Torque Teno Virus Loads as a Marker of Immunosuppression in Pediatric Kidney Transplant Recipients.

BACKGROUND: Long-term renal function and survival after kidney transplantation rely on appropriate immunosuppressive treatment to prevent the risk of rejection. New biomarkers are needed to accurately assess the degree of immunosuppression in renal transplant recipients in order to avoid organ rejection and the development of opportunistic infections. Highly prevalent in humans, torque teno virus (TTV), which belongs to the family Anelloviridae, is a small, nonenveloped, single-stranded DNA virus which has not been linked with any specific human illness, but which constitutes a major component of the human virome. Host antiviral responses allow TTV levels to be controlled; however, viral persistence remains, explaining the high prevalence in human populations, including healthy individuals. Important confounders of TTV load include time since transplantation, age, gender, obesity, and smoking status. AIMS: TTV-based guidance of immunosuppressive drug dosing could help with risk stratification, reducing the risk of infection, graft rejection and oncologic disease on an individual level, enabling long-term patient and graft survival. METHODS: Original studies were accessed by a systematic search from electronic databases including PubMed, ScienceDirect and Wiley Online Library. RESULTS: The presented data mainly derive from adult transplant recipients showing an association between TTV plasma levels and the immune status of the host: High-TTV load and high immunosuppression are associated with a risk of infection, and low-TTV load and low immunosuppression indicate a risk of rejection. However, there is minimal information on pediatric transplant recipients with further research required in this cohort. To date, it has been demonstrated that longer posttransplant times are significantly associated with lower TTV levels in children with renal transplant. Meanwhile, an association between lower TTV loads and increased risk of graft reject during the first year of transplantation was also reported. More recently, Eibensteiner et al. revealed a robust, independent association between TTV plasma load and the onset of Cytomegalovirus and BK virus infections. CONCLUSION: Data from randomized controlled trials are still missing, even in adults, but a multicenter randomized controlled trial for TTV-guided immunosuppression in adult kidney recipients (TTVguideIT) began in 2022. There is, therefore, great promise for TTV levels to be used as a biomarker that could potentially improve both graft and patient survival in transplantation.

Enhancement of Antiviral Effect of Plastic Film against SARS-CoV-2: Combining Nanomaterials and Nanopatterns with Scalability for Mass Manufacturing.

Direct contact with contaminated surfaces in frequently accessed areas is a confirmed transmission mode of SARS-CoV-2. To address this challenge, we have developed novel plastic films with enhanced effectiveness for deactivating the SARS-CoV-2 by means of nanomaterials combined with nanopatterns. Results prove that these functionalized films are able to deactivate SARS-CoV-2 by up to 2 orders of magnitude within the first hour compared to untreated films, thus reducing the likelihood of transmission. Nanopatterns can enhance the antiviral effectiveness by increasing the contact area between nanoparticles and virus. Significantly, the established process also considers the issue of scalability for mass manufacturing. A low-cost process for nanostructured antiviral films integrating ultrasonic atomization spray coating and thermal nanoimprinting lithography is proposed. A further in-depth investigation should consider the size, spacing, and shape of nanopillars, the type and concentration of nanoparticles, and the scale-up and integration of these processes with manufacturing for optimal antiviral effectiveness.

Discrimination between recent and non-recent HIV infections using routine diagnostic serological assays.

The suitability of routine diagnostic HIV assays to accurately discriminate between recent and non-recent HIV infections has not been fully investigated. The aim of this study was to compare an established HIV recency assay, the Sedia limiting antigen HIV avidity assay (LAg), with the diagnostic assays; Abbott ARCHITECT HIV Ag/Ab Combo and INNO-LIA HIV line assays. Samples from all new HIV diagnoses in Ireland from January to December 2016 (n = 455) were tested. An extended logistic regression model, the Spiegelhalter-Knill-Jones method, was utilised to establish a scoring system to predict recency of HIV infection. As proof of concept, 50 well-characterised samples were obtained from the CEPHIA repository whose stage of infection was blinded to the authors, which were tested and analysed. The proportion of samples that were determined as recent was 18.1% for LAg, 6.4% with the ARCHITECT, and 14.5% in the INNO-LIA assay. There was a significant correlation between the ARCHITECT S/CO values and the LAg results, r = 0.717, p < 0.001. ROC analysis revealed that an ARCHITECT S/CO < 250 had a sensitivity and specificity of 90.32% and 89.83%, respectively. Combining the Abbott ARCHITECT HIV Ag/Ab Combo assay and INNO-LIA HIV assays resulted in an observed risk of being recent of 100%. Analysis of the CEPHIA samples revealed a strong agreement between the LAg assay and the combination of routine assays (κ = 0.908, p < 0.001). Our findings provide evidence that assays routinely employed to diagnose and confirm HIV infection may be utilised to determine the recency of HIV infection.

Investigation of SARS-CoV-2 IgG Binding Capability to Variants of the SARS-CoV-2 Virus.

The SARS-CoV-2 pandemic has confirmed that the ability to rapidly mutate may be extremely beneficial for a virus. Not long after the first wave, new variants emerged with altered infectivity, disease severity, and mortality. These new strains most notably had numerous mutations of the spike (S) protein, a surface protein responsible for binding to and entering the host cell. The Delta and Omicron strains demonstrated increased immune evasion and improved binding affinity to the host cell receptor, angiotensin-converting enzyme 2 (ACE2). This study examines the ability of wild-type SARS-CoV-2 IgG to bind Delta and Omicron antigens, as well as their functional binding capabilities to two different S-ACE2 complexes. Twenty SARS-CoV-2 positive samples from patients who had recovered from infection with ancestral SARS-CoV-2 in the first wave of COVID-19 and 10 pre-pandemic control samples were studied. SARS-CoV-2 exposed patients showed significantly higher levels of IgG to SARS-CoV-2 S1/RBD (p < 0.001), N protein (p < 0.001), and Omicron spike variant (p = 0.01), but not to Delta spike variant (p = 0.966) when compared with controls. Furthermore, patient samples showed significantly greater inhibition of SARS-CoV-2 S1/RBD and E484K spike to ACE2 binding (p < 0.001 and p = 0.015, respectively). Conversely, there was no correlation between the binding inhibition of S1/RBD and E484K spike to ACE2 receptor. This study shows there is considerable cross-reactivity of IgG generated by wild-type SARS-CoV-2 infection to the Delta and Omicron variants.

Increased levels of PD-1 expression on CD8 T cells in patients post-renal transplant irrespective of chronic high EBV viral load.

Studies have identified solid organ transplant recipients who remain asymptomatic despite maintaining CHL. Factors which determine the CHL state remain poorly understood but are likely to involve immunological control of the viral infection. We monitored expression of PD-1, a marker of T-cell exhaustion and viral persistence, on CD8 T cells in patients who resolved EBV infection as determined by undetectable EBV DNA (REI) and CHL patients. PD-1 expression on CD8 T cells was increased in the first year post-transplant irrespective of EBV outcome, and most CD8 T cells continued to express PD-1 for up to three yr post-transplant. Although all patient groups showed similar frequencies of EBV-specific CD8+ T cells, PD-1 expression on these cells increased in the post-transplant groups compared with the pretransplant patients. Functional studies of EBV-specific CD8+ T cells stimulated with BZLF or LMP2 peptide pools revealed monofunctional IFN-γ responses. Our results indicate that PD-1 expression on CD8 T cells post-transplant may result from factors other than antigenic stimulation.

D614G SARS-CoV-2 Pseudovirus Infectivity and Binding of Spike Protein to the ACE2 Receptor Inversely Correlates with Serum SARS-CoV-2-Specific IgG Levels.

Understanding the functional characteristics of antibodies produced against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will assist in the determination of disease outcomes for this virus. In this study, the ability of antibodies to inhibit viral entry into the host cell through the interaction of the receptor binding domain of the viral spike protein and the angiotensin-converting enzyme 2 receptor on the human cell surface was investigated. The SARS-CoV-2 IgG levels in 20 SARS-CoV-2 positive patients were measured using an enzyme-linked immunosorbent assay, and the samples were further analyzed using a functional binding assay. Inhibition of viral infectivity was also measured using a pseudovirus neutralization assay against a D614G SARS-CoV-2 virus strain. A significant correlation between IgG levels and neutralizing antibody 50% inhibitory concentration (IC50) titers was observed (p < 0.05). Similarly, the IC50 titers obtained in the neutralization and binding assays were significantly correlated (p < 0.001). Varying levels of IgG and IC50 titers were observed for the SARS-CoV-2 antibody-positive samples, with one sample not showing any neutralizing capability despite detectable IgG levels. Gender comparisons showed no statistical differences in any of the assays. These results suggest that increased SARS-CoV-2 IgG levels correlate with greater protection against the entry of the virus into cells; however, further investigations in larger studies are needed to confirm the correlates of protection.

UV-Assisted Hyperbranched Poly(ß-amino ester) Modification of a Silica Membrane for Two-Step Microfluidic DNA Extraction from Blood.

Integrating nucleic acid extraction in amplification-based point-of-care diagnostics will be a significant feature for next-generation point-of-care virus detection devices. However, extracting DNA efficiently on a microfluidic chip poses many technological and commercialization challenges, including manual steps, multiple instruments, pretreatment processes, and the use of organic solvents (ethanol, IPA) that inhibit detection, which is not viable with routine testing such as viral load monitoring of transplant patients for post-operative care. This paper presents a microfluidic system capable of two-step DNA extraction from blood using a UV-assisted hyperbranched poly(ß-amino ester) (HPAE)-modified silica membrane for cytomegalovirus (CMV) detection in a rapid and instrument-free manner without the presence of amplification inhibitors. HPAEs of varying branch ratios were synthesized, screened, and coated on a silica membrane and bonded between two layers of poly(methyl methacrylate) (PMMA) substrates. Our system could selectively extract DNA from blood with an efficiency of 94% and a lower limit viral load of 300 IU/mL in 20 min. The extracted DNA was used as the template for real-time loop-mediated isothermal amplification (LAMP)-based detection of CMV and was found to produce a fluorescent signal intensity that was comparable with commercially extracted templates. This system can be integrated easily with a nucleic acid amplification system and used for routine rapid testing of viral load in patient blood samples.

Mumps-specific IgG, IgG subclasses and neutralization titres to the vaccine and outbreak mumps strains differ in vaccinated healthy controls, breakthrough mumps infection cases and naturally infected individuals.

BACKGROUND: Despite widespread use of the mumps vaccine resulting in significant reduction in the incidence of symptomatic mumps infection, large outbreaks continue to occur in highly vaccinated populations. OBJECTIVES: We examined the mumps-specific IgG, IgG subclasses and neutralization titres to the outbreak Genotype G5 and Jeryl Lynn vaccine (Genotype A) mumps strains. STUDY DESIGN: Sera from 207 individuals were classified into five distinct cohorts: healthy controls and mumps cases of 5-17 years and 18-25 years, and naturally infected individuals of 50+ years. Mumps specific IgG and IgG subclass levels were measured using modified ELISA assays with lysates and nucleoprotein antigens from both the mumps vaccine and circulating Genotype G5 strains. All sera were investigated for in vitro neutralizing antibody titres (GMT) using focus reduction neutralization assays. Data was analysed using the Kruskal-Wallis test and pairwise Wilcoxon tests. RESULTS: Mumps cases had higher mumps IgG levels compared to controls, to both the vaccine and outbreak strains, however levels decreased with age. Mumps IgG3 levels were significantly raised in mumps cases (p < 0.001). Neutralization titres were lower to the outbreak strain in all cohorts with titres markedly lower in the mumps cohorts compared to healthy controls. Mean GMT to the vaccine strain increased with age. The naturally infected group displayed the highest GMT to the JL vaccine and the lowest GMT to the outbreak strain. CONCLUSIONS: Antigenic differences between mumps vaccine strain and circulating mumps viruses decrease the cross-neutralization capacity of vaccine-induced antibodies which may play a role in breakthrough infection.

Surveillance of Epstein-Barr virus loads in adult liver transplantation: associations with age, sex, posttransplant times, and transplant indications.

Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication after adult orthotopic liver transplantation (AOLT). Besides EBV and immunosuppression, relatively little is known about the pretransplant clinical parameters associated with the risk of PTLD, and the benefit of using EBV surveillance to predict EBV-associated disease in AOLT patients is uncertain. The aims of this single-center study were to monitor EBV viral loads (VLs) in AOLT patients and to investigate any associations with age, sex, cytomegalovirus (CMV) serostatus, posttransplant times, and indications for transplantation. 1275 blood samples that were collected from 197 AOLT patients 1 day to more than 15 years after transplantation were investigated with quantitative polymerase chain reaction for EBV and CMV DNA. Seventy-two percent of the patients had EBV DNAemia less than 100 days after transplantation without clinical manifestations. No association was observed between the EBV copy numbers and the time since transplantation. EBV DNAemia was weakly associated with male sex but was not associated with age, CMV serostatus, or indications for AOLT. The highest EBV VL levels were observed in patients who presented with congenital liver diseases, whereas patients with viral hepatitis maintained high EBV VLs after transplantation. None of the patients developed PTLD during the study period; however, 3 patients presented with EBV-associated diseases. In conclusion, EBV DNAemia is common in AOLT patients, and routine EBV surveillance has limited value for predicting EBV-associated morbidity or mortality.

Human cytomegalovirus UL144 is associated with viremia and infant development sequelae in congenital infection.

Human cytomegalovirus (HCMV) strains may be genotyped based on polymorphisms that exist within the UL144 gene, which is one of 19 viral genes lost in attenuated laboratory strains. In the present study, UL144 genotypes in congenitally infected babies (congenital cytomegalovirus [cCMV]) were determined, and the relationship between the genotype, viral load, cytokine profile, and patient developmental outcome was investigated. All cCMV infections identified during 2006 and 2007 were included (n = 29). A portion of the infants were clinically assessed at birth and at 12 to 18 months postinfection for cCMV clinical sequelae (n = 18/29). The plasma viral load (PVL) was requested for 23/29 patients, and the UL144 genotype was determined (n = 27/29). The cytokine profile in patient plasma or serum was assessed (n = 20/29). UL144 genotypes A, B, and C were detected within the cCMV population at 33.3%, 29.6%, and 25.9%, respectively. UL144 A and C were associated with a high PVL (P < 0.04). Furthermore, a significant association between the developmental outcome and UL144 A and C was observed (P < 0.04). Only patients infected with UL144 B and A/B were described as having a normal clinical outcome. In addition, a significant correlation between interleukin 10 (IL-10) levels and the PVL was observed (P < 0.04); however, there was no association between the genotype and the cytokine profile. The present study determined that the specific detection of UL144 genotypes A and C was indicative of serious cCMV infection and more likely to lead to long-term cCMV-associated clinical manifestations. The inclusion of HCMV UL144 genotyping along with the recommended PVL monitoring following cCMV diagnosis may aid prediction of the clinical outcome.

Molecular epidemiological evaluation of the recent resurgence in mumps virus infections in Ireland.

Mumps is a vaccine-preventable disease; however, outbreaks have been reported in a number of countries with childhood immunization programs, particularly among young adults at the tertiary stage of education. We have retrospectively investigated the epidemiological, virological, and serological factors associated with mumps cases identified in Ireland from 2004 to 2009. Genetic analysis of mumps virus strain variability demonstrated that a single genotype, genotype G, was circulating, and it was also detected in cerebrospinal fluid samples obtained from patients with meningitis. We observed that younger individuals were disproportionately affected with neurological sequelae following mumps virus infection, and the average age of patients with mumps virus RNA detected in cerebrospinal fluid was 19.25 years (median, 19 years; range, 14 to 24 years). Our analysis showed a 4-fold rise in mumps cases in 2008-2009 and an increased incidence in infection in those >or=30 years of age. Over a 6-year period (2004 to 2009), a total of 7,805 serum samples were investigated; of this number, 1,813 (23%) were positive for mumps virus-specific IgM. We observed a strong bias for acute mumps virus infection in males compared to females (P < 10(-32)) that was independent of vaccination status.

First report of sudden death due to myocarditis caused by adenovirus serotype 3.

Myocarditis is a rare cause of sudden death in childhood. We describe the sudden death of a child from viral myocarditis, which we demonstrate was likely caused by an uncontrolled inflammatory response to a disseminated adenovirus serotype 3 infection originating in the tonsil.

Presence of low mumps-specific IgG in oral fluids is associated with high mumps viral loads.

BACKGROUND: Mumps outbreaks continue to occur in highly vaccinated populations. Although the diagnosis of mumps is primarily based on clinical symptoms, other viral infections such as parainfluenza can manifest in a similar manner. Therefore, laboratory confirmation of mumps virus infection is important. OBJECTIVES: The aims of this study were to examine mumps cases during the January 2018 to March 2019 period in Ireland as well as to evaluate the association between mumps RNA viral loads, mumps IgG levels, age and gender among patients with laboratory-confirmed mumps virus infection. STUDY DESIGN: Oral fluid samples requested for mumps RNA testing (n = 1296) were included in the study. The mumps N gene was detected by real time PCR and reported as Ct values. RESULTS: The proportion of samples received monthly with detectable mumps RNA increased from 10.26%-70.3% during the recent outbreak. Acute mumps cases occurred predominantly in the 16-25 years old age cohort (67.5 %) and in males (55.9 %). Mumps RNA viral loads were significantly higher in females (p < 0.001). During the outbreak, a significantly higher proportion of samples had Ct <30 (p < 0.05). A significant correlation was observed between mumps IgG levels and Ct values in oral fluid samples (p < 0.0001). CONCLUSIONS: The presence of low mumps virus-specific IgG in oral fluids is significantly associated with high mumps viral loads. Our findings show that mumps virus is maintained in circulation in the non-outbreak period and acute mumps cases occur predominantly in the MMR vaccinated young adult male population.

Mumps Outbreaks in Vaccinated Populations-Is It Time to Re-assess the Clinical Efficacy of Vaccines?

History illustrates the remarkable public health impact of mass vaccination, by dramatically improving life expectancy and reducing the burden of infectious diseases and co-morbidities worldwide. It has been perceived that if an individual adhered to the MMR vaccine schedule that immunity to mumps virus (MuV) would be lifelong. Recent mumps outbreaks in individuals who had received two doses of the Measles Mumps Rubella (MMR) vaccine has challenged the efficacy of the MMR vaccine. However, clinical symptoms, complications, viral shedding and transmission associated with mumps infection has been shown to be reduced in vaccinated individuals, demonstrating a benefit of this vaccine. Therefore, the question of what constitutes a good mumps vaccine and how its impact is assessed in this modern era remains to be addressed. Epidemiology of the individuals most affected by the outbreaks (predominantly young adults) and variance in the circulating MuV genotype have been well-described alluding to a collection of influences such as vaccine hesitancy, heterogeneous vaccine uptake, primary, and/or secondary vaccine failures. This review aims to discuss in detail the interplay of factors thought to be contributing to the current mumps outbreaks seen in highly vaccinated populations. In addition, how mumps diagnoses has progressed and impacted the understanding of mumps infection since a mumps vaccine was first developed, the limitations of current laboratory tests in confirming protection in vaccinated individuals and how vaccine effectiveness is quantified are also considered. By highlighting knowledge gaps within this area, this state-of-the-art review proposes a change of perspective regarding the impact of a vaccine in a highly vaccinated population from a clinical, diagnostic and public perspective, highlighting a need for a paradigm shift on what is considered vaccine immunity.

Kinetics of host immune responses and cytomegalovirus resistance in a liver transplant patient.

Among solid organ transplant (SOT) recipients, donor-seropositive/recipient-seronegative (D+/R-) cytomegalovirus (CMV) status is associated with the highest risk of ganciclovir-resistant CMV disease, which has been reported for patients receiving oral ganciclovir but not valganciclovir prophylaxis. We report a case of CMV breakthrough infection in a D+/R- liver transplant patient while he was receiving oral valganciclovir. Forty samples collected over 6 months were analyzed for the CMV viral load, lymphocyte counts, cytokine levels, and lymphocyte differentiation status. Genotypic resistance testing of the viral UL97 gene was performed when the patient failed to respond. CMV viremia occurred on day 50 post-transplant, and 5 samples taken between days 50 and 85 showed the wild-type UL97 genotype. The appearance of deletion 594-595 was observed from day 114 post-transplant. Viral loads declined when foscarnet was commenced and remained below 10,000 copies/mL when the lymphocyte count was greater than 1000/microL (P = 0.02). T cell responses revealed significant expansion of CD8+ terminal effector memory cells. CD4+ cells were largely populations of naïve and central memory cells. Circulating interleukin 10 (IL-10) levels correlated with the viral load (P < 0.0001). Seroconversion occurred on day 230. The CMV viral load in combination with lymphocyte counts and IL-10 may be a predictive marker for the risk of development of resistant CMV disease in D+/R- SOT patients.

Molecular epidemiology of circulating measles virus in Ireland 2002-2007.

The molecular characterization of measles virus (MeV) is a valuable epidemiological tool to monitor virus transmission and to discriminate between imported and endemic infection. There has been significant immigration into Ireland in recent years and many individuals originate from regions of high measles incidence. Ireland has had a number of outbreaks of MeV which appear attributable to sub-optimal vaccine uptake and possibly imported strains as new genotypes have been identified in recent years. To ascertain any significant changes in circulating measles genotypes we investigated 65 confirmed measles cases between the years 2002 and 2007. The laboratory diagnosis of measles was confirmed by detection of measles-specific IgM in oral fluid in conjunction with a real-time polymerase chain reaction assay targeting the MeV hemagglutinin gene. Phylogenetic analysis based on the 3' hypervariable region of the nucleoprotein gene was performed and three genotypes, all within measles clade D, were found to be circulating during this time period. In 2002 and 2003, genotype D8 (n = 2) was observed whereas genotype D7 was dominant in 2003 (n = 31). A distinct change in the circulating MeV genotype and increased genetic diversity was observed between 2004 and 2007. All cases were within genotype D4 (n = 32) but were phylogenetically distinct from each other. These data provide important epidemiologic baseline information on MeV in Ireland and facilitates detailed examination of measles transmission.

Systemic IL-1ß production as a consequence of corneal HSV-1 infection-contribution to the development of herpes simplex keratitis.

This study sought to identify potential therapeutic targets in herpes simplex keratitis (HSK) patients with active and inactive infection by investigating peripheral cytokine production. Peripheral blood mononuclear cells (PBMCs) and serum were prepared from healthy controls and HSK patients during active infection or following treatment (inactive infection). Serum antibody titres were determined by ELISA. Protein expression levels were analysed by Western blot. Cytokine levels were determined by multiplex ELISA. Active corneal herpes simplex virus type 1 (HSV-1) infection resulted in significantly elevated peripheral levels of IL-1ß in HSK patients compared to healthy controls, and remained significantly increased following treatment. Elevated production of IL-1ß in inactive patients was associated with significantly increased levels of IRF3 and STAT1, key proteins involved in promoting anti-viral immune responses. Our data suggest that inflammation persists beyond the period that it is clinically evident and that enhanced peripheral production of IL-1ß may have implications for HSV-1 viral clearance in active and inactive HSK patients.

Mycoplasma pneumoniae infection in a pediatric population: analysis of soluble immune markers as risk factors for asthma.

Epidemiologic and clinical evidence suggests that respiratory tract infection with Mycoplasma pneumoniae maybe implicated in the initiation and exacerbation of asthma. This study examines the incidence and frequency of M. pneumoniae infection in children and evaluates the serum cytokine profile and total immunoglobulin E (IgE) levels in a subgroup of patients with clinical presentation of either upper respiratory tract infections (URTI) or lower respiratory tract infections (LRTI). A total of 6986 serum samples were tested for specific IgM anti-M. pneumoniae, and a 4-year cyclical incidence of M. pneumoniae infection was confirmed; however; the peak age of highest incidence in the most recent epidemic fell to 3-4 years. A high incidence was also observed in the 6-7-year age group. Children presenting with LRTI, when compared with those patients presenting with URTI, had significantly higher serum levels of the proinflammatory cytokines, interleukin (IL)-1alpha, IL-6, the T-helper (Th)2-type cytokines, and IL-4 and IL-10. The Th1-type cytokines, IL-2 and IL-12, were within the normal range, whereas interferon-gamma levels were slightly raised. Total serum immunoglobulin E levels were significantly higher in the LRTI group (p < 0.02). Our findings support the emerging evidence that respiratory tract infection with Mycoplasma pneumoniae results in an increased proinflammatory and Th2-type cytokine response that may precede the initiation and exacerbation of asthma.

Epidemiologic and diagnostic evaluation of a recent mumps outbreak using oral fluid samples.

OBJECTIVE: To determine the optimal strategy to investigate mumps virus infection in a partially vaccinated cohort. STUDY DESIGN: 122 oral fluid and serum samples were collected in a recent outbreak in Ireland. The largest age cohort, students aged 18-21 years old attending third level institutions, were investigated using virus isolation, detection of mumps specific IgM, IgG, RT-PCR and molecular genotyping. RESULTS: 97% of patients had both detectable serum IgM and IgG. Mumps virus RNA was detected in 17 oral fluid samples and 14 of these originated from a single geographic location. Only 6 of the IgM positive samples had detectable mumps virus RNA whereas this could be detected in 11 IgM negative samples. Genotyping studies revealed that genotypes G and J were co-circulating during this outbreak. CONCLUSIONS: The use of an oral fluid sample to detect mumps virus RNA and IgM offers a major improvement over serological diagnosis in acute infection in both non-vaccinated or partially vaccinated individuals, and has the advantage that specimens are collected non-invasively.

Plasma EBV microRNAs in paediatric renal transplant recipients.

BACKGROUND: Epstein-Barr virus (EBV) was the first human virus identified to express microRNA (miRNA). To date, 44 mature miRNAs are encoded for within the EBV genome. EBV miRNAs have not been profiled in paediatric renal transplant recipients. In this study, we investigated circulating EBV miRNA profiles as novel biomarkers in paediatric renal transplant patients. METHODS: Forty-two microRNAs encoded within 2 EBV open reading frames (BART and BHRF) were examined in renal transplant recipients who resolved EBV infection (REI) or maintained chronic high viral loads (CHL), and in non-transplant patients with acute infectious mononucleosis (IM). RESULTS: Plasma EBV-miR-BART2-5p was present in higher numbers of IM (7/8) and CHL (7/10) compared to REI (7/12) patients. A trend was observed between the numbers of plasma EBV miRNAs expressed and EBV viral load (p < 0.07). Several EBV-miRs including BART7-3p, 15, 9-3p, 11-3p, 1-3p and 3-3p were detected in IM and CHL patients only. The lytic EBV-miRs, BHRF1-2-3p and 1-1, indicating active viral replication, were detected in IM patients only. One CHL patient developed post-transplant lymphoproliferative disease (PTLD) after several years and analysis of 10 samples over a 30-month period showed an average 24-fold higher change in plasma EBV-miR-BART2-5p compared to the CHL group and 110-fold higher change compared to the REI group. CONCLUSIONS: Our results suggest that EBV-miR-BART2-5p, which targets the stress-induced immune ligand MICB to escape recognition and elimination by NK cells, may have a role in sustaining high EBV viral loads in CHL paediatric kidney transplant recipients.