From Burkitt's lymphoma to chronic active Epstein-Barr virus (EBV) infection: an expanding spectrum of EBV-associated diseases

Epstein-Barr virus (EBV) is one of 8 known human herpesviruses. EBV infection usually occurs in early childhood and is subclinical. However, primary infection in adolescence or adulthood causes infectious mononucleosis in approximately half of infected individuals. Recently, the spectrum of human diseases associated with EBV infection has increased, primarily due to methodological advances in EBV detection. Initially, EBV was isolated from a cultured Burkitt lymphoma cell line, and has been felt to be etiologically linked to the development of Burkitt lymphoma, as well as other human malignancies. This review mainly focuses on pathogenetic mechanisms, many of which remain enigmatic, for the various human diseases, which are considered to be associated with EBV infection.     

FROM BURKITT'S LYMPHOMA TO CHRONIC ACTIVE EPSTEIN-BARR VIRUS (EBV) INFECTION: An Expanding Spectrum of EBV-Associated Diseases

Epstein-Barr virus (EBV) is one of 8 known human herpesviruses. EBV infection usually occurs in early childhood and is subclinical. However, primary infection in adolescence or adulthood causes infectious mononucleosis in approximately half of infected individuals. Recently, the spectrum of human diseases associated with EBV infection has increased, primarily due to methodological advances in EBV detection. Initially, EBV was isolated from a cultured Burkitt lymphoma cell line, and has been felt to be etiologically linked to the development of Burkitt lymphoma, as well as other human malignancies. This review mainly focuses on pathogenetic mechanisms, many of which remain enigmatic, for the various human diseases, which are considered to be associated with EBV infection.     

COMPARISON OF IMMORTALIZATION ASSAY AND POLYMERASE CHAIN REACTION DETECTION OF EPSTEIN-BARR VIRUS IN PEDIATRIC TRANSPLANT RECIPIENTS AND CONTROL SAMPLES

The polymerase chain reaction technique (PCR) has become a standard for the detection of Epstein-Barr virus (EBV). Several studies have shown that solid organ transplant recipients fated to develop post-transplant lymphoproliferative disease (PTLD) have higher mean levels of EB viremia as measured by PCR. We directly compared PCR and immortalization assay (IA) for EBV detection from control cell lines as well as from peripheral blood mononuclear cells (PBMC) and saliva samples from 9 pediatric solid organ transplant recipients. Results were expressed as the lowest amount of DNA and / or number of cells detected. All samples negative for EBV by PCR had amplifiable DNA detected using beta-actin primers. When control cell lines were assayed and positive in both assays, PCR was at least 200 times more sensitive than IA, as expected. When PBMC and saliva were compared, 1 patient, with a mononucleosis-like syndrome, was positive for EBV by IA only. When both IA and PCR were positive however, PCR was able to detect 5-500 times less EBV than IA, as expected. The associations of a positive test with each assay and the diagnosis of PTLD were similar.     

CD8 + T-LYMPHOCYTES INFILTRATE THE MYOCARDIUM IN FULMINANT HERPES VIRUS MYOCARDITIS

We report two cases of fulminant viral myocarditis in previously healthy children. They were caused by herpes simplex virus (HSV)-1 (in a boy aged 3 years) and Epstein-Barr virus (EBV) (in a boy aged 12 months). We obtained the diagnosis of HSV-1 myocarditis by immunohistochemistry and the diagnosis of EBV myocarditis by in situ hybridization. Histologic examination of heart tissue from the two boys revealed mononuclear cell infiltration of the myocardium. Immunohistochemical staining identified these cells as CD8 + T-lymphocytes. CD8 + T-lymphocytes induced by herpes virus infections may play an important role in the damage to heart muscle fibers seen in fulminant myocarditis in previously healthy children. To our knowledge, this is the first report of HSV-1 or EBV myocarditis (at least in children) in which viral infection has been demonstrated in the myocardium.     

CD8 + T-LYMPHOCYTE INFILTRATION AND APOPTOSIS IN FULMINANT EPSTEIN-BARR VIRUS HEPATITIS IN A PREVIOUSLY HEALTHY GIRL

A previously healthy 9-month old girl presented with fulminant hepatitis caused by the Epstein Barr virus (EBV). The patient developed fever, coma, and jaundice, and laboratory examination demonstrated acute liver failure. She did not respond sufficiently to conservative treatment and underwent liver transplantation with a graft from her father. Her condition improved transiently, but she died several weeks after surgery from a recurrence of liver failure. Histologic examination of the excised liver revealed massive panacinar necrosis and infiltration of mononuclear cells. Immunohistochemical staining identified these cells as CD8 + T-lymphocytes. A small number of apoptotic cells were observed, the nuclei of which were clearly labeled by terminal-deoxyribosyl-transferase-mediated deoxyuridine nick-end labeling. Tests for anti-EBV antibodies gave negative results, and EBV infection was diagnosed by in situ hybridization of liver tissue. CD8 + T-lymphocytes induced by the viral infection and apoptosis may have played an important role in damaging the hepatocytes of this patient.     

Epstein-Barr virus--positive undifferentiated thymic carcinoma in a 12-year-old white girl

Thymic epithelial malignant diseases are extremely rare in children. The authors report a 12-year-old white girl admitted for a polymetastatic tumor of the anterior mediastinum. Tumor proliferation was typical of an undifferentiated thymic carcinoma. A close link between Epstein-Barr virus (EBV) and the tumor was established by a high titer of anti-VCA IgA and the presence of EBV RNA and DNA in the tumor. In addition, monoclonal viral episomes were present in tumor cells, indicating that EBV infection was an early event in the oncogenic process. The patient died despite resection, irradiation, and chemotherapy.     

Monoclonal proliferation of Epstein-Barr virus-infected T-cells in a patient with virus-associated haemophagocytic syndrome

Virus-associated haemophagocytic syndrome (VAHS) is a non-neoplastic, generalized histiocytic proliferation disorder showing marked haemophagocytosis associated with systemic viral infection. We describe the case of a 1-year-old girl with Epstein-Barr virus (EBV)-related VAHS, in whom Southern blot analysis showed monoclonal proliferation of bone marrow cells with the EBV genome; detected with the Xho-1 fragment of the latent infection membrane protein genome. EBV serology showed anti-Epstein-Barr virus nuclear associated antigen (EBNA), anti-viral capsid antigen (VCA)-IgG, anti-VCA-IgA elevation and positive EBNA of Sheep red blood cells (SRBC)-rosette-forming bone marrow cells in the late period of her clinical course, indicative of EBV infection. DNA analysis of her bone marrow cells showed monoclonal rearrangement of the T-cell receptor- and- chain genes but not of the immunoglobulin heavy chain genes. Those results suggest that EBV may infect T-cells, after which the cells proliferate monoclonally. Repeated administration of epipodophyllotoxin VP-16-213 induced remission, but adrenocortical steroid, vincristine, and cyclophosphamide had no effect on the patient's condition. Ours is a first case report of VAHS showing monoclonal proliferation of EBV-infected T-cells.     

Epstein-Barr virus and post-transplant lymphoproliferative disease

There is convincing evidence that Epstein-Barr virus (EBV) is associated with post-transplant lymphoproliferative disease (PTLD). Primary EBV infection following transplantation occurs in as many as 90% of cases of PTLD in children and pretransplant EBV seronegativity is a recognized risk factor for developing PTLD. Other risk factors include young age at the time of transplant, the type of transplant that the recipient receives and the type and intensity of immunosuppression. The clinical presentation is often nonspecific and tissue biopsy is necessary to establish the diagnosis. There appears to be a correlation between PTLD and EBV viral load measured by polymerase chain reaction (PCR) of the peripheral blood and quantitative PCR may be a useful guide in the management of PTLD. Antiviral drugs and cytomegalovirus-immunoglobulin G may have a role in preventing PTLD. Because PTLD results from functional over-immunosuppression, the initial treatment is reduction of immunosuppression. Antiviral agents, interferon, immuno-based monoclonal therapy, cell-based therapy and chemotherapy also have a potential role in treating this disorder. At the present time there is no standardized approach to the evaluation and treatment of PTLD.     

Epstein-Barr virus DNA in lymphocytes of patients with the virus-associated hemophagocytic syndrome

The virus-associated hemophagocytic syndrome (VAHS) is a histiocytic proliferative disorder with bone marrow and liver failure for which the connection with a specific virus is often tenuous. Epstein-Barr virus (EBV) is one candidate for the association, but serologic or culture confirmation may be lacking in a particular case. As a means of directly identifying the presence of EBV in patients' cells, molecular hybridization studies were carried out using a radioactively labeled viral DNA segment. DNA from mononuclear cells of two children with VAHS had specific hybridization to the EBV DNA probe. One of the patients had serologic evidence for EBV infection. Several immunologic deficiencies were found. VAHS may represent one of several hematologic and/or immunologic dysfunctions caused by EBV.     

Incidence, kinetics, and risk factors of Epstein-Barr virus viremia in pediatric patients after allogeneic stem cell transplantation

After allogeneic hematopoietic stem-cell transplantation (allo-HSCT), EBV infections can be potentially dangerous and even life threatening. We evaluated the EBV viremia in 80 consecutive allo-HSCT with quantitative EBV-PCR every 2 weeks during the first 3 months and monthly thereafter until 1 yr after allo-HSCT or until death. We found a significantly more frequent viremia in patients who had in vivo T-cell depletion in which 23 out of 51 (45%) had EBV-PCR positivity. The EBV virus load was also significantly higher in the in vivo T-cell depleted group. Three patients developed clinical symptoms of EBV-PTLD and were treated with monoclonal anti-CD20 antibodies. No EBV- driven mortality was seen in this cohort. In our opinion EBV-PCR monitoring is mandatory after allo-HSCT. Most of the patients with EBV viremia had a good evolution after tapering the immune suppression, so this should be the first-line management of pediatric patients with EBV viremia. Monoclonal anti-CD20 antibodies should be reserved for those patients with early symptoms of EBV-PTLD.     

Epstein-Barr virus infection in Chediak-Higashi syndrome mimicking acute lymphocytic leukemia

We have had the opportunity to study a case of Chediak-Higashi syndrome (CHS) in the accelerated phase that was associated with Epstein-Barr virus (EBV) infection. The clinical course of a 12-year-old boy was characterized by fever, lymphadenopathy, hepatosplenomegaly, and pancytopenia. However, in the terminal stage, the appearance of an atypical lymphoblastic leukocytosis was morphologically indistinguishable from acute lymphocytic leukemia, accompanied by benign histiocytosis with hemophagocytosis. Autopsy examination revealed an atypical lymphoid infiltration favoring EBV infection as the primary diagnosis. This case underscores the fatal consequences of EBV infection in CHS.     

Kawasaki Disease and Epstein-Barr Virus

We report the results of virological (serological and molecular biological) studies of Epstein-Barr virus (EBV) in patients with Kawasaki disease (KD). Forty-nine (86%) of 57 Kawasaki disease patients and 15 (68%) of 22 patients with recurrent Kawasaki disease had serological evidence of primary Epstein-Barr virus infection during the first month after the onset of their disease based on the results of a sensitive method of detecting antibody to viral capsid antigen (VCA). The serological response to EBV was significantly low and transient. EBV sequences were identified directly in peripheral blood mononuclear cell (PBMC) DNA samples from 23 (56%) of 41 KD patients within 2 weeks after onset by means of the polymerase chain reaction (PCR). EBV sequences were also detected in 10 (83%) of 12 repeatedly tested KD patients within 3 months after onset. In contrast, only 7 (18%) of 40 control DNA samples were PCR-positive. These virological studies indicate that an unusual EBV-cell interaction may occur in KD.     

Epstein-Barr virus burden in adolescents with systemic lupus erythematosus

OBJECTIVE: We sought to determine whether patients with systemic lupus erythematosus (SLE) and a presumed primary or reactivated Epstein-Barr virus (EBV) serologic response had evidence of an active EBV infection. BACKGROUND: Patients with SLE often have what appears to be a primary or reactivated EBV serologic response. If these patients then present with fever, fatigue, adenopathy or leukopenia, it is not clear whether these symptoms are caused by worsening SLE or EBV infection. Establishing the correct diagnosis is crucial for management. METHODS: We examined the EBV burden in 13 adolescents with SLE and a presumed primary or reactivated EBV serologic response. All were taking prednisone; 2 each were also on azathioprine or intravenous pulse cyclophosphamide. EBV serologies were performed for all, and EBV burdens were assessed via immortalization assays and EBV DNA amplification of blood and saliva at least once. RESULTS: Seven patients had serologic patterns indicative of a primary EBV infection, while six had serologies indicative of a reactivated (secondary) EBV infection. Two of the latter were the only ones in whom a small amount of biologically active EBV was detected. CONCLUSION: In our series active EBV infection was not seen in most patients, despite serologic data that could be interpreted as a primary or reactivated infection. Thus the serologic profiles were more likely a consequence of immune dysregulation secondary to SLE or its therapy rather than rampant infection with EBV.     

Primary Epstein-Barr virus infections in children.

During a serioepidemiologic survey of a community, 13 (6.2%) of 209 children were found to be experiencing a current or recent primary Epstein-Barr virus (EBV) infection. The sera contained elevated antibody titers to viral capsid antigen of EBV, antibodies to early antigen (EA) of EBV, and specific IgM. The frequency of primary infections was highest in the first decade of life. The primary EBV infections were usually asymptomatic. The antibody to EA was directed predominantly to the R component. A heterophil antibody response was not detected.     

Epstein-Barr病毒相关移植后淋巴组织增生性疾病免疫治疗的最新进展

Epstein-Barr病毒相关的移植后淋巴组织增生性疾病(EBV-PTLD)是造血干细胞移植或实体器官移植后病死率极高的并发症。在过去的十年中,对于存在高危因素的患者,免疫治疗干预措施包括减少免疫抑制剂,CD20单克隆抗体(利妥昔单抗)单药治疗或与化疗相结合,输注EBV-特异性T细胞的过继免疫治疗,使得EBV-PTLD患者的存活率有了显著的提高。本文旨在对造血干细胞移植或实体器官移植后EBV-PTLD的高危因素、 临床表现及免疫治疗的最新进展进行总结。     

Prevalence of Epstein-Barr Viral DNA among children at a single hospital in Suzhou,China

ObjectiveThis study aimed to describe the prevalence of Epstein-Barr virus (EBV)-DNA among children in Suzhou, and to explore the association between plasma EBV load and disease diagnosis.MethodsAll children admitted to the Children's Hospital of Soochow University between January 2018 and September 2020 and subjected to the plasma EBV-DNA assay were included. The authors retrospectively collected demographic and discharge diagnostic information of the participants, and ascribed the disease distribution characteristics of children with positive plasma EBV-DNA by age and viral load.ResultsA total of 38,175 patients underwent plasma EBV-DNA PCR assay, of which 2786 (7.3%) had EBV-DNA in their plasma. Children aged 3–4 years had a high prevalence of EBV infection. Plasma EBV positivity was common with infectious mononucleosis (IM, 40.0%), respiratory infection (20.1%), atypical EBV infection (14.2%), acute leukemia (6.4%), hemophagocytic lymphohistiocytosis (HLH, 4.8%), and idiopathic thrombocytopenic purpura (ITP, 2.9%). With increasing age, plasma EBV positivity was more common in children with IM and atypical EBV infection. However, an inverse correlation was observed in children with respiratory infections and ITP. High levels of EBV loads were more likely to occur in HLH, IM, and atypical EBV infection, especially in HLH. However, lower viral loads were found in respiratory infection and acute leukemia.ConclusionsThis is a large sample study that revealed the prevalence of plasma EBV-DNA levels in children of various ages and presenting illnesses.     

Persistent Low Level Epstein-Barr Virus DNAemia in Childhood Cancer Survivors

Background: Clinical observation of Epstein-Barr virus (EBV) status has not documented in childhood cancer survivors (CCSs) sustaining long-term remission of malignant diseases. Thus, the aim of this study was to evaluate the EBV status in children with various malignant diseases after they completed their treatments. Patients and Methods: Thirty consecutive children with various malignant diseases previously received treatment at the University of Tsukuba Hospital. Nine cases had acute lymphoblastic leukemia (ALL), 10 had solid tumors, 4 had lymphoma, 4 had CNS tumors, and 3 had acute myeloid leukemia (AML). EBV DNA in 328 whole blood samples were monitored by real-time QPCR for all cases after treatment. Clinical records and laboratory data were also reviewed. Results: There were 6/30 (20%) cases with continuous detection of EBV DNA while there were 24/30 (80%) cases without continuous EBV DNA. EBV DNAemia was persistently observed in 4/9 (44.4%) cases with ALL and in 2/4 (50%) cases with lymphoma. Persistent EBV DNAemia can be observed for >5 years without any EBV associated symptoms or diseases. Conclusions: Childhood cancer survivors have persistent EBV DNAemia more frequently, which is thought to be observed in cases with ALL and lymphoma with higher tendency for >5 years after treatment. Persistent EBV DNAemia is frequent in CCSs aged 5–10 years. Any immunological alteration is speculative in a pathophysiology of persistent EBV DNAemia.     

急性淋巴细胞白血病并EB病毒感染的临床分析

目的 探讨EB病毒(EBV)在急性淋巴细胞白血病(ALL)儿童中的感染及其临床意义.方法采用荧光定量聚合酶链反应(FQ-PCR)技术检测EBV DNA,ELISA法检测EB病毒衣壳抗原IgM抗体(EBV-CA-IgM),共检测47例.其中新发45例,复发2例;年龄0～14岁[(8.06±3.71)岁].另取14例健康儿童作为健康对照组.男9例,女5例;年龄2～10岁[(7.24±2.54)岁].结合临床表现、诱导治疗骨髓完全缓解(CR)率、形态学CR状态下的微小残留病(MRD)、复发率及无事件生存(EFS)率等分析ALL患儿中EBV感染情况及其临床意义.结果 47例ALL患儿中检出EBV感染15例(31.9%),其中11例(23.40%)检出EBV DNA,EBV DNA水平为(3.28±5.95)×108copy·L-1;14例健康对照组外周血未检测到EBV DNA及EBV-CA-IgM.ALL中EBV感染组与非EBV感染组白细胞数分别为(78.00±58.38)×109 L-1、(27.46±60.10)×109 L-1(t=2.70,P=0.01),诱导治疗CR率分别为 46.7%、87.5%(P<0.01),MRD>10-3分别为90.0%、26.1%(P<0.01),复发率分别为53.8%、13.8%(P<0.01),EFS率分别为 23.1%、82.8%(P<0.01).结论 ALL并EBV感染具有高白细胞数、低诱导治疗CR率、高复发率、低EFS率,提示EBV感染可能参与儿童ALL的发生发展过程,亟待改善EBV感染ALL的治疗方法.     

Asymptomatic high Epstein-Barr viral load carriage in pediatric renal transplant recipients

High viral load carriage of EBV is one of the risks for PTLD in transplant recipients. We reviewed retrospectively in pediatric renal transplant recipients with EBV seronegative. EBV loads in peripheral blood and EBV-CTLs were measured every 1-3 months in 13 patients after grafting. Immunosuppressants were reduced when the patients were considered to have persistent high EBV loads (>1000 copies/μgDNA for over six months). All showed primary EBV infection: six with asymptomatic persistent high EBV loads (group A) and seven with neither EBV-associated symptoms nor persistent high EBV loads (group B). No patient developed PTLD in either group. Chronic rejection occurred in one patient in group A after immunosuppressants' reduction. There was no difference in renal dysfunction rates between the two groups. The maximum and increase rates in EBV loads were significantly higher in group A. The CTLs' percentage was significantly lower in group A when EBV loads first rose above 100 copies/μg DNA. This study suggests the possibility that EBV loads and CTLs' monitoring may be useful for avoidance of PTLD, as patients with asymptomatic persistent high EBV loads had higher EBV loads and lower percentages of CTLs.     

Epstein-Barr virus associated with immune thrombocytopenic purpura in childhood: a retrospective study

OBJECTIVE: Although Epstein-Barr virus (EBV) is known to cause immune thrombocytopenic purpura (ITP), the epidemiology of this pathogen in children with ITP is not known. In the present study, the clinicoepidemiology and laboratory characteristics of EBV-associated ITP in childhood were analysed retrospectively. METHODS: The study cohort consisted of 108 children in whom ITP was diagnosed between 1990 and 1998. Patients were divided into EBV or non-EBV groups according to their serological status at diagnosis. RESULTS: Thirty-five (32.4%) of 108 children had ITP associated with acute EBV infection. The clinical manifestations and laboratory data were similar in children with and without acute EBV. Responses to various modalities of therapy were analysed. The average time to achieve complete remission (platelet count > or =150 x 10(9)/L) in EBV and non-EBV groups was 26 and 16 days, respectively. CONCLUSIONS: The incidence of childhood ITP associated with acute EBV infection is relatively high in Taiwan. Patients with EBV-associated ITP tended to resolve more slowly than those without EBV infection.