EBV-associated Lymphoproliferative Disorders Research Articles

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

BackgroundEpstein-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.MethodsThis 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.ResultsThe 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.ConclusionsCompared 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.

EBV-Related Lymphoproliferative Diseases: A Review in Light of New Classifications.

Epstein-Barr virus (EBV) is a prevalent virus that can be detected in the vast majority of the population. Most people are asymptomatic and remain chronically infected throughout their lifetimes. However, in some populations, EBV has been linked to a variety of B-cell lymphoproliferative disorders (LPDs), such as Burkitt lymphoma, classic Hodgkin lymphoma, and other LPDs. T-cell LPDs have been linked to EBV in part of peripheral T-cell lymphomas, angioimmunoblastic T-cell lymphomas, extranodal nasal natural killer/T-cell lymphomas, and other uncommon histotypes. This article summarizes the current evidence for EBV-associated LPDs in light of the upcoming World Health Organization classification and the 2022 ICC classification.

CXCR4 WHIM syndrome is a cancer predisposition condition for virus-induced malignancies.

Warts, hypogammaglobulinaemia, infections and myelokathexissyndrome (WHIMS) is a rare combined primary immunodeficiency caused by the gain of function of the CXCR4 chemokine receptor. We present the prevalence of cancer in WHIMS patients based on data from the French Severe Chronic Neutropenia Registry and an exhaustive literature review. The median follow-up of the 14 WHIMS 'patients was 28.5 years. A central review and viral evaluation of pathological samples were organized, and we conducted a thorough literature review to identify all reports of WHIMS cases. Six French patients were diagnosed with cancer at a median age of 37.6 years. The 40-year risk of malignancy was 39% (95% confidence interval [CI]: 6%-74%). We observed two human papillomavirus (HPV)-induced vulvar carcinomas, three lymphomas (two Epstein-Barr virus [EBV]-related) and one basal cell carcinoma. Among the 155 WHIMS cases from the literature, 22 cancers were reported in 16 patients, with an overall cancer 40-year risk of 23% (95% CI: 13%-39%). Malignancies included EBV-associated lymphoproliferative disorders and HPV-positive genital and anal cancers as in the French cohort. Worldwide, nine cases of malignancy were associated with HPV and four with EBV. Immunocompromised WHIMS patients appear to be particularly susceptible to developing early malignancy, mainly HPV-induced carcinomas, followed by EBV-related lymphomas.

Chronic Epstein-Barr viral load carriage after pediatric organ transplantation.

Epstein-Barr virus (EBV) infection and EBV-associated post-transplant lymphoproliferative disorder (EBV/PTLD) is one of the most devastating complications occurring in pediatric solid organ transplant (SOT) recipients. Observations of SOT recipients undergoing serial EBV monitoring to inform reduction of immune suppression to prevent EBV-/PTLD has identified patients who maintain chronic high EBV load (CHL) in their blood. The CHL carrier state has been seen more commonly in pediatric compared to adult transplant recipients. Some but not all CHL may progress to EBV/PTLD. However, little is known regarding the biology of this CHL carrier state and the optimal clinical approach to CHL has not been established. This review summarizes the current knowledge and evidence of chronic high EBV load and introduces commonly adopted approaches from experts in this field.

HIV-associated CD8+ T-cell Skin Infiltrative Disease and EBV-associated Polymorphic B-cell Lymphoproliferative Disorder in an AIDS Patient Who Improved Dramatically with Antiretroviral Therapy Alone.

Human immunodeficiency virus (HIV)-associated CD8+ T-cell skin infiltrative disease with severe erythroderma has rarely been reported. While HIV-positive patients are prone to develop lymphoma, which is often associated with Epstein-Barr virus, polymorphic lymphoproliferative disorder is rare, accounting for <5% of cases. We herein report a 41-year-old HIV-positive man who presented with a fever, erythroderma, and lymphadenopathy and was diagnosed with the coexistence of both diseases. His condition improved significantly with continued antiretroviral therapy. This case suggests that HIV-induced immunodeficiency is central to the pathogenesis of both entities and that improvement of the immunodeficient state is an effective treatment.

Expression of the immune checkpoint molecules PD‑L1 and PD‑1 in EBV‑associated lymphoproliferative disorders: A meta‑analysis.

Epstein-Barr virus (EBV) has been implicated in the development of a wide range of lymphoproliferative disorders. In this process, the role of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) has remained to be clarified. A meta-analysis of 20 studies was performed and risk ratios (RRs) with 95% confidence intervals (CIs) were used to evaluate the association between PD-L1/PD-1 expression and the status of EBV infection. The results showed that the expression level of PD-L1 in tumor cells was significantly higher in EBV+ cases with a pooled RR of 2.26 (95% CI, 1.63-3.14; P<0.01), particularly in subtypes of diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin lymphoma. Similarly, EBV infection increased the expression of PD-L1 in immune cells with a pooled RR of 2.20 (95% CI, 1.55-3.12; P<0.01). In subtypes of DLBCL and post-transplant lymphoproliferative disorder, the expression of PD-L1 in immune cells is increased in EBV+ cases. Regarding the expression level of PD-1 in tumor-infiltrating lymphocytes (TILs), no significance was found between EBV infection and PD-1 expression, with a pooled RR of 1.10 (95% CI, 0.81-1.48; P>0.05). The present meta-analysis demonstrated that in EBV-associated lymphoproliferative disorders, EBV infection was associated with the expression level of PD-L1 in tumor cells and immune cells but was not associated with the expression of PD-1 in TILs.

Progressively transformed germinal center-like follicular T-cell lymphoma:a clinicopathological analysis of 14 cases

Objective: To investigate the clinicopathologic features of progressively transformed germinal center-like follicular T-cell lymphoma (PTGC-like FTCL). Methods: The clinicopathologic data of 14 PTGC-like FTCL cases that were diagnosed at the Beijing Friendship Hospital Affiliated to the Capital Medical University from January 2017 to January 2022 were retrospectively collected. Clinicopathological features, immunophenotype, and Epstein-Barr virus (EBV) infection status were analyzed in these cases. Polymerase chain reaction (PCR) was performed to detect the clonal gene rearrangements of T cell receptor (TCR) and the immunoglobulin (Ig) in 10 and 8 cases, respectively. Results: The male to female ratio was 5∶2. The median age was 61 years (range 32-70 years). All patients had lymphadenopathy at the time of diagnosis. By using the Ann Arbor system staging, seven cases were classified as stage Ⅰ-Ⅱ, and seven cases as stage Ⅲ-Ⅳ. Seven cases had B symptoms, four cases had splenomegaly, and two cases had skin rash and pruritus. Previously, three cases were diagnosed as classic Hodgkin's lymphoma, three cases as small B-cell lymphoma, two cases as atypical lymphoid hyperplasia unable to exclude angioimmunoblastic T-cell lymphoma (AITL), one case as EBV-associated lymphoproliferative disorder, and one case as peripheral T-cell lymphoma (PTCL) associated with the proliferation of B cells. All the 14 cases showed that the large nodules were composed of mature CD20+, IgD+B lymphocytes admixed with small aggregates of neoplastic cells with pale to clear cytoplasm. Moreover, hyperplastic germinal centers (GCs) and Hodgkin/Reed-Sternberg-like (HRS-like) cells were seen within these nodules in two and five cases, respectively. The neoplastic cells expressed CD3 (14/14), CD4 (14/14), PD1 (14/14), ICOS (14/14), CD10 (9/14), bcl-6 (12/14), CXCL13 (10/14), and CD30 (10/14). The HRS-like cells in five cases expressed CD20 (2/5), PAX5 (5/5), CD30 (5/5), CD15 (2/5), LCA (0/5), OCT2 (5/5) and BOB1 (2/5). Moreover, neoplastic T cells formed rosettes around HRS-like cells. EBV-encoded RNA (EBER) in situ hybridization showed scattered, small, positive bystander B lymphocytes in 8/14 cases, including 3/5 cases containing HRS-like cells. All tested cases (including five with HRS-like cells) showed monoclonal TCR gene rearrangement and polyclonal Ig gene rearrangement. Conclusions: PTGC-like FTCL is a rare tumor originated from T-follicular helper cells. It could be distinguished from angioimmunoblastic T-cell lymphoma by the formation of follicular structure, and lack of follicular dendritic cell proliferation outside the follicles and the polymorphous inflammatory background. In addition, it should be differentiated from lymphocyte-rich classical Hodgkin's lymphoma and low-grade B cell lymphoma.

Somatic Mutational Landscape and Transcriptomic Profiles of Lymphoproliferative Disorders with Epstein-Barr Virus Infection in Activated PI3K Delta Syndrome

Introduction: Germline gain-of-function variants in PIK3CD and PIK3R1 cause activated PI3K delta syndrome (APDS) types 1 and 2, respectively. Lymphoproliferative disorder (LPD) and susceptibility to various infections, including Epstein-Barr virus (EBV), are well-known features of APDS. EBV-associated LPDs are frequently observed in patients with APDS, and oligoclonal LPD might transform malignant lymphoma (ML). However, somatic molecular alterations in LPD and ML are not fully elucidated. Here, we report clinical characteristics and somatic mutational landscape and transcriptomic profiles of LPDs with EBV infection in APDS. Methods: LPD and ML in APDS diagnosed during 2011-2022 were recruited all over Japan. Clinical characteristics and outcomes were analyzed. EBV infection status was analyzed by EBER ISH and RNA sequencing (RNA-seq). Whole-exome sequencing (WES), RNA-seq, and single cell RNA-seq (scRNA-seq) were also performed. Results: Five LPD and 5 ML (borderline ML: n = 2, diffuse large B-cell lymphoma (DLBCL): n = 2, classical Hodgkin lymphoma: n = 1) cases were enrolled. Seven cases were APDS1 and 3 cases were APDS2. The median follow-up period was 2.9 (0.5-8.4) years. LPD cases were treated with rituximab monotherapy (n = 1), prednisolone (n = 3), and hematopoietic cell transplantation (HCT) (n = 1). Rituximab-combined chemotherapy was performed in borderline ML and DLBCL (n = 4) or ABVD regimen in Hodgkin lymphoma cases (n = 1). Sirolimus was used in two ML cases. HCT was performed in 9 cases. Two-year overall survival and event-free survival (events: relapse and death) were 78.8% and 70.0% in total LPDs, respectively, and 60% and 40% in ML cases. EBV was negative in 3 cases and positive in 2 cases of LPD cases, and positive in 4 cases, and negative in 1 case of ML cases. The median of 18 (10-48) and 42 (18-189) somatic variants were detected by tumor/germline pair WES in LPD (n = 5) and ML (n = 7, 2 samples were from the same patient at different time points), respectively. The recurrent variants were identified in ZFHX3 (n = 4), TRPM2 (n = 3), BEND3, CDH23, UBR4, ARAF, TET2, FBXO10, MAP4K1, KMT2C, KMT2D and PIK3R1 (n = 2) in LPD and ML cases. In transcriptome analysis, genes associated with lymphocyte activation including B-cell receptor signaling were upregulated in LPD, cell-cell adhesion, cellular response to TNF, and IL-18 signaling pathway were upregulated in ML samples. We performed correlation analysis to elucidate a relationship between EBV infection status and host transcriptomic profiles using RNA-seq data. Interestingly, in addition to cell-cell adhesion and inflammatory machinery, the upregulated molecules of the p53 pathway and negative regulation of the immune system were correlated with transcripts associated with EBV latency, such as EBNA, LMP-1, and LMP-2. In single-cell transcriptome analysis, LPD sample consisted of two large clusters of T cells and B cells with 10 subsets, and EBV-positive DLBCL sample consisted of one independent large cluster with 9 subsets. In LPD sample, components indicative of the normal lymphocyte differentiation process, including the germinal center, were preserved. The molecules involved in lymphocyte activation were upregulated in LPD subsets. In DLBCL sample, the genes associated with mitotic G2-M phases, chromatin organization and RNA metabolism were upregulated in the subsets in which EBV transcripts were more actively transcribed. Discussion and Conclusions: Our retrospective analysis demonstrated that the outcome of LPD and ML in APDS is not satisfactory. scRNA-seq data revealed that cells in LPD still retain the signature of normal lymph node. However, once transformed with EBV, EBV infection may affect epigenetic machineries including chromatin organizer followed by active RNA transcription involved in cell-cell adhesion, inflammatory machineries, molecules of p53 pathway and negative regulation of immune system in the host genome. As the outcome of ML is inferior to LPD, preemptive HCT would be an option for LPD cases.

P04 Leg ulceration in a patient with antisynthetase syndrome

Abstract A 42-year-old woman presented with leg ulceration on a background of antisynthetase syndrome and immunosuppression with rituximab, azathioprine and prednisolone. The initial lesion was an erythematous patch on the lower leg, which increased in size with violaceous changes. The area subsequently broke down to form an ulcer. On examination, she had a 7-cm ulcerating lesion with central necrosis. Clinically, the appearance was suspicious of pyoderma gangrenosum; biopsy demonstrated scarring without features of vasculitis, atypia or malignancy. The ulcer did not show improvement as expected after oral and topical steroid treatment, with new fleshy nodular growth. Repeat biopsy showed angiocentric atypical lymphocytes with positive Epstein–Barr virus (EBV)-encoded RNA (EBER) staining. Further incisional biopsy demonstrated large, atypical B lymphocytes with a diffuse sheet-like morphology and a poorly circumscribed base. Immunohistochemistry was positive for CD79a, CD30, CD20, MUM1, BCL6, and EBER. Overall, the findings were consistent with EBV-positive diffuse large B-cell lymphoma (DLBCL). The main differential diagnosis was EBV-positive mucocutaneous ulcer (MCU), another EBV-associated lymphoproliferative disorder, albeit with an indolent course (Dojcinov SD, Venkataraman G, Raffeld M et al. EBV positive mucocutaneous ulcer—a study of 26 cases associated with various sources of immunosuppression. Am J Surg Pathol 2010; 34:405–17). In this case, the diffuse sheet-like morphology and poorly circumscribed base favoured EBV-positive DLBCL. The lesion fully healed with withdrawal of immunosuppression and treatment with rituximab therapy, and involved field radiotherapy. First described in 2003, EBV-positive DLBCL is a rare, classically aggressive lymphoma initially believed to only occur in patients older than 50 years of age (Oyama T, Ichimura K, Suzuki R et al. Senile EBV+ B-cell lymphoproliferative disorders. Am J Surg Pathol 2003; 27:16–26). Since the revision of the World Health Organization classification in 2016, it is also recognized to present in younger patients, with an associated better prognosis. EBV-positive DLBCL occurs in both nodal and extranodal sites. Therefore, cutaneous presentations must complete staging investigations to rule out skin involvement secondary to a nodal lymphoma. Our patient highlights a rare complication of immunosuppression. We illustrate the relevance of considering rare causes of ulceration in patients with autoimmune conditions and immunosuppression and demonstrate the importance of considering malignancy in a nonhealing ulcer. Multiple biopsies may be needed in ulcers that poorly respond to treatment. While EBV-positive DLBCL and EBV-positive MCU can be difficult to differentiate, it is vital for prognostication.

Epstein-Barr virus-associated lymphoproliferative disorders after BNT162b2 mRNA COVID-19 vaccination

Epstein-Barr virus-associated lymphoproliferative disorders (EBV-LPD) is a rare disease characterized by persistent or recurrent inflammation accompanied by EBV infection of T or NK cells that is not self-limiting, and it is fatal, if untreated. After receiving the first dose of the BNT162b2 mRNA COVID-19 vaccine, a 79-year-old male presented to the hospital with a 2-week history of fever. Laboratory results indicated pancytopenia, elevated liver transaminase levels, hyperferritinemia, and hypofibrinogenemia. Computed tomography revealed hepatosplenomegaly, but lymphadenopathy was not observed. A bone marrow biopsy, a random skin biopsy, and a liver biopsy revealed no malignancy, but an infectious evaluation revealed EBV viremia (5.19 Log IU/ml). Flow cytometry and RT-PCR revealed that the EBV genome was localized in NK cells, suggesting the diagnosis of EBV-NK-LPD. We administered prednisolone, intravenous immunoglobulin, and etoposide, but the EBV-DNA load failed to decrease, and he died 2 months later. Recently, case reports of COVID-19 vaccination-related hemophagocytic lymphohistiocytosis have been published. Although the mechanisms and risk factors for EBV-LPD after BNT162b2 mRNA COVID-19 vaccination remain unknown, it is important to note the possibility of reactivation of EBV after COVID-19 vaccination to initiate early and targeted therapy.

Development of Epstein-Barr virus-associated lymphoproliferative disorder and hemophagocytic lymphohistiocytosis during long-term lenalidomide maintenance therapy in multiple myeloma.

Reactivation of Epstein-Barr virus (EBV) has been considered a very rare event among patients on immunomodulatory drugs (IMiDs) such as lenalidomide, and an association between the two has not well been recognized. We have recently experienced a rare case of multiple myeloma in which the patient had suffered EBV reactivation during long-term lenalidomide maintenance therapy. The patient subsequently developed EBV-associated lymphoproliferative disease (LPD) as well as EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), which was fatal despite intensive treatment. Although rare, clinicians should be aware that such fatal EBV reactivation could occur as a minor yet critical complication of long-term maintenance therapy with IMiDs in multiple myeloma patients. Regular monitoring and early detection of EBV reactivation would be beneficial for these patients, so that proper diagnostic examinations can be initiated without delay.

Prognosis of Superficial Epstein-Barr Virus-associated Lymphoproliferative Disorders Near the Gnathic Bone: Two Case Reports and Literature Review

Prognosis of Superficial Epstein-Barr Virus-associated Lymphoproliferative Disorders Near the Gnathic Bone: Two Case Reports and Literature Review

How I Diagnose EBV-Positive B- and T-Cell Lymphoproliferative Disorders.

Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (LPDs) encompass a group of well-defined entities of B-, T-, and natural killer (NK)-cell derivation. The diagnosis of these disorders is challenging because of clinical and morphologic features that may overlap with other benign and malignant EBV+ lymphoproliferations. This review describes our approach to the diagnosis of EBV-associated LPDs. Two cases are presented that illustrate how we diagnose EBV-associated LPDs. The first case represents a systemic EBV+ T-cell lymphoma of childhood and the second case an EBV+ mucocutaneous ulcer. The clinicopathologic features that help distinguish these entities from biological and morphologic mimickers are emphasized. The accurate diagnosis of EBV-associated LPDs requires the incorporation of histologic and immunophenotypic features, the assessment of the EBV latency program, and, most important, complete clinical findings. Clonality analysis is not helpful in distinguishing benign from malignant EBV+ LPDs. The better understanding of EBV-associated LPDs has resulted in the recognition of well-defined entities of B-, T-, and NK-cell derivation and consequently improvement of their treatment with curative intent. It is critical to distinguish benign from malignant EBV+ LPDs to avoid overtreatment.

In vitro and in vivo evidence that the switch from calcineurin to mTOR inhibitors may be a strategy for immunosuppression in Epstein–Barr virus–associated post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder is a life-threatening complication of immunosuppression following transplantation mediated by failure of T cells to control Epstein-Barr virus (EBV)-infected and transformed B cells. Typically, a modification or reduction of immunosuppression is recommended, but insufficiently defined thus far. In order to help delineate this, we characterized EBV-antigen-specific T cells and lymphoblastoid cell lines from healthy donors and in patients with a kidney transplant in the absence or presence of the standard immunosuppressants tacrolimus, cyclosporin A, prednisolone, rapamycin, and mycophenolic acid. Phenotypes of lymphoblastoid cell-lines and T cells, T cell-receptor-repertoire diversity, and T-cell reactivity upon co-culture with autologous lymphoblastoid cell lines were analyzed. Rapamycin and mycophenolic acid inhibited lymphoblastoid cell-line proliferation. T cells treated with prednisolone and rapamycin showed nearly normal cytokine production. Proliferation and the viability of T cells were decreased by mycophenolic acid, while tacrolimus and cyclosporin A were strong suppressors of T-cell function including their killing activity. Overall, our study provides a basis for the clinical decision for the modification and reduction of immunosuppression and adds information to the complex balance of maintaining anti-viral immunity while preventing acute rejection. Thus, an immunosuppressive regime based on mTOR inhibition and reduced or withdrawn calcineurin inhibitors could be a promising strategy for patients with increased risk of or manifested EBV-associated post-transplant lymphoproliferative disorder.

Clinicopathological features of angioimmunoblastic T-cell lymphoma pattern Ⅰ

Objective: To investigate the clinicopathological features of angioimmunoblastic T-cell lymphoma pattern Ⅰ (AITL Pattern Ⅰ). Methods: The clinicopathological data of 11 AITL Pattern Ⅰ cases that were diagnosed at the Beijing Friendship Hospital Affiliated to Capital Medical University (10 cases) and Beijing Lu Daopei Hospital (1 cases) from January 2019 to October 2021 were retrospectively collected. Immunophenotype, Epstein-Barr virus infection status and T cell receptor (TCR) clonality of the tumor cells were tested, and clinicopathological features of cases were analyzed. Results: Among the 11 AITL Pattern Ⅰ cases, the male to female ratio was 1.2∶1.0. The median age was 59 years (range 47-78 years). Seven cases had B symptoms, while eleven cases presented with systemic lymphadenopathy. According to Ann Arbor system staging, two cases were classified as stage Ⅰ-Ⅱ, and 9 cases as stage Ⅲ-Ⅳ. Hepatosplenomegaly was present in two cases (2/11), three cases (3/11) had skin rash and pruritus, and two cases (2/11) had pleural effusion. Previously, 6 cases (6/11) were diagnosed as reactive hyperplasia, 1 case (1/11) as EBV-associated lymphoproliferative disorder, and 4 cases (4/11) as hyperplasia of lymphoid tissue, which was unable to exclude lymphoma. Histologically, all the 11 cases showed hyperplastic follicles in the paracortical regions with well-formed germinal centers. The hyperplastic follicles showed ill-defined borders and attenuated mantle zones in 7 cases. Mantle zones completely disappeared in 4 cases. The follicles were surrounded by a thin layer of atypical lymphocytes with bright or faintly stained cytoplasm. In 2 cases, the clear cells were located between the germinal centers and the thin residual mantle cell layers, showing a circular growth pattern. The cells were medium in size, with irregular karyotype, coarse chromatin and indistinct nucleoli. Immunohistochemically, CD21 staining showed that the meshworks of follicular dendritic cells(FDC)were mainly confined to the follicles. There was a subtle expansion of the meshworks of FDC in 4 cases with ill-defined borders. The atypical cells surrounding the follicles expressed CD3 (11/11), CD4 (11/11), PD-1 (11/11), CXCL13 (6/11), ICOS (10/11) and CD10 (7/11). PD-1 staining showed a strong perifollicular pattern, and a small number of positive cells were scattered around the high endothelial veins in the interfollicular region. CXCL13, ICOS and CD10 showed similar distribution patterns. EBV-encoded small RNA probe (EBER) in situ hybridization showed that EBER positive B lymphocytes were scattered in the interfollicular region (5-20/HPF) in all cases. T cell receptor gene rearrangement was monoclonal in all cases. Conclusions: Diagnosing AITL Pattern Ⅰ may be challenging and requires comprehensive analysis of clinical manifestations, histological morphology, immunophenotype and gene rearrangement results.

EBV-associated lymphoproliferative disorders

Epstein-Barr-virus-associated lymphoproliferations (EBV-LPD) constitute awide spectrum from benign, self-limiting lymphoproliferations to malignant lymphoma. Because of the clinical and morphological heterogeneity of EBV-LPD and the high prevalence of EBV infections, knowledge of the diagnostic criteria is of great importance for the practice of diagnostic pathology. In this review, clinical and pathological characteristics of the non-malignant EBV-related LPD in patients with and without immunosuppression are presented and their current classification is discussed.EBV-LPD can be of B‑cell or T/NK-cell origin. Identification of EBV latency type and information about possible (iatrogenic) immunodeficiency of the patient are critical for diagnostic evaluation and separation from malignant lymphoma. The clinical context and the detection of EBV in T‑ and NK-cells are both essential for the diagnosis of EBV+ T/NK-cell LPD, which are rare in European countries.

Enhanced PD-L1 Expression in LMP1-positive Cells of Epstein-Barr Virus-associated Malignant Lymphomas and Lymphoproliferative Disorders: A Single-cell Resolution Analysis With Multiplex Fluorescence Immunohistochemistry and In Situ Hybridization.

Epstein-Barr virus (EBV) is associated with various types of human malignancies and with programmed death ligand (PD-L) 1 expression in neoplastic cells. However, in EBV-associated malignant lymphomas and lymphoproliferative disorders (LPDs), there is limited information regarding PD-L1 expression profiles among different histologic types and patterns of EBV latency. First, we investigated PD-L1 and EBV latent gene expression using conventional immunohistochemistry and in situ hybridization in 42 EBV-associated malignant lymphomas and LPDs. Classic Hodgkin lymphoma showed the highest PD-L1 expression with diffuse expression in all cases, followed by diffuse large B-cell lymphoma/Burkitt lymphoma, LPDs, and extranodal NK/T-cell lymphoma. EBV latency at the case level was not associated with PD-L1 expression. We further evaluated the expression of PD-L1 and EBV latent genes in tumor cells at single-cell resolution using multiplex fluorescence imaging. This analysis revealed that positivity rates of latent membrane protein (LMP) 1 in tumor cells were 1.0% to 89.5% (mean 35.4%) in latency type II/III cases, and LMP1 + cells showed more frequent PD-L1 expression than LMP1 - cells ( P &lt;0.0001, paired t test). In contrast, no association was observed between EBV nuclear antigen 2 and PD-L1 expression. Notably, tumor cells exhibiting Hodgkin/Reed-Sternberg cell-like morphology co-expressed PD-L1 and LMP1 more often than those that do not. Our observations suggested that LMP1 upregulates PD-L1 expression and is a potential biomarker for predicting the efficacy of immune checkpoint inhibitors. In addition, the heterogeneous expression of PD-L1 and EBV latent genes may produce diverse tumor cells with different oncogenic and immune-evasive properties, leading to resistance to targeted therapies.

EBV-POSITIVE B-CELL ULCERATIVE PROLIFERATION IN THE ORAL CAVITY

<h3>Objective</h3> Lymphoproliferative disorders (LPDs) are a group of conditions characterized by excessive production of lymphocytes manifested by lymphadenopathy, monoclonal lymphocytosis, and bone marrow infiltration. LPDs are often associated with Epstein-Barr virus (EBV) infection. EBV-associated LPDs most commonly appear in the setting of immunocompromised status such as HIV and in transplantation with the extended use of immunosuppressive medications. Individuals with primary immunodeficiency disorders, such as common variable immunodeficiency disease (CVID) or severe combined immunodeficiency, are also at risk of LPD. <h3>Case Summary</h3> A 67-year-old woman complained of mouth ulcerations for 3 months before presentation that were progressively getting worse. Past medical history included CVID, CD4 lymphopenia, rhinosinusitis, eosinophilic asthma, chronic back pain, anxiety, and depression. Medications included immunoglobulin replacement therapy, mepolizumab, montelukast, albuterol, cetirizine, bupropion, clonazepam, fluoxetine, and gabapentin. The patient was allergic to penicillin and azithromycin. Past surgical history was notable for removal of skin melanoma and total knee replacement. Review of systems included a 3-month, 25-lb weight loss, odynophagia, constipation, weakness, and fatigue. Extraoral examination was unremarkable. Intraoral examination revealed 3 × 2 cm² necrotizing palatal ulcerations bilaterally. Necrotizing ulceration was also noted on multiple areas of the gingiva. Differential diagnosis included acute necrotizing ulcerative periodontitis, deep fungal infection (aspergillosis), and lymphoma/LPD. Complete blood count with differential, EBV polymerase chain reaction (PCR), cytomegalovirus PCR and maxillofacial computed tomography (CT) were ordered. The CT scan was unremarkable and laboratory evaluation was negative except for positive EBV PCR. Oral biopsy demonstrated EBV positive B-cell ulcerative proliferation. Positron emission tomography/CT showed widespread fluorodeoxyglucose (FDG)-avid lymphadenopathy. An axillary lymph node biopsy showed atypical lymphoid proliferation in a background of atypical and reactive follicular hyperplasia most consistent with EBV-negative follicular lymphoma, which appeared histologically distinct from the oral EBV-positive LPD. The patient is currently being treated with single-agent rituximab therapy. <h3>Conclusions</h3> EBV may cause oral diseases including infectious mononucleosis, oral hairy leukoplakia, necrotizing ulcerative mucositis, non-Hodgkin's lymphoma, and EBV-related LPD. Persistent oral lesions in patients with CVID could be related to underlying systemic disease. This case is unique because the patient seemingly had follicular lymphoma unrelated to her EBV-positive LPD oral disease, yet in the setting of severe immunosuppression from CVID.

Unrelated cord blood transplantation for adult-onset EBV-associated T-cell and NK-cell lymphoproliferative disorders.

Adult-onset EBV-associated T-cell and NK-cell lymphoproliferative disorders (EBV-T/NK-LPDs) often progress rapidly, and require allogeneic stem cell transplantation early in the course of treatment. Unrelated cord blood transplantation (UCBT) is a readily available option for patients without HLA-matched donors. We retrospectively analyzed the outcomes of 12 UCBT in adult patients with chronic active EBV infection (CAEBV, n = 8), EBV-positive hemophagocytic lymphohistiocytosis following primary EBV infection (n = 2), hydroa vacciniforme-like lymphoproliferative disorder (n = 1), and systemic EBV-positive T-cell lymphoma of childhood (STCLC, n = 1). The median age at transplantation was 31.5years (range 19-58). At the median follow-up time for survivors, which was 6.3years (range 0.3-11.3), 3-year overall survival (OS) rates in all patients and 8 CAEBV patients were 68.2% (95% CI 28.6-88.9) and 83.3% (95% CI 27.3-97.5), respectively. Graft failure occurred in 4 of 8 CAEBV patients, requiring a second UCBT to achieve neutrophil engraftment. The cumulative incidence of grade II-IV acute GVHD was 33.3% (95% CI 9.1-60.4%). The EBV-DNA load became undetectable or very low after UCBT in all cases. UCBT may be a promising treatment option for adult-onset EBV-T/NK-LPDs.

Epstein-Barr virus-associated lymphoproliferative disorder of donor origin after heart transplantation

Post-Transplant Lymphoproliferative Disorder (PTLD) represents a group of lymphomas, which may develop after solid organ transplantation and decrease the survival of transplant recipients. The main challenge of treatment is to achieve disease remission by avoiding the risk of allograft rejection. This report describes a successful treatment of PTLD in an adult patient who underwent allogeneic stem cell transplantation as a child and cardiac transplantation as a young adult. We present the case of a 33-year-old female, who was diagnosed with a Diffuse Large B-Cell Lymphoma (DLBCL) triggered by Epstein - Barr virus (EBV) 8 months after receiving orthotopic heart transplantation from an EBV-positive donor. The patient was treated with R-CHOP chemotherapy followed by maintenance therapy with rituximab, resulting in complete morphologic and metabolic remission of the lymphoma. The echocardiographic examinations and routine endomyocardial biopsies performed during and after chemotherapy did not reveal any signs of cardiac allograft rejection. The patient was asymptomatic on Heart Failure (HF) therapy and continued to remain in complete remission after the cancer treatment. This case underlines the importance of timely surveillance and treatment of seronegative patients after receiving EBV-positive donor organs. Keywords: post-transplant lymphoproliferative disorder; EpsteinBarr virus; immunosuppression; cardiac transplantation; chemotherapy