A Case Report of Acute Liver Failure in a Child with Hepatitis a Virus and Epstein-Barr Virus Coinfection on the Background of Autoimmune Sclerosing Cholangitis.

Background: Fulminant hepatitis is a rare and severe form of acute liver failure (ALF) characterized by rapid and massive destruction of liver cells and associated with a high mortality rate. Infectious factors, in particular viral hepatitis, take a prominent place in the etiology of ALF, however, the presence of chronic liver pathology can play a significant role in the disease progression and development of ALF. Case Presentation: A 2-year-old child was hospitalized on the 4th day of the disease with manifestations of jaundice and general intoxication. The examination revealed markers of active hepatitis A virus infection and Epstein-Barr virus infection. From the seventh day of the disease, the child's condition began to progressively deteriorate due to manifestations of ALF. Despite the use of immunomodulatory and replacement therapy, the disease ended fatally on the 9th day. Pathohistological examination revealed manifestations of viral necrotic hepatitis on the background of autoimmune sclerosing cholangitis. Conclusion: The case is novel as regards the occurrence of two viral hepatitis with different modes of transmission on a background of unidentified liver disease.

[Effect of Plasma Epstein-Barr Virus Nucleic Acid Loads on the Clinical Features and Prognosis in Adult Secondary Hemophagocytic Lymphohistiocytosis].

OBJECTIVE: To investigate the effect of pre-treatment plasma Epstein-Barr virus (EBV) DNA copy number on the clinical features and prognosis of patients with adult secondary hemophagocytic lymphohistiocytosis(sHLH). METHODS: The clinical characteristics, survival rate, and prognostic factors of 171 patients with adult sHLH treated at Jiangsu Province Hospital from June 2017 to January 2022 were retrospectively analyzed in this study. Patients were divided into three groups, including the EBV DNA-negative group(<5.0×102 copies/ml), lower EBV-DNA loads group(5.0×102-8.51×104 copies/ml), and higher EBV-DNA loads group(＞8.51×104 copies/ml), according to pre-treatment plasma EBV-DNA copy number. Cox regression model was established for screening prognostic factors. Adult sHLH survival prediction model was constructed and realized through the nomogram based on EBV-DNA load after adjusted the factors affecting survival of etiology and treatment strategy.Concordance index (C-index) and calibration curves were calculated to verify model predictive and discriminatory capacity. RESULTS: Among 171 adult sHLH patients, 84 patients were not infected with EBV (EBV DNA-negative group), and 87 with EBV (EBV DNA-positive group, 48 lower EBV-DNA loads group and 39 higher EBV-DNA loads group). Consistent elevations in the levels of liver enzymes (ALT and AST), LDH, TG, ß 2-microglobulin and ferritin across the increasing of EBV-DNA load (all P <0.05), while the levels of fibrinogen decrease (P <0.001). The median follow-up time was 52 days (range 20-230 days), and 123 patients died. The overall survival (OS) rate of patients in EBV DNA-positive group was lower than that in EBV DNA-negative group (median OS: 40 days vs 118 days, P <0.001). Higher EBV-DNA loads had worse OS (median OS: 24 days vs 45 days vs 118 days, P <0.0001 for trend) compared to lower EBV-DNA loads and EBV DNA-negative group. Multivariate Cox analysis revealed that higher EBV-DNA loads (P =0.005), fibrinogen≤1.5 g/L (P ＝0.012), ferritin (P ＝0.041), associated lymphoma (P ＝0.002), and anti-tumor based strategy (P ＝0.001) were independent prognostic factors for OS. The C-indexes of 30 day, 90 days, 365 days survival rate were all greater than 0.8 of the nomogram model and calibration curves provided credibility to their predictive capability. Subgroup analysis showed that patients with higher EBV-DNA loads had a significantly worse prognosis in adult sHLH who were women, ferritin＞5 000 µg/L, ß2-microglobulin＞7.4 mmol/L and regardless of age, etiologies, HScore points. CONCLUSION: The EBV-DNA load is a strong and independent predictor for survival in patients with sHLH. The prognostic nomogram based on EBV-DNA loads was dependable and provides a visual tool for evaluating the survival of adult sHLH.

Clinical Characteristics of Peripheral Lymphocyte Subtypes in Chronic Active Epstein-Barr Virus Infection.

BACKGROUND: We aimed to analyze the clinical characteristics of peripheral Epstein-Barr virus (EBV)-infected lymphocyte subtypes in children with chronic active EBV infection (CAEBV). METHODS: The levels of peripheral EBV infection of CD4+ T cells, CD8+ T cells, and CD56+ natural killer (NK) cells were determined by flow cytometry and quantitative polymerase chain reaction (qPCR) in patients with CAEBV from July 2017 to July 2022. RESULTS: In total, 112 children with CAEBV were evaluated. Of these, CD4+ type, CD8+ type, and CD56+ type were defined in 44, 21, and 47 patients, respectively. Patients with CD8+ T-cell type had a significantly higher frequency of rash, while hepatomegaly was more common in patients with CD4+ T-cell type. Generally, patients with CD8+ T-cell type had the lowest overall survival rate (P = .017). Patients treated with chemotherapy and hematopoietic stem cell transplantation (HSCT) had a better prognosis (P = .001). In multivariate analysis, rash, hemophagocytic lymphohistiocytosis, CD8+ T-cell type, and no decrease of plasma EBV-DNA after treatment were independent indicators of poor prognosis (P = .002, .024, .022, and .012, respectively). CONCLUSIONS: In children with CAEBV, rash was more frequent in patients with CD8+ T-cell type, whereas patients with CD4+ T-cell type were more likely to develop hepatomegaly. Patients with CD8+ T-cell type had a poor prognosis despite receiving chemotherapy or further HSCT.

Spontaneous human CD8 T cell and autoimmune encephalomyelitis-induced CD4/CD8 T cell lesions in the brain and spinal cord of HLA-DRB1*15-positive multiple sclerosis humanized immune system mice.

Autoimmune diseases of the central nervous system (CNS) such as multiple sclerosis (MS) are only partially represented in current experimental models and the development of humanized immune mice is crucial for better understanding of immunopathogenesis and testing of therapeutics. We describe a humanized mouse model with several key features of MS. Severely immunodeficient B2m-NOG mice were transplanted with peripheral blood mononuclear cells (PBMCs) from HLA-DRB1-typed MS and healthy (HI) donors and showed rapid engraftment by human T and B lymphocytes. Mice receiving cells from MS patients with recent/ongoing Epstein-Barr virus reactivation showed high B cell engraftment capacity. Both HLA-DRB1*15 (DR15) MS and DR15 HI mice, not HLA-DRB1*13 MS mice, developed human T cell infiltration of CNS borders and parenchyma. DR15 MS mice uniquely developed inflammatory lesions in brain and spinal cord gray matter, with spontaneous, hCD8 T cell lesions, and mixed hCD8/hCD4 T cell lesions in EAE immunized mice, with variation in localization and severity between different patient donors. Main limitations of this model for further development are poor monocyte engraftment and lack of demyelination, lymph node organization, and IgG responses. These results show that PBMC humanized mice represent promising research tools for investigating MS immunopathology in a patient-specific approach.

Clinicopathological characteristics of methotrexate-related lymphoproliferative disorder of the thyroid: A study of 11 patients.

Methotrexate (MTX) is a well-known agent that can potentially cause lymphoproliferative disorder (LPD), known as MTX-related LPD (MTX-LPD). Only two cases of thyroid MTX-LPD have been reported to date. This study aimed to report 11 cases of MTX-LPDs arising in the thyroid gland and discuss their clinicopathological characteristics. Of the 747 patients with cytologically suspected lymphoma, 11 had received MTX. The mean age of the patients with MTX-LPD was 70.2 years (range: 51-82 years), and all were female. The duration of MTX administration ranged from 5 to 31 years (mean: 19.5 years). Nine patients (81.8 %) tested positive for anti-thyroglobulin antibody and/or anti-thyroid peroxidase antibody. In three patients, the tumor decreased in size or disappeared without surgery or chemotherapy after withdrawal of MTX therapy. Histologically, all eight nodules examined were B-cell lymphomas, and seven were mucosa-associated lymphoid tissue (MALT) lymphomas. Epstein-Barr virus-encoded small RNA in situ hybridization showed negative results for all six nodules examined. All five patients who were followed-up at our hospital exhibited progression-free survival for >3 years without chemotherapy. Six patients were transferred to other hospitals, and their follow-up details are unknown. MTX-LPDs occurring in the thyroid are characterized by a high female predominance, positivity for anti-thyroid autoantibodies, high prevalence of MALT lymphomas, negativity for Epstein-Barr virus, and good outcomes without chemotherapy. We recommend that patients with thyroid lymphoma should be checked for a history of MTX.

Clinical characteristics and literature review of chronic active Epstein-Barr virus-associated enteritis.

Chronic active Epstein-Barr virus (EBV) infection-associated enteritis (CAEAE) in nonimmunodeficient individuals is rare. To report a case of CAEAE, relevant articles were searched through databases. The clinical manifestations, endoscopic findings, strategies of treatment, prognoses, and follow-up results of CAEAE patients were analyzed. Including this report, seven citations in the literature provide descriptions of 27 cases of CAEAE. There were 21 males and six females, with a mean age of 40 years. The main clinical manifestations were fever (25/27), abdominal pain (14/27), diarrhea (16/27), hematochezia or bloody stools (13/27), and decreased hemoglobin and red blood cell counts in routine blood tests (14/27). Elevations in inflammatory markers, white blood cell (WBC) counts, and C-reactive protein (CRP) were common. Coagulation was often abnormal. Histopathology confirmed EBV-encoded small nuclear RNA (EBER) in the affected tissue via in situ hybridization. The average serum EBV DNA load was 6.3 × 10^5 copies/mL. All patients had varying degrees of intestinal ulcers endoscopically, and the ulcers and pathology were uncharacterized and misdiagnosed mostly as inflammatory bowel disease (IBD). The course of the disease was progressive and later complicated by intestinal bleeding, intestinal perforation, septic shock, and a high rate of emergency surgery. However, the conditions of the patients often did not improve after surgery, and some patients soon died due to reperforation or massive hematochezia. Hormone and antiviral treatment had no obvious effect. There was a significant difference in surgical and nonsurgical survival (p < 0.05). The proportion of patients who died within 6 months was as high as 63.6% (7/11). CAEAE belongs to a group of rare, difficult conditions, has an insidious clinical course, has a high case fatality rate, and may later develop into EBV-positive lymphoproliferative disorder (EBV-LPD), which in turn leads to carcinogenesis. Clinicians should raise awareness that in patients with multiple ulcers in the intestine of unknown etiology, attention should be paid to EBV serology, and histology to make the diagnosis as early as possible.

Epstein-Barr Virus Infection-Associated Facial Swelling: A Case Report.

Maxillofacial soft tissue swelling is a common clinical symptom with various etiologies. While odontogenic space infection is the most common cause, it is crucial not to overlook maxillofacial swellings caused by specific pathogenic infections and other local factors. This paper reports the case of an adult patient with right-sided swelling of his face, persistent oral mucosal ulcers, and recurrent hyperthermia for 30 days. He had received various antibiotics for the initial diagnosis of "right buccal space infection," but the antibiotics did not have any effect on his symptoms. None of the blood tests, histological examinations, bone marrow biopsies, and immune-related tests produced diagnostic findings. A diagnosis of Epstein-Barr virus (EBV) infection was finally confirmed by biopsy tissue genomics sequencing and quantitative analysis of EBV nucleic acid. In this report, we describe the diagnosis and treatment process for this patient and suggest that facial swelling could be an important clinical symptom of EBV infection.

Methotrexate-associated lymphoproliferative disorder: A rare pancreatic tumor diagnosed via endoscopic ultrasound-guided fine-needle biopsy.

A 73-year-old woman with a history of rheumatoid arthritis treated with methotrexate (MTX) for the last 10 years was referred to our hospital for a pancreatic tumor examination. Contrast-enhanced abdominal computed tomography revealed a 20-mm-diameter hypovascular tumor in the pancreatic tail. A hypoechoic mass with heterogeneous internal echo was found on an endoscopic ultrasound (EUS). An EUS-guided fine-needle biopsy (EUS-FNB) was performed with a 22-gauge Franseen-tip needle. Histologic examination of EUS-FNB specimens from the pancreatic tumor revealed the proliferation of atypical spindle cells. Immunohistochemical staining for CD20 and Ki-67 was positive in the atypical cells. Immunohistochemical staining for CD3 was partially positive in the atypical cells. Epstein-Barr virus-encoded RNA in situ hybridization showed positive staining. MTX-related lymphoproliferative disorder (MTX-LPD) with Epstein-Barr virus infection was diagnosed. MTX treatment was immediately discontinued, and treatment was initiated by a hematologist. However, her condition rapidly deteriorated, and she died of multiple organ failure 4 weeks after diagnosis. MTX-LPD can complicate gastrointestinal lesions. However, most lesions are localized in the stomach and rarely complicate pancreatic lesions. MTX-LPD is classified as an "iatrogenic" LPD. Therefore, immediate action, such as MTX discontinuation, is necessary. In conclusion, endoscopists should be aware that MTX-LPD lesions can occur in the pancreas and gastrointestinal tract. Moreover, EUS-FNB can be useful in the diagnosis of this rare pancreatic tumor.

Report of Two Contrasting Cases of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis: Comparison to Infectious Mononucleosis and Flow Cytometric Analysis of Bone Marrow.

Purpose: This study aims to investigate the characteristics of Epstein-Barr virus associated-hemophagocytic lymphohistiocytosis (EBV-HLH) and HLH caused by a severe form of infectious mononucleosis (IM-HLH) compared to IM by EBV, and thus also to assist in early diagnosis and providing appropriate treatment. Methods: Data for this analysis were collected from patients at the Department of General Medicine, Nara Medical University, between April 1, 2012, and August 1, 2020. EBV infection was diagnosed using clinical presentation and laboratory tests. HLH diagnosis followed the HLH-2004 protocol, supplemented by plasma EBV DNA detection. A range of clinical and laboratory parameters were collected, including age, sex, clinical outcomes, blood cell counts, hemoglobin, platelets, and various serum values. Plasma EBV DNA levels and flow cytometric analysis (FCM) of bone marrow were performed for HLH cases. Results: Among 1850 hospitalized patients, 14 cases were identified, including 2 HLH cases and 12 IM cases. Comparative analysis revealed distinctive features of HLH, including lower lymphocyte and platelet counts and higher levels of ferritin, soluble interleukin 2 receptor (sIL-2R), and D dimer compared to IM. Notably, one HLH case responded well to corticosteroid monotherapy, while the other case did not, resulting in a fatal outcome. Detection of a cluster of CD5-CD7 lymphocytes in bone marrow is a hallmark of EBV-HLH and useful to distinguish from IM-HLH. Conclusion: This study underscores the importance of early differentiation among EBV-HLH, IM-HLH, and IM in adults to guide appropriate treatment strategies. While specific laboratory markers help distinguish HLH from IM, a more detailed analysis of FCM is crucial for precise diagnosis of HLH cases and tailored therapeutic interventions.

Epstein-Barr virus infection with non-tumor-associated Anti-N-Methyl-D-Aspartate receptor encephalitis: a case report and review of literature.

To study a case of a middle-aged male with a non-tumor-associated Epstein-Barr virus (EBV) infection associated with Anti-N-methyl-D-aspartate receptor encephalitis (NMDARE), to explore the role of EBV in the pathogenesis of anti-NMDARE. The patient was diagnosed with "Anti-NMDARE, EBV infection" by using Cerebrospinal fluid (CSF) autoimmune encephalitis profile, and Metagenomics Next-Generation Sequencing (mNGS) pathogenic microbial assays, we discuss the relationship between EBV and NMDARE by reviewed literature. EBV infection may trigger and enhance anti-NMDARE, and the higher the titer of NMDAR antibody, the more severe the clinical presentation.

Clinical characteristics of peripheral lymphocyte subtypes in chronic active Epstein-Barr virus infection.

PURPOSE: To analyze the clinical characteristics of peripheral Epstein-Barr virus(EBV)-infected lymphocyte subtypes in children with chronic active EBV infection(CAEBV). METHODS: The levels of peripheral EBV infection of CD4 + T cells, CD8 + T cells, and CD56 + NK cells were determined by flow cytometry and qPCR in patients with CAEBV from July 2017 to July 2022. RESULTS: A total of 112 children with CAEBV were evaluated in the study. Of them, CD4 + type, CD8 + type, and CD56 + type were defined in 44, 21, and 47 patients, respectively. Patients with CD8 + T-cell type had a significantly higher frequency of rash, while hepatomegaly was more common in patients with CD4 + T-cell type. Generally, patients with CD8 + T-cell type had the lowest overall survival(OS) rate(P = 0.017). As for treatment, patients treated with chemotherapy and hematopoietic stem cell transplantation had a better prognosis(P = 0.001). In multivariate analysis, rash, HLH, CD8 + T-cell type, and no decrease of plasma EBV-DNA after treatment were indicated as independent factors of poor prognosis(P = 0.002, 0.024, 0.022, and 0.012, respectively). CONCLUSION: In children with CAEBV, the rash was more frequent in patients with CD8 + T-cell type, whereas patients with CD4 + T-cell type were more likely to develop hepatomegaly. Patients with CD8 + T-cell type had a poor prognosis despite receiving chemotherapy or further HSCT.

CD5 B-Cell Predominant Primary Immunodeficiency: Part of the Spectrum of MAGT1 Deficiency.

Background: Selective anti-polysaccharide antibody deficiency (SPAD) with CD5 B-cell predominance and autoimmune phenomena was identified in a male cohort first reported by Antall et al in 1999. The phenotypically likewise and genotypically identical X-linked immunodeficiency with magnesium defect, Epstein-Barr Virus infection, and neoplasia (XMEN) disease was defined as a novel primary immunodeficiency (PID) in 2011. Recent studies of the magnesium transporter 1 (MAGT1) gene mutation reveal glycosylation defects contributing to more phenotypic variance than the "XMEN" title pathologies. The updated title, "X-linked MAGT1 deficiency with increased susceptibility to EBV-infection and N-linked glycosylation defect," was proposed in 2020. Objectives: To reflect the patient population more accurately, a prospective classification update may consider MAGT1 glycobiological errors contributing to phenotypic variance but also pre-genetic testing era reports with CD5 B-cell predominance. Methods: Patient 1 from Antall et al presented at 28 years of age for further immunological evaluation of his CD5/CD19 B-cell predominance diagnosed at 5 years old. Design: Immune re-evaluation done through flow cytometry and next-generation sequencing. Results: Flow cytometry B-cell phenotyping revealed persistent CD5+CD19+ (93%). Flow cytometric histogram quantified reduced activator CD16+CD56+ natural killer and CD8+ T-cell receptor, Group 2, Member D (NKG2D) glycoprotein expression. A c.923-1_934 deletion loss of function mutation was identified in the MAGT1 gene. Conclusion: We suggest the novel PID XMEN, based on its CD5 B-cell predominance, had been discovered and reported over a decade earlier as CD5+ PID based on the MAGT1 mutation found in the same. We encourage consideration of combining these labels and recent findings to offer the most accurate classification of this disease.

Sintilimab treatment for chronic active Epstein-Barr virus infection and Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis in children.

BACKGROUND: Chronic active Epstein-Barr virus infection (CAEBV) and Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) are rare but life-threatening progressive diseases triggered by EBV infection. Glucocorticoid/immunosuppressants treatment is temporarily effective; however, most patients relapse and/or progress. Hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy; however, there are risks of transplantation-associated complications. Currently there is no standard treatment for CAEBV and EBV-HLH. Programmed death protein 1 (PD-1) inhibitors have achieved a high response in many EBV-related diseases. Sintilimab (a recombinant human IgG4 monoclonal antibody against PD-1) disrupts the interaction between PD-1 and its ligand, leading to T cell reinvigoration. METHODS: A retrospective analysis was performed on three children with CAEBV or EBV-HLH in the Children's Hospital of Soochow University between 12 December 2020 and 28 November 2022. The efficacy of sintilimab was evaluated. RESULTS: Three patients, including two males and one female, were analyzed. Among them, two children were diagnosed with CAEBV with intermittent fever for more than four years, and one child was diagnosed with EBV-HLH. After sintilimab treatment and a mean follow-up of 17.1 months (range 10.0-23.3 months), patients 1 and 3 achieved a complete clinical response and patient 2 achieved a partial clinical response. All three children showed a > 50% decrease in EBV-DNA load in both blood and plasma. EBV-DNA copies in sorted T, B, and NK cells were also markedly decreased after sintilimab treatment. CONCLUSION: Our data supported the efficacy of PD-1 targeted therapy in certain patients with CAEBV and EBV-HLH, and suggested that sintilimab could provide a cure for these diseases, without HSCT. More prospective studies and longer follow-up are needed to confirm these conclusions.

Changes in the gut microbiome can predict and decrease Epstein-Barr virus infection risk in children after liver transplantation.

OBJECTIVE: Primary Epstein-Barr virus (EBV) infection is observed in 60% of children during the first year after liver transplantation as usage of imm-unosuppressant. Finding predictive indicators of EBV infection is important to reduce the morbidity and mortality of EBV infection-related diseases by suggesting a dose reduction of immunosuppressant. METHODS: We compared and analysed the gut microbiome of EBV-infected children with an asymptomatic virus-carrying status and EBV-uninfected children after liver transplantation using high-throughput sequencing. RESULTS: Significant differences in gut microbiome composition in two groups were detected. In detail, Firmicutes and Lactobacillus were increased in EBV-infected group, while Clostridium was increased in EBV-uninfected group. Furthermore, CD4 percentage in T cells of blood showed a significant positive correlation with the content of Clostridium sp. CAG: 127 in EBV-uninfected group. CONCLUSION: Changes in the gut microbiome could predict and decrease the EBV infection risk of children after liver transplantation.

[Lymphomas in children and adolescents]. / Lymphome bei Kindern und Adoleszenten.

BACKGROUND: Lymphomas in children and adolescents differ from adulthood in relative frequency and variety of entities. In addition, young patients are cared for according to the specific standards of pediatric lymphoma study groups. OBJECTIVE: To present lymphomas of diagnostic and clinical relevance in the pediatric and adolescent group. MATERIAL AND METHODS: Selective literature research ( http://www.ncbi.nlm.nih.gov ) was combined with clinico-pathological experience of the authors. RESULTS: Children and adolescents are much more likely to suffer from aggressive and precursor cell lymphoma than is the case in adulthood. Unlike adult patients, Burkitt lymphomas and diffuse large B­cell lymphomas are not treated fundamentally differently. Entities that have been described relatively recently and are particularly common in young patients are high-grade B­cell lymphoma with 11q aberrations and large-cell B­cell lymphoma with IRF4 translocations. CONCLUSION: Lymphoma diagnosis in children and adolescents is characterized by the particular spectrum of diseases that occur at this age. Special knowledge about the clinical relevance of the diagnoses in childhood is helpful in order to enable rapid clinical decision making.

Epstein-Barr virus-associated B-cell lymphoproliferative disorder meeting the definition of CAEBV B cell disease: a case report.

BACKGROUND: Chronic active Epstein-Barr virus infection (CAEBV) is a systemic EBV-positive lymphoproliferative disorder (EBV-LPD) considered to be associated with a genetic immunological abnormality, although its cause is still unclear. EBV is usually detected in T cells or NK cells in CAEBV patients with only a few cases involving B cells described in East Asia, which may be due to differences in genetic and environmental factors. CASE DESCRIPTION: A 16-year-old boy who seemed to be diagnosed as CAEBV of B cell type was studied. The patient had IM-like symptoms persisting for more than 3 months, high levels of EBV DNA in the PB, and positive EBER in situ hybridization in B cells. In addition, to exclude underlying genetic disorders, we performed next-generation sequencing (NGS) and whole-exome sequencing (WES), which identified the missense mutation in PIK3CD (E1021K), ADA (S85L) and CD3D (Q140K) in the patient while no same genetic mutation was detected in his parents and sister. However, there is no diagnosis of CAEBV of B cell type in the most recent World Health Organization classification of tumors of hematopoietic and lymphoid tissues, therefore we finally diagnosed this patient as EBV-B-LPD. CONCLUSIONS: This study shows a rare case of a patient meeting the definition of CAEBV B-cell disease in East Asia. Meanwhile, the case indicates that the missense mutation and the disease are related.

Single-center "Argentine" analysis of post-transplant lymphoproliferative disorders: incidence, histopathological characteristics and EBV status

ABSTRACT Introduction: Post-transplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations occurring after solid organ or bone marrow transplantation. The primary aims of our study were to characterize cumulative incidence of PTLDs, clinical and pathological features according to the Epstein-Barr virus (EBV) status and survival. Methods: This was a retrospective cohort study on adult and pediatric patients, from January 2001 to December 2017. The cumulative incidence of PTLD was calculated by analyzing all the patients transplanted at our hospital, based on the database of the Organ Donation and Ablation Authority of Argentina (INCUCAI). The Kaplan-Meier method was used to plot the survival. Results: Fifty-eight cases of biopsy-confirmed PTLD were identified and 12 cases of clinical data were incomplete and these patients were excluded. The median age at the time of the PTLD diagnosis was 17.5 years (interquartile range [IQR] 9 - 57). The median interval between transplant and PTLD diagnosis was 39 months (IQR 9 - 113). The most commonly transplanted organ was the liver (24 cases, 52.2%), followed by kidney (20 cases, 43.5%). The Epstein-Barr encoding region in situ hybridization (EBER ISH) was positive in 29 (69.8%) of the 43 evaluable biopsies. The PTLD cumulative incidence was 1.84% (95%CI 1.77 - 1.91) for solid organ and 0.84% (95%CI 0.48 - 1.2) for bone marrow transplant patients. The overall survival rate at 5 years was 0.77 (95%CI 0.61 - 0.87). Subgroups by the EBV EBER status, transplant type, PTLD subtype and age group (adult vs. pediatric) showed no statistically significant association with the overall survival. Conclusion: The PTLD incidence was similar to that of previous series and the EBER did not appear as a relevant factor in our patient survival.

A Rare Case of Metachronous Peripheral T-cell Non-Hodgkin Lymphoma Following Epstein-barr Virus-positive Diffuse Large B-cell Lymphoma, Not Otherwise Specified.

We report a case of an elderly male who presented with enlarged abdominal lymph nodes and was diagnosed as having Epstein-Barr virus-positive diffuse large B-cell lymphoma, not otherwise specified (EBV+ DLBCL, NOS). He was started on chemotherapy which had to be discontinued after three cycles due to the development of life-threatening pneumocystis carinii pneumonia and poor performance status. Within two years, the patient presented with features of relapse. A repeat histopathological examination of the lymph node showed features of peripheral T-cell lymphoma, NOS and the clonality was confirmed by T-cell receptor gamma chain rearrangement assay. More studies are needed to understand the association of EBV+ DLBCL, NOS with other lymphomas.

Newly diagnosed extranodal NK/T-cell lymphoma, nasal type, at the injected left arm after BNT162b2 mRNA COVID-19 vaccination.

Anti-SARS-CoV-2 vaccines were developed in response to the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although the BNT162b2 mRNA vaccine is effective, adverse effects have been reported. Here, we report a case of extranodal NK/T-cell lymphoma, nasal type (ENKL), of the left arm following BNT162b2 mRNA vaccination. A 73-year-old male presented with a lump in the left arm, which was the site where he received the BNT162b2 mRNA vaccine 3 months prior. He was treated with topical corticosteroids and debridement, but the tumor progressed. Additionally, fever, night sweats, and general fatigue were observed. Laboratory findings included thrombocytopenia, elevated lactate dehydrogenase, and soluble interleukin-2 receptor levels. Skin biopsy led to a diagnosis of ENKL. The patient was treated with a 50% dose of SMILE therapy and radiotherapy, resulting in regression of the tumor. It seems that latent Epstein-Barr virus (EBV)-infected NK/T cells were reactivated by vaccination and contributed to the onset of ENKL. This is the first report of ENKL after BNT162b2 mRNA vaccination. The present case highlights the possible risk of development of malignant lymphoma, including ENKL at the injection site, after BNT162b2 COVID-19 vaccination.

[Delayed diagnosis of hydroa vacciniforme-like lymphoproliferative disorder in a patient with skin rashes].

Chronic active Epstein-Barr virus (CAEBV) infection is characterized by persistent EBV infection and can lead to fatal conditions such as hemophagocytic syndrome and malignant lymphoma through the clonal expansion of EBV-infected T or natural killer (NK) cells. Hydroa vacciniforme lymphoproliferative disorder (HV) and hypersensitivity to mosquito bites (HMB) have been identified as skin diseases in EBV-associated T- or NK-cell lymphoproliferative diseases. We present the case of a 33-year-old man. The patient had frequent episodes of a facial rash for three years before he visited our hospital, he visited several dermatologists but did not receive a diagnosis of HV. He was referred to the hematology department of our hospital for assessment of atypical lymphocytes in peripheral blood. Based on routine blood and bone marrow test we were unable to diagnose HV. However, when the patient's liver function deteriorated six months later, we considered the possibility of HV after reevaluating the skin rash. After performing EBV-related tests, we were able to definitively diagnose CAEBV with HV. It is crucial to be able to connect clinical observations to EBV-related tests when diagnosing CAEBV. Hematologists must be knowledgeable of the EBV-associated skin conditions of HV and HMB.