Role of matrix metalloproteinases in the pathogenesis of childhood gastroenteritis.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been implicated in the pathogenesis of gastrointestinal diseases, such as rotavirus gastroenteritis (GE). Kinetics of these biomarkers were examined in paired serum samples collected from bacterial enteritis patients with Campylobacter (n = 2) and Salmonella (n = 4) and viral GE patients with rotavirus (n = 27), norovirus (n = 25), and adenovirus (n = 11). At the time of hospital admission, all viral GE patients demonstrated increased MMP-9 and decreased MMP-2 and TIMP-2 serum levels. In contrast to viral GE patients, serum MMP-9 levels were not elevated at the time of hospital admission but elevated at the time of discharge; serum MMP-2 and TIMP-2 levels were decreased both at the time of admission and discharge in bacterial enteritis patients. Interestingly, the kinetics of serum MMP-2, MMP-9, and TIMP-2 levels were similar among the viral GE patients but distinct from bacterial enteritis patients. Thus, the involvement of MMPs and TIMPs in the pathophysiology of gastrointestinal symptoms likely varies depending on the etiological agent. Further studies are required to verify whether the extent of the bacterial enteritis or age of the patients influences these serum biomarkers. J. Med. Virol. 88:1341-1346, 2016. © 2016 Wiley Periodicals, Inc.

A Novel IgM-capture enzyme-linked immunosorbent assay using recombinant Vag8 fusion protein for the accurate and early diagnosis of Bordetella pertussis infection.

An ELISA that measures anti-PT IgG antibody has been used widely for the serodiagnosis of pertussis; however, the IgG-based ELISA is inadequate for patients during the acute phase of the disease because of the slow response of anti-PT IgG antibodies. To solve this problem, we developed a novel IgM-capture ELISA that measures serum anti-Bordetella pertussis Vag8 IgM levels for the accurate and early diagnosis of pertussis. First, we confirmed that Vag8 was highly expressed in all B. pertussis isolates tested (n = 30), but little or none in other Bordetella species, and that DTaP vaccines did not induce anti-Vag8 IgG antibodies in mice (i.e. the antibody level could be unaffected by the vaccination). To determine the immune response to Vag8 in B. pertussis infection, anti-Vag8 IgM levels were compared between 38 patients (acute phase of pertussis) and 29 healthy individuals using the anti-Vag8 IgM-capture ELISA. The results revealed that the anti-Vag8 IgM levels were significantly higher in the patients compared with the healthy individuals (P < 0.001). ROC analysis also showed that the anti-Vag8 IgM-capture ELISA has higher diagnostic accuracy (AUC, 0.92) than a commercial anti-PT IgG ELISA kit. Moreover, it was shown that anti-Vag8 IgM antibodies were induced earlier than anti-PT IgG antibodies on sequential patients' sera. These data indicate that our novel anti-Vag8 IgM-capture ELISA is a potentially useful tool for making the accurate and early diagnosis of B. pertussis infection.

[Results of Booster Vaccination in Children with Primary Vaccine Failure after Initial Varicella Vaccination].

In October 2014, the varicella vaccination policy in Japan was changed from a single voluntary inoculation to two routine inoculations. This paper reports the results of booster vaccination in children who did not show seroconversion after initial vaccination (i.e., primary vaccine failure : PVF) over a 7-year period prior to the introduction of routine varicella vaccination. Between November 2007 and May 2014, 273 healthy children aged between 1.1 and 14.5 years (median : 1.7 years) underwent varicella vaccination. Before and 4 to 6 weeks after vaccination, the antibody titers were measured using an immune adherence hemagglutination (IAHA) assay and a glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). In addition, side reactions were examined during the four-week period after vaccination. Children who did not show IAHA seroconversion (PVF) were recommended to receive a booster vaccination, and the measurement of antibody titers and an assessment of side reactions were performed after the booster dose. In May 2015, a questionnaire was mailed to each of the 273 participants to investigate whether they had developed varicella and/or herpes zoster after vaccination. After initial vaccination, the IAHA seroconversion rate was 75% and the mean antibody titer (Log2) with seroconversion was 4.7, while the gpELISA seroconversion rate was 84% and the mean antibody titer (Log10) with seroconversion was 2.4. Among children with PVF, 54 received booster vaccination within 81 to 714 days (median : 139 days) after the initial vaccination. After booster vaccination, the IAHA seroconversion rate was 98% and the mean antibody titer (Log2) with seroconversion was 5.8. Both the seroconversion rate and the antibody titer were higher compared with the values after the initial vaccination (p < 0.01). After booster vaccination, the gpELISA seropositive rate was 100% and the mean positive antibody titer (Log 10) was 3.6 ; similar results were obtained for the IAHA assay, with a significantly higher, antibody response than that after the initial vaccination (p < 0.01). Side reactions were generally minor, including fever (≥ 37.5 degrees C), rash at the injection site, and rash at other sites. There were no significant differences in the incidences of side reactions between the initial and booster vaccinations. A total of 185 participants responded to the questionnaire (response rate : 68%), and the period between receiving the initial vaccination and their response to the questionnaire ranged from 1.0 to 7.5 years (median : 4.0 years). The prevalence of breakthrough varicella after the initial vaccination was 17% among seroconverters who did not receive booster vaccination and 14% among non-seroconverters who received booster vaccination, showing no significant difference between the two groups. In conclusion, there are no safety issues regarding the administration of a booster vaccination to children with PVF after an initial varicella vaccination, and,a good antibody response can be expected.

EBV-associated T/NK-cell lymphoproliferative diseases in nonimmunocompromised hosts: prospective analysis of 108 cases.

EBV-associated T/NK-cell lymphoproliferative disease (T/NK-LPD) is defined as a systemic illness characterized by clonal proliferation of EBV-infected T or NK cells. We prospectively enrolled 108 nonimmunocompromised patients with this disease (50 men and 58 women; median onset age, 8 years; age range, 1-50 years) evidenced by expansion of EBV(+) T/NK cells in the peripheral blood; these were of the T-cell type in 64 cases and of the NK-cell type in 44, and were clinically categorized into 4 groups: 80 cases of chronic active EBV disease, 15 of EBV-associated hemophagocytic lymphohistiocytosis, 9 of severe mosquito bite allergy, and 4 of hydroa vacciniforme. These clinical profiles were closely linked with the EBV(+) cell immunophenotypes. In a median follow-up period of 46 months, 47 patients (44%) died of severe organ complications. During the follow-up, 13 patients developed overt lymphoma or leukemia characterized by extranodal NK/T-cell lymphoma and aggressive NK-cell leukemia. Fifty-nine received hematopoietic stem cell transplantation, 66% of whom survived. Age at onset of disease (≥ 8 years) and liver dysfunction were risk factors for mortality, whereas patients who received transplantation had a better prognosis. These data depict clinical characteristics of systemic EBV(+) T/NK-LPD and provide insight into the diagnostic and therapeutic approaches for distinct disease.

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

BACKGROUND: Chronic active Epstein-Barr virus (CAEBV) infection has high mortality and morbidity, and biomarkers for disease severity and prognosis are required. MicroRNAs (miRNAs) are small noncoding RNAs, and EBV encodes multiple miRNAs. Because plasma contains sufficiently stable miRNAs, circulating EBV-associated miRNA profiles were investigated as novel biomarkers in CAEBV infection. METHODS: Plasma miRNA expression was assessed for 12 miRNAs encoded within 2 EBV open reading frames (BART and BHRF). Expression levels were investigated in 19 patients with CAEBV infection, 14 patients with infectious mononucleosis, and 11 healthy controls. Relative expression levels of plasma miRNAs were determined by TaqMan probe-based quantitative assay. RESULTS: Plasma miR-BART1-5p, 2-5p, 5, and 22 levels in patients with CAEBV infection were significantly greater than those in patients with infectious mononucleosis and in controls. Plasma miR-BART2-5p, 4, 7, 13, 15, and 22 levels were significantly elevated in patients with CAEBV infection with systemic symptoms, compared with levels in patients with no systemic symptoms. The levels of miR-BART2-5p, 13, and 15 showed clinical cutoff values associated with specific clinical conditions, in contrast to plasma EBV loads. CONCLUSIONS: Levels of specific plasma EBV miRNAs were elevated differentially in patients with CAEBV infection. Several EBV miRNAs, particularly miR-BART2-5p, 13, and 15, are potentially biomarkers of disease severity or prognosis.

[Immunogenicity of additional varicella vaccination 3-5 years after the initial vaccination].

Additional varicella vaccination was carried out targeting 16 subjects who had immune adherence hemagglutination (IAHA) seroconversion following the initial varicella vaccination and did not contract breakthrough varicella after the initial vaccination. The median ages at the initial and additional vaccination were 2.1 (1.1-6.9) years old and 6.1 (4.4-10.5) years old, respectively. The mean interval between the initial and additional vaccination was 4.0 (3.2-5.2) years. IAHA and glycoprotein-based enzyme-linked immunosorbent assay (gpELISA) antibody titers were measured just before and 4-6 weeks after the additional vaccination. Side reaction was surveyed at four weeks after the additional vaccination, and compared with the results at the initial vaccination. IAHA and gpELISA seroconversion rates at the initial vaccination were 100% and 88% respectively. Prior to the additional vaccination, IAHA antibody titers significantly decreased in 50% of the subjects, and became negative in 38% of the subjects. On the other hand, a significant increase in IAHA antibody titers was observed in 25% of the subjects, and this is assumed to be the result of a subclinical infection after the initial vaccination. The positive rate of both antibodies after the additional vaccination was 100%, the mean IAHA antibody titer (Log2) after the initial/additional vaccination in seropositive subjects was 4.6/6.5, and the mean gpELISA antibody titer (Log10) was 2.3/4.0. The mean IAHA and gpELISA antibody titers were higher after the additional vaccination than after the initial vaccination (p < 0.01, p < 0.01). This is considered to be the booster effect due to the additional vaccination. At 0-2 days after the additional vaccination, a rash at the injection site was observed in 56% of the subjects, higher than the incidence after the initial vaccination (13%) (p < 0.05), but no severe systemic side reactions were observed at either the initial or the additional vaccination. In conclusion, an additional varicella vaccination 3-5 years after the initial vaccination is thought to have greater immunogenicity and is considered effective.

Anti-varicella-zoster virus antibody titers and seroprotection status from before the first dose of varicella vaccination to before entering elementary school in one region in Japan.

OBJECTIVE: We aimed to examine changes in anti-varicella-zoster virus (VZV) antibody titers and seroprotection status from before the first dose of vaccination to before 7 years old entering elementary school in children who received the routine two-dose varicella vaccination. METHODS: Participants were 37 healthy children who received the routine two-dose varicella vaccination at our hospital. A total of five serum samples per child were collected immediately before and 4-6 weeks after each dose of the vaccination and in the year before entry to elementary school. We measured anti-VZV antibody titers by immune adherence hemagglutination (IAHA) method and glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). A positive antibody titer and the seroprotection level were set as ≥2-fold and ≥16-fold, respectively, for IAHA antibody and as ≥50 units and ≥105 units, respectively, for gpELISA-IgG antibody. RESULTS: The rates of IAHA antibody positivity in the five samples (in order of collection) were 0%, 65%, 38%, 100%, and 59%, and the rates of seroprotection were 0%, 43%, 8%, 100%, and 43%. The rates of gpELISA-IgG antibody positivity were 8%, 81%, 89%, 100%, and 100%, and the rates of seroprotection were 5%, 54%, 70%, 100%, and 89%. The mean IAHA antibody titer and mean gpELISA-IgG antibody titer before entering elementary school were both lower than the respective titers obtained after the second vaccination (both p < 0.01). CONCLUSIONS: Routine two-dose varicella vaccination leads to good antibody production, but titers of acquired antibodies decrease before children enter elementary school.

Antitumor activities of valproic acid on Epstein-Barr virus-associated T and natural killer lymphoma cells.

Epstein-Barr virus (EBV), which infects B cells, T cells, and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, histone deacetylase (HDAC) inhibitors have been reported to have anticancer effects against various tumor cells. In the present study, we evaluated the killing effect of valproic acid (VPA), which acts as an HDAC inhibitor, on EBV-positive and -negative T and NK lymphoma cells. Treatment of multiple T and NK cell lines (SNT13, SNT16, Jurkat, SNK6, KAI3 and KHYG1) with 0.1-5 mM of VPA inhibited HDAC, increased acetylated histone levels and reduced cell viability. No significant differences were seen between EBV-positive and -negative cell lines. Although VPA induced apoptosis in some T and NK cell lines (SNT16, Jurkat and KHYG1) and cell cycle arrest, it did not induce lytic infection in EBV-positive T or NK cell lines. Because the killing effect of VPA was modest (1 mM VPA reduced cell viability by between 22% and 56%), we tested the effects of the combination of 1 mM of VPA and 0.01 µM of the proteasome inhibitor bortezomib. The combined treated of cells with VPA and bortezomib had an additive killing effect. Finally, we administered VPA to peripheral blood mononuclear cells from three patients with EBV-associated T or NK lymphoproliferative diseases. In these studies, VPA had a greater killing effect against EBV-infected cells than uninfected cells, and the effect was increased when VPA was combined with bortezomib. These results indicate that VPA has antitumor effects on T and NK lymphoma cells and that VPA and bortezomib may have synergistic effects, irrespective of the presence of EBV.

Application of flow cytometric in situ hybridization assay to Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases.

Epstein-Barr virus (EBV) infects various types of lymphocytes and is associated with not only B cell-origin lymphoma, but also T or natural killer cell lymphoproliferative diseases (T/NK LPD). Recently, we established a novel assay to identify EBV-infected cells using FISH. Using this assay, dual staining with antibodies to both surface antigens and an EBV-encoded small RNA (EBER) probe can be performed. In the present study, we applied this recently developed FISH assay to EBV-associated T/NK LPD to confirm its diagnostic utility. Using FISH, we prospectively analyzed peripheral blood from patients with suspected EBV-associated T/NK LPD. The results were compared with those obtained using immunobead sorting followed by quantitative PCR. In all, 26 patients were included study. Using FISH, 0.15-67.0% of peripheral blood lymphocytes were found to be positive for EBER. Dual staining was used to determine EBER-positive cell phenotypes in 23 of 26 subjects (88.5%). In five of seven patients with hydroa vacciniforme-like lymphoma (an EBV-positive cutaneous T cell lymphoma), EBER-positive cells were identified as CD3(+) CD4(-) CD8(-) TCRγδ(+) T cells. Furthermore, in a 25-year-old male patient with systemic EBV-positive T cell LPD, two lymphocyte lineages were positive for EBER: CD4(+) CD8(-) and CD4(-) CD8(+) T cells. Thus, we confirmed that our newly developed assay is useful for quantifying and characterizing EBV-infected lymphocytes in EBV-associated T/NK LPD and that it can be used not only to complement the pathological diagnosis, but also to clarify the pathogenesis and to expand the spectrum of EBV-associated diseases.

Detection of Mycoplasma pneumoniae by loop-mediated isothermal amplification (LAMP) assay and serology in pediatric community-acquired pneumonia.

Rapid diagnosis of Mycoplasma pneumoniae pneumonia is required for treatment with effective antimicrobial agents without delay; however, this capacity has not yet been established in clinical practice. Recently, a novel nucleic acid amplification method termed loop-mediated isothermal amplification (LAMP) has been used to rapidly diagnose various infectious diseases. In this study, we prospectively evaluated the efficacy of the LAMP assay to rapidly diagnose M. pneumoniae pneumonia in clinical practice. Three hundred sixty-eight children (median age, 3.8 years; range, 0.1-14.3 years) admitted to our hospital between April 2009 and March 2010 for community-acquired pneumonia were enrolled in this study. We obtained throat swabs on admission to detect M. pneumoniae DNA and paired serum samples on admission and at discharge to assay M. pneumoniae antibody titers. M. pneumoniae pneumonia was diagnosed by either a positive LAMP assay or a fourfold or greater increase in antibody titer. Overall, 46 children (12.5% of the patients with pneumonia) were diagnosed with M. pneumoniae pneumonia; of these, 27 (58.7%) were aged less than 6 years. Of the aforementioned 46 children, 38 (82.6%) and 37 (80.4%) were identified by LAMP and serology, respectively. When the results of serology were taken as the standard, the sensitivity and specificity and positive and negative predictive values of the LAMP assay were 78.4%, 97.3%, 76.3%, and 97.6%, respectively. We concluded the LAMP assay may be useful for rapid diagnosis of M. pneumoniae pneumonia.

[A study for the necessity of virus titer of varicella vaccine presently used].

Recently available varicella vaccine titers are several dozen times higher than the formulation standard in accompanying information, i.e., > or = 1,000 PFU/dose. We investigated changes in immunogenicity associated with vaccination using a reduced dose whose virus titer was close to that used when the vaccine was developed, and examined the need for the virus titer presently used. In a non blinded study of 43 children with no history of varicella infection, we administered 0.1 mL of varicella vaccine (1/5 of the normal dose) to 20 children 1 year 0 month to 4 years 5 months old (median: 1 year 5 months) and the standard 0.5mL dose to 23 children 1 year 2 months to 3 years 7 months old (median: 1 year 9 months). We measured IAHA and gpELISA antibody titer before vaccination and 4 to 6 weeks after vaccination. We defined "positive" as > or = 2 fold of IAHA titer and > or = 50 U of gpELISA antibody titer. We administered an additional 0.5mL of varicella vaccine to children whose IAHA titer failed to show seroconversion and remeasured antibody titer 4 to 6 weeks after revaccination. IAHA seroconversion was 25.0% (5/20) and gpELISA seroconversion 55.0% (11/20) in the 0.1 mL vaccination group, which was lower than that of 76.2% (16/21) and 87.0% (20/23), IAHA p < 0.01, gpELISA p < 0.05, in the 0.5 mL vaccination group. We administered an additional vaccination to 19 children--15 in the 0.1 mL vaccination group and 4 in the 0.5 mL vaccination group-with 100% seroconversion for both methods. Mean antibody titer after revaccination in the 0.1 mL vaccination group (IAHA 2 (6.0), gpELISA 10 (3.7)) was higher than those in the 0.5mL vaccination group who seroconverted following initial vaccination (IAHA 2(4.5), gpELISA 10(2.6)) (p < 0.01). We also measured virus titer in the remaining vaccine following vaccination of 0.1 mL (n = 20), and estimated virus titer administered to the 0.1 mL vaccination group to be 2,600-6,400 PFU/ dose. Varicella vaccine immunogenicity decreased if dosage was reduced to 1/5 of the standard dose, indicating that the present virus titer is necessary to maintain adequate immunogenicity. An additional administration of the standard dose to children who failed to seroconvert after initial 0.1 mL administration produced high antibody titers thought to constitute a booster effect.

Bortezomib induces apoptosis in T lymphoma cells and natural killer lymphoma cells independent of Epstein-Barr virus infection.

Epstein-Barr virus (EBV), which infects not only B cells, but also T cells and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, the proteasome inhibitor bortezomib was reported to induce apoptosis of EBV-transformed B cells. We evaluated the killing effect of this proteasome inhibitor on EBV-associated T lymphoma cells and NK lymphoma cells. First, we found that bortezomib treatment decreased the viability of multiple T and NK cell lines. No significant difference was observed between EBV-positive and EBV-negative cell lines. The decreased viability in response to bortezomib treatment was abrogated by a pan-caspase inhibitor. The induction of apoptosis was confirmed by flow cytometric assessment of annexin V staining. Additionally, cleavage of caspases and polyadenosine diphosphate-ribose polymerase, increased expression of phosphorylated IκB, and decreased expression of inhibitor of apoptotic proteins were detected by immunoblotting in bortezomib-treated cell lines. We found that bortezomib induced lytic infection in EBV-positive T cell lines, although the existence of EBV did not modulate the killing effect of bortezomib. Finally, we administered bortezomib to peripheral blood mononuclear cells from five patients with EBV-associated lymphoproliferative diseases. Bortezomib had a greater killing effect on EBV-infected cells. These results indicate that bortezomib killed T or NK lymphoma cells by inducing apoptosis, regardless of the presence or absence of EBV.

Effectiveness and safety of inactivated influenza vaccination in pediatric liver transplant recipients over three influenza seasons.

Annual influenza vaccination is recommended for pediatric liver transplant recipients, who are at high risk of influenza-related complications. However, effectiveness and safety of vaccination may differ among influenza seasons in this population and have not been fully evaluated. Subjects comprised 38 pediatric liver transplant recipients with or without influenza vaccination through the 2006-2007, 2007-2008 and 2008-2009 influenza seasons. Recipients received inactivated trivalent (AH1/AH3/B) influenza vaccine, and comparisons were made to non-vaccinated recipients with regard to effectiveness and safety. No significant differences were seen between recipient groups for acute allograft rejection, acute febrile illness, or influenza virus infection. No serious systemic adverse events were observed in vaccinated recipients. Seroprotection rate (defined as the proportion of recipients with HI antibody titer ≥ 1:40), seroconversion rate (proportion of recipients with a ≥ 4-fold increase in HI titers), and geometric mean titers were mostly elevated after vaccination for the three influenza antigens in each season. These three indicators of immunogenicity showed similar results in both vaccinated recipients and vaccinated healthy children in the 2007-2008 season. These findings suggest that pediatric liver transplant patients may respond safely to inactivated seasonal influenza vaccines in a similar manner to healthy children, and effectiveness varies among influenza seasons.

[Phases 3 and 4 immunization immunogenicity with combined measles-rubella vaccine].

A two-phase combined measles-rubella vaccine (MR) immunization schedule was introduced for age 1 and prior to primary school entry in Japan in April 2006. Further immunization was also introduced for 13 (Phase 3) and 18-year-old (Phase 4) cohorts for the 5-year period from April 2008 to March 2013. We surveyed Phases 3 and 4 MR immunization immunogenicity and safety. From August 2007 to December 2009, we conducted 3 Phase 3 and 15 Phase 4 immunizations. We then took paired serum samples (pre- and 4-6 weeks post-immunization), and measured measles antibody titers using hemagglutination inhibition (HI) and neutralizing test (NT), and rubella antibody titers using HI. Pre-positive measles HI antibody titer (> or = 8) was 72% (13/18) and pre-positive measles NT antibody titer (> or = 2) was 100% (18/18). Post-positive measles HI and NT antibody titers were 94% (17/18) and 100% (18/18). Mean post-immunization measles HI and NT antibody titers were significantly higher than pre-titers, with four-fold or greater increases seen in 9 (50%) and 6 (33%) subjects. Pre-positive rubella HI antibody titer (> or = 8) was 94% (17/18), and post-positive rubella HI antibody titer 100% (18/18). Mean post-immunization rubella HI antibody titer was significantly higher than pre-titer, with four-fold or greater increases seen in 8 subjects (44%). Paired HI antibody titers were measured in pre- and post-Phase 1 immunization for measles in 3 subjects and for rubella in 2 subjects. Those with post-Phase 1 measles HI antibody titers of 32, 64, and 128 yielded titers of 16, 8, and < 8 pre-Phase 3 or Phase 4 immunization, showing antibody reduction or seronegative conversion. Those with post-Phase 1 rubella HI antibody titers of 128 and 256 yielded titers of 64 and 32 in pre-Phase 4 immunization, showing antibody reduction. Seroconversion or four-fold or greater increases in titer were seen post-immunization in 60% (3/5) of these subjects. A clinical reaction survey of all subjects 4 weeks post-immunization, showed only 1 case of mild fever and no local or systemic adverse reactions such as generalized urticaria or anaphylaxis. In conclusion, Phases 3 and 4 MR immunogenicity was satisfactory.

Immunologic and virologic analyses in pediatric liver transplant recipients with chronic high Epstein-Barr virus loads.

BACKGROUND: Long-term Epstein-Barr virus (EBV) monitoring for potentially life-threatening posttransplant lymphoproliferative disorder (PTLD) has identified asymptomatic patients who maintain high EBV loads over long periods. METHODS: Thirty-one pediatric liver transplant recipients were designated as 11 chronic high EBV load carriers (EBV DNA level >5000 copies/mL of whole blood for >6 months) and 20 control recipients. Serial quantification of EBV DNA, measurement of interleukin 10 (IL-10) concentrations, EBV-specific tetramer staining, and relative quantification of EBV gene expression in peripheral blood mononuclear cells were performed. RESULTS: Most of the chronic high EBV load carriers were seronegative at transplant, the median time to resolution of a chronic high EBV load was 23 months, and no recipient developed late-onset PTLD. EBV DNA was detected predominantly in CD19(+) cells. The plasma concentration of IL-10 and the EBV-specific CD8(+) cell frequency did not differ significantly between the chronic high EBV load carriers and the control recipients. Analysis of gene expression showed that EBV-encoded small RNA 1, BamHI A rightward transcripts, and latent membrane protein 2 were positive in peripheral blood mononuclear cells from chronic high EBV load carriers. CONCLUSIONS: EBV-infected cells in the blood of chronic high EBV load carriers expressed a highly restricted set of latency genes, suggesting that the EBV-infected cells escaped from a T cell response.

Quantitative analysis of Epstein-Barr virus (EBV)-related gene expression in patients with chronic active EBV infection.

Chronic active Epstein-Barr virus (CAEBV) infection is a systemic Epstein-Barr virus (EBV)-positive lymphoproliferative disorder characterized by persistent or recurrent infectious mononucleosis-like symptoms in patients with no known immunodeficiency. The detailed pathogenesis of the disease is unknown and no standard treatment regimen has been developed. EBV gene expression was analysed in peripheral blood samples collected from 24 patients with CAEBV infection. The expression levels of six latent and two lytic EBV genes were quantified by real-time RT-PCR. EBV-encoded small RNA 1 and BamHI-A rightward transcripts were abundantly detected in all patients, and latent membrane protein (LMP) 2 was observed in most patients. EBV nuclear antigen (EBNA) 1 and LMP1 were detected less frequently and were expressed at lower levels. EBNA2 and the two lytic genes were not detected in any of the patients. The pattern of latent gene expression was determined to be latency type II. EBNA1 was detected more frequently and at higher levels in the clinically active patients. Quantifying EBV gene expression is useful in clarifying the pathogenesis of CAEBV infection and may provide information regarding a patient's disease prognosis, as well as possible therapeutic interventions.

Comparison of the levels of human herpesvirus 6 (HHV-6) DNA and cytokines in the cerebrospinal fluid and serum of children with HHV-6 encephalopathy.

Primary human herpesvirus-6 (HHV-6) infection is a common cause of acute sporadic encephalopathy in Japanese children. Occasionally, HHV-6 is not detected in the cerebrospinal fluid (CSF) of patients with encephalopathy, for example, in those with focal viral encephalitis, such as herpes simplex viral encephalitis. This indicates that HHV-6 encephalopathy is caused by an indirect mechanism, although this is not fully understood. HHV-6 DNA, cytokines (interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12 p70, tumor necrosis factor-alpha, interferon-gamma), and matrix metalloproteinase-9 were quantitated in both the CSF and serum of 13 patients with HHV-6 encephalopathy during the acute phase of the disease. HHV-6 DNA was detected in the CSF of seven patients with HHV-6 encephalopathy. The viral DNA concentration was significantly higher in serum than in CSF (mean 1.64 x 10(4) vs. 5.70 x 10(1) copies/ml; P = 0.003). The lack or low level of viral DNA in the CSF samples suggests that direct invasion of the central nervous system by HHV-6 is not the main cause of encephalopathy. Additionally, the IL-10 concentration was significantly higher in serum than in CSF (P < 0.001), whereas there was no significant difference in IL-6 levels between the CSF and serum samples. Interestingly, the IL-8 concentration was significantly higher in CSF than in serum (P = 0.038). The distribution of these cytokines differed between CSF and serum. The high CSF concentration of IL-8 could play an important role in the pathogenesis of encephalopathy.

An Investigation of Japanese Neonatal and Maternal Antibody Status against Pertussis.

To clarify the pertussis immune status of the Japanese population, we investigated levels of serum pertussis toxin (PT)-specific immunoglobulin G (IgG) antibody in infants and mothers between April 2016 and March 2018. A total of 206 infants (n = 22, < 32 weeks of gestational age [wGA]; n = 70, 32-36 wGA; n = 114, ≥ 37 wGA) and 170 mothers were enrolled. The maternal seroprevalence and antibody geometric mean titer (GMT) were 52.4% and 10.7 EU/mL, respectively. The antibody GMT, seroprevalence, and mean ratio of infant to maternal antibody titers of infants at < 32 wGA were 3.2 EU/mL, 13.6%, and 42.5%, respectively, and were significantly lower than those of infants at 32-36 wGA (9.7 EU/mL, 54.3%, and 110.2%) and infants at ≥ 37 wGA (12.1 EU/mL, 57.9%, and 112.6%). Of the 21 infants who underwent a second examination, five were positive in the first examination. Of those five, the GMT for PT had decreased by an average of 52.6% at 4.3- week intervals. In the second examination, two infants were seropositive. Approximately half of the mothers and infants were negative for anti-PT antibody. Thus, new vaccination strategies, such as the vaccination of pregnant women, are needed to prevent pertussis infection in early infancy.