Age and Epstein-Barr viral load at diagnosis of post-transplant lymphoproliferative disease are associated with patient survival in kidney transplant recipients.

INTRODUCTION: This study investigated variables associated with mortality in kidney transplant recipients (KTRs) diagnosed with post-transplant lymphoproliferative disease (PTLD) and a simultaneous Epstein-Barr virus (EBV) viremia. METHODS: This was a retrospective cohort study enrolling KTRs diagnosed with PTLD between 2018 and 2020. Outcome: death within two years after diagnosis. RESULTS: Among 1,625 KTRs who collected EBV viremia (by PCR, 2018-2020) for any reason, 238 (14.6%) had a positive viral load and 41 (17.2%) simultaneous PTLD. These 41 patients were 40.1 years old at diagnosis and 8.6 years after transplantation; 26.8% were induced with rATG and 92.7% were maintained on tacrolimus and azathioprine (TAC/AZA) as immunosuppressive regimen. Lymph nodes (75.6%) was the most common site of PTLD, followed by the gastrointestinal tract (48.8%), with 61.0% at Lugano stage IV and 80.5% monomorphic PTLD. The mean EBV viral load was 12,198 IU/mL. One- and two-year patient survival post-diagnosis was 60.4% and 46.8%, respectively. In the Cox regression analysis, age at PTLD diagnosis (HR for each year = 1.039; p < 0.001) and EBV viral load (HR for each log = 1.695; p = 0.026) were associated with risk of death. CONCLUSION: This study suggests that in patients predominantly on TAC/AZA, PTLD with simultaneous EBV positive viral load is a late event, and worse survival is associated with older age and EBV viral load at diagnosis.

Mechanistic Understanding of EBV+Lymphoproliferative Disease Development After Transplantation.

Posttransplant lymphoproliferative disorders (PTLDs) are among the most common malignant complications after transplantation, leading to a drastic reduction in patient survival rates. The majority of PTLDs are tightly linked to Epstein-Barr virus (EBV+PTLDs) and are the result of an uncontrolled proliferation of EBV-infected cells. However, although EBV infections are a common finding in transplant recipients, most patients with high EBV loads will never develop EBV+PTLD. Natural killer cells and EBV-specific CD8+ T lymphocytes are critical for controlling EBV-infected cells, and the impairment of these cytotoxic immune responses facilitates the unfettered proliferation of EBV-infected cells. Recent years have seen a considerable increase in available literature aiming to describe novel risk factors associated with the development of EBV+PTLD, which may critically relate to the strength of EBV-specific natural killer cell and EBV-CD8+ T lymphocyte responses. The accumulation of risk factors and the increased risk of developing EBV+PTLD go hand in hand. On the one hand, most of these risk factors, such as the level of immunosuppression or the EBV donor and recipient serologic mismatch, and distinct genetic risk factors are host related and affect cytotoxic EBV-specific immune responses. On the other hand, there is growing evidence that distinct EBV variants may have an increased malignant potential and are thus more likely to induce EBV+PTLD. Here, we aim to review, from a mechanistic point of view, the risk factors for EBV+PTLD in the host and the infecting EBV variants that may explain why only a minority of transplant recipients develop EBV+PTLD.

Cytokine Storm Syndromes Associated with Epstein-Barr Virus.

Epstein-Barr virus (EBV) is a ubiquitous and predominantly B cell tropic virus. One of the most common viruses to infect humans, EBV, is best known as the causative agent of infectious mononucleosis (IM). Although most people experience asymptomatic infection, EBV is a potent immune stimulus and as such it elicits robust proliferation and activation of the B-lymphocytes it infects as well as the immune cells that respond to infection. In certain individuals, such as those with inherited or acquired defects affecting the immune system, failure to properly control EBV leads to the accumulation of EBV-infected B cells and EBV-reactive immune cells, which together contribute to the development of often life-threatening cytokine storm syndromes (CSS). Here, we review the normal immune response to EBV and discuss several CSS associated with EBV, such as chronic active EBV infection, hemophagocytic lymphohistiocytosis, and post-transplant lymphoproliferative disorder. Given the critical role for cytokines in driving inflammation and contributing to disease pathogenesis, we also discuss how targeting specific cytokines provides a rational and potentially less toxic treatment for EBV-driven CSS.

From the midfacial destructive drama to the unfolding EBV story: a short history of EBV-positive NK-cell and T-cell lymphoproliferative diseases.

Epstein-Barr virus (EBV) is a ubiquitous gammaherpesvirus that has been related to oncogenesis of lymphoid and epithelial malignancies. Although the mechanism of EBV infection of NK and T cells remains enigmatic, it plays a pathogenic role in various EBV+ NK-cell and T-cell lymphoproliferative diseases (LPDs), through promotion of cell activation pathways, inhibition of cell apoptotic pathways, behaving as oncogenes, interacting with host oncogenes or acting epigenetically. The study of NK-cell LPDs, previously hampered by the lack of immunophenotypical and genotypical criteria of NK cells, has become feasible with the recently accepted criteria. EBV+ NK- and T-cell LPDs are mostly of poor prognosis. This review delivers a short history from primeval to recent EBV+ NK- and T-cell LPDs in non-immunocompromised subjects, coupled with increasing interest, and work on the biological and oncogenic roles of EBV.

Clinical epidemiology of Epstein-Barr virus-associated Lymphoproliferative Disorders (EBV-LPDs) in hospitalized children: A six-year multi-institutional study in China.

BACKGROUND: Epstein-Barr virus-associated lymphoproliferative disorders (EBV-LPDs) are a group of disorders involving lymphoid tissues or lymphocytes. The epidemiology and economic burden of hospitalized children with EBV-LPDs in China have not been well studied. This study aimed to reveal the epidemic characteristics and disease burden of EBV-LPDs among the Chinese hospitalized children, providing strategies for the prevention and management. METHODS: This study was based on the FUTang Updating medical REcords (FUTURE) database of China and collected the medical records from 27 tertiary children's hospitals between January 2016 and December 2021 in China, counting five types of EBV-LPDs, namely EBV-positive T-cell lymphoproliferative disease, NK/T cell lymphoma, extranodal NK/T-cell lymphoma (nasal type), systemic EBV-positive T-cell lymphoproliferative disease of childhood and posttransplant lymphoproliferative disorders. We conducted a retrospective syhthesis and analysis of the epidemiological characteristics, expenses, length of stay (LOS), as well as complications among hospitalized children diagnosed with five types of EBV-LPDs and compared parameters using appropriate statistical tests. RESULTS: The study described 153 children aged 0-18 years hospitalized with EBV-LPDs from 2016 to 2021 in the FUTURE database. The male-to-female ratio was 1.10:1, and more than half of the age distribution was in the 6-12 y group. Among EBV-LPDs cases, EBV+ T-LPD accounted for the largest proportion (65.36%). Complications were presented in 93 children with EBV-LPDs, mainly hemophagocytic lymphohistiocytosis (HLH). The median LOS of NKTL was 26.5 days [interquartile range (IQR) = 3-42], which was the longest among EBV-LPDs. The median hospitalization cost of PTLD was 10 785.74 United States dollars (IQR = 7 329.38-16 531.18), which was the heaviest among EBV-LPDs. CONCLUSIONS: Compared with the total number of hospitalized children in China during the same period and in the same age group, the proportion of EBV-LPD is very low. EBV-LPD can develop in all age groups, but it is more common in school-age children. Among 5 EBV-LPDs, the disease with the highest proportion is EBV+ T-LPD. The overall disease burden of EBV-LPD was heavy, especially the economic burden. HLH was one of the most common complications, which could directly affect the burden of patients because of prolonged hospitalization. These data are taken from a very large database, illustrating the epidemiological and economic burden of EBV-LPDs hospitalized children in China, which enriched the existing epidemiological and disease burden content of EBV-LPDs.

Hydroa vacciniforme lymphoproliferative disorder: a retrospective study of 42 paediatric cases.

Hydroa vacciniforme lymphoproliferative disorder (HVLPD) is a rare disease related to Epstein-Barr virus (EBV), mainly in children, and is an EBV-associated cutaneous T and natural killer (NK) cell lymphoproliferative disorder. The disorder in some patients may progress to EBV-associated systemic T or NK-cell lymphoma. To summarize the characteristics of HVLPD in Chinese paediatric patients and to examine the risk factors indicating poor prognosis. We performed a retrospective analysis of patients with HVLPD from the Department of Dermatology, Beijing Children's Hospital. Based on diagnosis, medical history, examination results, and immunophenotype, we analysed HVLPD in 42 paediatric cases in order to examine the clinical features, prognoses, and risk factors. Forty-two paediatric patients were enrolled, with a median onset age of five years. All patients presented with papulovesicular lesions, and 32 systemic HVLPD (sHVLPD) patients had systemic symptoms, including fever, lymphadenopathy, hepatomegaly, splenomegaly, and liver dysfunction. Of the sHVLPD cases, 13 also had severe mosquito bite allergy (SMBA). Twenty-five cases were T-type, and nine were CD56+-dominant type. Follow-up data showed that 12 patients had complete remission, and three patients died. SMBA is a risk factor for disease progression in patients with HVLPD, and the pathological CD56+-dominant phenotype is associated with poor prognosis.

Post-transplant lymphoproliferative disorder associated Epstein-Barr virus DNAemia after liver transplantation in children: Experience from single center.

The most prevalent malignancy that complicates both adult and pediatric solid organ transplantation is post-transplant lymphoproliferative disorder (PTLD). This study aimed to analyze the clinical and pathological characteristics, treatments, and outcomes of Epstein-Barr virus (EBV) DNAemia and PTLD in pediatric liver transplant recipients. A retrospective chart review was performed on 112 patients less than 18 years of age who underwent isolated orthotopic liver transplantation (OLT) between 2010 and 2022 at Ege University Children's Hospital. Data gathered for 1-year post-OLT included age at OLT, EBV, immunoglobulin (Ig)M/IgG status of the donor and recipient, indication for OLT, induction regimen, all immunosuppression levels, date and result of EBV polymerase chain reaction testing, rejection episodes documented by liver biopsy, and the development of PTLD. Forty-nine patients (43.75%) developed EBV DNAemia (median interval from surgery: 2 months, min-max: 2-36), of which 43 (87.8%) grafts came from living donors, and 6 (12.2%) came from deceased donors. Nine (18.4%) patients died during follow-up, and eight (16.3%) developed PTLD. Of these 8 patients; five patients developed EBV-related disease, one child developed hemophagocytic lymphohistiocytosis, one developed aplastic anemia, and one child developed B cell lymphoma. When PTLD patients and without-PTLD patients were compared, pediatric intensive care unit hospitalization, abnormal bone marrow biopsy findings, lymphadenopathy, age at diagnosis of EBV DNAemia, EBV viral load, tacrolimus (FK 506) pre-infection, were higher and tacrolimus 1-month levels were lower in patients with PTLD (p < 0.05). In logistic regression analysis, we showed that the age at diagnosis of EBV DNAemia was significantly higher in children with PTLD (p = 0.045; OR: 1.389; 95% CI: 1.007-1.914). PTLD is a rare but severe complication associated with EBV after OLT. This study demonstrated that PTLD is associated with older age, higher tacrolimus blood levels before EBV DNAemia, and higher peak EBV viral load at 1 month of EBV DNAemia.

HIV-associated cancers and lymphoproliferative disorders caused by Kaposi sarcoma herpesvirus and Epstein-Barr virus.

SUMMARYWithin weeks of the first report of acquired immunodeficiency syndrome (AIDS) in 1981, it was observed that these patients often had Kaposi sarcoma (KS), a hitherto rarely seen skin tumor in the USA. It soon became apparent that AIDS was also associated with an increased incidence of high-grade lymphomas caused by Epstein-Barr virus (EBV). The association of AIDS with KS remained a mystery for more than a decade until Kaposi sarcoma-associated herpesvirus (KSHV) was discovered and found to be the cause of KS. KSHV was subsequently found to cause several other diseases associated with AIDS and human immunodeficiency virus (HIV) infection. People living with HIV/AIDS continue to have an increased incidence of certain cancers, and many of these cancers are caused by EBV and/or KSHV. In this review, we discuss the epidemiology, virology, pathogenesis, clinical manifestations, and treatment of cancers caused by EBV and KSHV in persons living with HIV.

Highly sensitive detection of Epstein-Barr virus-infected cells by EBER flow FISH.

When Epstein-Barr virus (EBV) infection is suspected, identification of infected cells is important to understand the pathogenesis, determinine the treatment strategy, and predict the prognosis. We used the PrimeFlow™ RNA Assay Kit with a probe to detect EBV-encoded small RNAs (EBERs) and multiple surface markers, to identify EBV-infected cells by flow cytometry. We analyzed a total of 24 patients [11 with chronic active EBV disease (CAEBV), 3 with hydroa vacciniforme lymphoproliferative disorder, 2 with X-linked lymphoproliferative disease type 1 (XLP1), 2 with EBV-associated hemophagocytic lymphohistiocytosis, and 6 with posttransplant lymphoproliferative disorder (PTLD)]. We compared infected cells using conventional quantitative PCR methods and confirmed that infected cell types were identical in most patients. Patients with CAEBV had widespread infection in T and NK cells, but a small amount of B cells were also infected, and infection in patients with XLP1 and PTLD was not limited to B cells. EBV-associated diseases are believed to be complex pathologies caused by EBV infecting a variety of cells other than B cells. We also demonstrated that infected cells were positive for HLA-DR in patients with CAEBV. EBER flow FISH can identify EBV-infected cells with high sensitivity and is useful for elucidating the pathogenesis.

Monomorphic T-cell post-transplant lymphoproliferative disorder with features of HHV8-negative primary effusion lymphoma: an autopsy case and review of the literature.

A 67-year-old man underwent renal transplantation in his twenties. He developed refractory pleural effusion, with many large lymphocytes with severe atypia and mitosis in the effusion, indicating malignant lymphoma. He finally died of respiratory failure. An autopsy revealed atypical lymphocytes positive for CD3, CD4, and CD30 and negative for CD8, CD20, PAX5, human herpesvirus (HHV) 8, and Epstein-Barr virus-encoded small RNAs by immunohistochemistry and in situ hybridization. Atypical lymphocytes also had T-cell receptor gene rearrangements Jß2, Jγ2, and Jδ1 and chromosomal aberrations der(8)t(1;8)(q21;p21), add(13)(q12), add(14)(q32), and add(16)(q12-13). A few atypical lymphocytes were present at other sites. We finally diagnosed this case as monomorphic T-cell post-transplant lymphoproliferative disorder with features of HHV8-negative primary effusion lymphoma. A literature review only identified six cases (four HHV8-negative, two HHV8-positive) of effusion lymphoma of T-cell type, including the present case. Interestingly, about half of HHV8-negative and HHV8-positive cases had a history of renal transplantation in their twenties. All cases showed tumor CD30 expression, whereas CD4 and CD8 expressions were inconsistent. These findings indicated that this lymphoma may be associated with post-transplant lymphoproliferative disorder by renal transplantation at a young age, although further cases need to be analyzed.

Third-party virus-specific T cells for the treatment of double-stranded DNA viral reactivation and posttransplant lymphoproliferative disease after solid organ transplant.

Reactivation or primary infection with double-stranded DNA viruses is common in recipients of solid organ transplants (SOTs) and is associated with significant morbidity and mortality. Treatment with conventional antiviral medications is limited by toxicities, resistance, and a lack of effective options for adenovirus (ADV) and BK polyomavirus (BKPyV). Virus-specific T cells (VSTs) have been shown to be an effective treatment for infections with ADV, BKPyV, cytomegalovirus (CMV), and Epstein-Barr virus (EBV). Most of these studies have been conducted in stem cell recipients, and no large studies have been published in the SOT population to date. In this study, we report on the outcome of quadrivalent third-party VST infusions in 98 recipients of SOTs in the context of an open-label phase 2 trial. The 98 patients received a total of 181 infusions, with a median of 2 infusions per patient. The overall response rate was 45% for BKPyV, 65% for cytomegalovirus, 68% for ADV, and 61% for Epstein-Barr virus. Twenty percent of patients with posttransplant lymphoproliferative disorder had a complete response and 40% of patients had a partial response. All the VST infusions were well tolerated. We conclude that VSTs are safe and effective in the treatment of viral infections in SOT recipients.

Epstein-Barr virus-associated post-transplant lymphoproliferative disorders in pediatric transplantation: A prospective multicenter study in the United States.

BACKGROUND: Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorders (PTLD) is the most common malignancy in children after transplant; however, difficulties for early detection may worsen the prognosis. METHODS: The prospective, multicenter, study enrolled 944 children (≤21 years of age). Of these, 872 received liver, heart, kidney, intestinal, or multivisceral transplants in seven US centers between 2014 and 2019 (NCT02182986). In total, 34 pediatric EBV+ PTLD (3.9%) were identified by biopsy. Variables included sex, age, race, ethnicity, transplanted organ, EBV viral load, pre-transplant EBV serology, immunosuppression, response to chemotherapy and rituximab, and histopathological diagnosis. RESULTS: The uni-/multivariable competing risk analyses revealed the combination of EBV-seropositive donor and EBV-naïve recipient (D+R-) was a significant risk factor for PTLD development (sub-hazard ratio: 2.79 [1.34-5.78], p = .006) and EBV DNAemia (2.65 [1.72-4.09], p < .001). Patients with D+R- were significantly more associated with monomorphic/polymorphic PTLD than those with the other combinations (p = .02). Patients with monomorphic/polymorphic PTLD (n = 21) had significantly more EBV DNAemia than non-PTLD patients (p < .001) and an earlier clinical presentation of PTLD than patients with hyperplasias (p < .001), within 6-month post-transplant. Among non-liver transplant recipients, monomorphic/polymorphic PTLD were significantly more frequent than hyperplasias in patients ≥5 years of age at transplant (p = .01). CONCLUSIONS: D+R- is a risk factor for PTLD and EBV DNAemia and associated with the incidence of monomorphic/polymorphic PTLD. Intensive follow-up of EBV viral load within 6-month post-transplant, especially for patients with D+R- and/or non-liver transplant recipients ≥5 years of age at transplant, may help detect monomorphic/polymorphic PTLD early in pediatric transplant.

Epstein-Barr virus latency patterns in polymorphic lymphoproliferative disorders and lymphomas in immunodeficiency settings: Diagnostic implications.

Epstein-Barr virus (EBV) is responsible for many B cell lymphoproliferative disorders (LPD) spanning subclinical infection to immunodeficiency-related neoplasms. EBV establishes a latent infection in the host B cell as defined histologically by the expression of EBV latent membrane proteins and nuclear antigens. Herein, we characterize the latency patterns of immunodeficiency-related neoplasms including post-transplant lymphoproliferative disorders (PTLD) and therapy-related LPD (formerly iatrogenic) with latent membrane protein-1 (LMP-1) and EBV nuclear antigen-2 (EBNA-2) immunohistochemistry. The latency pattern was correlated with immunodeficiency and dysregulation (IDD) status and time from transplant procedure. 38 cases of EBV+ PTLD in comparison to 27 cases of classic Hodgkin lymphoma (CHL) and diffuse large B cell lymphoma (DLBCL) arising in either the therapy-related immunodeficiency setting (n = 12) or without an identified immunodeficiency (n = 15) were evaluated for EBV-encoded small RNAs by in situ hybridization (EBER-ISH) and for LMP-1 and EBNA-2 by immunohistochemistry. A full spectrum of EBV latency patterns was observed across PTLD in contrast to CHL and DLBCL arising in the therapy-related immunodeficiency setting. Polymorphic-PTLD (12 of 16 cases, 75 %) and DLBCL-PTLD (9 of 11 cases, 82 %) showed the greatest proportion of cases with latency III pattern. Whereas, EBV+ CHL in an immunocompetent patient showed exclusively latency II pattern (13 of 13 cases, 100 %). The majority of EBV+ PTLD occurred by three years of transplant procedure date and were enriched for latency III pattern (21 of 22 cases, 95 %). Immunohistochemical identification of EBV latency by LMP-1 and EBNA-2 can help classify PTLD in comparison to other EBV+ B cell LPD and lymphomas arising in therapy-related immunodeficiency and non-immunodeficiency settings.

Experimental infection of domestic turkeys with lymphoproliferative disease virus of North American origin.

Lymphoproliferative disease virus (LPDV) was first documented in wild turkeys in North America in 2009. LPDV infection is often subclinical but can manifest as lymphoid proliferation or round cell neoplasia. Despite high prevalence across many sampled areas corresponding to declining populations of wild turkeys, knowledge regarding LPDV pathogenesis, risk factors for disease development, and associated impacts on population dynamics are unknown. To understand transmission, viral shedding, and tissue tropism, we inoculated 21 domestic turkeys via the oral cavity, crop, nasal cavity, subcutis, or coelomic cavity. For 12 weeks, oropharyngeal swabs, cloacal swabs, and whole blood were collected weekly. At 1 week postinoculation, 3 turkeys (3/21; 14%) had detectable LPDV proviral DNA in blood by polymerase chain reaction, and 10 developed DNAemia (50%; 10/20) by 12 weeks. LPDV proviral DNA was intermittently detected in oropharyngeal and cloacal swabs. Splenomegaly was the most consistent gross finding in DNAemic birds (8/11; 73%). Lymphoid hyperplasia in the spleen was the most significant microscopic finding (9/11; 82%). Three turkeys (3/11; 27%) developed round cell neoplasia characterized by sheets of pleomorphic, round to polygonal cells in the adrenal gland, bone marrow, skin, small intestine, and/or spleen. LPDV was detected in the spleen and bone marrow from all turkeys with DNAemia and all neoplasms. Our study establishes that infection and disease with North American LPDV from wild turkeys can be experimentally reproduced in domestic turkeys, laying the groundwork for future investigations into LPDV pathogenesis, development of diagnostic techniques, and understanding the impacts of LPDV on wild turkey populations.

EBV-associated lymphoproliferative disease post-CAR-T cell therapy.

Epstein-Barr virus (EBV)-associated lymphoproliferative diseases (EBV-LPDs) are common complications that occur after solid organ transplantation or allogeneic hematopoietic stem-cell transplantation (HSCT). However, their occurrence and treatment post-chimeric antigen receptor-modified T (CAR-T) cell therapy has not been reported. Two patients had been diagnosed with EBV-positive aggressive B-cell lymphoma and experienced relapses after multiple lines of treatment. After receiving CAR-T cell therapy in tandem with autologous HSCT, the patients achieved complete remission. However, with a median time of 38.5 months after CAR-T cell therapy, B-cell-derived EBV-LPDs were diagnosed, and they were relieved through the administration of immune checkpoint inhibitor or B-cell-depleting agents. Collectively, our report suggests that EBV-LPDs may represent a long-term adverse event after CAR-T cell therapy, especially in patients who previously had EBV-positive disorders, and they can be resolved by immune normalization strategy or B-cell depleting therapy.

Characterization of T-/natural killer cell lymphoproliferative neoplasms associated with systemic, chronic, active Epstein-Barr virus in adults: A report of 5 cases in a Western population.

OBJECTIVES: Because of its low frequency in adult populations and clinical and laboratory overlap with hemophagocytic lymphohistiocytosis and other T-cell lymphomas, T-cell/natural killer (NK) cell systemic, chronic, active Epstein-Barr virus (EBV) (T/NK sCAEBV) infection remains underdiagnosed, preventing critical, prompt therapeutic interventions. METHODS: We report a 5-case series that included 2 adult patients with T/NK sCAEBV and 3 additional adult patients with T/NK lymphomas with concomitant systemic EBV infection to review these entities' overlapping diagnostic and clinical features. RESULTS: Approximately 95% of the world population has been infected with EBV during their lifetime, and infection is usually asymptomatic, with symptomatic cases eventually resolving spontaneously. A small subset of immunocompetent patients develops CAEBV, a life-threatening complication resulting from EBV-infected T-cell or NK cell neoplastic lymphocytes. The sites of end-organ damage in T/NK sCAEBV demonstrate pathologic findings such as reactive lymphoid proliferations, making the diagnosis difficult to establish, with the only curative option being an allogeneic hematopoietic stem cell transplant. CONCLUSIONS: This diagnosis is most prevalent in Asia, with few cases reported in Western countries. Adult age is an independent risk factor for poor outcomes, and most cases are diagnosed in pediatric populations.

An update on viral-induced cutaneous lymphoproliferative disorders. CME Part I.

Viral-induced cutaneous T-cell lymphomas are an uncommon group of lymphoproliferative disorders characterized by a viral infection of T and natural killer (NK) cells. This group of cutaneous T-cell lymphomas is more commonly encountered in Asians and Native Americans from Central and South America compared with Western populations. Viral-associated lymphoproliferative disorders include a spectrum of entities that range from nonneoplastic lesions, such as chronic active Epstein-Barr virus infection and infective dermatitis to malignant diseases, such as extranodal NK/T-cell lymphoma, hydroa vacciniforme-like T-cell lymphoma, and adult T-cell leukemia/lymphoma. This review article will focus on hydroa vacciniforme-like lymphoproliferative disorder, extranodal NK/T-cell lymphoma, adult T-cell leukemia/lymphoma, lymphomatoid granulomatosis, and Epstein-Barr virus-positive mucocutaneous ulcers. We will review the pathogenesis of these conditions and the challenges of making a timely diagnosis in early-stage disease and discuss the common clinicopathologic manifestations, mutational landscape, and approaches to treat these highly aggressive and frequently lethal types of lymphoma.

Epstein-Barr Virus Genome Deletions in Epstein-Barr Virus-Positive T/NK Cell Lymphoproliferative Diseases.

The main target cells for Epstein-Barr virus (EBV) infection and persistence are B lymphocytes, although T and NK cells can also become infected. In this paper, we characterize the EBV present in 21 pediatric and adult patients who were treated in France for a range of diseases that involve infection of T or NK cells. Of these 21 cases, 5 pediatric patients (21%) and 11 adult patients (52%) were of Caucasian origin. In about 30% of the cases, some of the EBV genomes contain a large deletion. The deletions are different in every patient but tend to cluster near the BART region of the viral genome. Detailed investigation of a family in which several members have persistent T or NK cell infection by EBV indicates that the virus genome deletions arise or are selected independently in each individual patient. Genome sequence polymorphisms in the EBV in these T or NK cell diseases reflect the geographic origin of the patient and not a distinct type of EBV (the 21 cases studied included examples of both type 1 and type 2 EBV infection). Using virus produced from type 1 or type 2 EBV genomes cloned in bacterial artificial chromosome (BAC) vectors, we demonstrate infection of T cells in cord blood from healthy donors. Our results are consistent with transient infection of some T cells being part of normal asymptomatic infection by EBV in young children. IMPORTANCE EBV contributes to several types of human cancer. Some cancers and nonmalignant lymphoproliferative diseases involving T or NK cells contain EBV. These diseases are relatively frequent in Japan and China and have been shown sometimes to have deletions in the EBV genome in the disease cells. We identify further examples of deletions within the EBV genome associated with T or NK cell diseases, and we provide evidence that the virus genomes with these deletions are most likely selected in the individual cases, rather than being transmitted between people during infection. We demonstrate EBV infection of cord blood T cells by highly characterized, cloned EBV genomes and suggest that transient infection of T cells may be part of normal asymptomatic infection by EBV in young children.

EBV+ lymphoproliferative diseases: opportunities for leveraging EBV as a therapeutic target.

Epstein-Barr virus (EBV) is a ubiquitous human tumor virus, which contributes to the development of lymphoproliferative disease, most notably in patients with impaired immunity. EBV-associated lymphoproliferation is characterized by expression of latent EBV proteins and ranges in severity from a relatively benign proliferative response to aggressive malignant lymphomas. The presence of EBV can also serve as a unique target for directed therapies for the treatment of EBV lymphoproliferative diseases, including T cell-based immune therapies. In this review, we describe the EBV-associated lymphoproliferative diseases and particularly focus on the therapies that target EBV.