Primary Epstein-Barr virus infection in early childhood

Emergence of CD4+ and CD8+ Polyfunctional T Cell Responses Against Immunodominant Lytic and Latent EBV Antigens in Children With Primary EBV Infection

Long term carriers were shown to generate robust polyfunctional T cell (PFC) responses against lytic and latent antigens of Epstein-Barr virus (EBV). However, the time of emergence of PFC responses against EBV antigens, pattern of immunodominance and difference between CD4+ and CD8+ T cell responses during various stages of EBV infection are not clearly understood. A longitudinal study was performed to assess the development of antigen-specific PFC responses in children diagnosed to have primary symptomatic (infectious mononucleosis [IM]) and asymptomatic (AS) EBV infection. Evaluation of IFN-γ secreting CD8+ T cell responses upon stimulation by HLA class I-specific peptides of EBV lytic and latent proteins by ELISPOT assay followed by assessment of CD4+ and CD8+ PFC responses upon stimulation by a panel of overlapping EBV peptides for co-expression of IFN-γ, TNF-α, IL-2, perforin and CD107a by flow cytometry were performed. Cytotoxicity of T cells against autologous lymphoblastoid cell lines (LCLs) as well as EBV loads in PBMC and plasma were also determined. Both IM and AS patients had elevated PBMC and plasma viral loads which declined steadily during a 12-month period from the time of diagnosis whilst decrease in the magnitude of CD8+ T cell responses toward EBV lytic peptides in contrast to increase toward latent peptides was shown with no significant difference between those of IM and AS patients. Both lytic and latent antigen-specific CD4+ and CD8+ T cells demonstrated polyfunctionality (defined as greater or equal to three functions) concurrent with enhanced cytotoxicity against autologous LCLs and steady decrease in plasma and PBMC viral loads over time. Immunodominant peptides derived from BZLF1, BRLF1, BMLF1 and EBNA3A-C proteins induced the highest proportion of CD8+ as well as CD4+ PFC responses. Diverse functional subtypes of both CD4+ and CD8+ PFCs were shown to emerge at 6–12 months. In conclusion, EBV antigen-specific CD4+ and CD8+ PFC responses emerge during the first year of primary EBV infection, with greatest responses toward immunodominant epitopes in both lytic and latent proteins, correlating to steady decline in PBMC and plasma viral loads.

Primary Epstein-Barr virus infection

Epstein-Barr virus (EBV) infects about 90% of adults worldwide. It is the main cause of infectious mononucleosis, which is observed most frequently in adolescents. The disease can last several weeks and is characterized by lymphocytosis, sore throat, lymphadenopathy, and fatigue. Exposure to oral secretions during deep kissing has been identified as the major source for primary EBV infection in adolescents. Oral secretions are also thought to be the source for younger children through intimate intact or sharing food and eating utensils, although this has not been confirmed. Unlike most acute viral illnesses such as influenza, the incubation period of symptomatic primary EBV infection is unusually long, lasting about six weeks. Diagnosis is typically made by heterophile antibody tests and/or EBV-specific antibody tests. Long-term consequences may result from acquisition of the virus, including nasopharyngeal carcinoma and lymphomas. Nevertheless, there remains a surprising dearth of knowledge regarding the establishment of an immune response to persistent EBV infection, especially during the incubation period. This lack of knowledge has impaired our ability to develop an effective prophylactic EBV vaccine, despite various attempts. Our greatest challenges in EBV research are to develop a prophylactic vaccine and devise treatment strategies for persons already infected with EBV.

Conjunctival tumor caused by Epstein-Barr virus-related infectious mononucleosis: Case report and review of literature

The conjunctival tumor associated with Epstein-Barr virus related infectious mononucleosis is a rare ocular manifestation. Only a few cases have been reported in the literature. We reported this rare condition that presented in a 5-year-old boy.

Comprehensive assessment of peripheral blood TCRβ repertoire in infectious mononucleosis and chronic active EBV infection patients

Epstein-Barr virus (EBV) primary infection is usually asymptomatic, but it sometimes progresses to infectious mononucleosis (IM). Occasionally, some people develop chronic active EBV infection (CAEBV) with underlying immunodeficiency, which belongs to a continuous spectrum of EBV-associated lymphoproliferative disorders (EBV⁺ LPD) with heterogeneous clinical presentations and high mortality. It has been well established that T cell-mediated immune response plays a critical role in the disease evolution of EBV infection. Recently, high-throughput sequencing of the hypervariable complementarity-determining region 3 (CDR3) segments of the T cell receptor (T cell receptor β (TCRβ)) has emerged as a sensitive approach to assess the T cell repertoire. In this study, we fully characterized the diversity of peripheral blood TCRβ repertoire in IM (n = 6) and CAEBV patients (n = 5) and EBV-seropositive controls (n = 5). Compared with the healthy EBV-seropositive controls, both IM and CAEBV patients demonstrate a significant decrease in peripheral blood TCRβ repertoire diversity, basically, including narrowed repertoire breadth, highly expanded clones, and skewed CDR3 length distribution. However, there is no significant difference between IM and CAEBV patients. Furthermore, we observed some disease-related preferences in TRBV/TRBJ usage and combinations, as well as lots of T cell clones shared by different groups (unique or overlapped) involved in public T cell responses, which provide more detailed insights into the divergent disease evolution.

Clinical characteristics and laboratory findings in Danish children hospitalized with primary Epstein-Barr virus infection

BACKGROUND

Epstein-Barr virus (EBV) positive infectious mononucleosis (IM) is a common disease in adolescents. However, IM is often considered a rare disease in early childhood. We aimed to describe the classical presentation of adolescent EBV-associated IM compared to EBV infection at younger age.

METHODS

All immunocompetent children hospitalized at Hvidovre University Hospital, Copenhagen between 2002 and 2013, who presented with clinical features that prompted a laboratory test for EBV, and who tested positive by presence of EBV-specific antibodies, heterophile antibodies or a positive EBV PCR were included (n = 95).

RESULTS

Children aged 1-2 years were the age group most commonly hospitalized with acute EBV infection (27% of the cohort), followed by teenagers aged 14-15 years (23%). Fever, cervical lymphadenopathy, tonsillitis and fatigue were the most common physical findings overall. Dividing the children into three age groups (0-4 years, 5-10 years and 11-15 years) revealed that the oldest age groups significantly more often suffered from headache, tonsillitis, sore throat, abdominal pain and nausea. Young children typically presented with a runny nose, fever, fatigue and cervical adenitis. Compared with children under 5, children aged 5-15 years more often showed lymphocytosis (84% vs 62%), elevated alanine aminotransferase (77% vs 33%) and lactate dehydrogenase (79% vs 44%).

CONCLUSION

EBV infection is common in young children, and children less than 3 years of age constitute the largest group of hospitalizations for acute EBV infection. EBV-associated IM should be suspected in febrile children of all ages with tonsillitis, lymphadenopathy, lymphocytosis and elevated liver enzymes.

The incidence of epstein-barr virus primary infection among suspected patients referred to namazi hospital of shiraz, iran

Background:

Many children become infected with Epstein-Barr virus (EBV) during their childhood. Since the clinical profile of EBV primary infection is challenging, it is important to use the best diagnostic clinical means. Detection of IgM against viral capsid antigen (VCA) by ELISA has been shown to be a reliable method.

Objectives:

This study was conducted to demonstrate the incidence of EBV primary infection, among suspected patients referred to Namazi hospital, Shiraz, Iran.

Patients and Methods:

The sample included 346 patients with an age range of 0 to 20 years (6.31 ± 4.66: 10.97 years). A volume of 5 mL of blood was collected from each case. The patients were divided to four age groups. The sera were tested for the presence of VCA-IgM by commercially available Anti-EBV-VCA ELISA kit.

Results:

The results indicated that 104 (30.0%) of the patients were EBV VCA IgM positive, with no significant difference in the incidence of EBV primary infection between males and females. However, the incidence of infection was significantly different between age group I (0 - 5 years) and III (11 - 15 years), and also between age group I (0 - 5 years) and IV (16 - 20 years) (P < 0.05).

Conclusions:

Considering the results, accurate and on time diagnosis of EBV primary infection in both children and adolescents will help prevent unnecessary hospitalization, medication and incorrect medical decisions. In addition, this will decrease further treatment costs and related medical procedures.

Infectious Mononucleosis

Infectious mononucleosis is a clinical entity characterized by sore throat, cervical lymph node enlargement, fatigue, and fever most often seen in adolescents and young adults and lasting several weeks. It can be caused by a number of pathogens, but this chapter only discusses infectious mononucleosis due to primary Epstein-Barr virus (EBV) infection. EBV is a γ-herpesvirus that infects at least 90% of the population worldwide. The virus is spread by intimate oral contact among teenagers and young adults. How preadolescents acquire the virus is not known. A typical clinical picture with a positive heterophile test is usually sufficient to make the diagnosis, but heterophile antibodies are not specific and do not develop in some patients. EBV-specific antibody profiles are the best choice for staging EBV infection. In addition to causing acute illness, there can also be long-term consequences as the result of acquisition of the virus. Several EBV-related illnesses occur including certain cancers and autoimmune diseases, as well as complications of primary immunodeficiency in persons with the certain genetic mutations. A major obstacle to understanding these sequelae has been the lack of an efficient animal model for EBV infection, although progress in primate and mouse models has recently been made. Key future challenges are to develop protective vaccines and effective treatment regimens.

Profile of EBV associated infectious mononucleosis

During a 5 year period, 33 children (22 males) were diagnosed to have infectious mononucleosis (M:F::2:1; age 9 mo-15 y). The common clinical features observed were fever (100%), lymphadenopathy (84%) hepatosplenomegaly (81%), tonsillar enlargement (45%), neck swelling (30%), upper respiratory symptoms (21%), epitrochlear node enlargement (20%), vomiting and diarrhea (1%). Ten children had complications; upper airway obstruction and hemophagocytic lymphohistocytosis occurred in four each and septic shock in two. EBV associated infectious mononucleosis in hospitalized children was found to affect mainly preschool children and had a favorable prognosis.

Epstein-Barr virus infection as a cause of cervical lymphadenopathy in children

OBJECTIVE

Cervical lymphadenopathy is a common pediatric problem; reactive hyperplasia, specific infective agents, and malignancy are mainly the differential diagnosis. The aim of our study was to detect the prevalence of Epstein-Barr virus infection among children who complained of cervical lymphadenopathy and also to evaluate the clinical manifestations of the disease in pediatric patients.

METHODS

One hundred and sixty children presented with cervical lymphadenopathy were subjected to Epstein-Barr Virus (EBV) serology testing. Cases that showed positivity to heterophile antibody test, and/or EBV-specific antibodies; IgM against viral capsid antigen (VCA-IgM) and IgG against viral capsid antigen (VCA-IgG) were evaluated clinically for manifestations of the disease.

RESULTS

Twenty-four cases (15%) showed positivity to EBV serology, all of them had posterior cervical lymph nodes enlargement, 70.8% had fever, 66.6% had tonsillo-pharyngitis, 58.3% had splenomegaly, 25% had hepatomegaly, 41.6% had generalized lymphadenopathy, while skin rash was detected in 12.5%, and both palatal petechiae and palpebral edema were detected in 8.3%.

CONCLUSIONS

EBV infection is not a rare cause of cervical lymphadenopathy in children. Posterior cervical lymphadenopathy in pediatric age group may represent a password for suspicion of EBV infection, while other clinical manifestations of the disease may include hepato-splenomegaly, skin rash, palpebral edema and palatal petechiae.

Heterogeneity of immune defects in three children with a chronic active Epstein-Barr virus infection

Three children, all girls, showed long-lasting clinical and serologic evidence of chronic active Epstein-Barr virus (EBV) infection. Extremely high serum titers of IgG- and IgA-type VCA antibodies and EA antibodies were present, whereas EBNA antibody titers were in the range of those found in seropositive individuals. All three patients repeatedly showed the presence of nonspecific pokeweed mitogen (PWM)-activatable suppressor cells in the peripheral blood. The analysis of EBV-specific cytotoxic T cells showed that one patient exhibited normal cytotoxicity, whereas a second patient demonstrated no EBV-specific cytotoxicity together with unusually high levels of virus-infected B cells in the blood and lymph node. The third patient repeatedly showed refractoriness of the circulating B cells to EBV infection, probably on the basis of some developmental defect. It was concluded that each patient has his or her own peculiar defect in the virus-host balance, indicating that heterogeneity may underlie the syndrome of chronic active EBV infection in humans.

The association of extrahepatic bile duct atresia and neonatal Epstein-Barr virus infection

An infant with uncorrectable extrahepatic bile duct atresia was found to have evidence of Epstein-Barr virus infection during the neonatal period. It is probable that the infection was acquired in utero. In view of the association of hepatitis with the Epstein-Barr virus in later life, it is possible that this infection was responsible for the development of bile duct obstruction.

Infectious mononucleosis in Greenland: a disease of the non-indigenous population

Greenland Eskimos have one of the highest incidences of nasopharyngeal carcinoma (NPC) in the world. Asian and African areas endemic for NPC show early infection with Epstein-Barr virus (EBV), and few cases of infectious mononucleosis (IM). Among 40 000 Eskimos and 10 000 Caucasians in Greenland there were 82 reported cases of IM from 1963 to 1980. Incidence rates from 1975 to 1980, age adjusted to the "world" population distribution, were 12.0 and 5.2/100 000/yr for males and females, respectively. Comparable Danish data revealed incidence rates of 97.4 and 105.1. From 1970 to 1981 Greenland hospital records verified 16 cases, of which only 2 were in Eskimos. The IM incidence in Eskimos is extremely low, and Danes living in Greenland have a comparatively much higher incidence.