Measurement of EBV-IgG anti-VCA avidity aids the early and reliable diagnosis of primary EBV infection

Investigation of atypical serological profiles for Epstein-Barr virus (EBV)

BACKGROUND

Commercial immunoassays that detect IgG and IgM directed toward VCA and IgG EBNA are used in combination to assess EBV immune status. However, this strategy does not always confirm/exclude recent/past EBV infection or absence of immunity.

OBJECTIVES

The aim of our study was to perform complementary investigations on samples with atypical EBV serological profiles, in order to identify the clinical situation they correspond to.

STUDY DESIGN

EBV serology was performed using EBV VCA IgM/IgG and EBNA IgG LXL® DiaSorin assay. Complementary investigations included ELISA IgM VCA, immunoblots, CMV IgM/IgG and CMV IgG avidity, and EBV PCR.

RESULTS

In our study, 12810 EBV serological results were analyzed, and 3580 atypical profiles were detected (28 %). Among these latter, isolated VCA IgG represented 42.9 %, the three positive markers accounted for 29.1 %, isolated EBNA IgG represented 18.5 %, isolated VCA IgM accounted for 6.4 % and positive VCA IgM & positive EBNA IgG represented 3.1 %. VCA IgG detected alone were specific in 100 % cases and EBNA IgG detected alone were specific in 91.7 % cases. VCA IgM detected alone were false positive or due to a cross reaction with CMV in 52.8 % cases. The pattern positive VCA IgM and positive EBNA IgG correspond to a false positive in VCA IgM, EBNA IgG or both in 83.4 % cases. Positive EBV VCA IgM/IgG and EBNA IgG were unreliable to detect active EBV infection in 66.7 % cases.

DISCUSSION

Atypical EBV serological profiles may correspond to several clinical situations and complementary investigations allow to determine the immune status in more than 98.5 % cases.

Epidemiological characteristics of Epstein-Barr virus infection in children and distribution of disease spectrum in hospitalized patients in shandong province

This study aims to investigate the epidemiological characteristics of Epstein-Barr virus (EBV) infection in children and the distribution of disease spectrum in hospitalized patients in Shandong Province. A retrospective analysis was conducted on the clinical data of children with EBV infection admitted to hospitals in Shandong Province from January 2022 to December 2022. The epidemiological characteristics, including age, gender, and clinical manifestations, were analyzed. The detection rate of EBV antibodies and the seropositivity rates of different antibodies were also examined. A total of 7124 children with EBV infection were included in this study, with an average age of 7.5 years. The male-to-female ratio was 1.43:1. Among the patients, the positive detection rate of EBV antibodies was 78.40%. The seropositivity rate of Epstein-Barr viral capsid antigen-Immunoglobin G antibodies was 57.09%. The highest incidence of EBV infection was observed in the age group 36-72 months. The urban positive rate was higher than that in rural areas. EBV infection in children in Shandong Province exhibits specific epidemiological characteristics, with a higher incidence in the age group of 36-72 months. Fever, sore throat, and fatigue are the main clinical manifestations. The detection rate of EBV antibodies is relatively high among hospitalized patients. These findings provide valuable information for controlling the transmission of children with suspected Epstein-Barr virus infection.

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

AIM

We aimed to investigate the seroprevalence of Epstein-Barr virus (EBV) infection in children before and during the COVID-19 pandemic.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

A case of infectious mononucleosis complicated with spontaneous atraumatic splenic rapture caused by Epstein-Barr virus infection

Splenic rupture is the most serious complication of infectious mononucleosis (IM) caused by Epstein-Barr virus (EBV) infection, with a mortality rate of over 1 in 10. We reported a case of spontaneous atraumatic splenic rupture secondary to IM in a young man. The patient presented with abdominal pain caused by splenic rupture as the initial symptom. The diagnosis and treatment process went through a series of twists and turns, including the emergency department, general surgery department, and infection department. This case suggests that clinicians should consider the possibility of EBV infection in young patients with spleen rupture without obvious cause to avoid misdiagnosis and missed diagnosis.

Hemophagocytic Lymphohistiocytosis Following BNT162b2 mRNA COVID-19 Vaccination

Although serious adverse events have remained uncommon, cases of myocarditis induced by messenger RNA (mRNA) COVID-19 vaccines have been reported. Here, we presented a rare but potentially fatal disorder, hemophagocytic lymphohistiocytosis, in a 14-year-old previously healthy adolescent after BNT162b2 mRNA vaccination. The initial evaluation showed splenomegaly, pancytopenia, hyperferritinemia, and hypofibrinogenemia. Further examination revealed positive blood EBV DNA, and other infectious pathogen surveys were all negative. Hemophagocytosis was observed in the bone marrow aspiration and biopsy. HLH was confirmed and intravenous immunoglobulin (IVIG) and methylprednisolone pulse therapy were given. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) was set up for cardiopulmonary support for 3 days due to profound hypotension. The patient was kept on oral prednisolone treatment for 28 days with the following gradual tapering. The hemogram and inflammatory biomarkers gradually returned to normal, and the patient was discharged. The fulminant presentation of HLH in our case could be the net result of both acute immunostimulation after COVID-19 vaccination and EBV infection. Our case suggests that the immune activation after COVID-19 vaccination is likely to interfere with the adequate immune response to certain infectious pathogens, resulting in a hyperinflammatory syndrome.

Analysis of two laboratory tests for determination of EBV-IM in children

This study aimed to explore the application value of two laboratory tests in the diagnosis of Epstein-Barr virus-associated infectious mononucleosis (EBV-IM) in children. From January 2018 to December 2020, 166 patients with EBV-IM were included in this study. Two methods were used in the analysis. The results of both tests were compared and analyzed. The age of onset of EBV-IM is mainly distributed in the range of 0-6 years, and no difference by gender is observed. The sensitivity and specificity of EBV testing by PCR were 49.4% and 89.8%, respectively, and the area under the receiver operating characteristic curve (AUC) was 0.714 (0.662-0.762). When using the immunofluorescence method to detect EBV antibodies, the two indices with the highest diagnostic efficacy were low-affinity EBV-CA IgG and EBV-CA IgM, and their AUC values were 0.798 (0.751-0.840) and 0.663 (0.609-0.713), respectively. When combining the two indices for testing, the AUC values of EBV-CA IgM + low-affinity EBV-CA IgG, EBV-DNA+EBV-CA IgM, and EBV-DNA+low-affinity EBV-CA IgG were 0.904 (0.867-0.933), 0.768 (0.719-0.812), and 0.963 (0.937-0.981), respectively. The diagnostic efficacy of the combined EBV-DNA+EBV-CA IgM + low-affinity EBV-CA IgG test was optimal compared with that of a single index or the combination of two indices, with an AUC of 0.999 (0.986-1.000; p < 0.05), sensitivity of 100%, and specificity of 89.8%. The combined immunofluorescence and real-time PCR methods have high sensitivity and specificity and good application value in the clinical diagnosis of EBV-IM.

Evaluation of Abbott Architect, Siemens Immulite, bioMerieux Vidas, and Euroimmune assays for determination of Epstein-Barr virus serological diagnosis

Serological tests detecting antibodies for Epstein-Barr virus (EBV) antigens are frequently used to define infection status. Several new automated assays are available for this purpose. We compared the performance of Architect, Immulite, Vidas, and Euroimmune immunofluorescence assays (IFA)/enzyme-linked immunosorbent assays (ELISA) for the detection of EBV viral capsid antigen (VCA) immunoglobulin M (IgM), VCA IgG, Epstein-Barr nuclear antigen (EBNA)-1 IgG. The routine diagnosis of EBV in our laboratory is done by anti-EBV VCA IgM IFT, anti-EBV VCA IgG IFT, and anti-EBNA-1 IgG ELISA (Euroimmune) Kits. Samples were tested with EBV Kits of Architect, Immulite, and Vidas for anti-VCA IgM, anti-VCA IgG, and anti-EBNA-1 IgG. The agreement between assays was calculated for each marker individually and for the determination of the EBV infection profile, based on the combination of three markers. BIOCHIP Sequence EBV (Avidity test) and/or EUROLINE EBV Profile 2 (IgG/IgM) were used as confirmatory assays to resolve discrepancies. The best concordance for VCA IgM detection was between Immulite and Vidas; for VCA IgG and EBNA-1 IgG were between Architect and Vidas. The sensitivities and specificities for VCA IgM were 97% and 88% for IFA, 100% and 94% for Architect, 100% and 99% for Vidas, and 100% and 100% for Immulite, respectively. The most problematic marker was EBNA-1 IgG with a 68.1% specificity by Immulite. Vidas panel had a perfect performance (100%) for determining all EBV profiles. Overall, evaluated assays had comparable performance. There were more discordant VCA IgG and EBNA-1 IgG results than VCA IgM results. The agreement between Architect and Vidas was better than other assays.

Characteristics of primary Epstein-Barr virus infection disease spectrum and its reactivation in children, in Suzhou, China

Epstein-Barr virus (EBV) is a globally prevalent herpesvirus associated with multiple diseases. This study aimed to determine the characteristics of primary EBV infection disease spectrum and reactivation in children, in Suzhou, China. All children admitted to the Children's Hospital of Soochow University between May 2018 and September 2020 with suspected EBV-associated disease and subjected to the indirect immunofluorescence assay for EBV-specific antibodies and plasma EBV-DNA assays were included. Of the 3567 children, 2782 (78.0%) tested positive for EBV. The positive rates of viral capsid antigen (VCA)-IgM, VCA-IgG, early antigen (EA)-IgG, nuclear antigen (EBNA)-IgG, and plasma EBV-DNA were 12.1%, 74.6%, 37.9%, 35.6%, and 31.1%, respectively. The lowest VCA-IgG and EBNA-IgG seropositivity rates occurred at ages between 8 and 36 months, then increased gradually in the older age groups. The EBV-IgM seropositivity rate was the highest in those aged 36 to <72 months. Primary EBV infection was more common in children aged 36 to <72 months. In past infections, reactivation mainly occurred in 8 to <36 months. The most common disease caused by primary EBV infection was infectious mononucleosis (56.1%), followed by a respiratory infection (17.0%). Respiratory infection (30.0%), EBV infection (29.2%), and hemophagocytic lymphohistiocytosis (HLH) (15.8%) were the commonest diseases caused by EBV reactivation. EBV reactivation was a risk factor for HLH (adjusted odds ratio, 16.4; 95% confidence interval, 7.9-34.0). Among reactivated patients, the viral load of HLH was higher than that of EBV infection and respiratory infection (p < .01). This is a retrospective large sample study that explored the characteristics of primary EBV infection disease spectrum and reactivation in children.

The variability of the serological response to SARS-corona virus-2: Potential resolution of ambiguity through determination of avidity (functional affinity)

Data on the serological response toward severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in 16 recent reports were analyzed and a high degree of variability was shown. Immunoglobulin M (IgM) responses were either found earlier than IgG, or together with IgG, later than IgG, or were missing. Therefore, clear distinctions between early, intermediate, and past infections are obviously not possible merely on the basis of IgM and IgG determinations. A review of publications on the serology of other virus groups shows that variable IgM responses can be found as well and therefore are not unique for SARS‐CoV‐2 infections. A model to explain this variability is proposed. The inclusion of avidity determination into regular diagnostic procedures has allowed to resolve such “atypical” serological constellations. The potential use of avidity determination for the diagnosis of COVID‐19, for risk assessment, epidemiological studies, analysis of cross reactions, as well as for the control of vaccination programs is suggested and discussed.

The serological response to SARS CoV‐2 infection is highly variable.

The mere detection of specific IgM and IgG does not allow to distinguish between acute and past infection.

The variable IgM and IgG responses after SARS CoV‐2 infection are analogous to serological findings in other virus systems.

Variable IgM and IgG responses can be rationally explained by models that describe immunoglobulin production by the immune system.

Avidity determination of SARS CoV‐2 IgG is suggested for resolution of diagnostic ambiguity.

Molecular profiling of gastric cancer in a population with high HIV prevalence reveals a shift to MLH1 loss but not the EBV subtype

The human immunodeficiency virus (HIV) pandemic heavily affects sub-Saharan Africa. It is associated with persistently active Epstein-Barr virus (EBV) infection. To determine if this translates into increased frequency of EBV-associated gastric cancer (EBVaGC), we evaluated molecular profiles of gastric cancer (GC) in Zambia. Patients with GC or premalignant gastric lesions were enrolled in Lusaka, Zambia. We used patients without any of these lesions as a control group. Chromogenic in situ hybridization (CISH) on tumor tissue was used to identify EBVaGC. To identify the microsatellite unstable subtype, immunofluorescence staining for MutL homolog 1 (MLH1) was used. Exposure to EBV and HIV was assessed serologically. We enrolled 369 patients (median age 52 years [IQR 41-65]; 198 (54%) female). Of these, 72 (20%) had GC and 35 (9%) had gastric premalignant lesions (PL). CISH identified EBVaGC in 5/44 (11%) of those with adequate tissue, while MLH1 loss was identified in 29/45 (64%). Both GC and PL were associated with the highest titers of antibodies to Early antigen-diffuse (OR 2.5, 95% CI 1.0-6.1, P = .048 and OR 3.9, 95% CI 1.1-12.9, P = .03, respectively) at high concentrations. Human immunodeficiency virus infection was associated with a range of antibodies to EBV, but not with any cancer subtype. Despite the association of HIV with persistent EBV, the proportion of EBVaGC in Zambia is similar to populations with a low prevalence of HIV infection. The proportion of microsatellite unstable tumors may be higher than other populations.

EBV miRNA expression profiles in different infection stages: A prospective cohort study

The Epstein-Barr virus (EBV) produces different microRNAs (miRNA) with distinct regulatory functions within the infectious cycle. These viral miRNAs regulate the expression of viral and host genes and have been discussed as potential diagnostic markers or even therapeutic targets, provided that the expression profile can be unambiguously correlated to a specific stage of infection or a specific EBV-induced disorder. In this context, miRNA profiling becomes more important since the roles of these miRNAs in the pathogenesis of infections and malignancies are not fully understood. Studies of EBV miRNA expression profiles are sparse and have mainly focused on associated malignancies. This study is the first to examine the miRNA profiles of EBV reactivation and to use a correction step with seronegative patients as a reference. Between 2012 and 2017, we examined the expression profiles of 11 selected EBV miRNAs in 129 whole blood samples from primary infection, reactivation, healthy carriers and EBV seronegative patients. Three of the miRNAs could not be detected in any sample. Other miRNAs showed significantly higher expression levels and prevalence during primary infection than in other stages; miR-BHRF1-1 was the most abundant. The expression profiles from reactivation differed slightly but not significantly from those of healthy carriers, but a specific marker miRNA for each stage could not be identified within the selected EBV miRNA targets.

Epstein-Barr Virus Epidemiology, Serology, and Genetic Variability of LMP-1 Oncogene Among Healthy Population: An Update

The Epstein-Barr virus (EBV) is a DNA lymphotropic herpesvirus and the causative agent of infectious mononucleosis. EBV is highly prevalent since it affects more than 90% of individuals worldwide and has been linked to several malignancies including PTLDs, which are one of the most common malignancies following transplantation. Among all the EBV genes, most of the recent investigations focused on studying the LMP-1 oncogene because of its high degree of polymorphism and association with tumorigenic activity. There are two main EBV genotypes, Type 1 and 2, distinguished by the differences in the EBNA-2 gene. Further sub genotyping can be characterized by analyzing the LMP-1 gene variation. The virus primarily transmits through oral secretions and persists as a latent infection in human B-cells. However, it can be transmitted through organ transplantations and blood transfusions. In addition, symptoms of EBV infection are not distinguishable from other viral infections, and therefore, it remains questionable whether there is a need to screen for EBV prior to blood transfusion. Although the process of leukoreduction decreases the viral copies present in the leukocytes, it does not eliminate the risk of EBV transmission through blood products. Here, we provide a review of the EBV epidemiology and the genetic variability of the oncogene LMP-1. Then, we underscore the findings of recent EBV seroprevalence and viremia studies among blood donors as a highly prevalent transfusion transmissible oncovirus.

Comparison of two automated instruments for Epstein-Barr virus serology in a large adult hospital and implementation of an Epstein-Barr virus nuclear antigen-based testing algorithm

Serology remains the mainstay for diagnosis of Epstein-Barr virus (EBV) infection. This study compared two automated platforms (BioPlex 2200 and Architect i2000SR) to test three EBV serological markers: viral capsid antigen (VCA) immunoglobulins of class M (IgM), VCA immunoglobulins of class G (IgG) and EBV nuclear antigen-1 (EBNA-1) IgG. Using sera from 65 patients at various stages of EBV disease, BioPlex demonstrated near-perfect agreement for all EBV markers compared to a consensus reference. The agreement for Architect was near-perfect for VCA IgG and EBNA-1 IgG, and substantial for VCA IgM despite five equivocal results. Since the majority of testing in our hospital was from adults with EBNA-1 IgG positive results, post-implementation analysis of an EBNA-based algorithm showed advantages over parallel testing of the three serologic markers. This small verification demonstrated that both automated systems for EBV serology had good performance for all EBV markers, and an EBNA-based testing algorithm is ideal for an adult hospital.

Epstein-Barr virus and cytomegalovirus mononucleosis: Important causes of febrile illness in returned travellers

BACKGROUND

Diagnosing the cause of fever in the returned traveller is challenging. Efforts often focus on identifying 'exotic' pathogens. Primary Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections cause clinical features that overlap with many exotic pathogens. The age-matched seroprevalence of both EBV and CMV is greater in tropical than temperate areas. We describe the clinical and laboratory features of returned travellers diagnosed with primary CMV and EBV syndromes.

METHODS

Patients with laboratory-confirmed primary EBV and CMV infections who had attended the Hospital for Tropical Diseases (HTD), London between 1st October 2011 and 1st October 2016 were identified. Clinical and laboratory data were obtained and analysed.

RESULTS

Twenty-two patients with primary EBV infection and 31 with primary CMV infection were identified. The commonest presenting features of both infections were fever (81.1%), headache (50.9%) and arthralgia/myalgia (49.1%). Cervical lymphadenopathy was seen more frequently with EBV than with CMV (59.1% vs. 25.8%, P = 0.02). Transaminitis (79.2%) and lymphocytosis (52.8%) were the commonest laboratory abnormalities in both groups.

CONCLUSIONS

Primary EBV and CMV infections are important causes of febrile illness in returning travellers. Identification of these pathogens prevents unnecessary, expensive investigations for more 'exotic' pathogens and impacts clinical management for example facilitating prognostication and antimicrobial stewardship.

Evaluation the Architect EBV VCA IgM, VCA IgG, and EBNA-1 IgG chemiluminescent immunoassays to assess EBV serostatus prior transplantation

Prior to transplantation of hematopoietic stem cells or solid organ, donor and recipient EBV serostatus has to be determined to assess risks of post-transplant lymphoproliferative disorders. Sensitivity of EBV Viral capsid antigens (VCA) IgG and EBV nuclear antigen-1 (EBNA-1) is critical to define past infection and a good specificity of VCA IgM is required to avoid any disqualification of cord blood (CB) units. Architect™ EBV antibody panel (Architect assay) providing a high throughput was compared to a semi-automated ELISA (Etimax assays Diasorin) to assess sensitivities and specificities of VCA and EBNA-1 IgG and VCA IgM on 419 sera collected from immunocompromised patients (n = 184) and from pregnant women who agreed to give CB cells (n = 235). Intra and inter-assay coefficient of variations ranged from 1.63% to 4.8% for VCA IgM, VCA IgG, and EBNA-1 IgG. Index of VCA IgG and IgM and EBNA IgG of the two assays were highly correlated. The concordance in the interpretation between the two assays was moderate for VCA IgM (kappa = 0.5), substantial for VCA IgG (kappa = 0.60) and good for EBNA-1 IgG (kappa = 0.75). Using serial dilutions of positive controls and in accordance with clinical results VCA IgG and EBNA IgG were detected at lower dilutions with Architect than Etimax. Conversely, 96.1% (74/77) of samples negative with Architect and positive with Etimax for VCA IgM did not have any heterophile antibodies and had VCA IgG and EBNA IgG antibodies supporting past infections. Architect™ EBV serology panel provided good sensitivities and specificities for EBV serostatus determination prior to transplantation.

Status of Epstein-Barr Virus Coinfection with Helicobacter pylori in Gastric Cancer

Epstein-Barr virus is a ubiquitous human herpesvirus whose primary infection causes mononucleosis, Burkett's lymphoma, nasopharyngeal carcinoma, autoimmune diseases, and gastric cancer (GC). The persistent infection causes malignancies in lymph and epithelial cells. Helicobacter pylori causes gastritis in human with chronic inflammation. This chronic inflammation is thought to be the cause of genomic instability. About 45%-word population have a probability of having both pathogens, namely, H. pylori and EBV. Approximately 180 per hundred thousand population is developing GC along with many gastric abnormalities. This makes GC the third leading cause of cancer-related death worldwide. Although lots of research are carried out individually for EBV and H. pylori, still there are very few reports available on coinfection of both pathogens. Recent studies suggested that EBV and H. pylori coinfection increases the occurrence of GC as well as the early age of GC detection comparing to individual infection. The aim of this review is to present status on coinfection of both pathogens and their association with GC.

Exercise and the Athlete With Infectious Mononucleosis

OBJECTIVE

To determine appropriate management of the active individual with infectious mononucleosis (IM), including issues of diagnosis, the determination of splenomegaly, and other measures of disease status, the relationship of the disease to chronic fatigue syndrome (CFS), and the risks of exercise at various points in the disease process.

DATA SOURCES

An Ovid/MEDLINE search (January 1996-June 2015) was widely supplemented by "similar articles" found in Ovid/MEDLINE and PubMed, reference lists, and personal files.

MAIN RESULTS

Clinical diagnoses of IM are unreliable. Traditional laboratory indicators (lymphocytosis, abnormal lymphocytes, and a heterophile-positive slide test) can be supplemented by more sensitive and more specific but also more costly Epstein-Barr antigen determinations. Clinical estimates of splenomegaly are fallible. Laboratory determinations, commonly by 2D ultrasonography, must take account of methodology, the formulae used in calculations and the individual's body size. The SD of normal values matches the typical increase of size in IM, but repeat measurements can help to monitor regression of the disease. The main risks to the athlete are spontaneous splenic rupture (seen in 0.1%-0.5% of patients and signaled by acute abdominal pain) and progression to chronic fatigue, best avoided by 3 to 4 weeks of restricted activity followed by graded reconditioning. A full recovery of athletic performance is usual with 2 to 3 months of conservative management.

CONCLUSIONS

Infectious mononucleosis is a common issue for young athletes. But given accurate diagnosis and the avoidance of splenic rupture and progression to CFS through a few weeks of restricted activity, long-term risks to the health of athletes are few.

The natural history of acute Q fever: a prospective Australian cohort

BACKGROUND

A detailed description of the natural history of acute Q fever, caused by infection with Coxiella burnetii, AIM: : To significantly increase understanding of the illness.

DESIGN

Subjects with provisional acute Q fever (n = 115) were recruited from primary care in rural Australia, and followed prospectively by interview and blood collection including for serological confirmation. A nested series of subjects with prolonged illness (cases), and those without (controls), were investigated in detail.

METHODS

Total phase I and phase II anti-C. burnetii antibodies were detected by complement fixation test; and IgG, IgM and IgA phase I and phase II titres by immunofluorescence. Flow cytometric analysis was conducted to enumerate circulating T cells subsets, B cells, monocytes and natural killer cells.

RESULTS

Serological testing confirmed acute Q fever in 73 subjects (63%). The acute illness featured fever, headache, sweats, fatigue and anorexia; and varied widely in severity, causing an average of 8 days in bed and 15 days out of work or other role in the first month of illness. The illness course varied from 2 days to greater than a year. No cases of chronic, localized Q fever infection, such as endocarditis, were identified. Neither severe nor prolonged illness were associated with persistence of C. burnetii DNA, altered patterns of C. burnetii-specific IgG, IgM or IgA antibody production, or altered leucocyte subsets.

CONCLUSIONS

The severity of acute Q fever alone predicted prolonged duration. Further studies are warranted to better understand the pathophysiology of prolonged illness after acute Q fever.

Modeling of EBV Infection and Antibody Responses in Kenyan Infants With Different Levels of Malaria Exposure Shows Maternal Antibody Decay is a Major Determinant of Early EBV Infection

The combination of Epstein-Barr virus (EBV) infection and high malaria exposure are risk factors for endemic Burkitt lymphoma, and evidence suggests that infants in regions of high malaria exposure have earlier EBV infection and increased EBV reactivation. In this study we analyzed the longitudinal antibody response to EBV in Kenyan infants with different levels of malaria exposure. We found that high malaria exposure was associated with a faster decline of maternally derived immunoglobulin G antibody to both the EBV viral capsid antigen and EBV nuclear antigen, followed by a more rapid rise in antibody response to EBV antigens in children from the high-malaria-transmission region. We also observed the long-term persistence of anti-viral capsid antigen immunoglobulin M responses in children from the high-malaria region. More rapid decay of maternal antibodies was a major predictor of EBV infection outcome, because decay predicted time to EBV DNA detection, independent of high or low malaria exposure.

Cytomegalic hepatitis in a patient receiving omalizumab

Cytomegalovirus is a double stranded DNA virus that can be present in nearly all organs and body fluids. The primary infection is usually asymptomatic in the immunocompetent host and it is common among adolescents and young adults. The symptomatic form appears, in the majority of cases, as a mononucleosis syndrome with full recovery without specific treatment. We report a case of a 25 years old woman who presented with hepatitis due to CMV infection and history of omalizumab administration one month earlier. This recombinant monoclonal antibody is used to control refractory asthma and chronic spontaneous urticarial as it inhibits human IgE. Despite that, the long course of the disease lead us to initiate treatment with valganciclovir. The improvement after that was rapid and complete.

Profiling of EBV-Encoded microRNAs in EBV-Associated Hemophagocytic Lymphohistiocytosis

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is a life-threatening complication of EBV infection. MicroRNAs (miRNAs) were small non-coding RNA, and EBV could encode miRNAs that are involved in the progression of infection. However, the profiles of EBV-miRNAs in EBV-HLH were unknown. Here, we aimed to profile the expression of EBV-miRNAs in children with EBV-HLH by analyzing 44 known EBV-miRNAs, encoded within the BamHI fragment H rightward open reading frame 1 (BHRF1) and the BamHI-A region rightward transcript (BART), in plasma and cellular targets by real-time quantitative PCR. The study included 15 children with EBV-HLH, 15 children with infectious mononucleosis (IM), and 15 healthy controls. CD8(+) T cells were found to be the cellular target of EBV infection in EBV-HLH, while CD19(+) B cells were infected with EBV in IM. We also found the greater levels of several miRNAs encoded by BART in EBV-HLH, compared to those in IM and healthy controls, whereas the levels of BHRF1 miRNAs were lower than those in IM. The profile and pattern of EBV-miRNAs in EBV-HLH indicated that EBV could display type II latency in EBV-HLH. Importantly, the level of plasma miR-BART16-1 continued decreasing during the whole chemotherapy, suggesting that plasma miR-BART16-1 could be a potential biomarker for monitoring EBV-HLH progression. The pathogenesis of EBV-HLH might be attributed to the abundance of EBV-miRNAs in EBV-HLH. These findings help elucidate the roles of EBV miRNAs in EBV-HLH, enabling the understanding of the basis of this disease and providing clues for its treatment.

Epstein-Barr virus (EBV) infection in Chinese children: a retrospective study of age-specific prevalence

Background

Epstein-Barr Virus (EBV) is a globally prevalent herpesvirus associated with infectious mononucleosis and many malignancies. The survey on EBV prevalence appears to be important to study EBV-related diseases and determine when to administer prophylactic vaccine. The purpose of this retrospective study was to collect baseline information about the prevalence of EBV infection in Chinese children.

Methodology/Principal Finding

We collected 1778 serum samples from healthy children aged 0 to 10, who were enrolled in conventional health and nutrition examinations without any EBV-related symptom in 2012 and 2013 in North China (n = 973) and South China (n = 805). We detected four EBV-specific antibodies, i.e., anti-VCA-IgG and IgM, anti-EBNA-IgG and anti-EA-IgG, by ELISA, representing all of the phases of EBV infection. The overall EBV seroprevalence in samples from North and South China were 80.78% and 79.38% respectively. The EBV seropositivity rates dropped slightly at age 2, and then increased gradually with age. The seroprevalence became stabilized at over 90% after age 8. In this study, the seroprevalence trends between North and South China showed no difference (P>0.05), and the trends of average antibody concentrations were similar as well (P>0.05).

Conclusions/Significance

EBV seroprevalence became more than 50% before age 3 in Chinese children, and exceed 90% after age 8. This study can be helpful to study the relationship between EBV and EBV-associated diseases, and supportive to EBV vaccine development and implementation.

Antibodies to Epstein-Barr virus and MRI disease activity in multiple sclerosis

BACKGROUND

Previous reports indicate an association between Epstein-Barr virus (EBV) antibody levels and multiple sclerosis (MS) disease activity, but the results have been conflicting.

OBJECTIVES

The objective of this paper is to study if EBV antibody levels reflect MRI disease activity in MS and examine the potential for EBV antibody levels as biomarkers for treatment response.

METHODS

A total of 87 MS patients were followed for two years prior to and during interferon beta (IFNB) treatment, with MRI examinations and serum measurement of IgM and IgG antibodies to viral capsid antigen (VCA), EBV nuclear antigen 1 (EBNA-1) and early antigen (EA). Associations between EBV antibody levels and MRI activity were assessed by a logistic regression model.

RESULTS

Higher anti-EBNA-1 IgG levels were associated with increased MRI activity, OR = 2.95 (95% CI 1.07-8.10; p = 0.036) for combined unique activity (CUA; the sum of T1Gd+ lesions and new or enlarging T2 lesions). Although most patients were anti-VCA IgM negative, there was an inverse association, OR = 0.32 (95% CI 0.12-0.84; p = 0.021) with CUA during IFNB treatment.

CONCLUSIONS

This study supports an association between anti-EBNA-1 IgG levels and MS disease activity. We also found an inverse association with anti-VCA IgM levels during IFNB treatment not previously described, indicating anti-VCA IgM as a possible biomarker for IFNB treatment response.

Performance of the architect EBV antibody panel for determination of Epstein-Barr virus infection stage in immunocompetent adolescents and young adults with clinical suspicion of infectious mononucleosis

The Architect EBV antibody panel is a new chemiluminescence immunoassay system used to determine the stage of Epstein-Barr virus (EBV) infection based on the detection of IgM and IgG antibodies to viral capsid antigen (VCA) and IgG antibodies against Epstein-Barr nuclear antigen 1 (EBNA-1). We evaluated its diagnostic accuracy in immunocompetent adolescents and young adults with clinical suspicion of infectious mononucleosis (IM) using the RecomLine EBV IgM and IgG immunoblots as the reference standard. In addition, the use of the antibody panel in a sequential testing algorithm based on initial EBNA-1 IgG analysis was assessed for cost-effectiveness. Finally, we investigated the degree of cross-reactivity of the VCA IgM marker during other primary viral infections that may present with an EBV IM-like picture. High sensitivity (98.3% [95% confidence interval {CI}, 90.7 to 99.7%]) and specificity (94.2% [95% CI, 87.9 to 97.8%]) were found after testing 162 precharacterized archived serum samples. There was perfect agreement between the use of the antibody panel in sequential and parallel testing algorithms, but substantial cost savings (23%) were obtained with the sequential strategy. A high rate of reactive VCA IgM results was found in primary cytomegalovirus (CMV) infections (60.7%). In summary, the Architect EBV antibody panel performs satisfactorily in the investigation of EBV IM in immunocompetent adolescents and young adults, and the application of an EBNA-1 IgG-based sequential testing algorithm is cost-effective in this diagnostic setting. Concomitant testing for CMV is strongly recommended to aid in the interpretation of EBV serological patterns.

Aluminum hydroxide influences not only the extent but also the fine specificity and functional activity of antibody responses to tick-borne encephalitis virus in mice

Aluminum hydroxide is the most widely used adjuvant in human vaccines and serves as a potent enhancer of antibody production. Its stimulatory effect strongly depends on the adsorption of the antigen to the adjuvant, which may influence antigen presentation and, as a consequence, the fine specificity of antibody responses. Such variations can have functional consequences and can modulate the effectiveness of humoral immunity. Therefore, we investigated the influence of aluminum hydroxide on the fine specificity of antibody responses in a model study in mice using an inactivated purified virus particle, the flavivirus tick-borne encephalitis (TBE) virus, as an immunogen. To dissect and quantify the specificities of polyclonal antibodies in postimmunization sera, we established a platform of immunoassays using recombinant forms of the major target of neutralizing antibodies (protein E) as well as individual domains of E (DIII and the combination of DI and DII [DI+DII]). Our analyses revealed a higher proportion of neutralizing than virion binding (as detected by enzyme-linked immunosorbent assay) antibodies after immunization with aluminum hydroxide. Furthermore, the induction of antibodies to DIII, a known target of potently neutralizing antibodies, as well as their contributions to virus neutralization were significantly greater in mice immunized with adjuvant and correlated with a higher avidity of these antibodies. Thus, our data provide evidence that aluminum hydroxide can lead to functionally relevant modulations of antibody fine specificities in addition to its known overall immune enhancement effect.

The impact of serological features in Chinese children with primary or past Epstein-Barr virus infections

BACKGROUND

Epstein-Barr virus (EBV) is a primary cause of infectious mononucleosis (IM) throughout the world, and the positive serology rate changes over time in infected individuals. The aim of this study was to explore the serological and clinical features among Chinese children with EBV infections. A retrospective study of children suspected of having IM was conducted. Peripheral blood samples were analyzed by indirect immunofluorescence to detect any EBV-specific antibodies. Samples were classed as positive (+) or negative (-) to immunoglobulins M (IgM) or G (IgG) to the viral capsid antigen (VCA) or EBV nuclear antigen (EBNA). A standard medical history was taken, including epidemiological data and noting any clinical manifestations.

RESULTS

Of 317 children, 37 were aged <8 months; 10 of these were VCA-IgM+, and the youngest was aged 1 month; 280 were aged >8 months. The EBV infection rate ranged from 21.4% among subjects aged 8-12 months to 84.2% in those aged >9 years. Serologically, children who tested as VCA-IgM+ together with VCA-IgG and EBNA-IgG- had longer hospital stays with more palatal petechiae and lymphadenopathy, especially among those with an atypical lymphocyte count of >10%. Children with the serological patterns [VCA-IgM-, VCA-IgG+ and EBNA-IgG-] and [VCA-IgM+ VCA-IgG+ and EBNA-IgG+] did not show specific clinical features.

CONCLUSIONS

Infants aged <8 months could be infected with EBV. About 84% of these Chinese children aged >9 years had serological evidence of EBV infection, whereas IM peaked in patients aged 2-3 years.

Serological diagnosis of Epstein-Barr virus infection: Problems and solutions

Serological tests for antibodies specific for Epstein-Barr virus (EBV) antigens are frequently used to define infection status and for the differential diagnosis of other pathogens responsible for mononucleosis syndrome. Using only three parameters [viral capsid antigen (VCA) IgG, VCA IgM and EBV nuclear antigen (EBNA)-1 IgG],it is normally possible to distinguish acute from past infection: the presence of VCA IgM and VCA IgG without EBNA-1 IgG indicates acute infection, whereas the presence of VCA IgG and EBNA-1 IgG without VCA IgM is typical of past infection. However, serological findings may sometimes be difficult to interpret as VCA IgG can be present without VCA IgM or EBNA-1 IgG in cases of acute or past infection, or all the three parameters may be detected simultaneously in the case of recent infection or during the course of reactivation. A profile of isolated EBNA-1 IgG may also create some doubts. In order to interpret these patterns correctly, it is necessary to determine IgG avidity, identify anti-EBV IgG and IgM antibodies by immunoblotting, and look for heterophile antibodies, anti-EA (D) antibodies or viral genome using molecular biology methods. These tests make it possible to define the status of the infection and solve any problems that may arise in routine laboratory practice.

The role of IgG avidity determination in diagnosis of Epstein-Barr virus infection in immunocompetent and immunocompromised patients

There is a high degree of variability in the serologic response to Epstein-Barr virus (EBV) infection, especially in viral capsid antigen (VCA)-IgM antibodies. Therefore, additional tests are needed to confirm primary infection. We evaluated the value of IgG avidity determination in diagnosis of EBV infection in immunocompetent and immunocompromised patients. A total of 236 serum samples from immunocompetent patients with symptoms suggestive of EBV infection were tested for the presence of VCA-IgM/IgG antibodies and IgG avidity. Using IgG avidity, acute primary infection was confirmed in 56.7% of the immunocompetent patients with positive and in 1.8% of patients with negative VCA-IgM. Recent primary infection was documented in 8.9% of the IgM positive and 3.5% of the IgM negative patients. In patients with indeterminate serology (equivocal IgM), 6.7% were classified by avidity index (AI) as acute primary infection, 10.0% as post-acute and 83.3% as past infection cases. Concerning the 32 immunocompromised patients, recent primary infection was documented in 3 of the 14 IgM positive patients. High AI was detected in 11 of these patients, indicating an IgM response due to reactivation. Determination of IgG avidity in combination with classical serologic markers seems to be a reliable method to confirm primary infection both in immunocompetent and immunocompromised patients. It may be especially useful to differentiate cases of primary infection in patients with undetectable VCA-IgM antibodies or indeterminate routine EBV serology.

Positive Epstein-Barr virus and cytomegalovirus IgM assays in primary HIV infection

We report three cases with misleading cytomegalovirus (CMV) or Epstein-Barr virus (EBV) immunoglobulin M (IgM) results during primary human immunodeficiency virus (HIV) infection. We determined the rate of positive anti-CMV IgM assays or anti-EBV capsid antigen IgM assays in sera from a group of well-characterized subjects with primary HIV infection as 2.9% (1/35; 95%CI: 0.15-16.6%) for each infection. The rate of positive anti-EBV capsid antigen IgM assays in subjects with positive hepatitis A virus IgM assays was 30% (6/20; 95%CI: 14.6-51.9%). Clinicians need to consider the limitations of IgM assays for diagnosis of herpesvirus infections, and consider testing for other infections with overlapping clinical manifestations.

Serological and virological investigation of the role of the herpesviruses EBV, CMV and HHV-6 in post-infective fatigue syndrome

Multiple previous studies have sought evidence for ongoing, active infection with, or reactivation of, Herpesviruses in patients with chronic fatigue syndrome (CFS), with conflicting results. This study aimed to clarify this by studying 20 patients enrolled in a well-characterized model of the onset and evolution of CFS, the prospective cohort of the Dubbo Infection Outcomes Study (DIOS). The patients selected for examination included five CFS patients with primary Epstein-Barr virus (EBV) infection; five CFS patients with acute viral infection not caused by EBV; and 10 matched controls with prompt resolution of primary EBV infection. Serum samples from three timepoints were assayed using a comprehensive range of serological assays for EBV, HHV-6, and CMV. Viral genomes were assessed using quantitative PCR assays. All patients were seropositive for HHV-6, and 10 were seropositive for CMV at infection baseline (five patients and five controls). Low titer CMV IgM antibodies were found at infection baseline in two of these cases and three control patients. HHV-6 IgG antibody titers were highest at infection baseline but did not differ between the CFS cases and the control patients. There were increases in EBV IgG VCA p18, EBNA-1 IgG, and EA IgG titers over time, but these did not differ between CFS cases and control patients. EBV and HHV6 DNA levels were at control levels in a minority of samples, and CMV was undetectable in all samples. These data do not support the hypothesis of ongoing or reactivated EBV, HHV-6, or CMV infection in the pathogenesis of CFS.

Coinfection with EBV/CMV and other respiratory agents in children with suspected infectious mononucleosis

BACKGROUND

Numerous studies have shown that Epstein-Barr virus (EBV) and cytomegalovirus (CMV) can infect immunocompetent patients simultaneously with other agents. Nonetheless, multiple infections with other agents in EBV/CMV-infected children have received little attention. We conducted a retrospective study of children with suspected infectious mononucleosis. Peripheral blood samples were analyzed by indirect immunofluorescence to detect EBV, CMV and other respiratory agents including respiratory syncytial virus; adenovirus; influenza virus types A and B; parainfluenza virus types 1, 2 and 3; Chlamydia pneumoniae and Mycoplasma pneumoniae. A medical history was collected for each child.

RESULTS

The occurrence of multipathogen infections was 68.9%, 81.3% and 63.6% in the children with primary EBV, CMV or EBV/CMV, respectively, which was significantly higher than that in the past-infected group or the uninfected group (p < 0.001). Of the multipathogen-infected patients, the incidence of C. pneumoniae in children with primary infection was as high as 50%, significantly higher than in the other groups (p < 0.001). In the patients with multipathogen infection and EBV/CMV primary infection, fever, rash, lymphadenopathy, hepatomegaly, splenomegaly, atypical lymphocytes and abnormal liver function were more frequent and the length of hospital stay and duration of fever were longer than in other patients.

CONCLUSION

Our study suggests that there is a high incidence of multipathogen infections in children admitted with EBV/CMV primary infection and that the distribution of these pathogens is not random.

Acute hepatitis E infection associated with a false-positive serology against Epstein-Barr virus

Hepatitis E virus is a major cause of acute viral hepatitis. The diagnosis of acute viral hepatitis E is based essentially on antibodies and hepatitis E virus RNA. We describe herein a case of acute hepatitis E associated with a false-positive serology for Epstein-Barr virus (EBV). This case report suggests that anti-viral capsid antigen IgM must be interpreted with caution in acute E hepatitis. When positive, EBV RNA polymerase chain reaction can be useful as a false positivity of anti-viral capsid antigen IgM and can be misinterpreted as an acute infection. EBV false positivity was probably related to polyclonal stimulation of the immune system, favoured by hepatitis E.

Evaluation of Epstein-Barr virus antibodies, anti-VCA avidity by immunofluorescence and immunoblot assays for assessment of Epstein-Barr virus immunologic state

Three hundred twenty two serum samples were evaluated by indirect immunofluorescence assay (IFA) and immunoblotting for the assessment of the immunologic status of Epstein-Barr virus (EBV). Serological profiles of 322 serum samples were classified by the IgM and IgG antibodies by the immunofluorescence assay as seronegative, acute infection, reactivation and past infection. Higher rates of seropositivity were determined in serum samples belonging to old age groups. Routine tests used for EBV diagnosis were efficient.

Prevalence of primary versus reactivated Epstein-Barr virus infection in patients with VCA IgG-, VCA IgM- and EBNA-1-antibodies and suspected infectious mononucleosis

BACKGROUND

In Epstein-Barr virus (EBV) infection, IgG- and IgM-antibodies to viral capsid antigen (VCA) and IgG-antibodies to Epstein-Barr nuclear antigen 1 (EBNA-1) can occur simultaneously both in late primary infection and during subclinical viral reactivation in immunocompetent persons, and the differential diagnosis is of importance.

OBJECTIVES

To study the prevalence of primary infection and serological reactivation in patients with suspected primary EBV infection and with all three parameters present.

STUDY DESIGN

Fifty serum samples from 43 consecutive patients referred for suspected infectious mononucleosis and positive for VCA IgG-, VCA IgM- and EBNA-1-antibodies by EIA, were tested for IgG-antibody avidity with an EBV IgG immunoblot. Sera were also tested for heterophile antibodies (HA). To verify the presence of IgM-antibodies an EBV IgM immunoblot was performed when high-avidity IgG-antibodies were found.

RESULTS AND CONCLUSIONS

Of 43 patients with suspected primary EBV infection and VCA IgG-, VCA IgM- and EBNA-1-antibodies present, only 18 patients (42%) had a late primary infection. Twenty-one patients (49%) had high-avidity IgG-antibodies, indicating an IgM response due to reactivation, thus suggesting other causes for their symptoms. In 10 of these 21 patients the presence of IgM-antibodies was confirmed by immunoblot, indicating reactivation as a cause of IgM-antibodies in at least 23% of the 43 patients studied. Of 18 patients with primary infection, HA were detected in 16 (94%) of 17 patients tested. Only one (5%) of the patients with high-avidity antibodies had HA. Absence of HA in patients with this serological pattern is therefore a good indicator of reactivation, and conversely, the presence of HA is a good indicator of primary infection. In HA negative patients, avidity testing could be used for differential diagnosis.

Post-infective and chronic fatigue syndromes precipitated by viral and non-viral pathogens: prospective cohort study

OBJECTIVE

To delineate the risk factors, symptom patterns, and longitudinal course of prolonged illnesses after a variety of acute infections.

DESIGN

Prospective cohort study following patients from the time of acute infection with Epstein-Barr virus (glandular fever), Coxiella burnetii (Q fever), or Ross River virus (epidemic polyarthritis).

SETTING

The region surrounding the township of Dubbo in rural Australia, encompassing a 200 km geographical radius and 104,400 residents.

PARTICIPANTS

253 patients enrolled and followed at regular intervals over 12 months by self report, structured interview, and clinical assessment.

OUTCOME MEASURES

Detailed medical, psychiatric, and laboratory evaluations at six months to apply diagnostic criteria for chronic fatigue syndrome. Premorbid and intercurrent illness characteristics recorded to define risk factors for chronic fatigue syndrome. Self reported illness phenotypes compared between infective groups.

RESULTS

Prolonged illness characterised by disabling fatigue, musculoskeletal pain, neurocognitive difficulties, and mood disturbance was evident in 29 (12%) of 253 participants at six months, of whom 28 (11%) met the diagnostic criteria for chronic fatigue syndrome. This post-infective fatigue syndrome phenotype was stereotyped and occurred at a similar incidence after each infection. The syndrome was predicted largely by the severity of the acute illness rather than by demographic, psychological, or microbiological factors.

CONCLUSIONS

A relatively uniform post-infective fatigue syndrome persists in a significant minority of patients for six months or more after clinical infection with several different viral and non-viral micro-organisms. Post-infective fatigue syndrome is a valid illness model for investigating one pathophysiological pathway to chronic fatigue syndrome.

Review of Epstein–Barr virus and post-transplant lymphoproliferative disorder post-solid organ transplantation (Review Article)

Post-transplant lymphoproliferative disorder (PTLD) following solid organ transplantation is an important form of post-transplant malignancy. PTLD is typically associated with Epstein-Barr virus (EBV) and occurs in the setting of profound immunosuppression resulting in a deficiency of EBV-specific cytotoxic T lymphocytes (CTL). Predisposing factors include EBV mismatch between donor and recipient, use of immunosuppression especially T-cell depletive therapies and genetic predisposition of recipients. The standard approach has been to reduce immunosuppression but is often insufficient to induce tumour regression. Further understanding of the immunobiology of PTLD has resulted in improved monitoring techniques (including EBV viral load determined by polymerase chain reaction) and newer treatment options. Recent work has highlighted a potential role for dendritic cells in both the pathogenesis and treatment of PTLD. Current treatment modalities include adoptive immunotherapy using ex vivo generated autologous EBV-specific CTL or allogeneic CTL, cytokine therapies, antiviral agents, and more recently, rituximab and dendritic-cell based therapies. This review focuses on the developments and progress in the pathogenesis, diagnosis and treatment of PTLD.

Analysis of the antibody response to an immunodominant epitope of the envelope glycoprotein of a lentivirus and its diagnostic potential

The envelope glycoprotein of small ruminant lentiviruses (SRLV) is a major target of the humoral immune response and contains several linear B-cell epitopes. We amplified and sequenced the genomic segment encoding the SU5 antigenic site of the envelope glycoprotein of several SRLV field isolates. With synthetic peptides based on the deduced amino acid sequences of SU5 in an enzyme-linked immunosorbent assay (ELISA), we have (i) proved the immunodominance of this region regardless of its high variability, (ii) defined the epitopes encompassed by SU5, (iii) illustrated the rapid and peculiar kinetics of seroconversion to this antigenic site, and (iv) shown the rapid and strong maturation of the avidity of the anti-SU5 antibody. Finally, we demonstrated the modular diagnostic potential of SU5 peptides. Under Swiss field conditions, the SU5 ELISA was shown to detect the majority of infected animals and, when applied in a molecular epidemiological context, to permit rapid phylogenetic classification of the infecting virus.

Preliminary evidence of mitochondrial dysfunction associated with post-infective fatigue after acute infection with Epstein Barr virus

BACKGROUND

Acute infectious diseases are typically accompanied by non-specific symptoms including fever, malaise, irritability and somnolence that usually resolve on recovery. However, in some individuals these symptoms persist in what is commonly termed post-infective fatigue. The objective of this pilot study was to determine the gene expression correlates of post-infective fatigue following acute Epstein Barr virus (EBV) infection.

METHODS

We followed 5 people with acute mononucleosis who developed post-infective fatigue of more than 6 months duration and 5 HLA-matched control subjects who recovered within 3 months. Subjects had peripheral blood mononuclear cell (PBMC) samples collected at varying time points including at diagnosis, then every 2 weeks for 3 months, then every 3 months for a year. Total RNA was extracted from the PBMC samples and hybridized to microarrays spotted with 3,800 oligonucleotides.

RESULTS

Those who developed post-infective fatigue had gene expression profiles indicative of an altered host response during acute mononucleosis compared to those who recovered uneventfully. Several genes including ISG20 (interferon stimulated gene), DNAJB2 (DnaJ [Hsp40] homolog and CD99), CDK8 (cyclin-dependent kinase 8), E2F2 (E2F transcription factor 2), CDK8 (cyclin-dependent kinase 8), and ACTN2 (actinin, alpha 2), known to be regulated during EBV infection, were differentially expressed in post-infective fatigue cases. Several of the differentially expressed genes affect mitochondrial functions including fatty acid metabolism and the cell cycle.

CONCLUSION

These preliminary data provide insights into alterations in gene transcripts associated with the varied clinical outcomes from acute infectious mononucleosis.

Correlation of psycho-neuroendocrine-immune (PNI) gene expression with symptoms of acute infectious mononucleosis

Acute infection is known to perturb psycho-neuroendocrine-immune (PNI) gene expression. Oligonucleotide microarrays were used to examine PNI gene expression in the peripheral blood of 13 subjects with infectious mononucleosis (IM). Novel peripheral blood gene expression activity was correlated with central-nervous-system-mediated symptoms including fatigue and sleep disturbance. Of note, expression of the MADS box transcription enhancer factor 2 polypeptide C (MEF2C) gene, previously implicated in skeletal muscle myogenesis, correlated with symptoms of musculo-skeletal pain and fatigue. Expression of the hypocretin/orexin receptor HCRTR2, which has been implicated in narcolepsy, correlated with sleep disturbance. And, VACHT, the vesicular acetylcholine transporter, was highly correlated with neurocognitive disturbance. The expression of both HCRTR2 and MEF2C in the peripheral blood was validated by reverse transcription PCR. Thus, investigation of the PNI response in peripheral blood may provide novel insights into the complex pathophysiology of centrally mediated disease states.

Characterization of the homo- and heterotypic immune responses after natural norovirus infection

Noroviruses (NoV) are a genetically and antigenically diverse group of viruses that are common causes of outbreaks of gastroenteritis in humans of all ages. Limited information has been obtained on type specificity of the NoV immune response. In this study, we characterized the homologous and heterologous antibody responses in adults from 13 outbreaks, representing 4 different NoV genotypes. NoV specific IgG and IgA antibodies were determined as well as the increase of antibody avidity. In addition, antibody-mediated blocking of NoV binding to its putative receptor was evaluated. Both homologous and heterologous serological responses were detected after NoV infection. The avidity of antibodies could not be used to distinguish between homologous and heterologous antibody responses. However, a homologous blocking response but not a heterologous response was detected after infection with NoV belonging to genogroup II.4 by a NoV ligand binding inhibition assay. Infection with NoV induces antibodies that can block virus ligand interactions. In contrast with all currently known antibody detection assays for NoV, this can be used as a type specific assay and may be an alternative for studying neutralizing antibodies.

Utilization of follow-up specimens from viremic blood donors to assess the value of west nile virus immunoglobulin G avidity as an indicator of recent infection

The value of West Nile virus immunoglobulin G avidity for distinguishing recent from past infection was investigated using 348 follow-up specimens from 170 viremic blood donors. Low avidity accurately indicated infection within the previous 4 months. However, due to rapid avidity maturation in some individuals, high avidity did not accurately indicate past infection.

Splenic infarction due to transient antiphospholipid antibodies induced by acute Epstein-Barr virus infection

Splenic infarction is a rare feature of infectious mononucleosis (IM) due to Epstein-Barr virus (EBV), limited to three case reports. We report the first case of splenic infarction during acute EBV infection associated with the transient induction of antiphospholipid antibodies. We discuss the role of antiphospholipid antibodies in thrombosis in acute viral infections and postulate other mechanisms of thrombosis. Once other more common causes of splenic infarction, such as endocarditis and lymphoma, have been excluded, the possibility of viral-induced antiphospholipid antibodies should be considered.

Serum Epstein-Barr virus DNA load in primary Epstein-Barr virus infection

Specific viral laboratory diagnosis of primary Epstein-Barr Virus (EBV) infection is usually based on antibody-detection assays. During acute, lytic phase of infection, viral DNA can also be detected in serum. In the present study, the diagnostic utility of EBV DNA detection and quantitation in serum in primary EBV infection was investigated. The level of EBV DNA in the serum of 98 immunocompetent patients aged 1-47 years with symptomatic, antibody-confirmed EBV primary infection was assessed using a quantitative real-time PCR assay. The association between viral load and time after onset of disease, age and clinical and laboratory data was investigated. Quantitative PCR detected EBV DNA in 93 of 98 samples (94.9%), and the measured viral loads ranged from 3.8 x 10(1) to 6.6 x 10(4) copies/ml. EBV DNA detection exhibited a sensitivity of 94.9% and a specificity of 97.4% for primary EBV infection. EBV DNA was always detectable until day 12 after onset of symptoms, whereas no further positive PCR results were found after a period of 22 days after onset of disease. Detection of EBV DNA also showed a clearer association with the clinical manifestation of disease than the presence of EBV specific VCA IgG antibodies of low avidity. EBV DNA load was found to correlate inversely with the time after onset of disease (P < 0.001), and higher viral load levels were detected in younger (P = 0.009) and in hospitalized patients (P = 0.038). The results indicate that real-time PCR is a reliable tool for diagnosis of primary EBV infection early in the course of disease. In addition, EBV DNA detection may serve as a useful diagnostic supplement in serologically indeterminate EBV infections.

Identification of primary and secondary measles vaccine failures by measurement of immunoglobulin G avidity in measles cases during the 1997 São Paulo epidemic

Despite almost universal use of measles vaccines in recent decades, epidemics of the disease continue to occur. Understanding the role of primary vaccine failure (failure to seroconvert after vaccination) and secondary vaccine failures (waning immunity after seroconversion) in measles epidemics is important for the evaluation of measles control programs in developing countries. After a measles epidemic in São Paulo, Brazil, 159 cases previously confirmed by detection of specific immunoglobulin M (IgM) antibodies were tested for IgG avidity, and a secondary immune response, defined by an IgG avidity index of at least 30%, was established in 30 of 159 (18.9%) patients. Among the 159 patients, 107 (67.3%) had not been vaccinated and 52 (32.7%) had received one or more doses of measles vaccine. Of the 107 unvaccinated patients, 104 (97.2%) showed a primary immune response, defined as an IgG avidity index of less than 30%. Among the 52 patients with documented vaccination, 25 (48.1%) showed a primary immune response and 27 (51.9%) showed a secondary immune response, thereby constituting a secondary vaccine failure. Primary vaccine failure was observed in 13 of 13 patients vaccinated prior to 1 year of age and in 43.5 and 12.5%, respectively, of patients receiving one or two doses after their first birthdays. These results provide evidence that measurement of IgG avidity can be used to distinguish between primary and secondary vaccine failures in vaccinated patients with measles; the method can also be a useful tool for the evaluation of measles control programs.