated short-term efficacy, their toxicities often preclude long-term use, and cessation if frequently associated with recurrent infection. Adoptive cell therapy (ACT) offers the potential to more rapidly reconstitute antimicrobial immune responses in the posttransplant setting.

RECENT FINDINGS

Traditional approaches to manufacture of adoptive T-cell therapies are time consuming and limited to single pathogen specificity. Recent advances in the understanding of immunogenic epitopes, improved methods for pathogen-specific T-cell isolation and cultureware technologies is allowing for rapid generation of ACTs for clinical use.

SUMMARY

The current review summarizes the potential infectious targets and manufacturing methodologies for ACTs and contrasts their clinical efficacy and safety to currently available pharmacotherapies for patients recovering after HSCT.

Epstein-Barr virus related post-transplant lymphoproliferative disorder prevention strategies in allogeneic hematopoietic stem cell transplantation

Epstein-Barr virus associated post-transplant lymphoproliferative disorders (EBV PTLD) are recognized as a significant cause of morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT). The number of patients at risk of developing EBV PTLD is increasing, partly as a result of highly immunosuppressive regimens, including the use of anti-thymocyte globulin (ATG). Importantly, there is heterogeneity in PTLD management strategies between alloHSCT centers worldwide. This review summarizes the different EBV PTLD prevention strategies being utilized including the alloHSCT and T-cell depletion regimes and the risk they confer; monitoring programs, including the timing and analytes used for EBV virus detection, as well as pre-emptive thresholds and therapy with rituximab. In the absence of an institution-specific policy, it is suggested that the optimal pre-emptive strategy in HSCT recipients with T-cell depleting treatments, acute graft vs host disease (GVHD) and a mismatched donor for PTLD prevention is (a) monitoring of EBV DNA post-transplant weekly using plasma or WB as analyte and (b) pre-emptively reducing immune suppression (if possible) at an EBV DNA threshold of >1000 copies/mL (plasma or WB), and treating with rituximab at a threshold of >1000 copies/mL (plasma) or >5000 copies/mL (WB). There is emerging evidence for prophylactic rituximab as a feasible and safe strategy for PTLD, particularly if pre-emptive monitoring is problematic. Future management strategies such as prophylactic EBV specific CTLs have shown promising results and as this procedure becomes less expensive and more accessible, it may become the strategy of choice for EBV PTLD prevention.

Comparison of ATG-thymoglobulin with ATG-Fresenius for Epstein-Barr virus infections and graft-versus-host-disease in patients with hematological malignances after haploidentical hematopoietic stem cell transplantation: a single-center experience

Two anti-thymocyte globulin (ATG) forms are used in graft-versus-host disease (GVHD) prophylaxis during haploidentical hematopoietic stem cell transplantations (haplo-HSCTs): ATG-thymoglobulin (ATG-T) and ATG-fresenious (ATG-F). However, comparable dosages for haplo-HSCT remain unclear. We compared and evaluated the effects of ATG-T (7.5 mg/kg) or ATG-F (20 mg/kg) dosages in a relatively homogenous population in haplotype HSCT settings. Patients administered ATG-T 7.5 mg/kg (n = 81) or ATG-F 20 mg/kg (n = 35) as part of GVHD prophylaxis during haplo-HSCT were enrolled. Incidence and severity of GVHD, Epstein–Barr virus (EBV) infection, and immune cell recovery were compared using the Mann-Whitney U rank test and chi-square test. Cumulative incidences of GVHD, EBV infection and its subgroups, and relapse mortality were computed; overall survival (OS) was analyzed using the Kaplan-Meier method, with the log-rank test used for univariate comparison. Risk factors for OS were analyzed by the Cox proportional hazards model. Incidence and cumulative incidence of all grades of acute GVHD and subgroups were comparable in both groups (all p > 0.05); however, cumulative incidence of any grade and limited chronic GVHD was significantly higher in the ATG-T group (p = 0.002, p = 0.007, respectively). Cumulative incidences of EBV infections, EBV-DNAemia, and EBV-related diseases were similar; relapse mortality and OS rates were comparable between both groups (all p > 0.05). ATG-T dosage (7.5 mg/kg) appeared comparable to ATG-F dosage (20 mg/kg) for haplo-HSCT. Currently approved ATG-T and ATG-F doses appear efficient to balance the risk–benefit ratio of GVHD, OS, relapse mortality, and EBV infection in haplo-HSCT.

Incidence, risk factors, and clinical outcomes associated with Epstein-Barr virus-DNAemia and Epstein-Barr virus-associated disease in patients after haploidentical allogeneic stem cell transplantation: A single-center study

Human leukocyte antigen (HLA)-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is an effective alternative to HLA-matched transplantation. However, Epstein-Barr virus (EBV) infection causes morbidity and mortality in patients undergoing haplo-HSCT. Here, we retrospectively evaluated the incidence and risk factors of EBV-DNAemia and EBV-associated diseases in 131 patients who underwent haplo-HSCT. Patients were classified into the no EBV infection groups, EBV-DNAemia group and EBV-associated disease group. Cumulative incidences of acute graft-vs-host disease, EBV infections, overall survival (OS), and relapse were analyzed. The cumulative incidences of EBV-DNAemia and EBV-associated disease were 26.9% and 33.3%, respectively. In multivariate analysis, cytomegalovirus (CMV)-DNAemia was confirmed as an independent risk factor associated with EBV-DNAemia and EBV-associated disease. Patients with EBV-associated disease had higher transplant-related mortality (TRM) rates and lower OS rates, but similar relapse rates. Overall, these findings demonstrated the cumulative incidences of EBV-DNAemia and EBV-associated disease and identified correlations of EBV infection with TRM, relapse, and OS. Additionally, CMV-DNAemia was a risk factor for EBV-DNAemia and EBV-associated disease.

A retrospective analysis on anti-CD20 antibody-treated Epstein-Barr virus-related posttransplantation lymphoproliferative disorder following ATG-based haploidentical T-replete hematopoietic stem cell transplantation

Posttransplantation lymphoproliferation disorder (PTLD) is a life-threatening complication after hematopoietic stem cell transplantation (HSCT). Anti-CD20 antibody is the most widely used antibody to eliminate infected B cells. Few studies have focused on prognostic factors predicting the outcome of EBV (Epstein-Barr virus)-PTLD. We conducted a retrospective analysis of 2571 haplo-HSCTs performed between 2010 and 2017 at the Peking University Institute of Hematology; seventy patients who had been treated with rituximab for PTLD were enrolled. The overall EBV-related PTLD frequency was 3.1%. With a median follow-up time of 365 days (range, 54-2659), the overall survival rate was 51.43% (36/70). The cumulative incidence of EBV-PTLD complete remission with anti-CD20 antibody monotherapy was 68.57% (48/70). EBV-PTLD-related mortality was 11.43% (8/70), while the transplantation-related mortality was 38.57% (27/70). Multivariate analysis showed that a decrease in EBV viral load 1 week after therapy was associated with high response rate of EBV-PTLD (p = 0.007, 0.106 (0.021-0.549)), low PTLD-related mortality (p = 0.010, HR 0.058 (0.007-0.503)), and transplantation-related mortality (p = 0.051, HR 0.441 (0.194-1.003)). For EBV-PTLD patients after haplo-HSCT who received rituximab as first-line therapy, non-decreased EBV viral load 1 week after anti-CD20 therapy could be high risk factor for poor outcomes.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key “safety net” in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible “safety net” for these immunocompromised hosts.

LMP1-specific cytotoxic T cells for the treatment of EBV-related post-transplantation lymphoproliferative disorders

Epstein-Barr virus-specific cytotoxic T lymphocytes (EBV-CTLs) represent a promising treatment option for EBV-associated post-transplantation lymphoproliferative disorders (PTLD). However, production of EBV-CTLs is often complicated and expensive. In the present study, we sought to establish an easy-to-use and economical production protocol for EBV-CTLs. EBV-CTLs were generated using latent membrane protein 1 (LMP1) peptides based on a modified generation protocol of cytokine-induced killer (CIK) cells. After 2-week culture, cells were well expanded (median total cell number: 9.82 × 10⁹; median expansion fold: 107.8) and the median EBV LMP1-specific CD8⁺ T cell number was 8.94 × 10⁸ (median frequency: 6.7%). However, the EBV-CTL products, unlike CIK cells, did not exhibit NK-like anti-tumor activity. Furthermore, the clinical efficacy of EBV-CTLs was demonstrated with a successful treatment of PTLD on a compassionate use basis in a patient following haploidentical hematopoietic stem cell transplantation. This study indicates the safety and efficacy of EBV LMP1-specific CTLs generated based on a modified generation protocol of CIK cells. Further investigation in a well-designed clinical study is warranted.

Pre-transplant sTIM-3 levels may have a predictive impact on transplant outcome in acute leukemia patients

Objectives: T-cell immunoglobulin and mucin domain-containing protein-3 (TIM-3) is considered as a negative regulator of T-cell driven immune response. This study is planned to investigate the prognostic role of pre-transplant soluble TIM-3 (sTIM-3) levels in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Methods: Pre-transplant serum sTIM-3 levels were measured in 177 allo-HSCT recipients [median age: 36(16-66) years; male/female: 111/66]. Results: Pre-transplant sTIM-3 levels were significantly higher in acute myeloid leukemia (AML) patients compared to acute lymphoblastic leukemia (ALL) patients (p = 0.01). Pre-transplant sTIM-3 levels were significantly lower in patients with abnormal cytogenetics (p = 0.017). Pre-transplant sTIM-3 levels were significantly higher in patients who developed viral hemorrhagic cystitis (p = 0.034). A positive correlation was demonstrated between sTIM-3 levels and acute graft versus host disease (GvHD) grade (p = 0.013; r = 0.299). Overall survival (OS) was not statistically different between low- and high-TIM-3 groups (%35.2 vs %20.4; p > 0.05). Primary diagnosis (p = 0.042), sinusoidal obstruction syndrome (p < 0.001), acute GvHD (p = 0.001), chronic GvHD (p = 0.009) and post-transplant relapse (p = 0.003) represented significant impact on OS. Discussion: Increased sTIM-3 levels in AML patients seem to be compatible with the previous reports. The inhibitor role of TIM-3 in cellular immune response may be a possible explanation for the association of sTIM-3 with viral infections and GvHD. However, the main challenge remains to be the ambiguous association of pre-transplant sTIM-3 levels and post-transplant complications, as allo-HSCT recipients are expected to represent donor genetic features in the post-transplant setting. Conclusion: Further studies are warranted to clarify the particular role of sTIM-3 in the allo-HSCT setting.

Post-transplantation lymphoproliferative disorders: Current concepts and future therapeutic approaches

Transplant recipients are vulnerable to a higher risk of malignancy after solid organ transplantation and allogeneic hematopoietic stem-cell transplant. Post-transplant lymphoproliferative disorders (PTLD) include a wide spectrum of diseases ranging from benign proliferation of lymphoid tissues to frank malignancy with aggressive behavior. Two main risk factors of PTLD are: Firstly, the cumulative immunosuppressive burden, and secondly, the oncogenic impact of the Epstein-Barr virus. The latter is a key pathognomonic driver of PTLD evolution. Over the last two decades, a considerable progress has been made in diagnosis and therapy of PTLD. The treatment of PTLD includes reduction of immunosuppression, rituximab therapy, either isolated or in combination with other chemotherapeutic agents, adoptive therapy, surgical intervention, antiviral therapy and radiotherapy. In this review we shall discuss the prevalence, clinical clues, prophylactic measures as well as the current and future therapeutic strategies of this devastating disorder.

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.

Epstein-Barr Virus-Associated Post-Transplant Lymphoproliferative Disorders after Hematopoietic Stem Cell Transplantation: Pathogenesis, Risk Factors and Clinical Outcomes

Epstein-Barr virus (EBV) is a ubiquitous virus belonging to the human γ-herpes virus subfamily. After primary infection, EBV maintains a life-long latent infection. A major concern is that EBV can cause a diverse range of neoplasms and autoimmune diseases. In addition, patients undergoing hematopoietic stem cell transplantation or solid organ transplantation can experience post-transplant lymphoproliferative disorders (PTLDs) due to dysfunction or suppression of host’s immune system, or uncontrolled proliferation of EBV-infected cells. In recent years, the number of EBV-associated PTLD cases has increased. This review focuses on the current understandings of EBV-associated PTLD pathogenesis, as well as the risk factors and clinical outcomes for patients after allogeneic stem cell transplantation.

Late Noninfectious Pulmonary Complications in Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is an established therapeutic modality for a number of malignant and nonmalignant conditions. Pulmonary complications following HSCT are associated with increased mortality and morbidity. These complications may be classified into infectious versus noninfectious, and early versus late based on the time of occurrence post-transplant. Thus, exclusion of infectious etiologies is the first step in the diagnoses of pulmonary complications. Late onset noninfectious pulmonary complications typically occur 3 months post-transplant. Bronchiolitis obliterans is the major contributor to late-onset pulmonary complications, and its clinical presentation, pathogenesis, and current therapeutic approaches are discussed. Idiopathic pneumonia syndrome is another important complication which usually occurs early, although its onset may be delayed. Organizing pneumonia is important to recognize due to its responsiveness to corticosteroids. Other late onset noninfectious pulmonary complications discussed here include pulmonary venoocclusive disease, pulmonary cytolytic thrombi, pleuroparenchymal fibroelastosis, thoracic air leak syndrome, and posttransplant lymphoproliferative disorders.

Herpes Virus Infections Other than Cytomegalovirus in the Recipients of Hematopoietic Stem Cell Transplantation

This review discusses the epidemiologic and clinical aspects of herpes viruses other than cytomegalovirus in patients who have undergone hematopoietic stem cell transplantation.

Lymphocyte subset at time of Epstein-Barr viremia post-allogeneic hematopoietic stem cell transplantation in children may predict development of post-transplant lymphoproliferative disease: CD8:CD20 ratio as a sensitive predictor

EBV-associated PTLD following allogeneic HSCT is a serious complication associated with significant mortality. In this retrospective study, we evaluated whether lymphocyte subset numbers and CD8:CD20 ratio at time of EBV viremia in children undergoing allogeneic HSCT could predict development of PTLD. Absolute lymphocyte count, lymphocyte subsets, and CD8:CD20 ratio at the time of EBV viremia were analyzed. Patients who were treated preemptively with rituximab for high blood EBV viral load were excluded. Out of 266 patients transplanted during the study period, 26 patients were included in the analysis. Patients were divided into two cohorts; cohort 1 included patients with EBV-associated PTLD (n = 5; four with proven, one with probable PTLD). Cohort 2 included patients with EBV viremia without PTLD (n = 21). Lymphocyte recovery was slower in the PTLD group. CD8:CD20 ratio was significantly lower in the PTLD group (median 0.15) compared to the non-PTLD group (median 2.4, P = .012). Using the ROC curve and 1 as the cutoff value, CD8:CD20 ratios were analyzed. In the PTLD group, 4/5 patients (80%) had a ratio <1 whereas in the non-PTLD group, all 21 patients had a ratio >1. Sensitivity and specificity were 80% and 100%, respectively. Negative and PPVs were 95% and 100%, respectively. Profoundly low T-cell count and CD8:CD20 ratio may be used to predict development of PTLD in the context of EBV viremia in children post-allogeneic HSCT. Further studies are needed to validate this finding.

Non-uniform in vivo Expansion of Epstein-Barr Virus-Specific T-Cells Following Donor Lymphocyte Infusion for Post-transplant Lymphoproliferative Disease

Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) is a life-threatening complication of T-lymphocyte deplete allogeneic hematopoietic stem cell transplantation (allo-HSCT). For patients with PTLD refractory to Rituximab, donor lymphocyte infusion (DLI) is established as a successful option for salvage therapy. However, although in vivo lymphocyte expansion has been correlated with good clinical outcome following DLI, the specificity and functional characteristics of EBV-specific T-cell responses remain poorly characterized. Here we describe two patients with Rituximab-refractory PTLD complicating T-cell deplete allo-HSCT, both of whom were successfully rescued with 1 × 10⁶/Kg unselected stem cell donor-derived DLI. Prospective analyses revealed that complete clinical and radiological responses were associated with in vivo expansion of T and NK cells. Furthermore, EBV MHC tetramer, and interferon gamma analyses revealed a marked increase in EBV-specific T-cell frequency from 4 weeks after DLI. Reactivity was demonstrated against a range of EBV latent and lytic antigens, including those detected in tumor biopsy material. The immunodominant EBV-specific T cell response expanding in vivo following infusion matched the dominant response present in the DLI preparations prior to administration. Furthermore, differences in the repertoire of subdominant antigen-specific T-cells were also detected, suggesting that antigen-encounter in vivo can shape the immune response. These results demonstrate the value of prospectively studying in vivo T-cell responses, by facilitating the identification of important specificities required for clinical efficacy. Applying this approach on a larger scale promises to yield data which may be essential for the optimization of future adoptive immunotherapeutic strategies for PTLD.

Combination of HLA-Matched Sibling Allogeneic Hematopoietic Stem Cell Transplantation With Unrelated Cord Blood Unit in Patients Aged 35 to 50 Years With Severe Aplastic Anemia: Preliminary Summary of a Single-Arm Trial

This study reports a single-arm trial in the interim phase in 4 patients with median age of 40.5 years who have undergone combined HLA-matched sibling donor (MSD) stem cell graft and an unrelated cord blood (UCB) unit for the treatment of severe aplastic anemia (SAA). The median time was 10 days for neutrophil engraftment (9-18 days) and 17 days for platelets (12-24 days). Median follow-up of 22 months (ranging from 16 to 29 months) showed survival of the 4 patients with complete hematological response. Acute graft-vs-host disease (GVHD) (grade II) occurred only in 1 patient, yet chronic GVHD was free. One patient showed a pattern of transient MSD graft followed by dominant UCB chimerism, and another 1 achieved mixed chimerism in the first 6 months after allogeneic hematopoietic stem cell transplantation (allo-HSCT) then evolved to a stable MSD graft. The other 2 patients sustained a full MSD graft during the post-HSCT period. Nevertheless, none of the patients developed primary and secondary graft failure up to the final follow-up. Although this is a small cohort, the dual transplantation combining HLA-matched sibling allogeneic hematopoietic stem cell transplantation with unrelated cord blood unit may deserve further exploration for treatment of SAA patients aged 35 to 50 years old.

Prospective Randomized Study Comparing Myeloablative Unrelated Umbilical Cord Blood Transplantation versus HLA-Haploidentical Related Stem Cell Transplantation for Adults with Hematologic Malignancies

In this prospective randomized study, we compared the outcomes of single-unit umbilical cord blood transplantation (UCBT) and unmanipulated haploidentical stem cell transplantation (haplo-SCT) with post-transplantation cyclophosphamide (PTCy) in adults with hematologic malignancies. All patients received a myeloablative conditioning (MAC) regimen consisting of thiotepa, busulfan, and fludarabine, with antithymocyte globulin (ATG) added for UCBT recipients. Nineteen patients were randomized to UCBT and the other 26 to haplo-HSCT. Four patients (15%) allocated to the haplo-HSCT arm lacked a suitable donor and were crossed over to the UCBT arm. Finally, 23 underwent UCBT and 22 underwent haplo-HSCT. The cumulative incidence of neutrophil recovery was 87% at a median of 19 days (range, 13 to 24 days) in the UCBT arm versus 100% at a median of 17 days (range, 13 to 25 days) in the haplo-SCT arm (P = .04). Platelet recovery was 70% at a median of 40 days (range, 18 to 129 days) in the UCBT arm versus 86% at a median of 24 days (range, 12 to 127 days) in the haplo-HCT arm (P = .02). Rates of acute graft-versus-host disease (GVHD) grade II-IV or grade III-IV, overall chronic GVHD, and extensive chronic GVHD in the UCBT and Haplo-SCT arms were 43% versus 36% (P = .8), 9% versus 9% (P = 1), 66% versus 43% (P = .04), and 41% versus 23% (P = .2), respectively. Two-year nonrelapse mortality and relapse in the 2 arms were 52% versus 23% (P = .06) and 17% versus 23% (P = .5), respectively. Two-year disease-free survival, overall survival, and GVHD/relapse-free survival in the 2 arms were 30% versus 54% (P = .2), 35% versus 59% (P = .1), and 17% versus 40% (P = .04), respectively. Our data show that in the context of an MAC regimen, haplo-SCT with PTCy provides improved outcomes compared with ATG-containing single-unit UCBT.

Successful preemptive therapy with single-dose rituximab for Epstein-Barr virus infection to prevent post-transplant lymphoproliferative disease after pediatric hematopoietic stem cell transplantation

BACKGROUND

The efficacy of preemptive treatment containing rituximab to prevent post-transplant lymphoproliferative disease (PTLD) in children has not yet been fully elucidated.

METHODS

We analyzed 19 pediatric patients who developed high Epstein-Barr virus (EBV) DNAemia (EBV viral load of greater than 40 000 copies/mL) after allogeneic hematopoietic stem cell transplantation (HSCT) and were preemptively administered rituximab. Rituximab was intravenously injected at a dose of 375 mg/m² once the EBV viral load was greater than 40 000 copies/mL.

RESULTS

In all 19 patients, EBV DNAemia was eradicated after a median of 9 days (range, 3-20 days), and PTLD did not occur. One patient had transient fever, and four patients did not fully recover B cell counts after transplantation. We suggested that delayed B cell recovery was caused by chronic graft-versus-host disease (GVHD) related drugs, not rituximab administration. And there were no other infection-related side effects.

CONCLUSIONS

In conclusion, preemptive therapy containing rituximab is expected to reduce the incidence of PTLD after HSCT and improve post-transplantation outcomes in children.

Early Experience With CliniMACS Prodigy CCS (IFN-gamma) System in Selection of Virus-specific T Cells From Third-party Donors for Pediatric Patients With Severe Viral Infections After Hematopoietic Stem Cell Transplantation

Viral reactivation is a frequent complication of allogeneic hematopoietic stem cell transplantation especially in children. For refractory cases, rapid virus-specific T-cell therapy would be ideally implemented within a few days. Over the course of a year in our pediatric cohort of 43 allogeneic transplantation, 9 patients fulfilled criteria for virus-specific T-cell therapy. Viral infections were due to cytomegalovirus (CMV) in 3, Epstein-Barr virus (EBV) in 2, and adenovirus (AdV) in 1 case, whereas >1 virus was detected in 3 cases. Viral diseases necessitating a T-cell therapy were CMV pneumonitis and colitis, AdV enteritis and cystitis, and EBV-induced posttransplantation lymphoproliferative disease. Cells were produced by the CliniMACS Prodigy CCS (IFN-gamma) System within 24 hours after mononuclear leukapheresis. Eight patients became completely asymptomatic, whereas 7 also cleared the virus. Six patients are alive without viral illness or sequelae demonstrating viral DNA clearance in peripheral blood with a median follow-up of 535 (350-786) days. One patient with CMV pneumonitis died of respiratory insufficiency. In 2 cases the viral illness improved or cleared, however, the patients died of invasive aspergillosis. No cases of graft-versus-host disease, rejection, organ toxicity, or recurrent infection were noticed. Virus-specific T-cell therapy implemented by the CliniMACS Prodigy CCS (IFN-gamma) System is an automated, fast, safe, and probably effective way to control resistant viral diseases after pediatric hematopoietic stem cell transplantation.

Death after hematopoietic stem cell transplantation: changes over calendar year time, infections and associated factors

Information on incidence, and factors associated with mortality is a prerequisite to improve outcome after hematopoietic stem cell transplantation (HSCT). Therefore, 55'668 deaths in 114'491 patients with HSCT (83.7% allogeneic) for leukemia were investigated in a landmark analysis for causes of death at day 30 (very early), day 100 (early), at 1 year (intermediate) and at 5 years (late). Mortality from all causes decreased from cohort 1 (1980-2001) to cohort 2 (2002-2015) in all post-transplant phases after autologous HSCT. After allogeneic HSCT, mortality from infections, GVHD, and toxicity decreased up to 1 year, increased at 5 years; deaths from relapse increased in all post-transplant phases. Infections of unknown origin were the main cause of infectious deaths. Lethal bacterial and fungal infections decreased from cohort 1 to cohort 2, not unknown or mixed infections. Infectious deaths were associated with patient-, disease-, donor type, stem cell source, center, and country- related factors. Their impact varied over the post-transplant phases. Transplant centres have successfully managed to reduce death after HSCT in the early and intermediate post-transplant phases, and have identified risk factors. Late post-transplant care could be improved by focus on groups at risk and better identification of infections of "unknown origin".

Survival outcomes of allogeneic hematopoietic cell transplants with EBV-positive or EBV-negative post-transplant lymphoproliferative disorder, A CIBMTR study

BACKGROUND

Post-transplant lymphoproliferative disorders (PTLD) are associated with significant morbidity and mortality following allogeneic hematopoietic cell transplant (alloHCT). Although most PTLD is EBV-positive (EBV^pos ), EBV-negative (EBV^neg ) PTLD is reported, yet its incidence and clinical impact remain largely undefined. Furthermore, factors at the time of transplant impacting survival following PTLD are not well described.

METHODS

Between 2002 and 2014, 432 cases of PTLD following alloHCT were reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). After exclusions, 267 cases (EBV^pos  = 222, 83%; EBV^neg  = 45, 17%) were analyzed.

RESULTS

Two hundred and eight patients (78%) received in vivo T-cell depletion (TCD) with either anti-thymocyte globulin (ATG) or alemtuzumab. Incidence of PTLD was highest using umbilical cord donors (UCB, 1.60%) and lowest using matched related donors (MRD, 0.40%). Clinical features and histology did not significantly differ among EBV^pos or EBV^neg PTLD cases except that absolute lymphocyte count recovery was slower, and CMV reactivation was later in EBV^neg PTLD [EBV^pos 32 (5-95) days versus EBV^neg 47 (10-70) days, P = .016]. There was no impact on survival by EBV status in multivariable analysis [EBV^neg RR 1.42, 95% CI 0.94-2.15, P = .097].

CONCLUSIONS

There is no difference in survival outcomes for patients with EBV^pos or EBV^neg PTLD occurring following alloHCT and 1-year survival is poor. Features of conditioning and use of serotherapy remain important.

Prognostic impact of EBV serostatus in patients with lymphomas or chronic malignancies undergoing allogeneic HCT

The influence of the donor (D) and recipient (R) pre-transplant Epstein-Barr Virus (EBV) serostatus on transplant outcomes (overall survival, relapse-free survival, relapse incidence, non-relapse mortality, acute and chronic GVHD) in 12,931 patients with lymphomas or chronic malignancies undergoing allogeneic hematopoietic cell transplant (allo-HCT) between 1997-2016 was analyzed. In multivariate analysis, the risk of development of chronic GVHD was increased for EBV R+/D+ (HR = 1.26; p = 0.003), R+/D- (HR = 1.21; p = 0.044), and R-/D + (HR = 1.21; p = 0.048) in comparison to R-/D- transplants. No significance was shown for other transplant outcomes; however, in univariate analysis, EBV-seropositive patients receiving grafts from EBV-seropositive donors (EBV R+/D+transplants) had inferior transplant outcomes in comparison to EBV-seronegative recipients of grafts from EBV-seronegative donors (EBV R-/D-): inferior overall survival (59.6% vs 65.9%), inferior relapse-free survival (51.1% vs 57.5%), increased incidence of chronic GVHD (49.5% vs 41.8%), and increased incidence of de novo chronic GVHD (30.5% vs 24.0%). In conclusion, an EBV-negative recipient with lymphoma or chronic malignancy can benefit from selection of an EBV-negative donor in context of chronic GVHD, while there are no preferences in donor EBV serostatus for EBV-seropositive recipient.

PD-L1 and PD1 expression in post-transplantation lymphoproliferative disease (PTLD) of childhood and adolescence: An inter- and intra-individual descriptive study covering the whole spectrum of PTLD categories

Therapy of children with post-transplantation lymphoproliferative disorder (PTLD) after hematopoietic stem cell (HSCT) and solid organ transplantation (SOT) can be challenging. In this retrospective study, we investigated PD-L1 and PD1 expression in all PTLD categories of childhood and adolescence to see whether checkpoint inhibition with PD-L1/PD1 inhibitors may serve as a therapy option. We included 21 patients aged 19 years or younger (at date of transplant) with PTLD following SOT or HSCT having adequate tumor samples available (n = 29). Using immunohistochemistry, we evaluated PD-L1/PD1 expression on both tumor cells and cells of the microenvironment in all samples. Availability of consecutively matched tumor samples during 6 of 21 patients' disease courses also allowed an intra-individual assessment of PD-L1/PD1 expression. We observed lower PD-L1 and higher PD1 expression in non-destructive lesions, and higher PD-L1 and lower PD1 expression in polymorphic and, in particular, in monomorphic PTLD, mostly diffuse large B-cell lymphomas (DLBCL, n = 10/21). The amount of PD-L1- and PD1-positive cells changed in the opposite way in sequential biopsies of the same individual correlating well with the PTLD category. This is the first comprehensive pediatric study assessing PD-L1 and PD1 expression on tumor cells and in the microenvironment of PTLD including not only monomorphic, but also non-destructive early lesions. PD-L1 expression of the tumor cells inversely correlated with PD1 expression in surrounding tissues, with the highest expression in DLBCL. Since PTLD can be therapeutically challenging, our results indicate a potential efficacy of checkpoint inhibitors if standard immune- and/or chemotherapy fail or are impossible. We therefore recommend routine staining of PD-L1 and PD1 in all PTLD categories.

First-Onset Herpesviral Infection and Lung Injury in Allogeneic Hematopoietic Cell Transplantation

Rationale: "Noninfectious" pulmonary complications are significant causes of morbidity and mortality after allogeneic hematopoietic cell transplant. Early-onset viral reactivations or infections are common after transplant. Whether the first-onset viral infection causes noninfectious pulmonary complications is unknown. Objectives: To determine whether the first-onset viral infection within 100 days after transplant predisposes to development of noninfectious pulmonary complications. Methods: We performed a retrospective review of 738 allogeneic hematopoietic cell transplant patients enrolled from 2005 to 2011. We also established a novel bone marrow transplantation mouse model to test whether herpesviral reactivation after transplant causes organ injury. Measurements and Main Results: First-onset viral infections with human herpesvirus 6 or Epstein-Barr virus within 100 days after transplant increase the risk of developing idiopathic pneumonia syndrome (adjusted hazard ratio [aHR], 5.52; 95% confidence interval [CI], 1.61-18.96; P = 0.007; and aHR, 9.21; 95% CI, 2.63-32.18; P = 0.001, respectively). First infection with human cytomegalovirus increases risk of bronchiolitis obliterans syndrome (aHR, 2.88; 95% CI, 1.50-5.55; P = 0.002) and grade II-IV acute graft-versus-host disease (aHR, 1.59; 95% CI, 1.06-2.39; P = 0.02). Murine roseolovirus, a homolog of human herpesvirus 6, can also be reactivated in the lung and other organs after bone marrow transplantation. Reactivation of murine roseolovirus induced an idiopathic pneumonia syndrome-like phenotype and aggravated acute graft-versus-host disease. Conclusions: First-onset herpesviral infection within 100 days after allogeneic hematopoietic cell transplant increases risk of pulmonary complications. Experimentally reactivating murine roseolovirus causes organ injury similar to phenotypes seen in human transplant recipients.

Postallogeneic stem cell transplant Hodgkin lymphoma: Rare presentation of an uncommon occurrence

Post-transplant lymphoproliferative disorders are rare but potentially life-threatening complication of HSCT. Although not frequently reported but PTLD can occur as a late post-transplant complication in HSCT recipients. A high index of suspicion should be kept for early diagnosis of these disorders as delay in diagnosis can have catastrophic implications.

Immune reconstitution following hematopoietic stem cell transplantation using different stem cell sources

Introduction: Adequate immune reconstitution post-HSCT is crucial for the success of transplantation, and can be affected by both patient- and transplant-related factors. Areas covered: A systematic literature search in PubMed, Scopus, and abstracts of international congresses is performed to investigate immune recovery posttransplant. In this review, we discuss the pattern of immune recovery in the post-transplant period focusing on the impact of stem cell source (bone marrow, peripheral blood stem cells, and cord blood) on immune recovery and HSCT outcome. We examine the impact of serotherapy on immune reconstitution and the need to tailor dosing of serotherapy agents when using different stem cell sources. We discuss new techniques being used particularly with cord blood and haploidentical grafts to improve immune recovery in each scenario. Expert opinion: Cord blood T cells provide a unique CD4+ biased immune reconstitution. Initial studies using targeted serotherapy with cord grafts showed improved immune recovery with limited alloreactivity. Two competing haploidentical approaches have developed in recent years including TCRαβ/CD19 depleted grafts and post-cyclophosphamide haplo-HSCT. Both approaches have comparable survival rates with limited alloreactivity. However, delayed immune reconstitution is still an ongoing problem and could be improved by modified donor lymphocyte infusions from the same haploidentical donor.

Outcome of Rituximab-Based Treatment for Post-Transplant Lymphoproliferative Disorder After Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Center Experience

Background

Post-transplant lymphoproliferative disorder (PTLD) is a rare complication following solid organ transplantation and allogeneic hematopoietic stem cell transplantation (Allo-HSCT), which gives rise to high mortality rates.

Material/Methods

This was a single-center retrospective analysis based on 27 patients who were diagnosed with PTLD following Allo-HSCT between January 1, 2007 and June 2018 at the Chinese PLA General Hospital. The purpose of this analysis was to investigate responses and prognostic factors of rituximab-based treatment.

Results

Twenty-seven patients were treated with rituximab. Among them, 20 of 27 patients (74.07%) had a complete response, 2 of 27 patients (7.41%) had a partial response, 5 of 27 patients (18.52%) had no response, and 22 of 27 patients (81.48%) cleared Epstein-Barr virus (EBV) copies. There were no obvious side effects. The 1-year overall survival (OS) estimate was 46.8% (95% CI, 23.1–65.5%). Univariate analysis revealed that lower OS was correlated with Eastern Cooperative Oncology Group (ECOG) score standard (3–4), Epstein-Barr virus (EBV) viral load (≥10⁶ copies/mL), bacteria or fungal infection, and EBV reactivation were positive after treatment with 1 or 2 doses of rituximab (P<0.05). Multivariate analysis showed that each of the following were independently associated with lower OS (P<0.05): female, ECOG score standard (3–4), and EBV reactivation were positive after treatment with 1 or 2 doses of rituximab.

Conclusions

Our results demonstrated that rituximab-based treatment was a safe and effective strategy for patients who were diagnosed with PTLD following Allo-HSCT. The identified prognostic factors may help to detect which PTLD patients are at a higher risk of mortality.

Evaluation of four commercial extraction-quantification systems to monitor EBV or CMV viral load in whole blood

BACKGROUND

Measurement of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) viral loads is commonly used to monitor posttransplant patients. Two new systems (eMAG/eSTREAM and Versant/kPCR) have been recently commercialized.

OBJECTIVES

To evaluate the performance of four systems to quantify CMV and EBV in whole blood.

STUDY DESIGN

Three extraction and real-time PCR amplification systems: m2000SP/RT (M2000), eMAG/eSTREAM (EMAG), and Versant/kPCR (KPCR) were compared with our routine system Qiasymphony/RGQ (QS/RGQ). The 4 systems were tested using 3 dilutions in triplicate according to the WHO international standard (WHO-IS) for intra-assay reproducibility; 56 whole blood samples (24 patients, 4 follow-ups) for CMV and 45 samples (27 patients, 3 follow-ups) for EBV.

RESULTS

For CMV, the mean of the WHO-IS (expected value: 4.7 Log IU/ml) was: QS/RGQ=4.84, M2000=4.61, EMAG=4.33, and KPCR=4.79. One patient (10 samples) presented a major underquantification by QS/RGQ. Of the 46 remaining samples, 41 were quantified with QS/RGQ, 43 with M2000, 33 with EMAG and 24 with KPCR. For EBV, the mean of the WHO-IS was: QS/RGQ=4.70, M2000=4.61, EMAG=4.62, and KPCR=4.57. Among the 45 samples, 43 were quantified with QS/RGQ, 39 with M2000, 40 with EMAG and 32 with KPCR.

CONCLUSION

The results obtained with the WHO-IS were very good. The results of patients' samples were well correlated with the announced sensitivity of each system. The elevated threshold of the KPCR CMV assay may be problematic for the follow-up of highly immunocompromised patients who require early introduction of treatment.

Low dose Rituximab for pre-emptive treatment of Epstein Barr virus reactivation after allogenic hematopoietic stem cell transplantation

INTRODUCTION

The most used preemptive therapy for Epstein Barr virus reactivation post allogeneic hematopoietic stem cell (HSCT) transplant is Rituximab, 375 mg/m2, once weekly until EBV viremia negativity. There is no data suggesting such a high dose.

OBJECTIVE

We hypothesized that a lower dose of Rituximab would be as efficient with less toxicity.

PATIENTS

In a retrospective, monocentric study, we analyzed 16 consecutive patients treated preemptively with low dose Rituximab for EBV reactivation post HSCT. Patients were treated with low Rituximab dose of 100 mg/m² weekly. Success was defined by a decrease of EBV viremia of 1 log¹⁰ and below 1000 UI/ml, and the absence of post-transplant lymphoproliferative disorder (PTLD).

RESULTS

Success rate was 93.4% (15/16). One (1/16, 6%) PTLD was diagnosed after preemptive therapy, despite a negative viremia.

CONCLUSION

A low dose of Rituximab of 100 mg/m² per injection for pre-emptive therapy of EBV reactivation post HSCT is safe and effective for preventing PTLD. Prospective, randomized, multicentric trials with larger number of patient are needed to determine the best rituximab dose.

Epstein Barr Virus Associated B-Cell Lymphomas and Iatrogenic Lymphoproliferative Disorders

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus, affecting up to 90% of the population. EBV was first identified as an oncogenic virus in a Burkitt lymphoma cell line, though subsequently has been found to drive a variety of malignancies, including diffuse large B-cell lymphoma (DLBCL) and other lymphoma subtypes. EBV has a tropism for B-lymphocytes and has the unique ability to exist in a latent state, evading the host immune response. In cases of impaired cell mediated immunity, as in patients with advanced age or iatrogenic immune suppression, the virus is able to proliferate in an unregulated fashion, expressing viral antigens that predispose to transformation. EBV-positive DLBCL not otherwise specified, which has been included as a revised provisional entity in the 2016 WHO classification of lymphoid malignancies, is thought to commonly occur in older patients with immunosenescence. Similarly, it is well-established that iatrogenic immune suppression, occurring in both transplant and non-transplant settings, can predispose to EBV-driven lymphoproliferative disorders. EBV-positive lymphoproliferative disorders are heterogeneous, with variable clinical features and prognoses depending on the context in which they arise. While DLBCL is the most common subtype, other histologic variants, including Burkitt lymphoma, NK/T-cell lymphoma, and Hodgkin lymphoma can occur. Research aimed at understanding the underlying biology and disease prevention strategies in EBV-associated lymphoproliferative diseases are ongoing. Additionally, personalized treatment approaches, such as immunotherapy and adoptive T-cell therapies, have yielded encouraging results, though randomized trials are needed to further define optimal management.

Adverse Effects of Virus-Specific T-Cell Therapy: An Integrative Review

Allogeneic hematopoietic stem cell transplant (HSCT) remains the mainstay in treating many hematologic malignancies. T-cell-depleted grafts designed to reduce graft-vs.-host disease (GVHD) may be complicated by severe viral infections that increase morbidity and mortality. Despite the use of antiviral pharmacologic therapy, challenges in controlling viral infections include drug resistance and/or side-effect intolerability. Virus-specific T-cell (VST) therapy is a promising targeted therapy for treating severe or drug-refractory viral infections after HSCT. An integrative review was conducted to inform advanced practitioners of the adverse effects associated with VST. A total of 836 articles were identified using PubMed, Scopus, and CINAHL databases, with 7 included in this review. Studies reviewed indicate that the adverse effects associated with VST therapy are limited and generally treatable. These studies reported low rates of adverse events of mild to moderate severity, including acute, recurrent, chronic, and de novo GVHD; cytokine release syndrome; infusion toxicity; and other adverse events. No deaths were attributed to VSTs in these studies.

Primary CNS post-transplant lymphoproliferative disorder following haploidentical HSCT using post-transplant high-dose cyclophosphamide

Neurological complications after hematopoietic stem cell transplantation (HSCT) are frequently life-threatening, and their clinical management can be highly challenging. In the case of central nervous system lesions post-HSCT, a definitive diagnosis is often difficult to reach because many different causative and contributing conditions may be present, including bacterial, fungal, or viral infections; original disease relapse; and post-transplant lymphoproliferative disorder (PTLD). Here, we report a case of a 32-year-old male patient with Philadelphia chromosomepositive acute lymphoid leukemia who underwent three HSCTs and was then diagnosed with primary central nervous system (PCNS) PTLD by brain biopsy. The third HSCT was a haplo-identical peripheral blood stem cell transplantation from his mother, with post-transplant high-dose cyclophosphamide and tacrolimus used as graft-versus-host disease prophylaxis. Four months after the HSCT, multiple small ring lesions were detected in the parabasal ganglia of the patient's brain during magnetic resonance imaging. A lesion biopsy indicated Epstein-Barr virus (EBV)-positive, diffuse large B-cell lymphoma. Because the patient had no evidence of systemic lymphadenopathy, we diagnosed him with PCNS-PTLD. There was no EBV DNA in this patient's cerebrospinal fluid. The diagnosis of PCNS-PTLD by EBV DNA polymerase chain reaction is difficult and highlights the importance of a brain biopsy to diagnose PCNS-PTLD, especially in cases showing no EBV DNA in the cerebrospinal fluid. Although a rare condition, it is essential to locate and analyze cases of PCNS-PTLD after HSCT to establish the optimal strategy for treatment or prophylaxis.