Acute Epstein-Barr Virus Infection Research Articles

Childhood Langerhans cell histiocytosis hematological involvement: severity associated with BRAFV600E loads.

Hematological involvement (HI) is one of the life-threatening risk organs (ROs) in Langerhans cell histiocytosis (LCH). Lahey criteria have defined HI since 1975 as hemoglobin <10 g/dL and/or platelets <100 G/L and/or leukopenia (white blood cell count <4 G/L) and/or neutrophils <1.5 G/. Among the 2313 patients <18 years old enrolled in the French National Histiocytosis Registry (1983-2023), 331 developed HI (median age at diagnosis: 1 year); median follow-up lasted 8.1 years. Bone-marrow aspirate smears and biopsies may show reactive histiocytes, hemophagocytosis or myelofibrosis but never confirm the diagnosis. Fifty-eight (17%) patients developed macrophage-activation syndrome, sometimes related to acute Epstein-Barr virus or cytomegalovirus infection, sometimes months before typical LCH manifestations appeared. Hemoglobin and platelet thresholds for initiating transfusion(s) appear to accurately distinguish 2 groups: mild HI (MHI; >7 g/dL and >20 G/L, respectively) and severe HI (SHI; ≤7 g/dL and ≤20 G/L). Each entity has different organ involvements, laboratory parameters, mutational status, blood BRAFV600E loads, drug sensitivities and outcomes (respective MHI and SHI 10-year survival rates: 98% and 73%). Since 1998, mortality first declined with combination Cladribine-cytarabine therapy, and then with mitogen-activated protein-kinase inhibitors since 2014. Forty-one (12%) patients developed neurodegenerative complications that have emerged as a risk for long-term survivors. These results suggest limiting the HI-RO definition to SHI, as it encompasses almost all medical complications of LCH. Future clinical trials might demonstrate that targeted-therapy approaches would be better adapted for these patients, while MHI can be managed with classic therapies.

Clinical utility of EBV DNA testing of blood in immunocompetent and immunocompromised patients: A single-center experience.

Epstein-Barr virus (EBV) causes different clinical presentations in immunocompetent and immunocompromised persons, and thus indications for testing vary between these populations. We reviewed our institution's EBV DNA testing across these populations to understand its clinical utility and appropriateness. We conducted a retrospective chart review of adult patients with positive EBV nucleic acid amplification (NAAT) testing from November 2022 to 2023. We recorded demographics, indications for testing, EBV-related diagnosis, laboratory results, and whether testing influenced patient treatment. Of 3560 EBV NAAT tests, 187 (5.3%) were positive, representing 124 unique adult patients (51 immunocompetent and 73 immunocompromised). Reactivation of EBV was the most common diagnosis in both populations, followed by acute EBV infection in the immunocompetent and non-posttransplant lymphoproliferative disorder malignancies in the immunocompromised. In immunocompromised patients, positive tests led to treatment changes more frequently than in immunocompetent patients (27.4% vs 11.7%, P=.06). Testing affected clinical management in 0% to 2% of cases when sent for sepsis/shock and nonspecific viral syndromes compared to 37% to 49% of cases when sent for posttransplant and malignancy screening/monitoring. EBV NAAT testinginfrequently influenced clinical management in immunocompetent individuals but had a notable impact in immunocompromised patients, particularly those undergoing posttransplant or malignancy screening. This underscores the need for targeted testing to optimize resource utilization and cost-effectiveness.

Analysis of the epidemiology and clinical characteristics of Epstein-Barr virus infection.

The Epstein-Barr virus (EBV) is responsible for a spectrum of human diseases and demonstrates a considerable prevalence among various populations. Advances in molecular epidemiological research have enhanced our comprehension of EBV-related pathologies. In this study, our objective was to examine the epidemiological profile and clinical features of EBV infection in Chongqing, China. We enrolled patients suspected of EBV-related diseases who were admitted to the First Affiliated Hospital of Chongqing Medical University between May 2013 and November 2022. Inclusion criteria were based on those who underwent EBV-specific immunofluorescence or plasma EBV-DNA testing. Among 13 584 inpatients, the overall seropositivity rates for EBNA-1-IgG, EBV-VCA-IgM, EBV-EA-IgG, EBV-EA-IgA, EBV-VCA-IgA, and EBV-DNA were 91.89%, 7.22%, 18.00%, 16.19%, 30.78%, and 18.00%, respectively. The seropositivity rate for EBNA-1-IgG steadily increased with age. The seropositivity rate for VCA-IgM, an indicator of acute EBV infection, was highest in patients aged 11-20 years at 26.41%, decreasing to 2%-6% in older patients. Additionally, among 205 outpatients, the EBV-DNA positivity rate was 14.15%. In 3670 individuals from health check-up centers, the seropositivity rates for EBV-EA-IgA and EBV-VCA-IgA were 11.96% and 28.09%, respectively, and the EBV-DNA positivity rate was 11.92%, all of which were lower than those in inpatients. Among the 762 EBV-DNA positive inpatients, adults aged 31-40 years were the least affected, with a seropositivity rate of 12.00%, which increased with age. The most common diseases associated with primary EBV infection were infectious mononucleosis (IM) (35.49%), followed by EBV infection (14.15%) and pneumonia (7.19%). The most common diseases associated with EBV reactivation were pneumonia (16.80%), nasopharyngeal carcinoma (NPC) (11.02%), and autoimmune diseases (7.04%). Patients with hemophagocytic lymphohistiocytosis (HLH) had the highest viral load, significantly higher than those with NPC, pneumonia, and liver cirrhosis. This large-scale retrospective study explores the epidemiological characteristics and disease spectrum of EBV infection across all age groups. The findings contribute to the improvement of diagnostic and management strategies for EBV infection.

Association between Epstein-Barr virus reactivation and severe malaria in pregnant women living in a malaria-endemic region of Cameroon.

Malaria kills nearly 619,000 people each year. Despite the natural immunity acquired to malaria, pregnant women and children under five die from severe forms of the disease in sub-Saharan Africa. Co-infection with acute Epstein-Barr Virus (EBV) infection has been shown to suppress the anti-malarial humoral responses, but little is known about the impact of EBV reactivation on malaria-associated morbidity. This study investigated the association between EBV reactivation and malaria severity in pregnant women living in a malaria-endemic region in Cameroon. A cross-sectional study was conducted on 220 pregnant women attending antenatal consultations in three health facilities in the West region of Cameroon. Malaria was diagnosed by microscopy, and Plasmodium species were identified by Nested PCR. Plasma samples were analyzed by ELISA for the presence of EBV nuclear antigen, EBV viral capsid antigen, and EBV early antigen to determine EBV reactivation. All statistics were performed using GraphPad Prism and SPSS software. The prevalence of malaria among pregnant women was 23.2%, of which 18.6% were P. falciparum mono-infections and 4.5% mixed infections (3.6% P. falciparum and P. malariae; 0.9% P. falciparum and P. ovale). 99.5% of the women were EBV seropositive, and 13.2% had EBV reactivation. Pregnant women with reactivated EBV were more likely to develop severe malaria than pregnant women with latent EBV (OR 4.33, 95% CI 1.08-17.25, p = 0.03). The median parasitemia in pregnant women with latent EBV was lower than in those with EBV reactivation (2816 vs. 19002 parasites/μL, p = 0.02). Our study revealed that lytic reactivation of EBV may be associated with the severity of malaria in pregnant women. Suggesting that, like acute infection, EBV reactivation should be considered a risk factor for severe malaria in pregnant women in malaria-endemic regions or could serve as a hallmark of malaria severity during pregnancy. Further detailed studies are needed.

Features of the neutrophil granulocyte phenotype in children with infectious mononucleosis

The course of infectious diseases caused by viruses, and their common outcome is determined by the activity of the inflammatory reaction which occurs both at the local and systemic levels. However, the features of neutrophil functions during inflammatory reaction are virtually unknown in the patients with infectious mononucleosis (IM), caused by Epstein–Barr virus (EBV). Hence, the aim of our study was to evaluate some characteristics of phenotypic spectrum of blood neutrophils in children with IM. Patients and methods. We examined 84 children aged 3 to 11 years with EBV infection with moderate or severe clinical course of the disease. All patients exhibited a positive test for EBV DNA in blood lymphocytes and appropriate serological markers of acute EBV infection. The control group consisted of 40 conditionally healthy children at the similar age range. The study of neutrophil phenotype was carried out by flow cytometry using direct immunofluorescence of whole peripheral blood samples. A study of the neutrophil phenotype with a combination of two functional antigens (CD64 and CD32) has revealed that in children with IM, regardless of age, the main fraction of blood neutrophils are double-negative cells, whereas in healthy children it consists of CD64-CD32+ neutrophils. The main fraction of neutrophils in the paired combination of CD64 and CD11b antigens in sick children aged 3-6 and 7-11 years was similar to the healthy controls (CD64-CD11b+), but with a change in the content of minor cell fractions. The number of CD64-CD15+ neutrophils (main fraction of cells in healthy children) proved to be significantly reduced in the IM patients of both age groups. However, we have revealed a marked increase in the level of double-negative cells for the CD64 and CD15 antigens. At the same time, the content of double-negative neutrophils for these markers was also increased in IM children of both age groups. The cells with CD11b-CD15+ and CD11b+CD15+ phenotypes comprised the main fractions in IM, as studied by a paired combination of CD11b and CD15 antigens; in healthy children – only CD11b+CD15+ neutrophils are detected. The phenotypic changes of neutrophils during IM suggest a decreased migratory ability of cells with high activity of proinflammatory functions. The established ontogenetic features of the neutrophil phenotype are significantly changed in the children with IM, probably, due to specific immunopathogenesis of the viral infection. The detected changes in phenotypic composition of neutrophils associated with IM may be caused both by the features of protective reaction of innate immune cells and pathogenic effects of the virus itself upon blood neutrophils.

Epstein-Barr virus as promoter of Lemierre syndrome: systematic literature review

PurposeTo investigate a possible link between acute Epstein-Barr virus infection and Lemierre syndrome, a rare yet life-threatening infection.MethodsA systematic review was conducted adhering to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Diagnosis criteria for Lemierre syndrome were established, and data extraction encompassed demographic data, clinical, and laboratory information.ResultsOut of 985 initially identified papers, 132 articles were selected for the final analysis. They reported on 151 cases of Lemierre syndrome (76 female and 75 male patients with a median of 18 years) alongside interpretable results for Epstein-Barr virus serology. Among these, 38 cases (25%) tested positive for acute Epstein-Barr virus serology. There were no differences in terms of age, sex, or Fusobacterium presence between the serologically positive and negative groups. Conversely, instances of cervical thrombophlebitis and pulmonary complications were significantly higher (P = 0.0001) among those testing negative. The disease course was lethal in one case for each of the two groups.ConclusionsThis analysis provides evidence of an association between acute Epstein-Barr virus infection and Lemierre syndrome. Raising awareness of this link within the medical community is desirable.

The Impact of Acute EBV Infection on Changes in the Serum Proteome in Children-A Pilot Study.

This study investigates the impact of Epstein-Barr virus (EBV) infection on children's proteomes across different phases of the disease, utilising seventy-nine blood samples categorised into three groups: EBV-naive patients, acute infectious mononucleosis (IM) cases, and convalescents followed up for 12 months post-IM. The aim is to identify proteins influenced by EBV infection, shedding light on the chronic processes triggered by the virus. The results reveal thirty-nine proteins distinguishing between naive patients and those with IM, including actin, lumican, peroxiredoxin-2, fibulin-1, gelsolin, and alpha-2-macroglobulin, which are involved in immune responses, cell adhesion, and inflammation. Elevated oxidative stress markers like peroxiredoxin-2 in IM patients suggest potential links to EBV's induction of reactive oxygen species. Increased levels of apolipoproteins A-I, A-IV, C-IV, and M during IM imply associations with viral infection, while complement system proteins (C1q, C1r, and C8 gamma chain) are also elevated, reflecting their role in the immune response and viral clearance. This study's focus on children provides unique insights into EBV's impact on young populations, emphasising proteomics' role in uncovering protein associations and understanding the virus's long-term consequences. However, specific relationships between identified proteins and EBV infection require further investigation.

Flow Cytometry as the Tool to Define Peripheral Blood Leukocyte Signatures in Acute EBV Infection.

Primary Epstein-Barr virus (EBV) infection which can manifest as infectious mononucleosis (IM) is commonly acquired during childhood. EBV primarily invades B cells leading to a lytic reaction; the control of the infection is handled by natural killer and T cells in immunocompetent individuals. The infection has a wide spectrum of clinical findings and can lead to serious complications in patients with certain underlying immunological dysfunctions. We retrospectively investigated peripheral white blood cell populations' surface marker characteristics in IM using a comprehensive flow cytometry marker panel. Twenty-one cases of IM and seventeen EBV-seropositive cases without IM serving as controls were included. We observed novel alterations in lymphocyte, neutrophil, and monocyte populations. In addition to increased activated cytotoxic T cells and low B cells, we demonstrated high T-large granular lymphocyte (T-LGL) populations in IM cases. Furthermore, despite T cells' increased HLA-DR expression, another activation marker, CD11b, was lower in T-LGL populations. Monocytes showed increased CD16 expression; CD64 was higher in neutrophils. Our findings point to monocyte and neutrophil activation which may account for acute clinical features and may contribute to the understanding of IM immunobiology. Furthermore, they may serve as a useful tool in investigating inherited and post-transplant conditions characterized by deficiencies in controlling EBV infection.

Acute cholestatic hepatitis due to infectious mononucleosis: A case report

Cholestatic hepatitis is a rare complication of acute Epstein-Barr virus (EBV) infection. Here, we presented a case of acute cholestatic hepatitis secondary to acute infectious mononucleosis, who presented with complaints of abdominal pain, yellowing of the eyes and body, itching, widespread body pain, fever, nausea and vomiting. It was emphasized that EBV infection should also be considered in the differential diagnosis of cholestatic hepatitis etiology.

Role of IL-27 in Epstein-Barr virus infection revealed by IL-27RA deficiency.

Epstein-Barr virus (EBV) infection can engender severe B cell lymphoproliferative diseases1,2. The primary infection is often asymptomatic or causes infectious mononucleosis (IM), a self-limiting lymphoproliferative disorder3. Selective vulnerability to EBV has been reported in association with inherited mutations impairing T cell immunity to EBV4. Here we report biallelic loss-of-function variants in IL27RA that underlie an acute and severe primary EBV infection with a nevertheless favourable outcome requiring a minimal treatment. One mutant allele (rs201107107) was enriched in the Finnish population (minor allele frequency = 0.0068) and carried a high risk of severe infectious mononucleosis when homozygous. IL27RA encodes the IL-27 receptor alpha subunit5,6. In the absence of IL-27RA, phosphorylation of STAT1 and STAT3 by IL-27 is abolished in T cells. In in vitro studies, IL-27 exerts a synergistic effect on T-cell-receptor-dependent T cell proliferation7 that is deficient in cells from the patients, leading to impaired expansion of potent anti-EBV effector cytotoxic CD8+ T cells. IL-27 is produced by EBV-infected B lymphocytes and an IL-27RA-IL-27 autocrine loop is required for the maintenance of EBV-transformed B cells. This potentially explains the eventual favourable outcome of the EBV-induced viral disease in patients with IL-27RA deficiency. Furthermore, we identified neutralizing anti-IL-27 autoantibodies in most individuals who developed sporadic infectious mononucleosis and chronic EBV infection. These results demonstrate the critical role of IL-27RA-IL-27 in immunity to EBV, but also the hijacking of this defence by EBV to promote the expansion of infectedtransformed B cells.

Angioimmunoblastic T-Cell Lymphoma with Concurrent EBV Viremia: A Challenging Case

Abstract Introduction/Objective Angioimmunoblastic T-cell lymphoma (AITL) represents only 1-2% of all non-Hodgkin lymphomas but is one of the most common non-cutaneous T-cell lymphomas. Although typically associated with latent Epstein Barr Virus (EBV) infection, recent studies have demonstrated the presence and prognostic impact of EBV viremia at the time of diagnosis. Here, we present a case of AITL in which the diagnosis was complicated by EBV viremia. Methods/Case Report A 41-year-old male presented to our hospital with generalized abdominal pain, diffuse lymphadenopathy, hepatomegaly, ascites, and diffuse body wall edema. A recent retroperitoneal lymph node biopsy reportedly demonstrated features suggesting an infectious process, and EBV PCR revealed a viral load of 141,050 copies/mL. A left axillary lymph node was excised, which demonstrated vascular proliferation and diffuse architectural effacement by a polymorphous infiltrate including variably sized lymphocytes with moderate to abundant clear cytoplasm, and occasional admixed neutrophils, plasma cells, and eosinophils. Immunohistochemical staining demonstrated an atypical CD4-positive, CD7-negative T-cell population in a vaguely nodular distribution, expressing Bcl-6, PD-1, ICOS, and CXCL13 without definite CD10 expression. CD21 immunostaining demonstrated markedly expanded follicular dendritic cell meshworks in a distribution similar to the atypical T-cell population. No B-cell or cytotoxic T-cell proliferation was seen, and in situ hybridization for EBV-encoded RNA (EBER ISH) demonstrated only scattered EBV- positive cells. Taken together, these findings supported a diagnosis of AITL over an atypical reaction to EBV infection. Next-generation sequencing demonstrated mutations in TET2, IDH2, and RHOA, further confirming the diagnosis. Results (if a Case Study enter NA) NA Conclusion AITL manifests with a diverse range of clinical symptoms and pathological features and may mimic infection. Additionally, acute EBV infection is well-known to mimic various lymphomas and has rarely been reported to mimic AITL. We present this case to raise awareness of the concurrent presentation of AITL with EBV viremia and to highlight features that may be helpful in distinguishing between the two.

Emperipolesis, Apoptosis and Hemophagocytosis during Acute Epstein-Barr Virus (EBV) infection: A Case Report

An eight-year-old patient had intermittent high grade fever and pharyngitis since one week. Later, he developed left-sided cervical lymphadenitis. Subsequently, he also developed palatal petechiae. Absolute lymphocyte count (ALC) was raised (ALC 20,262 cells/mm³). Hepatosplenomegaly was also detected. Clinically, the current case was diagnosed as a case of infectious mononucleosis. Possibility of infection by Epstein-Barr virus was considered. FNAC was done. Blood-mixed aspirate showed monocytoid cells with mild pleomorphic nuclei, and clumped chromatin. Inconspicuous nucleoli and abundant eosinophilic cytoplasm were seen. Foci of apoptosis were also seen. Frequent mitoses were seen. Findings were suggestive of acute reactive lymphocytic hyperplasia with hemophagocytosis and apoptosis. EBV DNA was detected by RT PCR with linear reporting range of 3.3×104 IU/ml. Herewith, we describe a case of infectious mononucleosis with emperipolesis and hemophagocytosis. Keywords: Epstein-Barr virus associated hemophagocytosis syndrome (EBVAHS).

Proteomic Analysis of Pediatric Hemophagocytic Lymphohistiocytosis: a Comparative Study with Healthy Controls, Sepsis, Critical Ill, and Active Epstein-Barr virus Infection to Identify Altered Pathways and Candidate Biomarkers

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome characterized by excessive activation of the immune system, along with uncontrolled proliferation of activated macrophages and lymphocytes. The clinical features of HLH often overlap with the clinical features of other severe inflammatory conditions such as sepsis, hindering accurate and timely diagnosis. In this study, we performed a data-independent acquisition mass spectrometry-based plasma proteomic analysis of 33 pediatric patients with HLH compared with four control groups: 39 healthy children, 43 children with sepsis, 39 children hospitalized in the pediatric intensive care unit without confirmed infections, and 21 children with acute Epstein-Barr virus infection. Proteomic comparisons between the HLH group and each of the control groups showed that HLH was characterized by alterations in complement and coagulation cascades, neutrophil extracellular trap formation, and platelet activation pathways. We identified eight differentially expressed proteins in patients with HLH, including plastin-2 (LCP1), vascular cell adhesion protein 1, fibrinogen beta chain, fibrinogen gamma chain, serum amyloid A-4 protein, extracellular matrix protein 1, apolipoprotein A-I, and albumin. LCP1 emerged as a candidate diagnostic marker for HLH with an area under the curve (AUC) of 0.97 in the original cohort and an AUC of 0.90 (sensitivity = 0.83 and specificity = 1.0) in the validation cohort. Complement C1q subcomponent subunit B was associated with disease severity in patients with HLH. Based on comparisons with multiple control groups, this study provides a proteomic profile and candidate biomarkers of HLH, offering researchers novel information to improve the understanding of this condition.

Diagnosis of Epstein-Barr and cytomegalovirus infections using decision trees: an effective way to avoid antibiotic overuse in paediatric tonsillopharyngitis

BackgroundThe incidence of tonsillopharyngitis is especially prevalent in children. Despite the fact that viruses cause the majority of infections, antibiotics are frequently used as a treatment, contrary to international guidelines. This is not only an inappropriate method of treatment for viral infections, but it also significantly contributes to the emergence of antibiotic-resistant strains. In this study, EBV and CMV-related tonsillopharyngitis were distinguished from other pathogens by using machine learning techniques to construct a classification tree based on clinical characteristics.Materials and methodsIn 2016 and 2017, we assessed information regarding 242 children with tonsillopharyngitis. Patients were categorized according to whether acute cytomegalovirus or Epstein-Barr virus infections were confirmed (n = 91) or not (n = 151). Based on symptoms and blood test parameters, we constructed decision trees to discriminate the two groups. The classification efficiency of the model was characterized by its sensitivity, specificity, positive predictive value, and negative predictive value. Fisher’s exact and Welch’s tests were used to perform univariable statistical analyses.ResultsThe best decision tree distinguished EBV/CMV infection from non-EBV/CMV group with 83.33% positive predictive value, 88.90% sensitivity and 90.30% specificity. GPT (U/l) was found to be the most discriminatory variable (p < 0.0001). Using the model, unnecessary antibiotic treatment could be reduced by 66.66% (p = 0.0002).DiscussionOur classification model can be used as a diagnostic decision support tool to distinguish EBC/CMV infection from non EBV/CMV tonsillopharyngitis, thereby significantly reducing the overuse of antibiotics. It is hoped that the model may become a tool worth considering in routine clinical practice and may be developed to differentiate between viral and bacterial infections.

Acute Epstein-Barr virus infection: Diagnostic challenge in young children, risk factors for hospitalisation and cytomegalovirus co-detection.

Acute Epstein-Barr virus (aEBV) and cytomegalovirus (CMV) infections frequently have similar manifestations. We aim to evaluate the characteristics of aEBV infection, risk factors for hospitalisation and differences according to CMV IgM detection (EBV-CMV co-detection) in children. Retrospective, single-centre study including patients <16 years diagnosed with aEBV infection (positive anti-EBV IgM/Paul-Bunnell test and acute symptomatology). EBV-CMV co-detection was defined as positive CMV IgM. Factors associated with age, hospitalisation and EBV-CMV co-detection were analysed in a multivariate analysis. A total of 149 patients were included (median age 4.6 years). Most frequent manifestations were fever (77%), cervical lymphadenopathy (64%) and elevated liver enzymes (54%). Younger children had lower rate of positive Paul-Bunnell test (35% vs. 87%; p < 0.01), but higher rate of EBV-CMV co-detection (54% vs. 29%; p = 0.03). These children tended to have less typical symptoms of infectious mononucleosis and higher hospitalisation rate. The overall antibiotic prescription was 49%. Hospitalisation (27 children; 18%) was independently associated with prior antibiotic therapy and anaemia. Sixty-two cases (42%) had EBV-CMV co-detection, which was independently associated with elevated liver enzymes and younger age. In this study, younger children with aEBV infection presented more frequently with atypical clinical symptoms, had higher EBV-CMV co-detection rates and were more often hospitalised. Hospitalisation was associated with prior antibiotic prescription.

The innate and T-cell mediated immune response during acute and chronic gammaherpesvirus infection.

Immediately after entry into host cells, viruses are sensed by the innate immune system, leading to the activation of innate antiviral effector mechanisms including the type I interferon (IFN) response and natural killer (NK) cells. This innate immune response helps to shape an effective adaptive T cell immune response mediated by cytotoxic T cells and CD4+ T helper cells and is also critical for the maintenance of protective T cells during chronic infection. The human gammaherpesvirus Epstein-Barr virus (EBV) is a highly prevalent lymphotropic oncovirus that establishes chronic lifelong infections in the vast majority of the adult population. Although acute EBV infection is controlled in an immunocompetent host, chronic EBV infection can lead to severe complications in immunosuppressed patients. Given that EBV is strictly host-specific, its murine homolog murid herpesvirus 4 or MHV68 is a widely used model to obtain in vivo insights into the interaction between gammaherpesviruses and their host. Despite the fact that EBV and MHV68 have developed strategies to evade the innate and adaptive immune response, innate antiviral effector mechanisms still play a vital role in not only controlling the acute infection but also shaping an efficient long-lasting adaptive immune response. Here, we summarize the current knowledge about the innate immune response mediated by the type I IFN system and NK cells, and the adaptive T cell-mediated response during EBV and MHV68 infection. Investigating the fine-tuned interplay between the innate immune and T cell response will provide valuable insights which may be exploited to design better therapeutic strategies to vanquish chronic herpesviral infection.

Clinical features of renal damage associated with Epstein-Barr virus infection in children.

To understand the renal damage and clinical features of pediatric patients with acute Epstein-Barr virus (EBV) infection. In this retrospective observational study, 548 pediatric patients who were admitted to and treated at the Xiamen Women and Children Health Center between January 2017 and December 2021 and who met the criteria of acute EBV infection were selected as participants. The sociodemographic and clinical data of these patients were collected for statistical analysis. The study population was divided into a renal damage group (41 patients) and a non-renal damage group (507 patients), and the characteristics of the two groups were compared. (1) Of the 548 enrolled patients, 340 and 208 were boys and girls, respectively. Among them, 41 patients showed renal damage (renal damage group), including 26 boys and 15 girls, and the incidence rate of renal damage was 7.48%. (2) The major renal involvements in the 41 pediatric patients with acute EBV infection in the renal damage group manifested as hematuria (56.1%), proteinuria (37.71%), hematuria + proteinuria (12.9%), edema (51.22%), hypertension (17.07%), oliguria (4.88%), and acute renal failure (2.44%). (3) The pediatric patients in the renal damage group had statistically significantly longer fever durations, higher blood EBV-DNA loads, and lower blood CD4+/CD8+ T lymphocyte ratios than those in the non-renal damage group. In pediatric patients, the incidence rate of acute EBV-induced renal damage is not low. The clinical manifestations are mostly hematuria or proteinuria, with an overall good prognosis, but occasionally severe renal damage such as acute renal failure. The possibility of secondary renal damage is high when pediatric patients with acute EBV have prolonged fever, high blood EBV-DNA loads, and decreased blood CD4+/CD8+ ratios.

Global DNA Methylation Levels in Epstein-Barr-Virus-Positive Iraqi Patients with Acute Lymphoblastic Leukaemia

Acute lymphoblastic leukemia (ALL) is one of the commonest hematological malignancies affecting children and adults. Recent evidence suggests an involvement of Epstein-Barr virus (EBV) in ALL pathogenicity. Epigenetic aberration, especially altered DNA methylation marks, is a key event of cancer development. The present study aims to investigate how the ALL epimethylome reacts to viral infection through the assessment of the total 5-methylcytosine (5mC) levels in ALL patients, according to EBV infection. The 5mC global DNA methylation levels in 50 diagnosed ALL patients (age mean 26.23 yrs; age range 10-60 yrs) and 25 age-matched healthy controls were assessed using MethylFlash™ Methylated DNA Quantification Kit. Acute primary EBV infection in the studied subjects was detected by measuring Epstein-Barr Virus (EBNA-1) IgG levels using ELISA. The results showed a significant (P˂0.001) decrease in 5mC levels in ALL-EBV positive cases as compared to those who were negative for EBV infection (0.234±0.117 vs. 0.441±0.153, respectively). The reduction in the average 5mC level seemed to be negatively correlated with EBV viral load (r = -0.599, p= 0.001). Additionally, 5mC levels were able to distinguish between ALL main subtypes (B-ALL and T-ALL; derived from B or T lymphocytes), where T-ALL cases showed significantly (P=0.005) higher 5mC levels than those of B-ALL cases (0.587±0.070 vs. 0.180±0.092, respectively). Also significantly (P=0.04) lower 5mC levels were detected in Philadelphia chromosome-positive (Ph+) ALL cases than in those who were negative to this genetic abnormality (Ph- -ALL) (0.13±0.021 vs. 0.179±0.093, respectively). Overall, the findings of the present study suggest an involvement of EBV infection in ALL pathogenicity, with the potential of utilizing the differences in global DNA methylation levels in ALL patients' risk stratification.

Differentiating fulminant EBV infection complicated by HLH from Lymphoma: report of a case and a brief literature review

Epstein-Barr virus (EBV) infection may present with fulminant constitutional symptoms, cytopenia(s), and systemic lymphadenopathy, raising clinical suspicion for lymphoma and prompting lymph node and bone marrow biopsies. At the microscopic level, the histopathologic findings in cases of acute EBV lymphadenitis may mimic certain lymphoid neoplasms, creating a range of differential diagnoses and diagnostic pitfalls.We present a case of fulminant EBV infection in an adolescent whose clinical and radiographic findings led to lymph node and bone marrow biopsies to rule out lymphoma. One week after being diagnosed with acute EBV infection (infectious mononucleosis), a 17-year-old Caucasian male presented with worsening symptoms including persistent fever, progressive, painful lymphadenopathy, and splenomegaly. A peripheral blood smear showed lymphocytosis with many reactive lymphocytes, anemia, and thrombocytopenia. Laboratory studies showed elevated ferritin, triglycerides, and soluble IL-2/CD25. A cervical lymph node biopsy demonstrated an EBV-positive, reactive B-immunoblast proliferation with large atypical lymphoid cells mimicking Reed-Sternberg cells of Hodgkin lymphoma, in addition to patchy vasculitis, coagulative necrosis, and prominent hemophagocytic activity. Bilateral bone marrow biopsies showed a hypercellular marrow with patchy infiltrates of similar EBV-positive, large atypical lymphoid cells, as well as prominent hemophagocytic activity. The diagnosis of acute EBV associated lymphoproliferation with concurrent hemophagocytic lymphohistiocytosis (HLH) was rendered.Recognition of common and uncommon clinical presentations of acute EBV infection is essential, particularly when histopathologic findings raise suspicion for a possible hematolymphoid neoplasm. Both the lymph node architectural and viral cytopathic changes observed in EBV lymphadenitis exhibit significant morphologic overlap with classic Hodgkin lymphoma (cHL) and several other lymphomas, including anaplastic large cell lymphoma, diffuse large B cell lymphoma, and angioimmunoblastic T cell lymphoma. Recognition of immunohistochemical staining patterns in EBV lymphadenitis is critical to avoid misdiagnosis. Conversely, bona fide lymphoma, particularly cHL, can masquerade as EBV infection. We provide a concise discussion and tables of the histopathologic differential diagnosis of EBV lymphadenitis, including cHL and other lymphomas. Pathologists should include acute EBV infection within the differential diagnosis when confronted with clinical and pathologic findings concerning for lymphoma, particularly in adolescents and young adults.

Seroprevalence of Epstein-Barr virus infection in children during the COVID-19 pandemic in Zhejiang, China.

We aimed to investigate the seroprevalence of Epstein-Barr virus (EBV) infection in children before and during the COVID-19 pandemic. All children admitted to the Children's Hospital Affiliated to Zhejiang University from January 2019 to December 2021 with suspected EBV-associated disease and EBV antibodies were detected by a two-step indirect method of chemiluminescence technology. A total of 44,943 children were enrolled in this study. The seroprevalence of EBV infections was compared from January 2019 to December 2021. The total seropositive rate of EBV infections was 61.02% between January 2019 and December 2021, and the seropositive trend decreased year by year. The total number of seropositive EBV infections in 2020 was reduced by 30% compared to that in 2019. In particular, nearly 30% and 50% reductions in the number of acute EBV infections and EBV reactivations or late primary infections from 2019 to 2020 were found, respectively. The number of acute EBV infections in children aged 1-3 years and EBV reactivation or late primary infection in children aged 6-9 years in 2020 sharply dropped by approximately 40% and 64% compared to that in 2019. Our study further demonstrated that the prevention and control measures for COVID-19 in China had a certain effect on containing acute EBV infections and EBV reactivations or late primary infections.