Quantification of Epstein-Barr virus DNA is helpful for evaluation of chronic active Epstein-Barr virus infection

GB and gH/gL fusion machinery: a promising target for vaccines to prevent Epstein-Barr virus infection

Epstein‒Barr virus (EBV) is a double-stranded DNA virus belonging to the family Orthoherpesviridae that is associated with the development of various tumors, such as lymphoma, nasopharyngeal carcinoma, and gastric cancer. There are no uniformly effective treatments for human EBV infection, and vaccines and immunotherapies are currently the main research directions. The glycoproteins gB and gH/gL are surface glycoproteins that are common to all herpesviruses, with subtle differences in structure and function between different viruses. The core membrane fusion machinery constituted by EBV gB and gH/gL is an important target of neutralizing antibodies in epithelial EBV infection due to its essential role in the fusion of viral and target cell membranes. In this article, we review the main modes of EBV infection, the structure and function of the core fusion machinery gB and gH/gL, and the development of neutralizing antibodies and prophylactic vaccines based on this target.

EBV-associated diseases: Current therapeutics and emerging technologies

EBV is a prevalent virus, infecting >90% of the world's population. This is an oncogenic virus that causes ~200,000 cancer-related deaths annually. It is, in addition, a significant contributor to the burden of autoimmune diseases. Thus, EBV represents a significant public health burden. Upon infection, EBV remains dormant in host cells for long periods of time. However, the presence or episodic reactivation of the virus increases the risk of transforming healthy cells to malignant cells that routinely escape host immune surveillance or of producing pathogenic autoantibodies. Cancers caused by EBV display distinct molecular behaviors compared to those of the same tissue type that are not caused by EBV, presenting opportunities for targeted treatments. Despite some encouraging results from exploration of vaccines, antiviral agents and immune- and cell-based treatments, the efficacy and safety of most therapeutics remain unclear. Here, we provide an up-to-date review focusing on underlying immune and environmental mechanisms, current therapeutics and vaccines, animal models and emerging technologies to study EBV-associated diseases that may help provide insights for the development of novel effective treatments.

Diagnostic value of serological and molecular biological tests for infectious mononucleosis by EBV in different age stages and course of the disease

Epstein-Barr virus (EBV)-based serologic antibody and viral nucleic acid assays have been found to be feasible means to diagnose infectious mononucleosis (IM) caused by EBV in children. In this study, we will further explore their diagnostic value for IM by EBV in different age stages and over the course of the disease. A collection of 616 children from clinically suspected IM cases was studied. Indirect immunofluorescence (IIF) for EBV-specific antibody (Euroimmun) combined with plasma EB viral nucleic acid assay (real-time fluorescence quantitative polymerase chain reaction reverse-transcription polymerase chain reaction) were used as reference methods. The diagnostic efficiency of the peripheral blood routine test, serologic antibody test, and plasma EB viral nucleic acid assay for the diagnosis of IM was evaluated, respectively. The sensitivity, specificity, Youden' index and the area under curve (AUC) were 93.08%, 87.77%, 0.81 and 0.904 (95% confidence interval [CI]: 0.878-0.931) for the peripheral lymphocyte test (lymphocytosis > 5 × 109 /L), 98.27%, 91.13%, 0.89 and 0.947 (95% CI: 0.927-0.967) for the plasma EBV-DNA test, and 84.08%, 96.33%, 0.80 and 0.902 (95% CI: 0.874-0.930) for the EBV viral capsid antigen (VCA)-IgG avidity test. The plasma EBV-DNA test has a higher diagnostic value than the VCA-IgG avidity test in children aged <6 years, especially aged <3 years; the peripheral lymphocyte test and plasma EBV-DNA test are suitable for the early stage of the disease, while the VCA-IgG avidity test for after 7 days of the disease. EBV antibody detection (IIF) should be combined with EBV nucleic acid detection in children age <6 years and the early stage of the disease.

The clinicopathologic features of chronic active Epstein-Barr virus infective enteritis

Chronic active Epstein-Barr virus infective enteritis (CAEBV enteritis) is rare and has not been well described yet. Therefore, we reported the clinicopathologic features of 11 patients with chronic active Epstein-Barr virus infective enteritis and their differences from inflammatory bowel disease. The major clinical presentations of chronic active Epstein-Barr virus infective enteritis were intermittent fever over 39 °C (100%), diarrhea (73%), abdominal pain (64%), lymphadenopathy (64%), splenomegaly (64%), and hepatomegaly (27%). The main endoscopic findings included numerous shallow, small, and irregular ulcers, mainly involving colon and small intestine together, no cobble-like appearance, and longitudinal ulcers. Compared to inflammatory bowel disease patients, the frequency of intermittent fever, hepatomegaly, splenomegaly, lymphadenopathy, the value of C-reactive protein, and serum Epstein-Barr virus DNA (EBV DNA) were significantly higher in chronic active Epstein-Barr virus infective enteritis patients (p < 0.01). The histologic findings show transmural inflammation with extended lymphoid infiltration, fissuring ulcers, and intraepithelial lymphocytosis. But chronic active Epstein-Barr virus infective enteritis lacked granulomas and connective tissue changes such as neural hypertrophy and thickened muscularis mucosae. Three chronic active Epstein-Barr virus infective enteritis patients died within 5 years of disease onset, and those three patients have received total colectomy, two of them died within 1 month after surgery. In this study, clinicopathologic features have been summarized to better recognize chronic active Epstein-Barr virus infective enteritis. There are resemblances between chronic active Epstein-Barr virus infective enteritis and inflammatory bowel disease, but some symptoms, signs, and indexes like intermittent fever, hepatomegaly, splenomegaly, lymphadenopathy, and elevated C-reactive protein, Epstein-Barr virus DNA are characteristics to differentiate chronic active Epstein-Barr virus infective enteritis and inflammation. Histopathological features also help the discrimination. Serum Epstein-Barr virus DNA and intestinal tissue in situ hybridization for Epstein-Barr virus-encoded RNA are recommended to exclude chronic active Epstein-Barr virus infective enteritis.

Rare case of Visceral form of Infectious Mononucleosis in Irkutsk Region

Infectious mononucleosis (MI) is caused by the Herpes viridae family of viruses. Currently, most researchers assign a leading role to the Epstein-Barr virus. In present time there are no unified clinical classification of infection mononucleosis, but many authors recognize the visceral form which involves cardiovascular system, adrenal glands, lungs, central neural system and others organs. The article describes a clinical case of MI in the 28-year-old patient. She applied for medical help with complaints of fever up to 39 °C, weakness in the legs and arms, weight loss and received symptomatic treatment on an outpatient department. After 2 months on the background of deterioration, she was hospitalized in an infectious diseases hospital with severe symptoms of intoxication, lymphoproliferative syndrome, myocarditis, pericarditis, hepatitis, polyneuropathy with quadriparesis, hypochromic anemia, thrombocytopenia. She was consulted by an oncologist and diagnosed with cervical cancer. Laboratory confirmation was obtained – Epstein-Barr virus was detected in the blood. Against the background of antiviral therapy, a regression of clinical symptoms was achieved in a week. The patient was transferred to a oncological hospital. It is recommended to examine patients with high fever of unknown etiology on myocardial infarction for the timely appointed etiotropic therapy.

Antiviral Drugs for EBV

Epstein–Barr virus (EBV) infects up to 95% of the adult human population, with primary infection typically occurring during childhood and usually asymptomatic. However, EBV can cause infectious mononucleosis in approximately 35–50% cases when infection occurs during adolescence and early adulthood. Epstein–Barr virus is also associated with several B-cell malignancies including Burkitt lymphoma, Hodgkin lymphoma, and post-transplant lymphoproliferative disease. A number of antiviral drugs have proven to be effective inhibitors of EBV replication, yet have resulted in limited success clinically, and none of them has been approved for treatment of EBV infections.

The clinical characteristics and the features of immunophenotype of peripheral lymphocytes of adult onset chronic active Epstein-Barr virus disease at a Tertiary Care Hospital in Beijing

Chronic active Epstein-Barr virus (CAEBV) infection is a rare disease with high mortality. Most of CAEBV patients have been reported from Japan and are pediatric cases.The goal was to describe the clinical characteristics and the immunophenotypic features of peripheral lymphocytes in adult onset CAEBV patients.We retrospectively reviewed and analyzed all adult onset CAEBV cases admitted to Peking Union Medical College Hospital (PUMCH) between 2012 and 2016. Demographic, clinical, laboratory data, and the immunophentyping data of peripheral lymphocytes were collected.There were 28 adult onset CAEBV patients. The median age was 45 (range, 20-81). Most of the patients presented with fever; splenomegaly; lymphadenopathy and hepatitis. Unlike pediatric cases reported, the manifestations of cardiovascular diseases in our patients were pulmonary arterial hypertension, decreased cardiac function and aorta vasculitis. Prevalence of interstitial pneumonitis in our patients were comparatively higher and prevalence of hypersensitivity to mosquito bites were comparatively lower than that reported by Japan. In this study, CAEBV patients had decreased B cell, NK cell, CD4 cell and CD8 cell counts. The prevalence of low level of B cells, NK cells, CD4 cells was relatively higher than reported ever.Chinese adult onset CAEBV patients have different clinical characteristics and are featured by an immunosuppression status as demonstrated by decreased B cell, NK cell, CD4 cell and CD8 cell.

Clinical features and outcomes in secondary adult hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by an infrequent but immune-mediated life-threatening disease, with confusing clinical manifestations, rapidly deteriorating health, high morbidity and mortality and challenging diagnosis.

AIM

The purpose of this study was to improve the recognition and understanding of HLH.

DESIGN

Retrospective observational cross-sectional study.

METHODS

Data were collected for all cases of adult patients diagnosed with HLH in a large cohort managed at a single medical center from January 2011 to December 2015.

RESULTS

The median age was 52 years (range 18-90 years) and 123 (60.0%) were male. Over 95% patients manifested fever, hyperferritinemia and elevated lactate dehydrogenase. Underlying triggers of HLH were as follows: 119 (58.0%) malignancies, 83 (40.5%) infections, 14 (6.8%) unknown triggers and 14 (6.8%) autoimmune disorders. The median overall survival was 55 days. And elderly patients (age ≥60 years) had a markedly worse survival compared with young patients (age <60 years) (median overall survival 24 days vs. 159 days, respectively; P <0.001). In a multivariable analysis, platelet <40 × 109/l (HR = 2.534; 95% CI 1.152-5.573; P = 0.021), PT prolonged >3 s (HR = 1.909; 95% CI 1.127-3.234; P = 0.016) and malignancy (HR = 1.614; 95% CI 1.008-2.582; P = 0.046) were correlated with poor survival.

CONCLUSION

HLH adult patients had very complex clinical manifestations as well as underlying diseases. Patients with PLT <40 ×109/l, PT prolonged >3 s and malignancy had inferior survival. It is of great importance to improve our understanding of this syndrome.

Real-time polymerase chain reaction for diagnosing infectious mononucleosis in pediatric patients: A systematic review and meta-analysis

In this meta-analysis, we evaluated the diagnostic role of Epstein-Barr virus deoxyribonucleic acid detection and quantitation in the serum of pediatric and young adult patients with infectious mononucleosis. The primary outcome of this meta-analysis was the sensitivity and specificity of Epstein-Barr virus (EBV) deoxyribonucleic acid (DNA) detection and quantitation using polymerase chain reaction (PCR). A systematic review and meta-analysis was performed by searching for articles that were published through September 24, 2014 in the following databases: Medline, Cochrane, EMBASE, and Google Scholar. The following keywords were used for the search: "Epstein-Barr virus," "infectious mononucleosis," "children/young adults/infant/pediatric," and "polymerase chain reaction or PCR." Three were included in this analysis. We found that for detection by PCR, the pooled sensitivity for detecting EBV DNA was 77% (95%CI, 66-86%) and the pooled specificity for was 98% (95%CI, 93-100%). Our findings indicate that this PCR-based assay has high specificity and good sensitivity for detecting of EBV DNA, indicating it may useful for identifying patients with infectious mononucleosis. This assay may also be helpful to identify young athletic patients or highly physically active pediatric patients who are at risk for a splenic rupture due to acute infectious mononucleosis.

Clinical characteristics and prognostic factors of adult hemophagocytic syndrome patients: a retrospective study of increasing awareness of a disease from a single-center in China

Background

Hemophagocytic lymphohistiocytosis (HLH) is a relatively rare but life-threatening disease with confusing clinical manifestations, rapidly deteriorating health, high morbidity and mortality.

Methods

To improve the recognition as well as understanding of this disorder, we analyzed clinical characteristics and prognostic factors from 85 adult patients diagnosed with HLH in our hospital from April 2005 to June 2014.

Results

Patients with HLH displayed variable clinical markers across a wide spectrum. These included fever and hyperferritinemia (100%), elevated lactate dehydrogenase (LDH) (98.8%), two or three cytopenia (92.2%), splenomegaly (72.9%), hypofibrinogenemia (69.4%), hypertriglyceridemia (64.7%), hemophagocytosis (51.7%), and hepatomegaly (24.7%). Patients with active Epstien-Barr Virus (EBV) infection had a median overall survival (OS) of 65 days. Those displaying malignancy had very poor survival (median OS: 40 days). However, patients in rheumatic and non-EBV infection groups had relatively superior prognosis (not reached). Univariate analysis showed that Fibrinogen (Fbg) <1.5 g/L, platelet number (PLT) <40 × 10⁹/L and LDH ≥1000 U/L were factors that negatively affected survival (P = 0.004, 0.000, 0.002). Multivariate analysis showed that PLT <40 × 10⁹/L was the independent adverse factor (HR = 0.350, 95% CI: 0.145-0.844, P = 0.019).

Conclusions

HLH had very complex clinical manifestations and high death rate. Patients with active EBV infection, malignancy, Fbg <1.5 g/L, PLT <40 × 10⁹/L and LDH ≥1000 U/L had high risk of death as well as inferior survival, and these patients require systemic targeted treatments as early as possible.

Hemophagocytic lymphohistiocytosis: clinical analysis of 103 adult patients

To investigate the clinical features of adult patients with hemophagocytic lymphohistiocytosis (HLH) and to explore possible risk factors for death, we retrospectively reviewed the medical records of 103 adult HLH patients hospitalized from 1997 to 2012. We analyzed the underlying diseases, clinical characteristics, laboratory findings, outcomes, and prognostic factors. The most common cause of HLH was hematologic malignancies (n = 49), followed by infectious diseases (n = 24) and autoimmune disorders (n = 14); 24 cases were of unknown etiology. Eight patients had a combination of underlying diseases. HLH was clinically characterized by high fever (96.1%), splenomegaly (79.6%), hepatomegaly (65.0%), lymphadenopathy (53.4%), proteinuria (31.1%), skin rash (25.2%), gastrointestinal hemorrhage (14.6%), disseminated intravascular coagulation (13.6%), increased creatinine (7.8%), and central nervous system involvement (12.6%) including altered mental status (9.7%) and cranial hemorrhage (2.9%). Laboratory abnormalities included cytopenia (99.0%), serum ferritin >500 ug/L (98.4%), liver dysfunction (98.1%), hypertriglyceridemia (88.5%), hemophagocytosis in bone marrow smear (87.4%), and hypofibrinogenemia (60.9%).In addition to the treatment they received for the underlying causes, patients received therapy for HLH consisting of corticosteroids, immunosuppressive drugs, and intravenous immunoglobulin. Twenty-six patients (25.2%) recovered after treatment, and 19 of them achieved long-term remission during follow-up. Seventy-seven patients (74.8%) died because of tumor, sepsis, multiple organ failure, or HLH-related organ hemorrhage and coagulopathy. The deceased patients were more likely to be older at disease onset, male, and to present with splenomegaly and thrombocytopenia, compared to the survivors. Treatment for the underlying diseases combined with corticosteroids, immunosuppressive agents, and immunoglobulin therapy may improve the prognosis of HLH. More attention should be paid to high-risk patients to prevent the development of serious complications associated with HLH.

Prevalence of human papillomavirus and Epstein-Barr virus DNA in Chinese children with tonsillar and/or adenoidal hypertrophy

Tonsillar and adenoidal hypertrophy are prevalent otolaryngologic disorders in children, but their pathogenesis is largely unknown. The presence of human papillomavirus (HPV) and Epstein-Barr virus (EBV) DNA in 146 tonsil and/or adenoid tissue specimens from 104 Chinese children with tonsillar and/or adenoidal hypertrophy were screened using flow-through hybridization gene-chip technology and real-time fluorescence-based quantitative PCR. Then, the relationships between the prevalence of the viruses and other clinical characteristics of tonsillar and/or adenoidal hypertrophy were analyzed. No patient had HPV DNA. EBV DNA was detected in 19/42 (45.2%) tonsil tissues and 72/104 (69.2%) adenoid tissue specimens (P < 0.05). EBV DNA was not related to the patients' age, gender, disease course, or nationality, but children positive for EBV were less likely to snore; 14/15 (93.3%) patients who did not snore and 59/89 (66.3%) patients who snored were EBV positive. EBV DNA, but not HPV DNA was detected in Chinese children with tonsillar and/or adenoidal hypertrophy. Adenoid tissues might more susceptible than tonsil tissues to EBV infection. In addition, EBV infection did not aggravate snoring in patients with tonsillar and/or adenoidal hypertrophy.

A novel molecular microbiologic technique for the rapid diagnosis of microbial invasion of the amniotic cavity and intra-amniotic infection in preterm labor with intact membranes

PROBLEM

The diagnosis of microbial invasion of the amniotic cavity (MIAC) has been traditionally performed using traditional cultivation techniques, which require growth of microorganisms in the laboratory. Shortcomings of culture methods include the time required (days) for identification of microorganisms, and that many microbes involved in the genesis of human diseases are difficult to culture. A novel technique combines broad-range real-time polymerase chain reaction with electrospray ionization time-of-flight mass spectrometry (PCR/ESI-MS) to identify and quantify genomic material from bacteria and viruses.

METHOD OF STUDY

AF samples obtained by transabdominal amniocentesis from 142 women with preterm labor and intact membranes (PTL) were analyzed using cultivation techniques (aerobic, anaerobic, and genital mycoplasmas) as well as PCR/ESI-MS. The prevalence and relative magnitude of intra-amniotic inflammation [AF interleukin 6 (IL-6) concentration ≥ 2.6 ng/mL], acute histologic chorioamnionitis, spontaneous preterm delivery, and perinatal mortality were examined.

RESULTS

(i) The prevalence of MIAC in patients with PTL was 7% using standard cultivation techniques and 12% using PCR/ESI-MS; (ii) seven of ten patients with positive AF culture also had positive PCR/ESI-MS [≥17 genome equivalents per PCR reaction well (GE/well)]; (iii) patients with positive PCR/ESI-MS (≥17 GE/well) and negative AF cultures had significantly higher rates of intra-amniotic inflammation and acute histologic chorioamnionitis, a shorter interval to delivery [median (interquartile range-IQR)], and offspring at higher risk of perinatal mortality, than women with both tests negative [90% (9/10) versus 32% (39/122) OR: 5.6; 95% CI: 1.4-22; (P < 0.001); 70% (7/10) versus 35% (39/112); (P = 0.04); 1 (IQR: <1-2) days versus 25 (IQR: 5-51) days; (P = 0.002), respectively]; (iv) there were no significant differences in these outcomes between patients with positive PCR/ESI-MS (≥17 GE/well) who had negative AF cultures and those with positive AF cultures; and (v) PCR/ESI-MS detected genomic material from viruses in two patients (1.4%).

CONCLUSION

(i) Rapid diagnosis of intra-amniotic infection is possible using PCR/ESI-MS; (ii) the combined use of biomarkers of inflammation and PCR/ESI-MS allows for the identification of specific bacteria and viruses in women with preterm labor and intra-amniotic infection; and (iii) this approach may allow for administration of timely and specific interventions to reduce morbidity attributed to infection-induced preterm birth.

Microtubule depolymerization activates the Epstein–Barr virus lytic cycle through protein kinase C pathways in nasopharyngeal carcinoma cells

Elevated levels of antibodies against Epstein–Barr virus (EBV) and the presence of viral DNA in plasma are reliable biomarkers for the diagnosis of nasopharyngeal carcinoma (NPC) in high-prevalence areas, such as South-East Asia. The presence of these viral markers in the circulation suggests that a minimal level of virus reactivation may have occurred in an infected individual, although the underlying mechanism of reactivation remains to be elucidated. Here, we showed that treatment with nocodazole, which provokes the depolymerization of microtubules, induces the expression of two EBV lytic cycle proteins, Zta and EA-D, in EBV-positive NPC cells. This effect was independent of mitotic arrest, as viral reactivation was not abolished in cells synchronized at interphase. Notably, the induction of Zta by nocodazole was mediated by transcriptional upregulation via protein kinase C (PKC). Pre-treatment with inhibitors for PKC or its downstream signalling partners p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) abolished the nocodazole-mediated induction of Zta and EA-D. Interestingly, the effect of nocodazole, as well as colchicine and vinblastine, on lytic gene expression occurred only in NPC epithelial cells but not in cells derived from lymphocytes. These results establish a novel role of microtubule integrity in controlling the EBV life cycle through PKC and its downstream pathways, which represents a tissue-specific mechanism for controlling the life-cycle switch of EBV.