Comparison of Whole Blood and Plasma for Monitoring Cytomegalovirus and Epstein-Barr Virus.

Monitoring Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection after transplantation is recommended to enable preemptive therapy. However, the most suitable sample type remains unclear. Patients who underwent hematopoietic stem cell or liver transplantation were included in this study. Viral loads in sequential whole-blood and plasma samples were retrospectively analyzed. EBV DNA was detected more frequently in whole blood (55%) than in plasma (18%). The detection rate of CMV DNA was similar between the two sample types. The correlation of viral loads between the two sample types were 0.515 and 0.688 for EBV and CMV, respectively. Among paired samples in which EBV DNA was detected in whole blood, the plasma EBV detection rate was significantly higher in patients who underwent hematopoietic stem cell transplantation than in those who underwent liver transplantation. The viral DNA load in whole blood and plasma showed similar trends. The EBV detection rate was higher in whole blood, and a high correlation was observed between CMV DNA loads and whole blood and plasma. These results indicate that whole blood is more sensitive for monitoring both EBV and CMV, whereas plasma is a potential alternative sample for monitoring CMV.

Single-Cell Transcriptomic Analysis of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis.

Epstein-Barr virus (EBV) infection can lead to infectious mononucleosis (EBV-IM) and, more rarely, EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), which is characterized by a life-threatening hyperinflammatory cytokine storm with immune dysregulation. Interferon-gamma (IFNγ) has been identified as a critical mediator for primary HLH; however, the detailed role of IFNγ and other cytokines in EBV-HLH is not fully understood. In this study, we used single-cell RNA sequencing to characterize the immune landscape of EBV-HLH and compared it with EBV-IM. Three pediatric patients with EBV-HLH with different backgrounds, one with X-linked lymphoproliferative syndrome type 1 (XLP1), two with chronic active EBV disease (CAEBV), and two patients with EBV-IM were enrolled. The TUBA1B + STMN1 + CD8 + T cell cluster, a responsive proliferating cluster with rich mRNA detection, was explicitly observed in EBV-IM, and the upregulation of SH2D1A-the gene responsible for XLP1-was localized in this cluster. This proliferative cluster was scarcely observed in EBV-HLH cases. In EBV-HLH cases with CAEBV, upregulation of LAG3 was observed in EBV-infected cells, which may be associated with an impaired response by CD8 + T cells. Additionally, genes involved in type I interferon (IFN) signaling were commonly upregulated in each cell fraction of EBV-HLH, and activation of type II IFN signaling was observed in CD4 + T cells, natural killer cells, and monocytes but not in CD8 + T cells in EBV-HLH. In conclusion, impaired responsive proliferation of CD8 + T cells and upregulation of type I IFN signaling were commonly observed in EBV-HLH cases, regardless of the patients' background, indicating the key features of EBV-HLH.

Comparison of plasma proteomic profiles of patients with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis and infectious mononucleosis.

Primary Epstein-Barr virus (EBV) infection occasionally causes EBV-infectious mononucleosis (EBV-IM) and EBV-hemophagocytic lymphohistiocytosis (EBV-HLH). Although EBV-IM is mostly mild and self-limiting, EBV-HLH is a life-threatening disease characterized by excessive immune activation. However, the pathogenesis of EBV-HLH is yet to be fully elucidated. A diagnostic biomarker for EBV-HLH is desirable because early diagnosis and treatment are critical for the effective management of patients. In this study, the proteomic profiling of plasma was performed using liquid chromatography-mass spectrometry to identify proteins specific to EBV-IM and EBV-HLH. Furthermore, pathway analysis was performed for the proteins upregulated in patients with EBV-IM and EBV-HLH. Compared to healthy controls, 63 and 18 proteins were upregulated in patients with EBV-IM and EBV-HLH, respectively. Pathway and process enrichment analyses revealed that the complement system was the most enriched category of upregulated proteins in EBV-IM, whereas proteins related to immune effector processes were the most enriched in EBV-HLH. Among the 18 proteins upregulated in EBV-HLH, seven were exclusive to EBV-HLH. These specific proteins were associated with three pathways, and apolipoprotein E was commonly found in all the pathways. Proteomic analysis may provide new insights into the host response to EBV infection and the pathogenesis of EBV-related diseases.

Updated guidelines for chronic active Epstein-Barr virus disease.

Chronic active Epstein-Barr virus disease (CAEBV), formerly named chronic active Epstein-Barr virus infection, is characterized by systemic inflammation and clonal proliferation of Epstein-Barr virus (EBV)-infected T or NK cells. As CAEBV is a potentially life-threatening illness, appropriate diagnosis and therapeutic interventions are necessary for favorable clinical outcomes. Substantial evidence regarding the pathogenesis and treatment of CAEBV has been accumulated since previous guidelines for the diagnosis of CAEBV were proposed. To reflect this evidence, we updated the guidelines for the diagnosis and treatment of CAEBV to improve clinical management of the disease. The details of the updated guidelines are presented in this report. Diagnosis of CAEBV now requires confirmation of a high copy number of EBV genome and EBV-infected T or NK cells. An EBV DNA load ≥ 10,000 IU/mL in whole blood is proposed as the diagnostic cutoff value for CAEBV in this updated guideline. A standard treatment approach for CAEBV has not been established, and hematopoietic stem cell transplantation (HSCT) is considered the only curative treatment. Chemotherapy can be administered to control disease activity before HSCT.

Diagnostic and disease severity determination criteria for hydroa vacciniforme lymphoproliferative disorders and severe mosquito bite allergy.

Hydroa vacciniforme lymphoproliferative disorder (HV-LPD) and severe mosquito bite allergy (SMBA) are both cutaneous forms of Epstein-Barr virus (EBV)-associated T/natural killer (NK) cell LPDs and are closely related to chronic active EBV disease (CAEBV) and EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). HV-LPD is further divided into classic HV, a benign subtype mediated by EBV-positive γδT cells, and systemic HV, another life-threatening subtype mainly associated with EBV-positive αßT or γδT cells. The vast majority of patients with SMBA have increased numbers of EBV-infected NK cells in the blood. Clinical symptoms of HV-LPD and SMBA often overlap in the same patient and may progress to more serious disease conditions equivalent to the systemic form of CAEBV. To define the disease spectrum of HV-LPD and SMBA, we propose the diagnostic criteria and the determination criteria for disease severity. The proposed diagnostic criteria are consistent with those for CAEBV and EBV-HLH in the guidelines for the management for CAEBV and related disorders 2023.

Interferon alfa-2b in patients with low-grade lymphomatoid granulomatosis and chemotherapy with DA-EPOCH-R in patients with high-grade lymphomatoid granulomatosis: an open-label, single-centre, phase 2 trial.

BACKGROUND: Lymphomatoid granulomatosis is a rare Epstein-Barr virus-associated B-cell lymphoproliferative disorder with a median overall survival of less than 2 years. In this study, we hypothesised that low-grade lymphomatoid granulomatosis is immune-dependent and high-grade lymphomatoid granulomatosis is immune-independent. On the basis of this hypothesis, we investigated the activity and safety of new treatment with immunotherapy in patients with low-grade disease and standard chemotherapy in patients with high-grade disease. METHODS: In this open-label, single-centre, phase 2 trial, we enrolled patients aged 12 years or older with untreated, or relapsed or refractory lymphomatoid granulomatosis at the National Cancer Institute (National Institutes of Health, Bethesda, MD, USA). Patients with low-grade disease received dose-escalated interferon alfa-2b, starting at 7·5 million international units subcutaneously three times per week for up to 1 year past best response, and patients with high-grade disease received six cycles every 3 weeks of intravenous, dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab (DA-EPOCH-R). Starting doses were 50 mg/m2 per day as a continuous intravenous infusion from day 1 to day 4 (96 h) for etoposide; 60 mg/m2 twice daily by mouth from day 1 to day 5 for prednisone; 0·4 mg/m2 per day as a continuous intravenous infusion from day 1 to day 4 (96 h) for vincristine; 750 mg/m2 intravenous on day 5 for cyclophosphamide; 10 mg/m2 per day as a continuous intravenous infusion from day 1 to day 4 (96 h) for doxorubicin; and 375 mg/m2 intravenous on day 1 for rituximab. The doses of doxorubicin, etoposide, and cyclophosphamide were adjusted up or down on the basis of neutrophil and platelet nadirs. Patients with residual or progressive disease after initial therapy crossed over to alternative therapy. The primary endpoint was the proportion of patients who had an overall response and the 5-year progression-free survival after initial or cross-over treatment. Analysis of response included all participants who underwent restaging imaging; safety analysis included all patients who received any dose of study drugs. The trial is open for enrolment and is registered at ClinicalTrials.gov, NCT00001379. FINDINGS: 67 patients were enrolled between Jan 10, 1991, and Sept 5, 2019 (42 [63%] were male). 45 patients received initial treatment with interferon alfa-2b (16 of whom crossed over to DA-EPOCH-R) and 18 received initial treatment with DA-EPOCH-R (eight of whom crossed over to interferon alfa-2b); four underwent surveillance only. After initial treatment with interferon alfa-2b, the overall response was 64% (28 of 44 evaluable patients) with 61% (27 of 44) having a complete response, whereas, after cross-over treatment with interferon alfa-2b, the overall response was 63% (five of eight evaluable patients) with 50% (four of eight) having a complete response. After initial treatment with DA-EPOCH-R, the overall response was 76% (13 of 17 evaluable patients) with 47% (eight of 17) having a complete response, whereas, after cross-over treatment with DA-EPOCH-R, the overall response was 67% (ten of 15 evaluable patients) with 47% (seven of 15) having a complete response. 5-year progression-free survival was 48·5% (95% CI 33·2-62·1) after initial treatment with interferon alfa-2b, 50·0% (15·2-77·5) after cross-over treatment with interferon alfa-2b, 25·4% (8·2-47·2) after initial treatment with DA-EPOCH-R, and 62·5% (34·9-81·1) after cross-over treatment with DA-EPOCH-R. The most common grade 3 or worse adverse events in patients treated with interferon alfa-2b included neutropenia (27 [53%] of 51 patients), lymphopenia (24 [47%]), and leukopenia (24 [47%]). The four most common grade 3 or worse adverse events in patients treated with DA-EPOCH-R included neutropenia (29 [88%] of 33 patients), leukopenia (28 [85%]), infection (18 [55%]), and lymphopenia (17 [52%]). Serious adverse events occurred in 13 (25%) of 51 patients receiving treatment with interferon alfa-2b and 21 (64%) of 33 patients receiving DA-EPOCH-R, with five treatment-related deaths: one thromboembolic, one infection, and one haemophagocytic syndrome with interferon alfa-2b, and one infection and one haemophagocytic syndrome with DA-EPOCH-R. INTERPRETATION: Interferon alfa-2b is efficacious for treating low-grade lymphomatoid granulomatosis and hence reducing progression to high-grade disease, whereas patients with high-grade lymphomatoid granulomatosis showed expected responses to chemotherapy. Uncontrolled immune regulation of Epstein-Barr virus is hypothesised to result in the emergence of low-grade disease after chemotherapy, for which treatment with interferon alfa-2b is efficacious. FUNDING: Intramural Research Programs of the National Cancer Institute and National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Droplet Digital PCR Development for Adenovirus Load Monitoring in Children after Hematopoietic Stem Cell Transplantation.

Human adenovirus (AdV) reactivation after hematopoietic stem cell transplantation (HSCT) is associated with life-threatening clinical manifestations. Although real-tme quantitative PCR (qPCR) has been widely used to measure AdV loads, it has not been standardized for AdV. Droplet digital PCR (ddPCR) is a novel pathogen detection technology that enables the absolute quantification of viral loads. ddPCR would enable a more accurate AdV DNA detection compared with qPCR. In this study, ddPCR was developed for AdV DNA and its performance characteristics compared with those of qPCR. AdV DNAemia incidence during the first 12 weeks after allogenic HSCT was then retrospectively examined by qPCR and ddPCR in 97 HSCT procedures using the preserved 545 DNA samples. ddPCR exhibited better reproducibility and sensitivity, as well as equivalent quantifiability, compared with qPCR. AdV DNA among HSCT patients was detected in 11 (2.0%) and 49 (9.0%) of 545 samples by qPCR and ddPCR, respectively. AdV DNA levels >1000 copies/mL were observed in five cases by qPCR and/or ddPCR. However, two patients developed fulminant hepatitis and died; other patients remained asymptomatic with subsequently undetectable AdV DNA. In conclusion, ddPCR was more sensitive and reproducible in detecting AdV DNA among pediatric HSCT recipients than qPCR. ddPCR offers the potential to provide a more accurate DNAemia detection, determine cutoff values for treatment initiation, and enable antiviral efficacy assessment.

A STING inhibitor suppresses EBV-induced B cell transformation and lymphomagenesis.

Epstein-Barr virus-associated lymphoproliferative disease (EBV-LPD) is frequently fatal. Innate immunity plays a key role in protecting against pathogens and cancers. The stimulator of interferon genes (STING) is regarded as a key adaptor protein allowing DNA sensors recognizing exogenous cytosolic DNA to activate the type I interferon signaling cascade. In terms of EBV tumorigenicity, the role of STING remains elusive. Here we showed that treatment with the STING inhibitor, C-176, suppressed EBV-induced transformation in peripheral blood mononuclear cells. In an EBV-LPD mouse model, C-176 treatment also inhibited tumor formation and prolonged survival. Treatment with B cells alone did not affect EBV transformation, but suppression of EBV-induced transformation was observed in the presence of T cells. Even without direct B cell-T cell contact in a transwell system, the inhibitor reduced the transformation activity, indicating that intercellular communication by humoral factors was critical to prevent EBV-induced transformation. These findings suggest that inhibition of STING signaling pathway with C-176 could be a new therapeutic target of EBV-LPD.

Immune cell infiltration landscapes in pediatric acute myocarditis analyzed by CIBERSORT.

BACKGROUND: Myocarditis is an inflammatory disease of the myocardium, which leads to cardiac dysfunction and heart failure. Previous studies have suggested that complex cross-talk between innate and adaptive immune responses is involved in the pathogenesis of acute myocarditis. Immunohistochemistry is the current standard method for the evaluation of infiltrating immune cells, however, it is difficult to investigate and quantify many immune cell populations using this technique. METHODS: Endomyocardial biopsy samples of five pediatric patients with myocarditis were analyzed by cell-type identification by estimating relative subsets of RNA transcript (CIBERSORT), a computational method for quantifying cell fractions from tissue gene expression profiles. CIBERSORT results were then compared with immunohistochemistry analyses. RESULTS: Significant results of immune infiltrate deconvolution were obtained in four patients with fulminant myocarditis by CIBERSORT analysis. Among 22 immune cell types, 19 cell types were detected in one or more patients. Activated NK cells were the most prevalent population in two patients, whereas activated memory CD4+ T cells and M2 macrophages were the most prevalent population in one patient each. Overall CIBERSORT results were consistent with those of immunohistochemistry, although some discrepancies were observed. CONCLUSIONS: Infiltrating immune cell subsets detected by CIBERSORT analysis can reflect the time course of innate and adaptive immune responses in acute myocarditis. CIBERSORT may have the potential to characterize the detail of infiltrating immune cells in myocardial tissues and provide novel insights into the pathogenesis of acute myocarditis.

Viral DNA Loads in Various Blood Components of Patients With Epstein-Barr Virus-Positive T-Cell/Natural Killer Cell Lymphoproliferative Diseases.

To evaluate diagnostic values for Epstein-Barr virus (EBV) DNA loads in different blood components of patients with EBV-positive T-cell/natural killer cell lymphoproliferative diseases, EBV DNA loads were compared among disease categories in each blood component from 59 patients. Plasma viral loads were significantly higher in "active" disease in chronic active EBV infection. EBV DNA was not detected in the plasma from 7 patients in whom EBV DNA was detected in peripheral blood mononuclear cells and whole blood. Diagnostic cutoff values for whole blood EBV DNA loads of patients with chronic active EBV infection compared with those of infectious mononucleosis was 104.2 (15 800) IU/mL.

Correction: Treatment with silver nitrate versus topical steroid treatment for umbilical granuloma: A non-inferiority randomized control trial.

[This corrects the article DOI: 10.1371/journal.pone.0192688.].

Publisher Correction: Defective Epstein-Barr virus in chronic active infection and haematological malignancy.

In the version of this Letter originally published, in the sentence beginning "The major driver role of DDX3X mutations...", the citation "Fig. 2a-f" should have been "Fig. 2". In addition, in the sentence beginning "Another finding of interest was the presence of identical driver mutations...", the citation "Fig. 3a,b and Fig. 4" should have been "Fig. 3". This has now been amended in all versions of the Letter.

Defective Epstein-Barr virus in chronic active infection and haematological malignancy.

Epstein-Barr virus (EBV) infection is highly prevalent in humans and is implicated in various diseases, including cancer1,2. Chronic active EBV infection (CAEBV) is an intractable disease classified as a lymphoproliferative disorder in the 2016 World Health Organization lymphoma classification1,2. CAEBV is characterized by EBV-infected T/natural killer (NK) cells and recurrent/persistent infectious mononucleosis-like symptoms3. Here, we show that CAEBV originates from an EBV-infected lymphoid progenitor that acquires DDX3X and other mutations, causing clonal evolution comprising multiple cell lineages. Conspicuously, the EBV genome in CAEBV patients harboured frequent intragenic deletions (27/77) that were also common in various EBV-associated neoplastic disorders (28/61), including extranodal NK/T-cell lymphoma and EBV-positive diffuse large B-cell lymphoma, but were not detected in infectious mononucleosis or post-transplant lymphoproliferative disorders (0/47), which suggests a unique role of these mutations in neoplastic proliferation of EBV-infected cells. These deletions frequently affected BamHI A rightward transcript microRNA clusters (31 cases) and several genes that are essential for producing viral particles (20 cases). The deletions observed in our study are thought to reactivate the lytic cycle by upregulating the expression of two immediate early genes, BZLF1 and BRLF14-7, while averting viral production and subsequent cell lysis. In fact, the deletion of one of the essential genes, BALF5, resulted in upregulation of the lytic cycle and the promotion of lymphomagenesis in a xenograft model. Our findings highlight a pathogenic link between intragenic EBV deletions and EBV-associated neoplastic proliferations.

Reactivation of human herpesviruses 6 and 7 in Kawasaki disease.

Objectives: Kawasaki disease (KD) is one of the most common childhood vasculitides. Some serological studies have suggested an etiological relationship between KD and human herpesvirus (HHV)-6 or HHV-7. However, primary or reactivated HHV-6 and -7 has not been fully investigated in patients with KD. Methods: Twenty-three patients with KD were prospectively enrolled in this study. Peripheral blood was collected in the acute and convalescence phases, and HHV-6 and -7 viral loads were measured by real-time PCR. Results: In the acute phase, HHV-6 and -7 DNA was detected in 7 (30%) patients each, compared to 13 (57%) and 9 (39%) patients in the convalescence phase, respectively. HHV-6 and -7 DNA loads were significantly higher in the convalescence phase than in the acute phase. Significant increases in HHV-6 and -7 DNA loads were not observed in disease control patients. Taking into account HHV-6 and -7 serostatus, reactivation of HHV-6 and -7 was observed in 7 and 9 patients, respectively. KD patients with HHV-6 reactivation showed higher C-reactive protein levels and more frequently required steroid therapies than patients without reactivation. Conclusion: HHV-6 and -7 reactivation is frequent in KD patients. HHV-6 reactivation might exacerbate the severity of KD.

Ureteral dilatation detected in magnetic resonance imaging predicts vesicoureteral reflux in children with urinary tract infection.

OBJECTIVE: Urinary tract infection (UTI), one of the most common bacterial infections occurring during infancy and early childhood, is frequently associated with vesicoureteral reflux (VUR). Although several guidelines recommend performing ultrasonography as a screening test, its utility is not adequate and appropriate screening tests are strongly desirable. In this study, we evaluate the use of magnetic resonance imaging (MRI) as a screening test for VUR in children with UTI. METHODS: We prospectively studied 108 patients with suspected UTI between April 2014 and March 2016. UTI was diagnosed on the basis of diffusion-weighted MRI (DW-MRI) and urine culture findings. We measured ureteral dilatation using MRI in 96 patients with UTI and assessed the relationship between ureteral dilatation in MRI and VUR in 46 patients who underwent voiding cystourethrography (VCUG). RESULTS: Among 108 patients, 88 and 8 were diagnosed with upper and lower UTI, respectively. Among 46 patients who underwent VCUG, 23 had VUR (14 low grade and 9 high grade). Patients with ureteral dilatation detected on MRI had VUR more frequently than those without ureteral dilatation (any grades VUR, 71% vs. 32%; P = 0.02; high-grade VUR, 38% vs. 2%, P = 0.007). Overall, ureteral dilatation findings on MRI achieved sensitivity 65.2% and specificity 73.9% as a screening test for VUR. In addition, DW-MRI achieved sensitivity 100% and specificity 81.8% in the diagnosis of upper UTI. CONCLUSION: These findings suggested that MRI is a valuable tool for screening of VUR as well as diagnosis of upper UTI.

Antitumor effects of duvelisib on Epstein-Barr virus-associated lymphoma cells.

Epstein-Barr virus (EBV) is a ubiquitous oncogenic virus that is associated with B cell lymphomas, including Burkitt lymphoma and Hodgkin lymphoma. Previous studies have shown that the phosphatidylinositol 3-kinase (PI3K)/Akt pathway is activated in EBV-associated lymphomas and can be a novel therapeutic target. An oral dual inhibitor of PI3Kγ and PI3Kδ, duvelisib, is in clinical trials for the treatment of lymphoid malignancies. In this study, we evaluated how duvelisib affects the activity of the PI3K/Akt signaling pathway and if it has antitumor effects in EBV-associated lymphoma cell lines. We found that the PI3K/Akt signaling pathway was activated in most of the B and T cell lymphoma cell lines tested. Additionally, duvelisib treatment inhibited cellular growth in the tested cell lines. Overall, B cell lines were more susceptible to duvelisib than T and NK cell lines in vitro regardless of EBV infection. However, the additional influence of duvelisib on the tumor microenvironment was not assessed. Duvelisib treatment induced both apoptosis and cell cycle arrest in EBV-positive and -negative B cell lines, but not in T cell lines. Furthermore, duvelisib treatment reduced the expression of EBV lytic genes (BZLF1 and gp350/220) in EBV-positive B cell lines, suggesting that duvelisib suppresses the lytic cycle of EBV induced by B cell receptor signaling. However, duvelisib did not induce a remarkable change in the expression of EBV latent genes. These results may indicate that there is therapeutic potential for duvelisib administration in the treatment of EBV-associated B cell lymphomas and other B cell malignancies.

Treatment with silver nitrate versus topical steroid treatment for umbilical granuloma: A non-inferiority randomized control trial.

OBJECTIVE: The aim of this prospective multicenter randomized controlled trial was to compare the efficacy of silver nitrate cauterization against that of topical steroid ointment in the treatment of neonatal umbilical granuloma. METHODS: An open-label, non-inferiority randomized controlled trial was conducted from January 2013 to January 2016. The primary endpoint for the silver nitrate cauterization and topical steroid ointment groups was the healing rate after 2 weeks of treatment, applying a non-inferiority margin of 10%. The healing rate was evaluated until completion of 3 weeks of treatment. RESULTS: Participants comprised 207 neonates with newly diagnosed umbilical granuloma, randomized to receive silver nitrate cauterization (n = 104) or topical steroid ointment (n = 103). Healing rates after 2 weeks of treatment were 87.5% (91/104) in the silver nitrate cauterization and 82% (82/100) in the topical steroid ointment group group. The difference between groups was -5.5% (95% confidence interval, -19.1%, 8.4%), indicating that the non-inferiority criterion was not met. After 3 weeks of treatment, the healing rate with topical steroid ointment treatment was almost identical to that of silver nitrate cauterization (94/104 [90.4%] vs. 91/100 [91.0%]; 0.6% [-13.2 to 14.3]). No major complications occurred in either group. CONCLUSIONS: This study did not establish non-inferiority of topical steroid ointment treatment relative to silver nitrate cauterization, presumably due to lower healing rates than expected leading to an underpowered trial. However, considering that silver nitrate cauterization carries a distinct risk of chemical burns and that the overall efficacy of topical steroid ointment treatment is similar to that of silver nitrate cauterization, topical steroid ointment might be considered as a good alternative in the treatment of neonatal umbilical granuloma due to its safety and simplicity. To clarify non-inferiority, a larger study is needed.

Comprehensive detection of viruses in pediatric patients with acute liver failure using next-generation sequencing.

BACKGROUND: Pediatric acute liver failure (PALF) is a rare and severe syndrome that frequently requires liver transplantation. Viruses are one of the most frequent causes of this disease, however, pathogenic viruses are not determined in many patients. Recently next-generation sequencing (NGS) has been applied to comprehensively detect pathogens of infectious diseases of unknown etiology. OBJECTIVES: To evaluate an NGS-based approach for detecting pathogenic viruses in patients with PALF or acute hepatitis of unknown etiology. STUDY DESIGN: To detect virus-derived DNA and RNA sequences existing in sera/plasma from patients, both DNA and RNA sequencing were performed. First, we validated the ability of NGS to detect viral pathogens in clinical serum/plasma samples, and compared different commercial RNA library preparation methods Then, serum/plasma of fourteen patients with PALF or acute hepatitis of unknown etiology were evaluated using NGS. RESULTS: Among three RNA library preparation methods, Ovation RNA-Seq System V2 had the highest sensitivity to detect RNA viral sequences. Among fourteen patients, sequence reads of torque teno virus, adeno-associated virus, and stealth virus were found in the sera of one patient each, however, the pathophysiological role of these three viruses was not clarified. Significant virus reads were not detected in the remaining 11 patients. CONCLUSIONS: This finding might be due to low virus titer in blood at the time of referral or a non-infectious cause might be more frequent. These results suggest an NGS-based approach has potential to detect viral pathogens in clinical samples and would contribute to clarification of the etiology of PALF.

Epstein-Barr virus infection-induced inflammasome activation in human monocytes.

Inflammasomes are cytoplasmic sensors that regulate the activity of caspase-1 and the secretion of interleukin-1ß (IL-1ß) or interleukin-18 (IL-18) in response to foreign molecules, including viral pathogens. They are considered to be an important link between the innate and adaptive immune responses. However, the mechanism by which inflammasome activation occurs during primary Epstein-Barr virus (EBV) infection remains unknown. Human B lymphocytes and epithelial cells are major targets of EBV, although it can also infect a variety of other cell types. In this study, we found that EBV could infect primary human monocytes and the monocyte cell line, THP-1, inducing inflammasome activation. We incubated cell-free EBV with THP-1 cells or primary human monocytes, then confirmed EBV infection using confocal microscopy and flow cytometry. Lytic and latent EBV genes were detected by real-time RT-PCR in EBV-infected monocytes. EBV infection of THP-1 cells and primary human monocytes induced caspase-dependent IL-1ß production, while EBV infection of B-cell or T-cell lines did not induce IL-1ß production. To identify the sensor molecule responsible for inflammasome activation during EBV infection, we examined the mRNA and the protein levels of NLR family pyrin domain-containing 3 (NLRP3), absent in melanoma 2 (AIM2), and interferon-inducible protein 16 (IFI16). Increased AIM2 levels were observed in EBV-infected THP-1 cells and primary human monocytes, whereas levels of IFI16 and NLRP3 did not show remarkable change. Furthermore, knockdown of AIM2 by small interfering RNA attenuated caspase-1 activation. Taken together, our results suggest that EBV infection of human monocytes induces caspase-1-dependent IL-1ß production, and that AIM2, acting as an inflammasome, is involved in this response.