Epstein-Barr virus genome-positive T lymphocytes in a boy with chronic active EBV infection associated with Kawasaki-like disease

Coronary Artery Bypass Grafting for a Young Female Patient With Chronic Active Epstein-Barr Virus Infection

A 24-year-old woman with chronic active Epstein-Barr virus (CAEBV) infection successfully underwent coronary artery bypass grafting for triple coronary arteries with chronic total occlusion and aneurysms. This case underscores the importance of accurate assessment and treatment of coronary artery lesions in patients with CAEBV infection.

Emerging evidence of microbial infection in causing systematic immune vasculitis in Kawasaki disease

Kawasaki disease (KD) is a systematic vasculitis that is often complicated by coronary artery lesions and is a leading cause of acquired heart disease in developed countries. Previous studies have suggested that genetic susceptibility, together with an inducing infectious agent, could be involved in KD pathogenesis; however, the precise causative agent of this disease remains unknown. Moreover, there are still debates concerning whether KD is an infectious disease or an autoimmune disease, although many studies have begun to show that various pathogens functioning as critical inducers could activate different kinds of immune cells, consequently leading to the dysfunction of endothelial cells and systematic vasculitis. Here in this review, we attempt to summarize all the available evidence concerning pathogen infections associated with KD pathogenesis. We also discuss the related mechanisms, present a future perspective, and identify the open questions that remain to be investigated, thereby providing a comprehensive description of pathogen infections and their correlations with the host immune system in leading to KD.

Coronary artery dilation in children with febrile illnesses other than Kawasaki disease: A case report and literature review

Background

Coronary artery dilation (CAD) had rarely been described as a cardiac complication of febrile disease other than Kawasaki disease (KD). There are rare cases complicated by CAD reported in patients with Mycoplasma pneumoniae (MP) infection.

Case presentation

A 6-year-old boy with severe Mycoplasma pneumoniae pneumonia (MPP) was transferred to our hospital due to significant respiratory distress on the 11th day from disease onset. Nadroparin, levofloxacin, and methylprednisolone followed by oral prednisone were aggressively prescribed. His clinical condition gradually achieved remission, and the drugs were withdrawn on the 27th day. Regrettably, the recurrent fever attacked him again in the absence of infection-toxic manifestations. Necrotizing pneumonia (NP) was found on chest CT. And echocardiography revealed right CAD (diameter, 3.40mm; z-score, 3.8), however, his clinical and laboratory findings did not meet the diagnostic criteria of KD. CAD was proposed to result from MP infection, and aspirin was prescribed. Encouragingly, the CAD regressed one week later (diameter, 2.50mm; z-score, 1.4). Additionally, the child defervesced seven days after the initiation of prednisone and Nadroparin treatment. The patient was ultimately discharged home on the 50th day. During follow-up, the child was uneventful with normal echocardiography and fully resolved chest CT lung lesions.

Conclusions

CAD can develop in patients with severe MP infection. Pediatricians should be alert to the possibility of CAD in patients with severe MP infection and recognize that CAD might also develop in febrile disease rather than KD.

Possible Concomitant Aggressive NK Cell Leukemia and EBV-positive T-cell lymphoma; Using the online beta version of WHO-HAEM5 and videoconferencing software to make diagnoses accessible in an emerging economy

BACKGROUND

Using the World Health Organization Classification 5th edition (beta version online; WHO-HAEM5bv) in emerging economies is key to global healthcare equity. Although there may be ongoing updates, hesitancy in accepting and reporting these diagnoses in publication conflicts with the WHO's commitment to global accessibility. Aggressive NK cell leukemia (ANKL) and systemic EBV-positive T-cell lymphoma of childhood (SEBVTCL) with CD4-positive immunophenotype are both rare entities, are most described in Asians and East Asians, are associated with prior systemic chronic active EBV disease (CAEBV), and presentation with Hemophagocytic Lymphohistiocytosis (HLH). Recognizing and diagnosing any one of these entities requires not only training and experience in hematopathology, but good cooperation between clinical physicians and all areas of the laboratory. We describe a 30-year-old woman who presented to a Vietnam hospital and was rapidly diagnosed with ANKL, SEBVTCL, and HLH using WHO-HAEM5bv essential criteria, aided by expert consultation from a United States (US) board certified hematopathologist in real-time using video conferencing software.

METHODS

Zoom™ videoconferencing software; Immunohistochemistry; flow cytometric immunophenotyping; polymerase chain reaction (PCR), Next Generation Sequencing (NGS).

RESULTS

At the time of hospital admission, automated complete blood count (CBC) with differential count showed slight anemia, slight lymphocytosis, and moderate thrombocytopenia. HIV serology was negative. Whole blood PCR for EBV was positive showing 98,000 copies/ml. A lymph node biopsy revealed histology and immunohistochemistry consistent with the online beta version WHO-HAEM5 classification of SEBVTCL arising in CAEBV. Blood and bone marrow studies performed for staging revealed no histologic or immunohistochemical evidence of T-cell lymphoma in the bone marrow core, however, atypical blood smear lymphocyte morphology and blood immunophenotyping by flow cytometry were consistent with WHO-HAEM5 classification of ANKL. NGS revealed no evidence of genetic variant(s) associated with HLH in Vietnam. All laboratory studies were performed at Blood Transfusion Hematology Hospital (BTHH) in Ho Chi Minh City Vietnam.

CONCLUSION

Although Vietnam, an emerging economy, currently lacks the laboratory infrastructure to more rigorously confirm a rare synchronous presentation of two distinct EBV-driven T/NK cell neoplasms, these two concomitant diagnoses were made using only laboratory techniques available in Vietnam with the help of WHO-HAEM5bv and real-time video consultation by a US hematopathologist.

Epstein-Barr virus downregulates the α7 nicotinic acetylcholine receptor of CD8+ T lymphocytes might associate with coronary artery lesions in Kawasaki disease patients

OBJECTIVES

Kawasaki disease (KD) is a systemic vasculitis that is caused by immunological dysregulation in children exposed to pathogens like Epstein-Barr virus (EBV). Myocardial ischemia or infarction due to coronary artery lesions (CALs) might be lethal. However, it is unclear how pathogens, immunomodulation, and CALs interact, particularly in KD patients co-infected with the most widespread virus, EBV.

METHODS

We investigated pathogen carriage and fundamental clinical data in 281 KD patients. Immunological differences between CALs and non-CALs in KD patients under different conditions were analyzed. Then, the effect of infection by different pathogens on the immune response was excluded, and most EBV co-infected KD patients were included to assess the incidence of CALs, the level of immune modulation, and regulatory mechanisms in different EBV infection states.

RESULTS

Our results showed multiple pathogenic infections occur in KD patients, with EBV being the most prevalent. The incidence of CALs in the EBV-DNA (+) acute infection group, EBV-DNA (-) acute infection group, and EBV latent infection group was 0 (0/6), 27.27% (3/11) and 41.67% (10/24), respectively. The two groups were younger and had increased IL-6 levels and B cells, decreasing CD8+ T cells than the EBV-DNA (+) acute infection group. Interestingly, the increased B cells were not associated with immunoglobulin release. Additionally, these patients down-regulated α7 nicotinic acetylcholine receptor (α7nAChR) and downstream molecule PI3K/AKT/mTOR while activating the NF-κB.

CONCLUSION

Patients with different EBV infection statuses exhibit different incidences of CALs. In acute EBV-DNA (-) infected and latent EBV-infected patients, the number of CD8+ T cells decreased and downregulated CD8+ T cells' α7nAChR and PI3K/AKT/mTOR, which may associate with CALs, while the expression of NF-κB and the pro-inflammatory factor IL-6 was upregulated by inhibiting the anti-inflammatory molecule α7nAChR.

Phenomapping approach to interpreting coronary dimensions in febrile children

Importance

Coronary artery dilation may occur in febrile children with and without Kawasaki disease (KD).

Objective

We explored the application of unsupervised learning algorithms in the detection of novel patterns of coronary artery phenotypes in febrile children with and without KD.

Methods

A total of 239 febrile children (59 non-KD and 180 KD patients), were recruited. Unsupervised hierarchical clustering analysis of phenotypic data including age, hemoglobin, white cell count, platelet count, C-reactive protein, erythrocyte sedimentation rate, albumin, alanine aminotransferase, aspartate aminotransferase, and coronary artery z scores were performed.

Results

Using a cutoff z score of 2.5, the specificity was 98.3% and the sensitivity was 22.1% for differentiating non-KD from KD patients. Clustering analysis identified three phenogroups that differed in a clinical, laboratory, and echocardiographic parameters. Compared with phenogroup I, phenogroup III had the highest prevalence of KD (91%), worse inflammatory markers, more deranged liver function, higher coronary artery z scores, and lower hematocrit and albumin levels. Abnormal blood parameters in febrile children with z scores of coronary artery segments <0.5 and 0.5-1.5 was associated with increased risks of having KD to 8.7 (P = 0.003) and 4.4 (P = 0.002), respectively.

Interpretation

Phenomapping of febrile children with and without KD identified useful laboratory parameters that aid the diagnosis of KD in febrile children with relatively normal-sized coronary arteries.

Coronary Artery Z-scores in Febrile Children with Suspected Kawasaki's Disease-The Value of Serial Echocardiography

BACKGROUND

 Progressive enlargement of the coronary artery (CA) diameters on serial echocardiography can support diagnosis of Kawasaki's disease (KD) even CA dimensions are within the normal range.

METHODS

 A single-center, retrospective study compared mean Z-scores of the proximal CA internal diameters in children hospitalized with non-KD febrile illnesses (FCs) with those of KD patients.

RESULTS

 A total of 223 patients with suspicion of KD have been admitted over a period of 16 years and data were evaluable for 176 children. Distributions for age, sex, and body surface area were similar for both groups. FC had a significantly shorter duration of hospitalization, higher levels of hemoglobin, lower levels of liver transaminases, and segmented neutrophils, respectively. The majority of FC patients (75/82, 91.5%) had normal CA Z-scores (p < 0.001) and only 3 (3.7%) had CA Z-score ≥2.5 standard deviation (SD). In KD, subjects (46/94, 49.5%) had a CA dilation (Z-score ≥2.5 SD) and the maximum CA Z-score (Zmax) was significantly higher compared with FC patients (p < 0.001). On serial echocardiograms, FC patients showed a mild decrease, whereas KD patients developed a significant increase of CA Zmax (p < 0.001). Seven KD patients had a segmental dilation of a CA which has been confirmed by cardiac catheter. In FC, no segmental dilation of any CA was documented by echocardiography.

CONCLUSION

 This study found that mean CA dimensions in FCs were smaller and did not increase in serial echocardiograms compared with KD patients.

The NHLBI Study on Long-terM OUtcomes after the Multisystem Inflammatory Syndrome In Children (MUSIC): Design and Objectives

BACKGROUND

The Long-terM OUtcomes after the Multisystem Inflammatory Syndrome In Children (MUSIC) study aims to characterize the frequency and time course of acute and long-term cardiac and non-cardiac sequelae in multisystem inflammatory syndrome in children associated with COVID-19 (MIS-C), which are currently poorly understood.

METHODS

This multicenter observational cohort study will enroll at least 600 patients <21 years old who meet the Centers for Disease Control and Prevention case definition of MIS-C across multiple North American centers over 2 years. The study will collect detailed hospital and follow-up data for up to 5 years, and optional genetic testing. Cardiac imaging at specific time points includes standardized echocardiographic assessment (all participants) and cardiac magnetic resonance imaging (CMR) in those with left ventricular ejection fraction (LVEF) <45% during the acute illness. The primary outcomes are the worst LVEF and the highest coronary artery z-score of the left anterior descending or right coronary artery. Other outcomes include occurrence and course of non-cardiac organ dysfunction, inflammation, and major medical events. Independent adjudication of cases will classify participants as definite, possible, or not MIS-C. Analysis of the outcomes will include descriptive statistics and regression analysis with stratification by definite or possible MIS-C. The MUSIC study will provide phenotypic data to support basic and translational research studies.

CONCLUSION

The MUSIC study, with the largest cohort of MIS-C patients and the longest follow-up period to date, will make an important contribution to our understanding of the acute cardiac and non-cardiac manifestations of MIS-C and the long-term effects of this public health emergency.

Coronary artery aneurysms in children is not always Kawasaki disease: a case report on Takayasu arteritis

Background

Coronary artery (CA) aneurysms in children are a rare but potentially life-threatening finding and are highly associated with Kawasaki disease (KD).

Case presentation

We describe a four-year-old female with a vasculitis and CA aneurysms. She had a prolonged course with recurrent fever and systemic inflammation several times upon discontinuation of steroid treatment. Due in part to the CA aneurysms, she initially was diagnosed with KD but due to the unusual clinical course, further evaluation was performed. Abdominal and chest MRI/A revealed diffuse aortitis suggestive of a large vessel vasculitis, specifically Takayasu arteritis. With treatment targeted for Takayasu arteritis, there was resolution of fever and inflammation and the CA aneurysms improved.

Conclusions

This case demonstrates the utility in broadening the differential diagnosis in cases of presumed KD with CA involvement in which the clinical course is atypical for KD.

A Pediatric Case Report of Epstein-Barr Virus-associated Hemophagocytic Lymphohistiocytosis With Pericardial Effusion and Multiple Coronary Artery Aneurysms

Pediatric coronary artery aneurysms (CAAs) are mainly detected in Kawasaki disease and in chronic active Epstein-Barr virus (EBV) infection sometimes, and cardiac complications are rare in viral-associated hemophagocytic lymphohistiocytosis (HLH) patients. Here, we report a pediatric case of EBV-associated HLH with pericardial effusion and multiple CAAs, whereas the patient did not fulfill the diagnostic criteria of Kawasaki disease or chronic active EBV. The case indicates that CAAs may occur in EBV-HLH. Specifically, in a patient with a long-term fever and a high EBV DNA copy number, the detection of cardiac complications may help signal the possible occurrence of HLH, and CAAs may affect the prognosis for high risk of cardiac events.

Case Report: Pediatric Chronic Active Epstein-Barr Virus Infection With Giant Sinus of Valsalva Aneurysms and Aorta and Its Branch Dilations

Chronic active Epstein-Barr virus infection (CAEBV), which often manifests as persistent infectious mononucleosis-like symptoms and can involve multiple organs, is a prolonged or reactivated status of primary EBV infection. Cardiovascular damage is one of the rare but severe complications correlated with poor prognosis among all CAEBV patients. Few published articles have demonstrated systemic arterial lesions involving branches of the aorta as cardiovascular complications. Herein, we report a rare pediatric case of CAEBV associated with giant sinus of Valsalva aneurysms and aorta and its branch dilations.

Perspective of Immunopathogenesis and Immunotherapies for Kawasaki Disease

Kawasaki Disease (KD) is an acute inflammatory illness that mostly occurs in children below 5 years of age, with intractable fever, mucocutaneous lesions, lymphadenopathy, and lesions of the coronary artery (CAL). KD is sharing clinical symptoms with systemic inflammatory syndrome in children (MIS-C) which is related to COVID-19. Certain genes are identified to be associated with KD, but the findings usually differ between countries and races. Human Leukocyte Antigen (HLA) allele types and toll-like receptor (TLR) expression are also correlated to KD. The acute hyperinflammation in KD is mediated by an imbalance between augmented T helper 17 (Th17)/Th1 responses with high levels of interleukin (IL)-6, IL-10, IL-17A, IFN-γ, and IP-10, in contrast to reduced Th2/Treg responses with lower IL-4, IL-5, FoxP3, and TGF-β expression. KD has varying phenotypic variations regarding age, gender, intravenous immunoglobulin (IVIG) resistance, macrophage activation and shock syndrome. The signs of macrophage activation syndrome (MAS) can be interpreted as hyperferritinemia and thrombocytopenia contradictory to thrombocytosis in typical KD; the signs of KD with shock syndrome (KDSS) can be interpreted as overproduction of nitric oxide (NO) and coagulopathy. For over five decades, IVIG and aspirin are the standard treatment for KD. However, some KD patients are refractory to IVIG required additional medications against inflammation. Further studies are proposed to delineate the immunopathogenesis of IVIG-resistance and KDSS, to identify high risk patients with genetic susceptibility, and to develop an ideal treatment regimen, such as by providing idiotypic immunoglobulins to curb cytokine storms, NO overproduction, and the epigenetic induction of Treg function.

Chronic Active Epstein-Barr Virus Infection: Is It Immunodeficiency, Malignancy, or Both?

Simple Summary

Chronic active Epstein–Barr virus (EBV) infection (CAEBV) is a rare syndrome of unknown etiology characterized by prolonged infectious mononucleosis-like symptoms and proliferation of EBV-infected T and/or natural killer cells. CAEBV has been primarily reported in East Asia and Latin America, suggesting a genetic predisposition in its pathogenesis. The clinical course of CAEBV is heterogeneous ranging from an indolent and occasionally self-limiting disease to an aggressive and fatal condition, but its prognosis is generally poor. This heterogeneous clinical picture does not suggest a simple etiology for the syndrome. Clinicopathological investigations of CAEBV suggest that it has aspects of both malignant neoplasm and immunodeficiency. This article summarizes the latest findings on CAEBV and discusses critical unsolved questions regarding its pathogenesis and disease concept.

Abstract

Chronic active Epstein–Barr virus (EBV) infection (CAEBV) is a rare syndrome characterized by prolonged infectious mononucleosis-like symptoms and elevated peripheral blood EBV DNA load in apparently immunocompetent persons. CAEBV has been primarily reported in East Asia and Latin America, suggesting a genetic predisposition in its pathogenesis. In most cases of CAEBV, EBV induces proliferation of its unusual host cells, T or natural killer (NK) cells. The clinical course of CAEBV is heterogeneous; some patients show an indolent course, remaining in a stable condition for years, whereas others show an aggressive course with a fatal outcome due to hemophagocytic lymphohistiocytosis, multiple organ failure, or progression to leukemia/lymphoma. The pathogenesis of CAEBV is unclear and clinicopathological investigations suggest that it has aspects of both malignant neoplasm and immunodeficiency. Recent genetic analyses of both viral and host genomes in CAEBV patients have led to discoveries that are improving our understanding of the nature of this syndrome. This article summarizes the latest findings on CAEBV and discusses critical unsolved questions regarding its pathogenesis and disease concept.

Chronic active Epstein-Barr virus infection manifesting as coronary artery aneurysm and uveitis

Background

Chronic active Epstein–Barr virus (CAEBV) infection is a type of lymphoproliferative disorder characterized by chronic or recurrent infectious mononucleosis (IM)-like symptoms, which can have less-frequent clinical presentations. The prognosis of CAEBV is poor, and hematopoietic stem cell transplantation (HSCT) has been shown to be the only potentially effective treatment. In this article, we present a special CAEBV case of a patient who had no typical IM-like symptoms at the early stage, but manifested with severe and progressive coronary artery aneurysm (CAA), abdominal aortic lesions, and severe uveitis. These manifestations were uncommon features and could only be blocked by HSCT.

Case presentation

A 4-year-old girl with no special medical history complained of decreased vision for 10 months and cough after physical activities for three months. The blurred vision grew rapidly worse within one month, until only light perception remained. She was diagnosed with uveitis and cataract, and received prednisone and ciclosporin A treatment. However, her vision did not improve. Physical examination showed slight hepatosplenomegaly. Ultrasonic cardiogram showed bilateral CAA (5.0 mm and 5.7 mm for inner diameters), and abdominal CT scan revealed a thickened aortic wall, as well as stenosis and dilation of the segmental abdominal aorta. Other significant findings were increased EBV-DNA (3.29 × 10⁴ copies/mL) from peripheral blood, positive EBV antibodies (EBV-CA-IgG, EBV-EA-IgA, and EBV-NA-IgG), and positive EBV-encoded small RNAs found by bone marrow biopsy. Based on her clinical manifestations and evidence for EBV infection, we diagnosed CAEBV. She received allogeneic HSCT, and the cataract operation was performed after HSCT. EBV-DNA could not be detected in peripheral blood after HSCT. Her CAAs did not progress, and uveitis was well controlled. Her vision recovered gradually over the 3 years after HSCT.

Conclusions

We present a rare CAEBV case of a patient who suffered from uncommon and severe cardiovascular and ocular involvement that was relieved by HSCT. Therefore, early recognition and diagnosis of CAEBV are of vital importance to improve its prognosis. In summary, this atypical CAEBV case could help us recognize similar cases more easily, make the right diagnosis as early as possible, and deliver proper and timely treatment.

Nationwide survey of systemic chronic active EBV infection in Japan in accordance with the new WHO classification

Systemic chronic active Epstein-Barr virus infection (sCAEBV) was defined as a T- or NK-cell neoplasm in the 2017 World Health Organization (WHO) classification. To clarify the clinical features of sCAEBV under this classification and review the effects of chemotherapy, we performed a nationwide survey in Japan from 2016 through 2018 of patients with sCAEBV newly diagnosed from January 2003 through March 2016. One hundred cases were evaluated. The patients were aged 1 to 78 years (median, 21) and included 53 males and 47 females. Spontaneous regression was not observed in patients with active disease. In the childhood-onset group (age, <9 years), 78% of the patients were male. In contrast, 85% of the patients in the elderly-onset group (age, >45 years) were female. The prognosis of the childhood-onset group was better than those of the adolescent/adult- and elderly-onset groups. The main chemotherapies used were a combination of cyclosporine A, steroids, and etoposide (cooling therapy) in 52 cases and cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) in 45 cases. The rate of complete response (CR), defined as complete resolution of disease activity, was 17% for cooling therapy and 13% for CHOP. Virological CR was not observed. The 3-year overall survival rates in patients treated with chemotherapy only (n = 20), chemotherapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT; n = 47), and allo-HSCT only (n = 12) were 0%, 65%, and 82%, respectively. Distinct characteristics were observed between childhood- and elderly-onset sCAEBV, and they appeared to be different disorders. Chemotherapy is currently insufficient to resolve disease activity and eradicate infected cells. The development of an effective treatment is urgently needed.

Kawasaki disease: pathophysiology and insights from mouse models

Kawasaki disease is an acute febrile illness and systemic vasculitis of unknown aetiology that predominantly afflicts young children, causes coronary artery aneurysms and can result in long-term cardiovascular sequelae. Kawasaki disease is the leading cause of acquired heart disease among children in the USA. Coronary artery aneurysms develop in some untreated children with Kawasaki disease, leading to ischaemic heart disease and myocardial infarction. Although intravenous immunoglobulin (IVIG) treatment reduces the risk of development of coronary artery aneurysms, some children have IVIG-resistant Kawasaki disease and are at increased risk of developing coronary artery damage. In addition, the lack of specific diagnostic tests and biomarkers for Kawasaki disease make early diagnosis and treatment challenging. The use of experimental mouse models of Kawasaki disease vasculitis has considerably improved our understanding of the pathology of the disease and helped characterize the cellular and molecular immune mechanisms contributing to cardiovascular complications, in turn leading to the development of innovative therapeutic approaches. Here, we outline the pathophysiology of Kawasaki disease and summarize and discuss the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

This Review outlines the pathophysiology of Kawasaki disease and discusses the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

Kawasaki disease is a childhood systemic vasculitis leading to the development of coronary artery aneurysms; it is the leading cause of acquired heart disease in children in developed countries.

The cause of Kawasaki disease is unknown, although it is suspected to be triggered by an unidentified infectious pathogen in genetically predisposed children.

Kawasaki disease might not be a normal immune response to an unusual environmental stimulus, but rather a genetically determined unusual and uncontrolled immune response to a common stimulus.

Although the aetiological agent in humans is unknown, mouse models of Kawasaki disease vasculitis demonstrate similar pathological features and have substantially accelerated discoveries in the field.

Genetic and transcriptomic analysis of blood samples from patients with Kawasaki disease and experimental evidence generated using mouse models have demonstrated the critical role of IL-1β in the pathogenesis of this disease and the therapeutic potential of targeting this pathway (currently under investigation in clinical trials).

Role of Viral and Host microRNAs in Immune Regulation of Epstein-Barr Virus-Associated Diseases

Epstein-Barr virus (EBV) is an oncogenic human herpes virus that was discovered in 1964. Viral non-coding RNAs, such as BamHI-A rightward fragment-derived microRNAs (BART miRNAs) or BamHI-H rightward fragment 1-derived miRNAs (BHRF1 miRNA) in EBV-infected cells have been recently reported. Host miRNAs are also upregulated upon EBV infection. Viral and host miRNAs are important in maintaining viral infection and evasion of host immunity. Although miRNAs in EBV-infected cells often promote cell proliferation by targeting apoptosis or cell cycle, this review focuses on the regulation of the recognition of the host immune system. This review firstly describes the location and organization of two clusters of viral miRNAs, then describes evasion from host immune surveillance systems by modulating viral gene expression or inhibiting innate and acquired immunity by viral miRNAs as well as host miRNAs. Another topic is the enigmatic depletion of viral miRNAs in several types of EBV-infected tumor cells. Finally, this review introduces the strong correlation of nasopharyngeal cancer cases with a newly identified single nucleotide polymorphism that enhances BART miRNA promoter activity.

Epstein - Barr virus positive T and NK-cell lymphoproliferations: Morphological features and differential diagnosis

The spectrum of Epstein-Barr virus (EBV)-positive T and NK-cell lymphoproliferations is broad and ranges from reactive self-limited disorders to neoplastic processes with a fulminant clinical course. EBV plays an important role promoting lymphomagenesis, although the precise mechanisms remain elusive. EBV-positive lymphoproliferative disorders (LPD) are more common in East Asia (China, Japan, Korea and Taiwan), and Latin America suggesting a strong genetic predisposition. The revised 2016 World Health Organization (WHO) lymphoma classification recognizes the following malignant NK- and T-cell lymphomas; extranodal NK/T-cell lymphoma, nasal type (ENKTCL), aggressive NK-cell leukemia (ANKL), and the provisional entity within the group of peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) "primary EBV-positive nodal T or NK cell lymphoma". Disorders presenting mainly in children and young adults include chronic active EBV infection (CAEBV) - systemic and cutaneous forms - which are not considered malignant disorders but were included in the WHO classification for the first time because of the differential diagnosis with other T- or NK-cell lymphomas. CAEBV, cutaneous form, includes hydroa vacciniforme-like LPD (HV-LPD) and severe mosquito bite allergy (SMBA). Finally, systemic EBV-positive T-cell lymphoma of childhood was recognized as lymphoma because of its fulminant clinical course. Given the shared pathogenesis of these disorders, overlapping features are common demanding a close clinical, morphological and molecular correlation for an accurate diagnosis. This review summarizes the clinical, histopathological and molecular features of EBV-associated T and NK-cell LPD, highlighting the main features that might aid in the differential diagnosis.

The Global Landscape of EBV-Associated Tumors

Epstein-Barr virus (EBV), a gamma-1 herpesvirus, is carried as a life-long asymptomatic infection by the great majority of individuals in all human populations. Yet this seemingly innocent virus is aetiologically linked to two pre-malignant lymphoproliferative diseases (LPDs) and up to nine distinct human tumors; collectively these have a huge global impact, being responsible for some 200,000 new cases of cancer arising worldwide each year. EBV replicates in oral epithelium but persists as a latent infection within the B cell system and several of its diseases are indeed of B cell origin; these include B-LPD of the immunocompromised, Hodgkin Lymphoma (HL), Burkitt Lymphoma (BL), Diffuse Large B cell Lymphoma (DLBCL) and two rarer tumors associated with profound immune impairment, plasmablastic lymphoma (PBL) and primary effusion lymphoma (PEL). Surprisingly, the virus is also linked to tumors arising in other cellular niches which, rather than being essential reservoirs of virus persistence in vivo, appear to represent rare cul-de-sacs of latent infection. These non-B cell tumors include LPDs and malignant lymphomas of T or NK cells, nasopharyngeal carcinoma (NPC) and gastric carcinoma of epithelial origin, and leiomyosarcoma, a rare smooth muscle cell tumor of the immunocompromised. Here we describe the main characteristics of these tumors, their distinct epidemiologies, histological features and degrees of EBV association, then consider how their different patterns of EBV latency may reflect the alternative latency programmes through which the virus first colonizes and then persists in immunocompetent host. For each tumor, we discuss current understanding of EBV's role in the oncogenic process, the identity (where known) of host genetic and environmental factors predisposing tumor development, and the recent evidence from cancer genomics identifying somatic changes that either complement or in some cases replace the contribution of the virus. Thereafter we look for possible connections between the pathogenesis of these apparently different malignancies and point to new research areas where insights may be gained.

Coronary artery dilation associated with anti-synthetase syndrome in an adolescent

BACKGROUND

Idiopathic inflammatory myopathies (IIM) are a group of systemic autoimmune disorders primarily affecting skeletal muscle. Pediatric coronary artery dilation is frequently discussed in Kawasaki disease. However, it has yet to be reported in the IIMs or antisynthetase syndrome. We report a unique case of a patient with IIM, antisynthetase syndrome and coronary artery dilation.

CASE PRESENTATION

We report an adolescent presenting with joint symptoms, fever, and eye swelling with a clinical diagnosis of Juvenile Dermatomyositis. He subsequently developed diastolic hypotension with evidence of coronary artery dilation. He received steroids and immunoglobulin and followed by immunosuppressants with mild improvement in his symptoms. The adolescent later developed dyspnea and cough with CT lungs evident for cystic changes; lung biopsy showed interstitial fibrosis and inflammation, and muscle biopsy was abnormal as well. The anti-pl-12 antibody was positive. Following several weeks of treatment, an echocardiogram showed improvement in coronary artery dilation. His joint symptoms, muscle strength and respiratory symptoms have also improved.

CONCLUSIONS

Coronary artery dilation is not well understood in IIMs or antisynthetase syndrome. Pathobiology of coronary artery involvement, its treatment and prognosis, and association with IIM and antisynthetase syndrome needs further exploration.

Aetiological Significance of Infectious Stimuli in Kawasaki Disease

Kawasaki disease (KD) is a pediatric vasculitis syndrome that is often involves coronary artery lesions (e. g., coronary artery aneurysms). Although its causal factors and entire pathogenesis remain elusive, the available evidence indicates that the pathogenesis of KD is closely associated with dysregulation of immune responses to various viruses or microbes. In this short review, we address several essential aspects of the etiology of KD with respect to the immune response to infectious stimuli: 1) the role of viral infections, 2) the role of bacterial infections and the superantigen hypothesis, 3) involvement of innate immune response including pathogens/microbe-associated molecular patterns and complement pathways, and 4) the influence of genetic background on the response to infectious stimuli. Based on the clinical and experimental evidence, we discuss the possibility that a wide range of microbes and viruses could cause KD through common and distinct immune processes.

Kawasaki disease: guidelines of the Italian Society of Pediatrics, part I - definition, epidemiology, etiopathogenesis, clinical expression and management of the acute phase

The primary purpose of these practical guidelines related to Kawasaki disease (KD) is to contribute to prompt diagnosis and appropriate treatment on the basis of different specialists’ contributions in the field. A set of 40 recommendations is provided, divided in two parts: the first describes the definition of KD, its epidemiology, etiopathogenetic hints, presentation, clinical course and general management, including treatment of the acute phase, through specific 23 recommendations.

Their application is aimed at improving the rate of treatment with intravenous immunoglobulin and the overall potential development of coronary artery abnormalities in KD. Guidelines, however, should not be considered a norm that limits treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient’s condition, and disease severity or complications.

An Efficient and Simple Method to Establish NK and T Cell Lines from Patients with Chronic Active Epstein-Barr Virus Infection

A number of methods have been described to establish NK/T cell lines from patients with lymphoma or lymphoproliferative syndrome. These methods employed feeder cells, purified NK or T cells with as much as 10 mL of blood, or a high-dose of IL-2. This study presents a new method with a powerful and simple strategy to establish NK and T cell lines by culturing the peripheral blood mononuclear cells (PBMC) with the addition of recombinant human IL-2 (rhIL-2), and uses as little as 2 mL of whole blood. The cells can proliferate quickly in two weeks and be maintained for more than 3 months. With this method, 7 NK or T cell lines have been established with a high success rate. This method is simple, reliable, and applicable to establishing cell lines from more cases of CAEBV or NK/T cell lymphoma.

EBV in T-/NK-Cell Tumorigenesis

Epstein-Barr virus (EBV), which is associated with B-cell proliferative disorders, also transforms T- or natural killer (NK)-lineage cells and has been connected with various T- or NK (T/NK)-cell malignancies, such as extranodal NK/T-cell lymphoma-nasal type and aggressive NK-cell leukemia. Chronic active EBV (CAEBV) disease , which occurs most often in children and young adults in East Asia, is an EBV-associated T-/NK-cell lymphoproliferative disease. Patients with CAEBV often progress to overt lymphoma or leukemia over a long-term clinical course. EBV's transforming capacity in B cells is well characterized, but the molecular pathogenesis of clonal expansion caused by EBV in T/NK cells has not yet been clarified. In the primary infection, EBV infects B cells and epithelial cells and may also infect some T/NK cells. In some individuals, because of poor presentation by specific human leukocyte antigens or the genetic background, EBV-infected T/NK cells evade host immunity and survive. Occasionally, with the help of viral oncogenes, EBV-associated T/NK lymphoproliferative diseases, such as CAEBV, may develop. The subsequent accumulation of genetic mutations and/or epigenetic modifications in driver genes, such as DDX3X and TP53, may lead to overt lymphoma and leukemia. Activation-induced cytidine deaminase and the APOBEC3 family, driven by EBV infection, may induce chromosomal recombination and somatic mutations.

Hematopoietic Stem Cell Transplantation for the Treatment of Epstein-Barr Virus-Associated T- or NK-Cell Lymphoproliferative Diseases and Associated Disorders

Chronic active Epstein-Barr virus infection (CAEBV) is a prototype of EBV-associated T- and/or NK-cell (EBV⁺ T/NK-cell) lymphoproliferative disorders. Most subtypes of these are lethal. We established a unified treatment strategy composed of step 1 (immunochemotherapy: steroids, cyclosporine A, and etoposide), step 2 (multi-drug block chemotherapy), and step 3 (allogeneic hematopoietic stem cell transplantation; HSCT) for CAEBV and its related diseases. Allogeneic HSCT is the only cure for CAEBV with few exceptions. Primary-EBV infection-associated hemophagocytic lymphohistiocytosis (primary-EBV HLH) is also an EBV⁺ T/NK-cell lymphoproliferation. The nature of EBV⁺ T/NK cells in CAEBV and those in primary-EBV HLH differ. In primary-EBV HLH, most patients need step 1 only and some require step 2 for the successful induction of apoptosis in EBV-infected T cells; however, some exceptional patients require HSCT. We herein present our single institutional experience of CAEBV and primary-EBV HLH, together with that of post-transplant EBV⁺ T/NK-cell lymphoproliferative disease. We also discuss some practical points on HCST with a review of the literature.

A distinct subtype of Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorder: adult patients with chronic active Epstein-Barr virus infection-like features

The characteristics of adult patients with chronic active Epstein-Barr virus infection are poorly recognized, hindering early diagnosis and an improved prognosis. We studied 54 patients with adult-onset chronic active Epstein-Barr virus infection diagnosed between 2005 and 2015. Adult onset was defined as an estimated age of onset of 15 years or older. To characterize the clinical features of these adults, we compared them to those of 75 pediatric cases (estimated age of onset <15 years). We compared the prognosis of adult-onset chronic active Epstein-Barr virus infection with that of patients with nasal-type (n=37) and non-nasal-type (n=45) extranodal NK/T-cell lymphoma. The median estimated age of onset of these lymphomas was 39 years (range, 16–86 years). Compared to patients with pediatric-onset disease, those in whom the chronic active Epstein-Barr virus infection developed in adulthood had a significantly decreased incidence of fever (P=0.005), but greater frequency of skin lesions (P<0.001). Moreover, hypersensitivity to mosquito bites and the occurrence of hydroa vacciniforme were less frequent in patients with adult-onset disease (P<0.001 and P=0.0238, respectively). Thrombocytopenia, high Epstein-Barr virus nuclear antigen antibody titer, and the presence of hemophagocytic syndrome were associated with a poor prognosis (P=0.0087, P=0.0236, and P=0.0149, respectively). Allogeneic hematopoietic stem cell transplantation may improve survival (P=0.0289). Compared to pediatric-onset chronic active Epstein-Barr virus infection and extranodal NK/T-cell lymphoma, adult-onset chronic active Epstein-Barr virus infection had a poorer prognosis (P<0.001 and P=0.0484, respectively). Chronic active Epstein-Barr virus infection can develop in a wide age range, with clinical differences between adult-onset and pediatric-onset disease. Adult-onset chronic active Epstein-Barr virus infection is a disease with a poor prognosis. Further research will be needed.

Importance of anatomical dominance in the evaluation of coronary dilatation in Kawasaki disease

Introduction In Kawasaki disease, although coronary dilatation is attributed to vasculitis, the effect of myocardial inflammation is underestimated. Coronary dilatations are determined by Z-scores, which do not take into account dominance. The aim of the present study was to describe the impact of coronary dominance on dilatation in Kawasaki disease.

METHODS

We performed a retrospective analysis of coronary dilatations according to angiography categorisation of dominance.

RESULTS

Of 28 patients (2.6 [0.2-10.1] years), right dominance was present in 15 patients and left in 13. Early dilatation was present in all patients, of whom 11 were ipsilateral to the dominant segment and 17 contralateral. Ipsilateral dilatations were present at diagnosis (9/11 versus 6/17, p=0.02) compared with contralateral dilatations, which developed 2 weeks after diagnosis (9/11 versus 16/17, p=0.29). Coronary artery Z-scores of patients with contralateral dilatation increased at 2 weeks, before returning to baseline values (2.0±2.2 at diagnosis, 4.1±1.8 at 2 weeks, 1.8±1.2 at 3-6 months, p=0.001), compared with patients with ipsilateral dilatation in whom Z-scores were maximal at diagnosis and remained stable (3.0±0.9, 2.7±1.1 and 2.6±1.5, respectively, p=0.13). Dominant coronary artery Z-scores were higher compared with non-dominant segments at diagnosis (3.0±0.9 versus 1.0±0.8, p<0.001) and at late follow-up (2.6±1.5 versus 0.4±1.4, p=0.002) in patients with ipsilateral dilatation.

CONCLUSION

Progression of coronary dilatation after diagnosis may be a sign of dilatation secondary to vasculitis, as opposed to regression of Z-scores in ipsilateral dilatations, probably related to physiological vasodilatation in response to carditis. This needs to be validated in larger studies against vasculitic and myocardial inflammatory markers.

How we treat chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus infection (CAEBV) is a prototype of the EBV-associated T- or NK-cell lymphoproliferative diseases, which also include hypersensitivity to mosquito bites and severe-type hydroavacciniforme. The manifestations of CAEBV are often self-limiting with minimum supportive care or only prednisolone and cyclosporine A with or without etoposide. However, allogeneic hematopoietic stem cell transplantation (HSCT) is the only cure, without which patients with CAEBV die within several years. A severe hypercytokinemia and hemophagocytic syndrome, which may occur suddenly, often results in a fatal clinical course. At out institute, we have established a 3-step strategy, including allogeneic HSCT, for the treatment of CAEBV. Seventy-nine patients with CAEBV and related diseases have been treated to date. The 3-year overall survival rate (3y-OS) is currently 87.3 ± 4.2% after planned allogeneic HSCT. However, 3y-OS in patients with uncontrolled active disease is only 16.7 ± 10.8%. To maximize survival rates with minimized late sequelae, we recommend earlier initiation and completion of the 3-step treatment without watchful waiting. We present six illustrative and difficult cases (including severe hypercytokinemia or emergent HSCT) and discuss them together with 73 residual cases.

Transcriptional Analysis of Intravenous Immunoglobulin Resistance in Kawasaki Disease Using an Induced Pluripotent Stem Cell Disease Model

BACKGROUND

Approximately 10-20% of Kawasaki disease (KD) patients are resistant to intravenous immunoglobulin (IVIG) treatment. Further, these patients are at a particularly high risk of having coronary artery abnormalities. The mechanisms of IVIG resistance in KD have been analyzed using patient leukocytes, but not patient vascular endothelial cells (ECs). The present study clarifies the mechanisms of IVIG resistance in KD using an induced pluripotent stem cell (iPSC) disease model.

METHODS AND RESULTS

Dermal fibroblasts or peripheral blood mononuclear cells from 2 IVIG-resistant and 2 IVIG-responsive KD patients were reprogrammed by the episomal vector-mediated transduction of 6 reprogramming factors. KD patient-derived iPSCs were differentiated into ECs (iPSC-ECs). The gene expression profiles of iPSC-ECs generated from IVIG-resistant and IVIG-responsive KD patients were compared by RNA-sequencing analyses. We found that the expression ofCXCL12was significantly upregulated in iPSC-ECs from IVIG-resistant KD patients. Additionally, Gene Set Enrichment Analysis (GSEA) revealed that gene sets involved in interleukin (IL)-6 signaling were also upregulated.

CONCLUSIONS

The first iPSC-based model for KD is reported here. Our mechanistic analyses suggest thatCXCL12, which plays a role in leukocyte transmigration, is a key molecule candidate for IVIG resistance and KD severity. They also indicate that an upregulation of IL-6-related genes may be involved in this pathogenesis.

Epstein-Barr virus: more than 50 years old and still providing surprises

It is more than 50 years since the Epstein-Barr virus (EBV), the first human tumour virus, was discovered. EBV has subsequently been found to be associated with a diverse range of tumours of both lymphoid and epithelial origin. Progress in the molecular analysis of EBV has revealed fundamental mechanisms of more general relevance to the oncogenic process. This Timeline article highlights key milestones in the 50-year history of EBV and discusses how this virus provides a paradigm for exploiting insights at the molecular level in the diagnosis, treatment and prevention of cancer.

The Epstein-Barr Virus (EBV) in T Cell and NK Cell Lymphomas: Time for a Reassessment

While Epstein-Barr virus (EBV) was initially discovered and characterized as an oncogenic virus in B cell neoplasms, it also plays a complex and multifaceted role in T/NK cell lymphomas. In B cell lymphomas, EBV-encoded proteins have been shown to directly promote immortalization and proliferation through stimulation of the NF-κB pathway and increased expression of anti-apoptotic genes. In the context of mature T/NK lymphomas (MTNKL), with the possible exception on extranodal NK/T cell lymphoma (ENKTL), the virus likely plays a more diverse and nuanced role. EBV has been shown to shape the tumor microenvironment by promoting Th2-skewed T cell responses and by increasing the expression of the immune checkpoint ligand PD-L1. The type of cell infected, the amount of plasma EBV DNA, and the degree of viral lytic replication have all been proposed to have prognostic value in T/NK cell lymphomas. Latency patterns of EBV infection have been defined using EBV-infected B cell models and have not been definitively established in T/NK cell lymphomas. Identifying the expression profile of EBV lytic proteins could allow for individualized therapy with the use of antiviral medications. More work needs to be done to determine whether EBV-associated MTNKL have distinct biological and clinical features, which can be leveraged for risk stratification, disease monitoring, and therapeutic purposes.

Early diagnosis and follow-up of chronic active Epstein-Barr-virus-associated cardiovascular complications with cardiovascular magnetic resonance imaging: A case report

INTRODUCTION

Chronic active Epstein-Barr virus (EBV) infection (CAEBV) is characterized as chronic or recurrent mononucleosis-like symptoms and elevated EBV deoxyribonucleic acid (EBV-DNA) copies. Cardiovascular complications have high morbidity and mortality. The treatment regimen for CAEBV has not been established yet, resulting in poor prognoses. Herein, we present a case of cardiovascular magnetic resonance imaging (CMRI) evaluation with a series of sequences for CAEBV-associated cardiovascular involvement, which has never been reported.

CASE PRESENTATION

A 16-year-old female (body weight, 55 kg) developed a persistent fever and a positive EBV-DNA level of 28,000 copies/mL. Computed tomography angiography (CTA) showed aneurysms involving the aorta and its major branches, as well as multiple aneurysms and stenoses of the coronary arteries. CMRI of the coronary arteries depicted the dilution and stenosis of the arterial lumen as well as the thickening of the arterial wall. Late gadolinium enhancement (LGE) showed subendocardial and transmural delayed enhancement of the left ventricle, suggesting myocardial infarction.CAEBV and associated cardiovascular complications were diagnosed. After treatment with Medrol and Leflunomide, the clinical manifestation and serological parameters reversed to normal. However, the EBV-DNA level increased again to 13,900 copies/mL 2 months later. A follow-up with aorta CTA showed that the arterial walls of the bilateral common iliac artery aneurysms were thicker with new-onset mural thrombi. The aorta CTA also showed new-onset occlusion of the right coronary artery, but a follow-up of CMRI at the same day did not find new-onset delayed enhancement lesion.

CONCLUSION

This case reminds clinicians of the vital importance of early diagnosis and close follow-up of CAEBV-associated cardiovascular complications. With cine imaging, coronary artery imaging, LGE imaging, and other novel techniques, CMRI can effectively and comprehensively reveal the early and dynamic changes, and act as an important tool in the field of cardiovascular diseases.

Lymphocytic Arteritis in Epstein-Barr Virus Vulvar Ulceration (Lipschütz Disease): A Report of 7 Cases

Epstein-Barr virus (EBV) infection can rarely present as painful genital ulcers, mostly in young female adolescents. Typically diagnosed by clinical findings, EBV vulvar ulceration (EBVVU) is rarely biopsied. Herein, the authors report the histopathology in 8 biopsies from 7 EBVVU patients, all serologically confirmed for acute (4/7) or reactivated-chronic (3/7) EBV infection. The 7 women all presented with 1 or more painful, punched-out vulvar ulcers. Only patients with acute EBV infection showed other clinical findings: fever and/or atypical lymphocytosis affected 75% (3/4); lymphadenopathy in 50%; and malaise/fatigue, dysuria and/or hepatomegaly in 25%. All reactivated-chronic EBVVU had a solitary ulcer, and 2 had history of a similar episode of vulvar ulceration (aphthosis). Histopathologically, lymphocytic arteritis was identified in 88% (7/8); a submucosal scar was found in the eighth specimen. Other histopathologies included venulitis (62%), endarteritis obliterans (38%), thrombosis (25%), neutrophilic sebaceous adenitis (25%), and mucosal lymphoid hyperplasia (12%). Dense angiocentric CD3 CD4 T-cell lymphocyte-predominant infiltrates were found, regionally or diffusely. In 2 specimens, neutrophils compromised half of the infiltrate. Minor components of CD8, CD20, and CD30 lymphocytes, CD123 plasmacytoid monocytes, CD68 macrophages, and plasma cells were present. Small-vessel endothelium and smooth muscle adjacent to the ulcers faintly expressed cytoplasmic EBV latent membrane protein-1 (LMP1). In situ hybridization for early EBV mRNA (EBER) identified rare solitary or scattered clustered positive lymphocytes in 38%. Polymerase chain reaction for EBV DNA was positive in one EBER positive biopsy. EBV infection has been documented in muscular vessel vasculitis. Based on the aforementioned, EBVVU appears to be the consequence of localized lymphocytic arteritis.

Unusual Indolent Course of a Chronic Active Epstein-Barr Virus-Associated Natural Killer Cell Lymphoproliferative Disorder

Natural killer (NK) cell lymphoproliferative disorders are uncommon and the Epstein-Barr virus (EBV) plays an important aetiological role in their pathogenesis. We report a 20-year-old male with a chronic active EBV infection associated with a NK cell lymphoproliferative disorder which had an unusual indolent course. He presented to the Sultan Qaboos University Hospital in Muscat, Oman, in December 2011 with a history of intermittent fever and coughing. Examinations revealed generalised lymphadenopathy, hepatosplenomegaly, leukocytosis, transaminitis, diffuse bilateral lung infiltrates and bone marrow lymphocyte involvement. A polymerase chain reaction (PCR) test revealed a high EBV viral load in the peripheral blood cells. The patient received a course of piperacillin-tazobactam for Klebsiella pneumoniae, but no active treatment for the lymphoproliferative disorder. However, his lymphocyte count, serum lactate dehydrogenase and liver enzymes dropped spontaneously. In addition, EBV PCR copies fluctuated and then decreased significantly. He remained clinically asymptomatic over the following four years.

Chronic active EBV infection: the experience of the Samsung Medical Center in South Korea

BACKGROUND

Chronic active EBV infection (CAEBV) of T-cell or NK-cell type is an EBV+ polyclonal, oligoclonal or often monoclonal lymphoproliferative disorder (LPD) recognized as representing the spectrum of EBV-associated T-cell and NK-cell LPD with different clinical presentations; one systemic and two cutaneous disorders including hydroa vacciniforme-like T-cell LPD and mosquito bite hypersensitivity. The systemic form of the disease is characterized by fever, persistent hepatitis, hepatosplenomegaly and lymphadenopathy, which shows varying degrees of clinical severity depending on the immune response of the host and the EBV viral load.

CASE REPORTS

We described the clinicopathological findings of two children with CAEBV with a brief review of the literature.

CONCLUSIONS

Recognition of the disease is important for adequate management of the patient. EBV analysis should be included in the principal diagnostic tests for febrile children.

Pulmonary arterial hypertension associated with chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus (EBV) infection (CAEBV), characterized by persistent infectious mononucleosis-like symptoms, can lead to cardiovascular complications including coronary artery aneurysm or myocarditis. Here, we present the case of an 11-year-old boy with pulmonary arterial hypertension (PAH) and junctional ectopic tachycardia associated with CAEBV. The patient did not have any major symptoms attributed to CAEBV, such as fever, lymphadenopathy or splenomegaly when the PAH developed. Mild liver dysfunction was found at the first examination, and it persisted. Two years after the PAH symptoms appeared, CAEBV was evident, based on deteriorated liver function, hepatosplenomegaly, and coronary artery aneurysms. CAEBV should be considered as a cause of secondary PAH, particularly when liver dysfunction coexists.

Co-infections, inflammation and oncogenesis: future directions for EBV research

Epstein-Barr virus (EBV) is aetiologically linked to a wide range of human tumours. Some arise as accidents of the virus' lifestyle in its natural niche, the B lymphoid system; these include B-lymphoproliferative disease of the immunocompromised, Hodgkin Lymphoma, Burkitt Lymphoma and particular forms of diffuse large B cell lymphoma. Interestingly, HIV infection increases the incidence of each of these B cell malignancies, though by different degrees and for different reasons. Other EBV-associated tumours arise through rare viral entry into unnatural target tissues; these include all cases of nasal T/NK cell lymphoma and of undifferentiated nasopharyngeal carcinoma plus a small but significant subset of gastric carcinomas, a tumour type more generally associated with chronic Helicobacter pylori infection. Understanding EBV's involvement in the pathogenesis of these different malignancies is an important long-term goal. This article focuses on two overlapping, but relatively neglected, areas of research that could contribute to that goal. The first addresses the mechanisms whereby coincident infections with other pathogens increase the risk of EBV-positive malignancies, and takes as its paradigm the actions of holoendemic malaria and HIV infections as co-factors in Burkitt lymphomagenesis. The second widens the argument to include both infectious and non-infectious sources of chronic inflammation in the pathogenesis of EBV-positive tumours such as T/NK cell lymphoma, nasopharyngeal carcinoma and gastric carcinoma.

Current research on chronic active Epstein-Barr virus infection in Japan

Epstein-Barr virus (EBV) infection is usually asymptomatic and persists lifelong. Although EBV-infected B cells have the potential for unlimited proliferation, they are effectively removed by the virus-specific cytotoxic T cells, and EBV-associated lymphoproliferative disease develops only in immunocompromised hosts. Rarely, however, individuals without apparent immunodeficiency develop chronic EBV infection with persistent infectious mononucleosis-like symptoms. These patients have high EBV-DNA load in the peripheral blood and systemic clonal expansion of EBV-infected T cells or natural killer (NK) cells. Their prognosis is poor with life-threatening complications including hemophagocytic lymphohistiocytosis, organ failure, and malignant lymphomas. The term "chronic active EBV infection" (CAEBV) is now generally used for this disease. The geographical distribution of CAEBV is markedly uneven and most cases have been reported from Japan and other East Asian countries. Here we summarize the current understanding of CAEBV and describe the recent progress of CAEBV research in Japan.

Viral infections associated with Kawasaki disease

BACKGROUND/PURPOSE

Kawasaki disease (KD) is a disease of unknown cause. To investigate the infectious etiology of Kawasaki disease, we initiated a prospective case-control study to investigate possible links between common viral infections and Kawasaki disease.

METHODS

We enrolled 226 children with KD and 226 age- and sex-matched healthy children from February 2004 to March 2010. Throat and nasopharyngeal swabs were taken for both viral isolation and polymerase chain reaction (PCR) for various viruses.

RESULTS

The mean age of the 226 KD cases was 2.07 years, and the male to female ratio was 1.43 (133 boys to 93 girls). Their mean fever duration was 7.5 days with a mean peak temperature of 39.7°C. In addition to the typical symptoms of fever, neck lymphadenopathy, lip fissure and/or strawberry tongue, skin rash, nonpurulent bulbar conjunctivitis, palm/sole erythema, and induration followed by periungual desquamation, these KD cases also exhibited cough (69%), rhinorrhea (58%), and diarrhea (45%). Cases of KD had a significantly higher positive rate of viral isolation in comparison with the control group (7.5% vs. 2.2%, p = 0.02). Compared with the control group, cases of KD were more likely to have overall positive rates of viral PCR (50.4% vs. 16.4%, p < 0.001) and for various viruses including enterovirus (16.8% vs. 4.4%, p < 0.001), adenovirus (8.0% vs. 1.8%, p = 0.007), human rhinovirus (26.5% vs. 9.7%, p < 0.001), and coronavirus (7.1% vs. 0.9%, p = 0.003).

CONCLUSION

We found that some common respiratory viruses, such as adenoviruses, enteroviruses, rhinoviruses, and coronaviruses, were associated with KD cases.

Reproduction of epstein-barr virus infection and pathogenesis in humanized mice

Epstein-Barr virus (EBV) is etiologically associated with a variety of diseases including lymphoproliferative diseases, lymphomas, carcinomas, and autoimmune diseases. Humans are the only natural host of EBV and limited species of new-world monkeys can be infected with the virus in experimental conditions. Small animal models of EBV infection, required for evaluation of novel therapies and vaccines for EBV-associated diseases, have not been available. Recently the development of severely immunodeficient mouse strains enabled production of humanized mice in which human immune system components are reconstituted and express their normal functions. Humanized mice can serve as infection models for human-specific viruses such as EBV that target cells of the immune system. This review summarizes recent studies by the author's group addressing reproduction of EBV infection and pathogenesis in humanized mice.

Immunologic difference between hypersensitivity to mosquito bite and hemophagocytic lymphohistiocytosis associated with Epstein-Barr virus infection

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening, virus-triggered immune disease. Hypersensitivity to mosquito bite (HMB), a presentation of Chronic Active Epstein-Barr Virus infection (CAEBV), may progress to HLH. This study aimed to investigate the immunologic difference between the HMB episodes and the HLH episodes associated with EBV infection. Immunologic changes of immunoglobulins, lymphocyte subsets, cytotoxicity, intracellular perforin and granzyme expressions, EBV virus load and known candidate genes for hereditary HLH were evaluated and compared. In 12 HLH episodes (12 patients) and 14 HMB episodes (4 patients), there were both decreased percentages of CD4+ and CD8+ and increased memory CD4+ and activated (CD2+HLADR+) lymphocytes. In contrast to HMB episodes that had higher IgE levels and EBV virus load predominantly in NK cells, those HLH episodes with virus load predominantly in CD3+ lymphocyte had decreased perforin expression and cytotoxicity that were recovered in the convalescence period. However, there was neither significant difference of total virus load in these episodes nor candidate genetic mutations responsible for hereditary HLH. In conclusion, decreased perforin expression in the HLH episodes with predominant-CD3+ EBV virus load is distinct from those HMB episodes with predominant-NK EBV virus load. Whether the presence of non-elevated memory CD4+ cells or activated lymphocytes (CD2+HLADR+) increases the mortality rate in the HLH episodes remains to be further warranted through larger-scale studies.

Plasma viral microRNA profiles reveal potential biomarkers for chronic active Epstein-Barr virus infection

BACKGROUND

Chronic active Epstein-Barr virus (CAEBV) infection has high mortality and morbidity, and biomarkers for disease severity and prognosis are required. MicroRNAs (miRNAs) are small noncoding RNAs, and EBV encodes multiple miRNAs. Because plasma contains sufficiently stable miRNAs, circulating EBV-associated miRNA profiles were investigated as novel biomarkers in CAEBV infection.

METHODS

Plasma miRNA expression was assessed for 12 miRNAs encoded within 2 EBV open reading frames (BART and BHRF). Expression levels were investigated in 19 patients with CAEBV infection, 14 patients with infectious mononucleosis, and 11 healthy controls. Relative expression levels of plasma miRNAs were determined by TaqMan probe-based quantitative assay.

RESULTS

Plasma miR-BART1-5p, 2-5p, 5, and 22 levels in patients with CAEBV infection were significantly greater than those in patients with infectious mononucleosis and in controls. Plasma miR-BART2-5p, 4, 7, 13, 15, and 22 levels were significantly elevated in patients with CAEBV infection with systemic symptoms, compared with levels in patients with no systemic symptoms. The levels of miR-BART2-5p, 13, and 15 showed clinical cutoff values associated with specific clinical conditions, in contrast to plasma EBV loads.

CONCLUSIONS

Levels of specific plasma EBV miRNAs were elevated differentially in patients with CAEBV infection. Several EBV miRNAs, particularly miR-BART2-5p, 13, and 15, are potentially biomarkers of disease severity or prognosis.

An elderly patient with chronic active Epstein-Barr virus infection with mixed cryoglobulinemia and review of the literature

A 76-year-old woman was diagnosed with chronic active Epstein-Barr virus (EBV) infection (CAEBV) with sustained fever, anemia, numbness of the lower limbs, and liver dysfunction. The patient had an unusual anti-EBV antibody profile and high viral load, positive rheumatoid factor, and cryoglobulinemia. She suffered from recurrent hemosputum with pleural effusion and thrombocytopenia caused by CAEBV infection, and she died in July 2008. Here, we present a rare case of CAEBV infection with cryoglobulinemia in an elderly patient.