Characterization and treatment of chronic active Epstein-Barr virus disease: a 28-year experience in the United States. Blood. 2011;117:5835-5849. [PMID: 21454450 DOI: 10.1182/blood-2010-11-316745]

Haemophagocytic lymphohistiocytosis and Epstein-Barr virus: a complex relationship with diverse origins, expression and outcomes

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus with rare but severe potential for lymphoproliferative complications. EBV is associated with a variety of presentations of haemophagocytic lymphohistiocytosis (HLH). HLH is a life-threatening hyperinflammatory syndrome that can occur in patients with genetic defects associated with dysregulation of the immune response (familial HLH) or arise in patients with underlying infection or malignancy (non-familial or secondary HLH). EBV can both serve as the incidental trigger of familial HLH or as the driving factor in patients with selective inherited vulnerability (e.g. X-linked lymphoproliferative disease). Alternatively, acute infection can idiosyncratically cause non-neoplastic HLH in patients without inherited predisposition (i.e. secondary HLH), while EBV-associated T/natural killer (NK)-cell lymphoproliferative disorders and lymphomas can cause neoplasia-associated HLH. The present review will discern between EBV-associated familial and non-familial HLH and highlight diagnostic and therapeutic considerations. Non-familial EBV-associated HLH is a major diagnostic dilemma, as it represents a diverse spectrum of disease ranging from highly curable (non-neoplastic EBV-HLH) to indolent but incurable (chronic active EBV) to acutely fatal (systemic EBV-positive T-cell lymphoma of childhood). Increased clinical awareness and understanding of this rare and potentially devastating subset of EBV-related complications is desperately needed to improve survival for patients with neoplasia-associated HLH.

Hsa-miR-372-5p regulates the NIMA related kinase 7 and IL-1β release in NK/T-cell lymphoma

Epstein-Barr virus (EBV) infection is prevalent and associated with distinct diseases including infectious mononucleosis (IM), chronic active EBV infection (CAEBV) and NK/T-cell lymphoma (NKTL). However, the specific roles of EBV in these diseases remain unclear. Here, the whole miRNA expression datasets derived from 7 IM, 6 CAEBV, and 3 NKTL biopsies were obtained. Homo sapiens microRNA-372-5p (Hsa-miR-372-5p) was upregulated in both CAEBV and NKTL patients. Overexpression of hsa-miR-372-5p altered the expression of over 100 proteins. In addition, hsa-miR-372-5p may target NIMA related kinase 7 to regulate NLRP3 inflammasome activation in host cell. Taken together, we reported different miRNA expression profiles in distinct EBV associated diseases, which provided novel insights to understand how host miRNAs contribute to the mechanism of EBV associated diseases. Hsa-miR-372-5p, as well as other differential expressed miRNA, might serve as potential targets in the therapy of various EBV associated diseases.

Clinical Features of Intestinal Ulcers Complicated by Epstein-Barr Virus Infection: Importance of Active Infection

Clinical characteristics of intestinal ulcers complicated with Epstein-Barr virus (EBV) infection remain poorly studied. This study is aimed at providing further insight into clinical features of this patient cohort. The presence of serum EBV DNA was assessed in 399 patients with colonic ulcers, of which 30 cases were positive. In EBV-positive patients, the EBV-encoded RNA (EBER) was detected in intestinal tissues of 13 patients (EBER-positive group). The test was negative in 17 patients (EBER-negative group). Acute EBV infection rate in patients with colonic ulcer was 7.52%. Age and sex differences between two groups were not statistically significant. Fever, abdominal lymph node enlargement, and crater-like gouged ulcer morphology were more common in the EBER-positive group (P < 0.05). The albumin level in the EBER-positive group was significantly lower compared to that in the EBER-negative group (P < 0.05). The copy count of EBV DNA in the blood of patients from the EBER-positive group was higher, and the prognosis was worse (P < 0.05). Clinical manifestations were more severe in the EBER-positive group. Endoscopic, histopathological, and biochemical findings were also more serious in this group of patients. The findings point to the importance of assessing the EBER expression in patients with intestinal ulcers of various etiology. EBER positivity should be viewed as a diagnostic marker of more severe condition requiring more aggressive treatment.

[EBV and immunodeficiency]

Epstein-Barr virus (EBV), discovered in 1964, is a double-stranded DNA virus belonging to the Herpesviridae family. EBV has a lymphoid tropism with transforming capacities using different oncogenic viral proteins. This virus has two replication cycles: a lytic cycle mainly occuring during primary infection and a latent cycle allowing viral persistence into host memory B cells. More than 90% of adults are seropositive for EBV worldwide, with a past history of asymptomatic or mild primary infection. EBV infection can sometimes cause life-threatening complications such as hemophagocytic lymphohistiocytosis, and lead to the development of lymphoproliferative disorders or cancers. Risk factors associated with these phenotypes have been recently described through the study of monogenic primary immune deficiencies with EBV susceptibility. We here review the virological and immunological aspects of EBV infection and EBV-related complications with an overview of current available treatments.

Hepatosplenic T-cell lymphoma: a rare but challenging entity

Hepatosplenic T-cell lymphoma (HSTCL) is a rare T-cell neoplasm that most commonly arises from a small subset of γ/δ T-cell receptor-expressing lymphocytes. HSTCL is more common in adolescent and young adults and has a rapidly progressive clinical course and poor outcome due to its refractoriness to conventional chemotherapy regimens. Approximately 20% of the cases arise in the background of chronic immunosuppression or immune dysregulation. Patients commonly present with constitutional symptoms, hepatic and liver enlargement, and cytopenias; hematophagocytic syndrome can also occur. The most frequent chromosomal aberrations associated with HSTCL are isochromosome 7q and trisomy 8, and most cases harbor mutations in genes involved in chromatin modification or the JAK/STAT pathway. The rarity of this disease, along with lack of nodal involvement and presenting symptoms that mimic different entities including infectious etiologies, makes this lymphoma a significant diagnostic challenge. In this review, we highlight the clinical and pathologic features of HSTCL. Moreover, we summarize the results of recent molecular studies suggesting potential targets for novel therapeutics strategies.

Patients With Natural Killer (NK) Cell Chronic Active Epstein-Barr Virus Have Immature NK Cells and Hyperactivation of PI3K/Akt/mTOR and STAT1 Pathways

BACKGROUND

Chronic active Epstein-Barr virus (CAEBV) presents with high levels of viral genomes in blood and tissue infiltration with Epstein-Barr virus (EBV)-positive lymphocytes. The pathogenesis of CAEBV is poorly understood.

METHODS

We evaluated 2 patients with natural killer (NK) cell CAEBV and studied their NK cell phenotype and signaling pathways in cells.

RESULTS

Both patients had increased numbers of NK cells, EBV predominantly in NK cells, and immature NK cells in the blood. Both patients had increased phosphorylation of Akt, S6, and STAT1 in NK cells, and increased total STAT1. Treatment of 1 patient with sirolimus reduced phosphorylation of S6 in T and B cells, but not in NK cells and did not reduce levels of NK cells or EBV DNA in the blood. Treatment of both patients' cells with JAK inhibitors in vitro reduced phosphorylated STAT1 to normal. Patients with T- or B-cell CAEBV had increased phosphorylation of Akt and S6 in NK cells, but no increase in total STAT1.

CONCLUSIONS

The increase in phosphorylated Akt, S6, and STAT1, as well as immature NK cells describe a new phenotype for NK cell CAEBV. The reduction of STAT1 phosphorylation in their NK cells with JAK inhibitors suggests a novel approach to therapy.

Chronic active Epstein-Barr virus infection: A heterogeneous entity requiring a high index of suspicion for diagnosis

Chronic active Epstein-Barr virus infection of T- and NK-cell type, systemic form, is a rare entity within the spectrum of EBV-driven T- and NK-cell lymphoproliferative disorders. Established diagnostic criteria and a characteristic clinical course help to differentiate it from other closely related EBV-positive neoplasms and clinical states. We present a patient and review the natural history, pathologic features, pathogenesis, and differential diagnosis of this entity.

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.

Chronic active Epstein-Barr virus: a multidisciplinary approach

A 17-year-old Caucasian male presented to ENT with angular stomatitis, oral ulceration and cervical lymphadenopathy. Over the subsequent 18 months he developed recurrent upper respiratory tract infections, pyrexia of unknown origin, oral ulceration and maxillary sinus osteomyelitis. Extensive investigation ensued from various specialties. Positive investigations included a mild but persistently elevated serum Epstein-Barr virus PCR; however, no unifying diagnosis was elicited. It is noteworthy that a significant factor contributing to a delay in his diagnosis was poor compliance with invasive investigations. Ultimately, deteriorating liver function prompted liver biopsy which confirmed a diagnosis of chronic active Epstein-Barr virus infection (CAEBV). This enabled referral for curative treatment in the form of a stem cell transplant. CAEBV is extremely rare in Western countries. Due to fatal complications early diagnosis is critical for successful treatment. Our case highlights the need for regular clinical re-evaluation and a comprehensive multispecialty approach in such cases.

Epstein-Barr virus (EBV) induced pneumonitis in an immunocompetent adult: A case report

Epstein Barr Virus (EBV) is one of the herpes viruses that is responsible for causing infectious mononucleosis, lymphomas, and carcinomas primarily in immunocompromised individuals. We present a case of EBV-induced pneumonitis in an immunocompetent female, successfully treated with steroids. The patient is a 70 year-old female with a history of infectious mononucleosis in her teens who presented to the emergency room with worsening shortness of breath, associated with cough and fever. She underwent extensive work up and her serologic workup revealed positive anti-EBV antibodies, pointing towards the diagnosis of EBV induced pneumonitis. EBV-induced Pneumonitis is a very rare entity and is especially hardly seen among immunocompetent individuals. This interesting case shows that in this new era of viral pneumonias, EBV induced pneumonitis should be considered among differentials when dealing with lung infections. Prompt initiation of treatment with steroids or antiviral medication may result in complete recovery. The choices among treatment options can be individualized according to the severity of disease, course of disease progression, and side effect profile of medications. In our case we were able to successfully treat the patient with high dose steroids only.

Potential anti-EBV effects associated with elevated interleukin-21 levels: a case report

BACKGROUND

Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4⁺ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8⁺ T cells able to contain chronic virus infections.

CASE PRESENTATION

We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4⁺ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8⁺ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pT_FH, p = 0.01), reduced frequencies of peripheral CD4⁺ Bcl-6⁺ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pT_FH formation, pT_FH and CD4⁺ IL-21⁺ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman's rho: - 0.86, p < 0.001.

CONCLUSIONS

To the best of our knowledge, this is the first report of elevated CD4⁺ IL-21⁺ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.

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.

Co-Occurrence of Familial Hemophagocytic Lymphohistiocytosis Type 2 and Chronic Active Epstein-Barr Virus in Adulthood

We report, to the best of our best knowledge, the oldest individual to ever be diagnosed with Familial Hemophagocytic Lymphohistiocytosis (FHL) Type 2 from homozygous c.1349C>T (p.T450M) missense variants in the PRF1 gene. This rare case advanced in complexity with a simultaneous diagnosis of Chronic Active Epstein-Barr Virus (CAEBV) - a distinct clinical entity from acute EBV infections and a well-described trigger of Hemophagocytic Lymphohistiocytosis (HLH). This is, to the best of our knowledge, the only individual to ever be diagnosed with CAEBV in the setting of this specific variant and the oldest to be diagnosed with a coexisting perforin variant. This case provides understanding of EBV, human genetics, and lymphoproliferative disorders while adding a unique differential diagnosis to adults who present with fever of unknown origin and diffuse lymphadenopathy without evidence of malignancy. This report explores the diagnosis and treatment of both HLH and CAEBV, encouraging discussion regarding current clinical management and future research needs.

Epstein-Barr virus-positive inflammatory follicular dendritic cell sarcoma presenting as a solitary colonic mass: two rare cases and a literature review

AIMS

Follicular dendritic cell (FDC) sarcoma is a rare neoplasm originating from follicular dendritic cells in germinal centres. It is classified as conventional and Epstein-Barr virus (EBV)-positive inflammatory FDC sarcoma according to the 2019 World Health Organization classification of digestive system tumours; the latter is rarer. So in view of the rarity and difficulty in diagnosis, the aim of the manuscript is to share our experience of diagnosing EBV-positive inflammatory FDC sarcoma.

METHODS AND RESULTS

Here, we describe the clinicopathological features, gross description, histomorphology, immunophenotype, EBV-encoded mRNA (EBER) in-situ hybridisation, gene rearrangement and clinical follow-up of two patients with EBV-positive inflammatory FDC sarcoma in the colon, and review the relevant literature. The tumours were found in two males, aged 53 and 48 years, respectively, with a tumour diameter between 10 and 45 mm. Both cases occurred in the colon and presented as pedunculated colonic masses. Microscopically, scanty atypical ovoid to spindle neoplastic cells were mixed in a background of florid lymphoplasmacytic infiltration. The nuclei of these atypical cells showed vesicular chromatin and small, distinct nucleoli. Immunohistochemistry demonstrated that the atypical stromal cells were positive for CD21, CD23, CD35, and D2-40. EBER in-situ hybridisation also gave positive results in two cases. There was a mean follow-up of 9 months (range, 7-11 months).

CONCLUSION

EBV-positive inflammatory FDC sarcoma is an extremely rare tumour with a distinct morphology and phenotype. Therefore, it is very important to recognise it particularly for correct diagnosis and prevention of misdiagnosis and mistreatment.

Impact of melphalan dose during reduced-intensity conditioning on engraftment of cord blood transplantation for chronic Epstein-Barr virus-associated T or NK cell lymphoproliferative diseases

The rejection rate in cord blood transplants for chronic Epstein-Bar virus-associated T or natural killer cell lymphoproliferative diseases using our standard reduced-intensity conditioning "LPAM140 regimen," which includes fludarabine, melphalan (LPAM), etoposide, and antithymocyte globulin, has been high. To ensure better engraftment, we increased the LPAM dose to 210 mg/m² ("LPAM210 regimen"). Patient data (n = 22; LPAM140, n = 7; LPAM210, n = 15) were analyzed retrospectively. The engraftment rate after the LPAM210 regimen (100.0%) was significantly higher than that after the LPAM140 regimen (57.1%; P = .002). Fludarabine combined with melphalan (210 mg/m² ) had a favorable impact on engraftment.

Epstein-Barr virus infection in ulcerative colitis: a clinicopathologic study from a Chinese area

BACKGROUND

Opportunistic Epstein-Barr virus (EBV) infection in patients with ulcerative colitis (UC) has attracted increasing attention. This study aimed to evaluate the clinicopathological characteristics and clinical outcomes of UC with intestinal EBV infection and to explore the predictive value of blood EBV DNA for the presence of EBV in the intestine.

METHODS

Both peripheral blood and intestinal biopsies from 92 consecutive UC inpatients were included in this study. Normal colonic mucosal tissues from 20 colon cancer patients were used as controls. EBV testing and assessment were performed by EBV-DNA polymerase chain reaction (PCR), EBV-encoded small RNA in situ hybridization (EBER-ISH) and immunohistochemistry.

RESULTS

A total of 36 patients (39.1%) had UC with superimposed EBV colitis [EBER greater than 2/high-power field (HPF)]. EBER counts and disease activity were significantly correlated (p < 0.05). The major endoscopic findings revealed more irregular and longitudinal ulcers in patients with superimposed EBV colitis (p = 0.016, p = 0.021, respectively). Age, steroid dependence, and irregular ulcerations were identified as possible risk factors. The best EBER cut-off point for outcome prediction was 2.5/HPF. At a cut-off value of 2035 copies/ml, the sensitivity and specificity of the blood EBV-DNA PCR analysis for predicting EBV presence in the intestine were 76.5% and 68.5%, respectively. EBV-infected cells in UC with high EBV concentrations mainly included B lymphocytes by clinicopathology, and the infection might have progressed from the latent to the lytic phase of the EBV life cycle.

CONCLUSION

The EBER count is positively correlated with disease activity. The best cut-off point for outcome prediction is 2.5/HPF. A high EBV viremia load may effectively predict EBV presence in the colonic mucosa.

Chronic active Epstein-Barr virus infection involving gastrointestinal tract mimicking inflammatory bowel disease

Background

Chronic active Epstein-Barr virus infection (CAEBV) is a rare disease, which is difficult to be differentiated from inflammatory bowel disease (IBD). To cause the attention, we present twelve cases of CAEBV in immunocompetent patients with gastrointestinal tract involvement.

Methods

Twelve patients who fulfilled the diagnostic criteria of CAEBV were enrolled in this retrospective study. The control group was consisted of twenty-four IBD patients with EBV-DNA value increased in peripheral blood. The clinicopathologic and endoscopic characteristics were reviewed and analyzed.

Results

The major clinical presentations of CAEBV patients were intermittent fever (100%), hepatomegaly/splenomegaly (58%), lymphadenopathy (50%), diarrhea (50%) and hematochezia (50%). Compared with IBD patients, the incidence of intermittent fever and increased level of ferritin were significantly higher among CAEBV patients. The median values for EBV detected in peripheral blood were significantly higher in CAEBV group (1.42*10^6 copies/μg) than in IBD group (3.2*10^3 copies/μg, p<0.05). The main endoscopic findings of CAEBV included multifocal or isolated, irregular, multiform ulcers and diffuse inflammation, lacking of typical cobblestone appearance. Ten patients died within 5 years of disease onset. The average survival time is 21 months.

Conclusions

Symptoms such as intermittent fever, increased level of ferritin and atypical endoscopic findings could be a sign for CAEBV. Early detections of EBV-DNA in serum and EBV-encoded small nuclear RNA (EBER) by in situ hybridization in intestinal tissue are essential for differential diagnosis between CAEBV and IBD.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Chronic Active Epstein-Barr Virus-Associated Enteritis: CT Findings and Clinical Manifestation

Aim

To improve the identification and computed tomography (CT) diagnostic accuracy of chronic active Epstein-Barr virus (EBV)-associated enteritis (CAEAE) by evaluating its CT findings and clinical manifestation.

Methods

The data of three patients with pathologically and clinically confirmed CAEAE who underwent CT enterography (CTE) were retrospectively reviewed from January 2018 to October 2019. The following data were evaluated: imaging characteristics (length of involvement, pattern of mural thickening, pattern of attenuation, perienteric abnormalities), clinical symptoms, endoscopic records, laboratory examinations, and pathologic findings.

Results

Based on CT findings, two patients demonstrated segmental bowel wall thickening (involvement length >6 cm), asymmetric thickening, layered attenuation, fat stranding, and adenopathy, whereas the remaining one had no positive finding. The endoscopic results of all patients showed numerous irregular ulcers in the colon, and one patient had a focal esophageal ulcer. The major clinical symptoms were abdominal pain (n = 3), retrosternal pain (n = 1), fever (n = 3), diarrhea (n = 2), hematochezia (n = 1), and adenopathy (n = 3). The main laboratory examination indicators were increased serum EBV DNA load (n = 1) and increased inflammatory markers (n = 3). With regard to the main pathologic findings, all patients showed positive EBV-encoded RNA (EBER) situ hybridization in the colonic biopsy specimen, with one patient being positive in the esophagus.

Conclusion

CAEAE is rare and is usually misdiagnosed as inflammatory bowel disease (IBD). The imaging features of CAEAE overlap with those of Crohn's disease and ulcerative colitis. The presence of segmental and asymmetric bowel wall thickening, layered attenuation, and fat stranding in the CTE image may be helpful in differentiating CAEAE from IBD.

Germline CBM-opathies: From immunodeficiency to atopy

Caspase recruitment domain (CARD) protein-B cell CLL/lymphoma 10 (BCL10)-MALT1 paracaspase (MALT1) [CBM] complexes are critical signaling adaptors that facilitate immune and inflammatory responses downstream of both cell surface and intracellular receptors. Germline mutations that alter the function of members of this complex (termed CBM-opathies) cause a broad array of clinical phenotypes, ranging from profound combined immunodeficiency to B-cell lymphocytosis. With an increasing number of patients being described in recent years, the clinical spectrum of diseases associated with CBM-opathies is rapidly expanding and becoming unexpectedly heterogeneous. Here we review major discoveries that have shaped our understanding of CBM complex biology, and we provide an overview of the clinical presentation, diagnostic approach, and treatment options for those carrying germline mutations affecting CARD9, CARD11, CARD14, BCL10, and MALT1.

An Update on XMEN Disease

“X-linked immunodeficiency with magnesium defect, Epstein-Barr virus (EBV) infection, and neoplasia” (XMEN) disease is an inborn error of glycosylation and immunity caused by loss of function mutations in the magnesium transporter 1 (MAGT1) gene. It is a multisystem disease that strongly affects certain immune cells. MAGT1 is now confirmed as a non-catalytic subunit of the oligosaccharyltransferase complex and facilitates Asparagine (N)-linked glycosylation of specific substrates, making XMEN a congenital disorder of glycosylation manifesting as a combined immune deficiency. The clinical disease has variable expressivity and impaired glycosylation of key MAGT1-dependent glycoproteins in addition to Mg²⁺ abnormalities can explain some of the immune manifestations. NKG2D, an activating receptor critical for cytotoxic function against EBV, is poorly glycosylated and invariably decreased on CD8⁺ T cells and natural killer (NK) cells from XMEN patients. It is the best biomarker of the disease. The characterization of EBV-naïve XMEN patients has clarified features of the genetic disease that were previously attributed to EBV infection. Extra-immune manifestations, including hepatic and neurological abnormalities have recently been reported. EBV-associated lymphomas remain the main cause of severe morbidity. Unfortunately, treatment options to address the underlying mechanism of disease remain limited and Mg²⁺ supplementation has not proven successful. Here, we review the expanding clinical phenotype and recent advances in glycobiology that have increased our understanding of XMEN disease. We also propose updating XMEN to “X-linked MAGT1 deficiency with increased susceptibility to EBV-infection and N-linked glycosylation defect” in light of these novel findings.

Epstein-Barr virus infection in patients with chronic gastritis without Helicobacter pylori infection

BACKGROUND/AIMS

The association of Epstein-Barr virus (EBV) with gastric malignancies has been proven by many studies in the literature. However, information about EBV-associated inflammation/gastritis remains limited. The aim of this study is to establish the prevalence of latent EBV infection in patients with chronic gastritis without H. pylori infection.

MATERIALS AND METHODS

In this study, 119 patients with gastritis without H. pylori infection were included. Furthermore, 28 patients with H. pylori gastritis were included in the study as a control group. Chromogenic in situ hybridization (EBV-encoded RNA) and immunohistochemistry (LMP-1 antibody) were performed in all 147 cases. The prevalence of EBV and its relationship with age, sex, the affected part of the stomach, the density of inflammation, inflammatory activity, intestinal metaplasia, and atrophy were analyzed.

RESULTS

In this study, 14 cases showed positive immunostaining for EBV. EBV positivity was seen mostly in the lymphoid tissue (13 cases), but it was also detected at the gastric epithelium (7 cases). The mean age of the patients was 44 years, which was slightly younger than that of the EBV-negative cases (48 years). The inflammation density was higher in EBV-positive cases than the EBV-negative gastritis cases (p=0.002). Intestinal metaplasia was detected in 7% of the cases. EBV-positive cases had a higher incidence of atrophy without intestinal metaplasia (21% vs 3.8% without EBV).

CONCLUSION

EBV was detected in 12% of the cases with gastritis without H. pylori infection. Endoscopic follow-up may be appropriate for patients with gastritis, who have atrophy without intestinal metaplasia and are H. pylori negative but EBV positive.

A case of abdominal-pelvic infiltrative lesion of chronic active Epstein–Barr virus infection

Epstein–Barr virus (EBV) belongs to a subfamily of herpesviruses, also known as human herpesvirus type 4. EBV is widely distributed in the population, with a high infection rate of 90%. EBV infects mainly B lymphocytes, stimulates cell proliferation and transformation and even causes cancer. In recent years, it has been found that it can also infect T lymphocytes, epithelial cells and natural killer (NK) cells and can cause related diseases. EBV infection can cause a variety of clinical symptoms and clinical manifestations, which brings some confusion to clinical diagnosis and easily leads to missed diagnosis and misdiagnosis. In this article, we report a case of EBV-induced severe abdominal and pelvic infection, which eventually led to death.

The promise of a prophylactic Epstein-Barr virus vaccine

The worldwide burden of disease due to Epstein-Barr virus (EBV) infection is enormous. Diseases include endemic Burkitt lymphoma, infectious mononucleosis, cancers after transplantation, Hodgkin lymphoma, and nasopharyngeal carcinoma. A prophylactic EBV vaccine has the potential to significantly reduce the incidence and/or the severity of all these diseases. Infectious mononucleosis can be nasty and prolonged with a median duration of 17 days. Patients, especially children, undergoing bone marrow or solid organ transplantation may develop post-transplant lymphoproliferative disorder (PTLD). Preventing or modifying primary EBV infection could reduce the incidence PTLD, and also certain lymphomas and nasopharyngeal carcinoma. EBV is a major environmental risk factor for multiple sclerosis (MS). Contracting EBV is essential to getting MS, and having a childhood case of infectious mononucleosis increases that risk. Vaccinating against EBV could be vaccinating against MS.

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.

Epstein-Barr virus NK and T cell lymphoproliferative disease: report of a 2018 international meeting

Epstein-Barr virus (EBV) normally infects B cells, but in some persons the virus infects T or NK cells. Infection of B cells can result in infectious mononucleosis, and the virus is associated with several B cell malignancies including Hodgkin lymphoma, Burkitt lymphoma, and diffuse large B cell lymphoma. Infection of T or NK cells with EBV is associated with extranodal NK/T cell lymphoma, aggressive NK-cell leukemia, systemic EBV-associated T-cell lymphoma, and chronic active EBV disease, which in some cases can include hydroa vacciniforme-like lymphoproliferative disease and severe mosquito bite allergy. While NK and T cell lymphoproliferative disease is more common in Asia and Latin America, increasing numbers of cases are being reported from the United States and Europe. This review focuses on classification, clinical findings, pathogenesis, and recent genetic advances in NK and T cell lymphoproliferative diseases associated with EBV.

Epstein-Barr virus-associated B-cell lymphoproliferative disorders and lymphomas: a review

In this review, we focus on B-cell lymphoproliferative disorders (LPDs) and lymphomas associated with Epstein-Barr virus (EBV). In some of these diseases-such as EBV-positive diffuse large B-cell lymphoma (DLBCL), not otherwise specified-virus detection is required for the diagnosis, while in others its detection is not necessary for diagnosis. EBV infection has three main latency patterns (types III, II, and I). Different latency patterns are found in different LPD types and are related to the host immune system status. For each of the LPDs/lymphomas, we discuss the clinical presentation, epidemiology, pathology, immunophenotype, and genetic or molecular basis. We provide data for a better understanding of the relationships among the discussed diseases and other information that can be useful in differential diagnosis. Not included in this review are classic Hodgkin lymphoma and some specific variants of DLBCL, as these entities are discussed in separate reviews in this issue.

A new therapy in Epstein-Barr virus-associated lymphoproliferative disease: a case report and a revision of the literature

Background

Systemic chronic active Epstein-Barr virus infection is an extremely rare childhood disease. Since chronic active Epstein-Barr virus infection can trigger the onset of Epstein-Barr virus-associated lymphoproliferative disease. The clinical manifestations of the disease vary according to the site of involvement; therefore, management may be challenging. Currently, there are no standardized guidelines for treating Chronic active Epstein-Barr virus infection effectively.

Case presentation

We report a case of chronic active Epstein-Barr virus infection in a 5-year-old Chinese boy with intestinal, vascular, and neurological involvement. At age of 2 years and 7 months old, he had hepatomegaly and been diagnosed with Epstein-Barr virus infection. After treatment, he showed some clinical improvement. At age of 3 years and 3 months old, he presented with recurrent fever and diarrhea. Then he received methylprednisolone for 1 year and his symptoms ameliorated. At the age of 5 years, his symptoms recurred and had gastrointestinal hemorrhage and developed polyuria, frequent convulsions and hyponatremia. He was transferred to our hospital for further management. He was unconscious on admission and was diagnosised Epstein-Barr virus-lymphoproliferative disorder, based on the results in situ hybridization of EBV-encoded miRNA in sigmoid colon. Three-dimensional CT angiography demonstrated an aneurysm in the right internal carotid artery. Abdominal CT showed dilatation of vessels in part of the intestinal wall. He was also diagnosised Epstein-Barr virus encephalitis based on the elevated Epstein-Barr virus antibody titers and presence of Epstein-Barr virus DNA in the Cerebrospinal Fluid.

A repeated duodenal artery embolization and symptomatic therapy could not control the hemorrhage after admission. He subsequently received treatment with ganciclovir, glucocorticoid, thalidomide, and propranolol. Hemorrhage was controlled in 5 days; his symptoms improved. The fever did not recur and the CSF pressure was also normalized. A follow-up CT at 3 months after admission showed regression of the aneurysm in the right internal carotid artery and the vascular lesion in the duodenum.

Discussion and conclusions

A new treatment protocol including thalidomide and propranolol resulted in a marked improvement in his clinical symptoms, and shows promise as a novel and effective therapeutic approach for Chronic active Epstein-Barr virus infection-associated lymphoproliferative disorder.

Unusual lymphoid malignancy and treatment response in two children with Down syndrome

BACKGROUND

Lymphoid malignancies other than acute lymphoblastic leukemia (ALL) are rare in children with Down syndrome (DS). Information about the toxicity of chemotherapy and prognosis is largely derived from the experience of children with DS and ALL or children without DS.

PROCEDURE

We describe the treatment and outcome of two unusual lymphoid malignancies in children with DS. One patient was diagnosed with Burkitt lymphoma (BL) and the second, after treatment for B precursor ALL, with T-cell EBV-positive proliferative disorder (LPD).

RESULTS

BL was treated with standard doses of LMB group B therapy subsequently intensified to group C therapy, including high-dose methotrexate (HD-MTX, 3-8 g/m² ). The patient did not experience excessive toxicity and remains in complete remission 13 months later. Despite presentation with disseminated disease the patient with T-cell EBV-positive LPD after treatment for B precursor ALL responded to dexamethasone and rituximab and remains in complete remission two years later.

CONCLUSIONS

Upfront reduction of the high treatment intensity, which is associated with excellent survival outcomes in BL, may not be warranted in all children with DS. Response to therapy and prognosis of T-cell EBV-positive LPD in a patient with DS was not predicted by reported experience in the absence of DS.

Reactivation and dynamics of cytomegalovirus and Epstein-Barr virus after rabbit antithymocyte globulin and cyclosporine for aplastic anemia

OBJECTIVES

This study aimed to identify the natural course of cytomegalovirus (CMV)/Epstein-Barr virus (EBV) after rabbit antithymocyte globulin and cyclosporine (rATG-CsA) for aplastic anemia (AA).

METHODS

In 113 prospectively observed AA patients treated with rATG-CsA, the CMV/EBV cohort was classified into two groups by baseline viremic status: no viremia (CMV-G1, n = 112; EBV-G1, n = 98) and the presence of viremia (CMV-G2, n = 1; EBV-G2, n = 13).

RESULTS

In CMV-G1, the mean CMV load increased up to 3 months but was completely resolved from 6 months. The mean EBV load of EBV-G1 showed a peak at 1 month and then gradually decreased over time but remained detectable throughout the observation period. EBV-G2 showed fluctuating EBV dynamics. With reactivation rates of 38.4% in CMV-G1 and 62.2% in EBV-G1, a longer time to rATG-CsA from diagnosis and a lower absolute lymphocyte count at 1 month from rATG-CsA were significantly associated with CMV and EBV reactivation, respectively. The mean peak CMV and EBV loads of patients with CMV-related (3.5%) and EBV-related (0.9%) diseases were evidently higher than those of the remaining patients without CMV and EBV diseases in the respective cohort.

CONCLUSION

Considering frequent reactivation and distinct courses of CMV/EBV, virologic surveillance is recommended after rATG-CsA for AA.

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.

Inflammatory pseudotumor-like follicular dendritic cell sarcoma: a rare presentation of a hepatic mass

Follicular dendritic cell (FDC) sarcoma is a rare, low-grade malignant tumor originating from follicular dendritic cells in germinal centers that accounts for 0.4% of all soft tissue sarcomas. FDC sarcoma is classified into two types, the classic FDC sarcoma and inflammatory pseudotumor (IPT)-like follicular dendritic cell (FDC) sarcoma, the latter of which is rarer. IPT-like FDC sarcoma mainly involves the spleen and liver with non-specific clinical and imaging manifestations. It is often misdiagnosed as an inflammatory disease such as a liver abscess or a malignant tumor such as hepatocellular carcinoma, with a pathological morphology similar to inflammatory pseudotumors. IPT-like FDC sarcoma mainly consists of a large number of inflammatory and round, oval and spindle cells with less pleomorphism. These tumor cells are arranged in a whorled, storiform, or sheet pattern. The immunophenotype of IPT-like FDC sarcoma is the same as that of FDC sarcoma and is positive for CD21, CD23, and CD35, and positive for EBER in situ hybridization (ISH). This disease is easily misdiagnosed because it is so rare that clinicians and pathologists may not consider it in diagnosis. Here, a case of IPT-like FDC sarcoma in the liver was reported, and the related literature was reviewed to summarize the clinicopathological features, treatment, and prognosis of this rare new type of FDC sarcoma, providing new knowledge of this rare neoplasm.

A clinicopathologic study of the spectrum of systemic forms of EBV-associated T-cell lymphoproliferative disorders of childhood: A single tertiary care pediatric institution experience in North America

BACKGROUND

Systemic forms of EBV-associated T-cell lymphoproliferative disorders of childhood (S-EBV-T-LPD) comprise three major forms: EBV-positive hemophagocytic lymphohistiocytosis (EBV-HLH), systemic EBV-positive T-cell lymphoma (S-EBV-TCL), and systemic chronic active EBV infection (S-CAEBV). These disorders occur rarely in children in Western countries. Here, we described eight children of such entities.

DESIGN

Eight cases (six clinical and two autopsy) with S-EBV-T-LPD of childhood were retrospectively identified from 1990 to 2015. Clinicopathologic parameters including histomorphology, immunophenotype, EBV studies, and T-cell receptor gene rearrangement studies were recorded.

RESULTS

Patients include five females and three males of Hispanic, Asian, and Caucasian origins with an age range of 14 months to 9 years. Fever, hepatosplenomegaly, cytopenias, abnormal EBV serologies, and very high EBV viral loads were common findings. Histologic findings showed EBV⁺ T-cell infiltrates with variable degrees of architectural distortion and cytologic atypia ranging from no to mild cytologic atypia to overt lymphoma and tissue hemophagocytosis. All showed aberrant CD4⁺ or CD8⁺ T cells with dim to absent CD5, CD7, and CD3, and bright CD2 and CD45 by flow cytometry or loss of CD5 by immunohistochemistry. TCR gene rearrangement studies showed monoclonal rearrangements in all clinical cases (6/6). Outcomes were poor with treatment consisting of chemotherapy per the HLH-94 or HLH-2004 protocols with or without bone marrow transplant.

CONCLUSION

In this large pediatric clinicopathologic study of S-EBV-T-LPD of childhood in the United States, EBV-HLH, S-EBV-TCL, and S-CAEBV show many overlapping features. Diagnosis is challenging, and overall outcome is poor using current HLH-directed therapies.

EBV-Associated Lymphoproliferative Disorders: Update in Classification

Although about 90% of the world's population is infected by EBV only a small subset of the related infections result in neoplastic transformation. EBV is a versatile oncogenic agent involved in a multitude of hematopoietic, epithelial, and mesenchymal neoplasms, but the precise role of EBV in the pathogenesis of many of the associated lymphoid/histiocytic proliferations remains hypothetical or not completely understood. Additional studies and use of evolving technologies such as high-throughput next-generation sequencing may help address this knowledge gap and may lead to enhanced diagnostic assessment and the development of potential therapeutic interventions.

Hydroa vacciniforme-like lymphoproliferative disorder: an EBV disease with a low risk of systemic illness in whites

Patients with classic hydroa vacciniforme-like lymphoproliferative disorder (HVLPD) typically have high levels of Epstein-Barr virus (EBV) DNA in T cells and/or natural killer (NK) cells in blood and skin lesions induced by sun exposure that are infiltrated with EBV-infected lymphocytes. HVLPD is very rare in the United States and Europe but more common in Asia and South America. The disease can progress to a systemic form that may result in fatal lymphoma. We report our 11-year experience with 16 HVLPD patients from the United States and England and found that whites were less likely to develop systemic EBV disease (1/10) than nonwhites (5/6). All (10/10) of the white patients were generally in good health at last follow-up, while two-thirds (4/6) of the nonwhite patients required hematopoietic stem cell transplantation. Nonwhite patients had later age of onset of HVLPD than white patients (median age, 8 vs 5 years) and higher levels of EBV DNA (median, 1 515 000 vs 250 000 copies/ml) and more often had low numbers of NK cells (83% vs 50% of patients) and T-cell clones in the blood (83% vs 30% of patients). RNA-sequencing analysis of an HVLPD skin lesion in a white patient compared with his normal skin showed increased expression of interferon-γ and chemokines that attract T cells and NK cells. Thus, white patients with HVLPD were less likely to have systemic disease with EBV and had a much better prognosis than nonwhite patients. This trial was registered at www.clinicaltrials.gov as #NCT00369421 and #NCT00032513.

Primary immune regulatory disorders for the pediatric hematologist and oncologist: A case-based review

An array of monogenic immune defects marked by autoimmunity, lymphoproliferation, and hyperinflammation rather than infections have been described. Primary immune regulatory disorders pose a challenge to pediatric hematologists and oncologists. This paper focuses on primary immune regulatory disorders including autoimmune lymphoproliferative syndrome (ALPS) and ALPS-like syndromes, immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) and IPEX-like disorders, common variable immunodeficiency (CVID), CVID-like, and late-onset combined immunodeficiency (CID) disorders. Hyperinflammatory disorders and those associated with increased susceptibility to lymphoid malignancies are also discussed. Using a case-based approach, a review of clinical pearls germane to the clinical and laboratory evaluation as well as the treatment of these disorders is provided.

Determination of Epstein-Barr Virus-Infected Lymphocyte Cell Types in Peripheral Blood Mononuclear Cells as a Valuable Diagnostic Tool in Hematological Diseases

Background

High loads of Epstein-Barr virus (EBV) in peripheral blood mononuclear cells (PBMCs) can be indicative of a broad spectrum of diseases, ranging from asymptomatic infection to fatal cancers.

Methods

We retrospectively investigated the EBV-infected cell types in PBMCs among 291 patients. Based on EBV-infected cell types, the clinical features and prognoses of 93 patients with EBV-associated (EBV⁺) T/natural killer (NK)–cell lymphoproliferative diseases (LPDs) T/NK-LPDs) were investigated over a 5-year period.

Results

Although B-cell-type infection was found in immunocompromised patients and patients with asymptomatic high EBV carriage, infectious mononucleosis, EBV⁺ B-cell LPDs and B-cell lymphomas, T-cell, NK-cell or multiple-cell-type infection in immunocompetent hosts were highly suggestive of EBV⁺ T/NK-LPDs, EBV⁺ T/NK-cell lymphomas, and aggressive NK-cell leukemia. Patients with non–B-cell infection had a poorer prognosis than those with B-cell-type infection. In our cohort, 79.6% of patients with EBV⁺ T/NK-LPDs were >18 years old, and NK cells were identified as EBV-infected cell type in 54.8%. Nearly half of patients with EBV⁺ T/NK-LPDs had genetic defects associated with immunodeficiency. However, hemophagocytic lymphohistiocytosis, and not genetic defects, was the only parameter correlated with poor prognosis of EBV⁺ T/NK-LPDs.

Conclusions

Determination of EBV-infected cell types among PBMCs is a valuable tool for the differential diagnosis of EBV⁺ hematological diseases.

In this study, determination of Epstein-Barr virus-infected cell types in peripheral blood mononuclear cells of 291 patients with high Epstein-Barr virus loads were retrospectively investigated, which indicate it is a valuable tool for Epstein-Barr virus-associated hematological diseases.

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-Associated T and NK-Cell Lymphoproliferative Diseases

EBV-associated T and NK-cell lymphoproliferative diseases (EBV-T/NK LPDs) are characterized by the transformation and proliferation of EBV-infected T or NK cells. The 2016 revised World Health Organization classification recognizes the following EBV-positive lymphoproliferative disorders (LPD): chronic active EBV infection (CAEBV) of T- and NK-cell type (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity primary EBV-positive nodal T/NK-cell lymphoma. EBV-associated hemophagocytic lymphohistiocytosis (HLH), although not included in the WHO classification because it is a reactive, inflammatory disease, is included in this review because it can be life-threatening and may have overlapping features with other EBV+ T/NK LPDs. EBV+ T/NK LPDs are rare diseases difficult to diagnose and manage properly, because some LPDs have unusual presentations, and discrepancies between clinical and histological findings might be encountered. Furthermore, EBV+ T/NK disorders share some clinico-pathological features, and may evolve into other categories during the clinical course, including malignant transformation of CAEBV. Here, we review the EBV+ T/NK LPDs in terms of their definitions, clinical features, histology, immunophenotype, molecular findings, and pathogenesis. This review aims to increase our understanding and awareness of the differential diagnosis among the different EBV+ T/NK LPDs. New insights into the genetic characteristics of these disorders will also be discussed.

Chronic active EBV infection associated with NK cell lymphoma and hemophagocytic lymphohistiocytosis in a 27-year-old woman: A case report

RATIONALE

Chronic active Epstein-Barr virus infection (CAEBV) is a common infectious disease that often affects multiple organs or systems. However, it is liable to be neglected and misdiagnosed owing to its insidious onset, lack of specific findings in the early phase, and a general lack of awareness among clinicians. PATIENT CONCERNS:: a 27-year-old woman case has been described who was initially misdiagnosed as drug-induced liver injury due to onset presentation of mild splenomegaly, recurrent liver dysfunction, and disputable pathological evidence of liver biopsy.

DIAGNOSES

CAEBV complicated with natural killer (NK) cell lymphoma and hemophagocytic lymphohistiocytosis (HLH) was diagnosed by in situ hybridization of liver tissue section with EBV-encoded RNA -1 probe and flow cytometry of bone marrow.

INTERVENTIONS

After admission, the patient received symptomatic treatment and antiviral therapy (combination of acyclovir and foscarnet sodium) as well as adjuvant treatment (thymosin alpha 1 and methylprednisolone); later, the patient received etoposide and dexamethasone for diagnosis of EBV associated HLH. Subsequently, the disease progressed to NK cell lymphoma and the patient received the revised EPOCH chemotherapy regimen [etoposide (100 mg/d, d1-5), dexamethasone (7.5 mg/d, d1-5; 5 mg/d, d6-14), cyclophosphamide (0.8 g/d, d1-2), and pegaspargase (3750 u/d, tid, d1-2)].

OUTCOMES

Although the patient received a series of therapies and other comprehensive measures, finally she died of gastrointestinal hemorrhage and multiple organ failure.

LESSONS

Liver is one of the main target organs of EBV infection. In the clinical setting of unexplained fever and liver injury, it is necessary to be aware of CAEBV, as well as its fatal complication such as EBV associated NK cell lymphoma and HLH.

Advances in the Study of Chronic Active Epstein-Barr Virus Infection: Clinical Features Under the 2016 WHO Classification and Mechanisms of Development

Chronic active Epstein-Barr virus infection (CAEBV) is one of the Epstein-Barr virus (EBV)-positive T- or NK-lymphoproliferative diseases. It is considered rare and geographically limited to Japan and East Asia. However, CAEBV is drawing international attention, and the number of case reported worldwide is increasing, after its classification in the EBV-positive T- or NK-cell neoplasms, in the 2016 WHO classification. In this article, I review current advances in the study of CAEBV under the new definition and show future directions. In CAEBV, EBV-infected T or NK cells clonally proliferate and infiltrate multiple organs, leading to their failure. These characteristics define CAEBV as a lymphoid neoplasm. However, the main symptom of CAEBV is inflammation. Recently, the mechanisms underlying the development of CAEBV have gradually become clearer. EBV infection of T or NK cells can occur during the acute phase of primary infection with a high EBV load in the peripheral blood. In addition, it was reported that cytotoxic T cells decreased in numbers or showed dysfunction in CAEBV. These findings suggest that undetermined immunosuppressive disorders may underlie persistent infection of T or NK cells. Furthermore, EBV itself contributes to the survival of host cells. In vitro EBV infection of T cells induced intercellular survival-promoting pathways. Constitutive activation of NF-kB and STAT3 was observed in EBV-positive T or NK cells in CAEBV, promoting not only cell survival but also CAEBV development. During the disease course, CAEBV can lead to two lethal conditions: hemophagocytic lymphohistiocytosis and chemotherapy-resistant lymphoma. It is necessary to start treatment before these conditions develop. At present, the only effective treatment strategy for eradicating EBV-infected T or NK cells is allogeneic stem cell transplantation (allo-HSCT). However, patients with an active disease, in which the condition is accompanied by fever, liver dysfunction, progressive skin lesions, vasculitis, or uveitis, had worse outcomes after allo-HSCT, than patients with an inactive disease had. Unfortunately, current chemotherapies are insufficient to improve the activity of CAEBV. Based on the molecular mechanisms for the development of the disease, the NF-kB, or JAK/STAT mediating pathways are attractive candidate targets for new treatments.

Systemic Epstein-Barr Virus-Positive T/NK Lymphoproliferative Diseases With SH2D1A/XIAP Hypomorphic Gene Variants

X-linked lymphoproliferative disease (XLP) is one of the X-linked primary immunodeficiency diseases (PIDs) with defective immune response to Epstein-Barr virus (EBV) infection. Chronic active EBV infection (CAEBV) and EBV-hemophagocytic lymphohistiocytosis (HLH) are recognized as systemic EBV-positive T-cell and natural killer (NK)-cell lymphoproliferative diseases (LPDs) arising from the clonal proliferations of EBV-infected T cells and NK cells. A high incidence of CAEBV in East Asia implies the unknown genetic predisposition. In patients with XLP, EBV-infected cells are generally B cells. No mutation of SH2D1A/XIAP genes has ever been identified in patients with systemic EBV-positive T-cell and NK-cell LPD. We report herewith a male case of NK-cell type CAEBV with SH2D1A hypomorphic mutation (c.7G > T, p.Ala3Ser), two male cases of CAEBV/EBV-HLH with XIAP hypomorphic variant (c.1045_1047delGAG, p.Glu349del), and another female case of CD4⁺CAEBV with the same XIAP variant. The female underwent bone marrow transplantation from an HLA-matched sister with the XIAP variant and obtained a complete donor chimerism and a cure of laryngeal LPD lesion, but then suffered from donor-derived CD4⁺ T cell EBV-LPD. These observations demonstrated that SH2D1A and XIAP genes are critical for the complete regulation of EBV-positive T/NK cell LPD. X-linked lymphoproliferative disease (XLP) is one of the X-linked primary immunodeficiency diseases (PIDs) reported to have a defective immune response to Epstein-Barr virus (EBV) infection. Mutations in SH2D1A and XIAP genes cause XLP. Systemic EBV-positive T-cell and natural killer (NK)-cell lymphoproliferative diseases (LPDs) consist of three major types: EBV-positive hemophagocytic lymphohistiocytosis (HLH), chronic active EBV infection (CAEBV), and EBV-positive T-cell/NK-cell lymphoma. CAEBV is recognized as a poor prognostic disease of EBV-associated T-cell and NK-cell LPD arising from the clonal proliferation of EBV-infected T cells (CD4⁺, CD8⁺, and TCRγδ⁺) and/or NK cells. The majority of cases with CAEBV were reported from East Asia and South America. In Caucasian patients with CAEBV disease, the target of infection is exclusively B cells. These imply a genetic predisposition to EBV-positive T/NK cell LPD according to ethnicity. In reported cases with XLP, EBV-infected cells are B cells. On the other hand, no mutation of SH2D1A/XIAP genes have been determined in patients with T/NK-cell-type (Asian type) CAEBV. We here describe, for the first time, four case series of CAEBV/EBV-HLH patients who carried the hypomorphic variants of XLP-related genes. These cases included a male patient with CAEBV carrying SH2D1A hypomorphic mutation (c.7G > T, p.Ala3Ser) and two male patients with CAEBV/EBV-HLH carrying the XIAP hypomorphic variant (c.1045_1047delGAG, p.Glu349del), along with another female patient with CAEBV carrying the same XIAP variant. The female case underwent bone marrow transplantation from a healthy HLA-matched sister having the same XIAP variant. Although a complete donor chimerism was achieved with the resolution of laryngeal LPD lesions, systemic donor-derived CD4⁺ T-cell EBV-LPD developed during the control phase of intractable graft- vs. -host-disease. These observations demonstrated that SH2D1A and XIAP genes are critical for the complete regulation of systemic EBV-positive T/NK-cell LPD.

Validation of Multiplex Serology detecting human herpesviruses 1-5

Human herpesviruses (HHV) cause a variety of clinically relevant conditions upon primary infection of typically young and immunocompetent hosts. Both primary infection and reactivation after latency can lead to more severe disease, such as encephalitis, congenital defects and cancer. Infections with HHV are also associated with cardiovascular and neurodegenerative disease. However, most of the associations are based on retrospective case-control analyses and well-powered prospective cohort studies are needed for assessing temporality and causality. To enable comprehensive investigations of HHV-related disease etiology in large prospective population-based cohort studies, we developed HHV Multiplex Serology. This methodology represents a low-cost, high-throughput technology that allows simultaneous measurement of specific antibodies against five HHV species: Herpes simplex viruses 1 and 2, Varicella zoster virus, Epstein-Barr virus, and Cytomegalovirus. The newly developed HHV species-specific ('Monoplex') assays were validated against established gold-standard reference assays. The specificity and sensitivity of the HHV species-specific Monoplex Serology assays ranged from 92.3% to 100.0% (median 97.4%) and 91.8% to 98.7% (median 96.6%), respectively. Concordance with reference assays was very high with kappa values ranging from 0.86 to 0.96 (median kappa 0.93). Multiplexing the Monoplex Serology assays resulted in no loss of performance and allows simultaneous detection of antibodies against the 5 HHV species in a high-throughput manner.

Emerging technologies for the detection of viral infections

Viruses represent one of the major environmental agents that cause human illness and disease. However, the ability to diagnose viral infections is limited by detection capability and scope. Here we describe several emerging technologies that provide rapid and/or high-quality viral diagnostic information. Two technologies, novel CRISPR-based diagnostics and a portable DNA sequencing instrument, are uniquely suited to increase the number of viral agents analyzed, even in point of care settings. We also discuss a phage-based method for generating comprehensive viral profiles of previous exposure/infection and a fluid-phase immunoassay that yields highly quantitative viral antibody analyses. Future applications of these approaches will accelerate on-site clinical diagnosis of viral infections and provide insights into the role viruses play in complex diseases.