Comparison of serum and whole blood levels of cytomegalovirus and Epstein-Barr virus DNA

Epstein-Barr Virus Monitoring after an Allogeneic Hematopoietic Stem Cell Transplant: Review of the Recent Data and Current Practices in Canada

Epstein-Barr virus-related post-transplantation lymphoproliferative disorder (EBV-PTLD) is a serious complication following hematopoietic stem cell transplantation (HSCT). A pre-emptive strategy using rituximab, which aims to manage patients early at the time of EBV reactivation to avoid PTLD, has been recommended by the most recent ECIL-6 guidelines in 2016. However, there is still a great heterogeneity of viral-load monitoring protocols, targeted patient populations, and pre-emptive treatment characteristics between centers, making precise EBV monitoring recommendations difficult. We conducted a literature review from the most recent publications between 1 January 2015 and 1 August 2023, to summarize the emerging data on EBV-PTLD prevention strategies in HSCT recipients, including the EBV-DNA threshold and use of rituximab. We also present the results of a survey of current practices carried out in 12 of the main HSCT centers across Canada. We confirm that pre-emptive rituximab remains an efficient strategy for EBV-PTLD prevention. However, there is an urgent need to perform prospective, randomized, multicentric trials with larger numbers of patients reflecting current practices to determine the best clinical conduct with regards to rituximab dosing, timing of treatment, and criteria to initiate treatments. Longer follow-ups will also be necessary to assess patients' long-term outcomes.

The IPTA Nashville Consensus Conference on Post-Transplant lymphoproliferative disorders after solid organ transplantation in children: III - Consensus guidelines for Epstein-Barr virus load and other biomarker monitoring

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders after solid organ transplantation in children. In this report from the Viral Load and Biomarker Monitoring Working Group, we reviewed the existing literature regarding the role of Epstein-Barr viral load and other biomarkers in peripheral blood for predicting the development of PTLD, for PTLD diagnosis, and for monitoring of response to treatment. Key recommendations from the group highlighted the strong recommendation for use of the term EBV DNAemia instead of "viremia" to describe EBV DNA levels in peripheral blood as well as concerns with comparison of EBV DNAemia measurement results performed at different institutions even when tests are calibrated using the WHO international standard. The working group concluded that either whole blood or plasma could be used as matrices for EBV DNA measurement; optimal specimen type may be clinical context dependent. Whole blood testing has some advantages for surveillance to inform pre-emptive interventions while plasma testing may be preferred in the setting of clinical symptoms and treatment monitoring. However, EBV DNAemia testing alone was not recommended for PTLD diagnosis. Quantitative EBV DNAemia surveillance to identify patients at risk for PTLD and to inform pre-emptive interventions in patients who are EBV seronegative pre-transplant was recommended. In contrast, with the exception of intestinal transplant recipients or those with recent primary EBV infection prior to SOT, surveillance was not recommended in pediatric SOT recipients EBV seropositive pre-transplant. Implications of viral load kinetic parameters including peak load and viral set point on pre-emptive PTLD prevention monitoring algorithms were discussed. Use of additional markers, including measurements of EBV specific cell mediated immunity was discussed but not recommended though the importance of obtaining additional data from prospective multicenter studies was highlighted as a key research priority.

Pre-Emptive Use of Rituximab in Epstein-Barr Virus Reactivation: Incidence, Predictive Factors, Monitoring, and Outcomes

Post-transplant lymphoproliferative disease (PTLD) is a fatal complication of hematopoietic cell transplantation (HCT) associated with the Epstein-Barr virus (EBV). Multiple factors such as transplant type, graft-versus-host disease (GVHD), human leukocyte antigens (HLA) mismatch, patient age, and T-lymphocyte-depleting treatments increase the risk of PTLD. EBV reactivation in hematopoietic cell transplant recipients is monitored through periodic quantitative polymerase chain reaction (Q-PCR) tests. However, substantial uncertainty persists regarding the clinically significant EBV levels for these patients. Guidelines recommend initiating EBV monitoring no later than four weeks post-HCT and conducting it weekly. Pre-emptive therapies, such as the reduction of immunosuppressive therapy and the administration of rituximab to treat EBV viral loads are also suggested. In this study, we investigated the occurrence of EBV-PTLD in 546 HCT recipients, focusing on the clinical manifestations and risk factors associated with the disease. We managed to identify 67,150 viral genomic copies/mL as the cutoff point for predicting PTLD, with 80% sensitivity and specificity. Among our cohort, only 1% of the patients presented PTLD. Anti-thymocyte globulin (ATG) and GVHD were independently associated with lower survival rates and higher treatment-related mortality. According to our findings, prophylactic measures including regular monitoring, pre-emptive therapy, and supportive treatment against infections can be effective in preventing EBV-related complications. This study also recommends conducting EBV monitoring at regular intervals, initiating pre-emptive therapy when viral load increases, and identifying factors that increase the risk of PTLD. Our study stresses the importance of frequent and careful follow-ups of post-transplant complications and early intervention in order to improve survival rates and reduce mortality.

Incidence and antiviral treatment of cytomegalovirus infection in infants with biliary atresia

PURPOSE

Patients with biliary atresia (BA) and cytomegalovirus (CMV) infection may have poorer outcomes after Kasai portoenterostomy (KPE) than uninfected patients, suggesting a rationale for antiviral treatment (AVT). We aimed to describe the incidence of CMV infection and of AVT in BA patients, and to detect any differences between infected and uninfected patients to conclude if AVT is of use.

METHODS

Data on BA patients who underwent KPE 2004-2020 were retrospectively collected, and the outcome was analyzed with regard to CMV status.

RESULTS

Fifteen out of forty-six (33%) BA patients had signs of ongoing CMV infection. They did not differ significantly from the CMV-negative patients regarding rate of prematurity, birth weight, or biochemical markers but were slightly older at KPE. All patients received steroids postoperatively and all patients with ongoing CMV infection received AVT with very good effect on viremia and without major side effects. The AVT consisted of oral valganciclovir (10-40 (- 58) mg/kg/d) or intravenous ganciclovir (5.3-11 mg/kg/d).

CONCLUSION

Ongoing CMV infection is common in this group of patients. The viremia can effectively be treated with AVT without any major side effects. Larger, randomized studies are needed to clarify the possible effect on clinical outcome.

Cytomegalovirus and Glioblastoma: A Review of the Biological Associations and Therapeutic Strategies

Glioblastoma is the most common and aggressive malignancy in the adult central nervous system. Cytomegalovirus (CMV) plays a crucial role in the pathogenesis and treatment of glioblastoma. We reviewed the epidemiology of CMV in gliomas, the mechanism of CMV-related carcinogenesis, and its therapeutic strategies, offering further clinical practice insights. To date, the CMV infection rate in glioblastoma is controversial, while mounting studies have suggested a high infection rate. The carcinogenesis mechanism of CMV has been investigated in relation to various aspects, including oncomodulation, oncogenic features, tumor microenvironment regulation, epithelial–mesenchymal transition, and overall immune system regulation. In clinical practice, the incidence of CMV-associated encephalopathy is high, and CMV-targeting treatment bears both anti-CMV and anti-tumor effects. As the major anti-CMV treatment, valganciclovir has demonstrated a promising survival benefit in both newly diagnosed and recurrent glioblastoma as an adjuvant therapy, regardless of surgery and the MGMT promoter methylation state. Immunotherapy, including DC vaccines and adoptive CMV-specific T cells, is also under investigation, and preliminary results have been promising. There are still questions regarding the significance of CMV infection and the carcinogenic mechanism of CMV. Meanwhile, studies have demonstrated the clinical benefits of anti-CMV therapy in glioblastoma. Therefore, anti-CMV therapies are worthy of further recognition and investigation.

Survey of Viral Reactivations in Elite Athletes: A Case-Control Study

Exercise-induced immune perturbations have been proposed to increase susceptibility to viral infections. We investigated the replication of persisting viruses as indicators of immune function in elite cross-country skiers after ten months of sustained high-performance exercise. The viruses evaluated, nine human herpesviruses (HHVs) and torque teno virus (TTV), are typically restrained in health but replicate actively in immunosuppressed individuals. We collected sera from 27 Finnish elite cross-country skiers at the end of the competition's season and 27 matched controls who perform moderate exercise. We quantified all the HHVs and-TTV via highly sensitive qPCRs. To verify equal past exposures between the groups, we assessed the IgG antibody prevalences toward HHV-4 (Epstein-Barr virus, EBV) and HHV-5 (human cytomegalovirus, HCMV). We found equal TTV DNA prevalences in athletes (63%) and controls (63%) and loads with respective geometric means of 1.7 × 103 and 1.2 × 103 copies/mL of serum. Overall, the copy numbers were low and consistent with those of healthy individuals. Neither of the groups presented with herpesvirus viremia despite similar past exposures to HHVs (seroprevalences of EBV 70% vs. 78% and HCMV 52% vs. 44% in athletes and controls, respectively). We found no evidence of increased replication of persistent viruses in elite athletes, arguing against impaired viral immunity due to high-performance exercise.

Assessment of the FilmArray ME panel in 4199 consecutively tested cerebrospinal fluid samples

OBJECTIVES

In central nervous system infections, early and correct management is of utmost importance. Rapid syndromic panel testing can potentially provide valuable guidance. The FilmArray meningitis/encephalitis (ME) panel detects 14 pathogens through multiplex PCR. Our study objectives were to assess its performance compared with established diagnostic procedures, especially real-time quantitative PCR for detection of viruses, and to determine the diagnostic and clinical significance of discrepant results.

METHODS

All cerebrospinal fluid samples sent for viral diagnostics to our microbiological laboratory over 34 months were analysed with the ME panel and in-house real-time PCR for herpes simplex virus type 1 (HSV-1), HSV-2, varicella zoster virus and enteroviruses. Other pathogens detected by the panel were confirmed by routine diagnostic procedures. Discrepant results were analysed through interpretation of biological and clinical data, and performance data were calculated for individual pathogens.

RESULTS

Altogether, 315 pathogens were detected by the ME panel in 4199 cerebrospinal fluid samples (7.5%) and an additional 21 viral targets were identified using real-time PCR. Thirty-four ME panel detections were not confirmed, totalling 55 discrepant results. After discrepancy analysis, 20 false-positive and 21 false-negative ME panel results remained. Performance varied between pathogens. Sensitivity for HSV-1 was calculated at 82.4% (59.0%-93.8%) with three false-negative results. Also noteworthy were 13 false-negative enterovirus and eight false-positive Streptococcus pneumoniae results.

CONCLUSIONS

Our analysis shows good performance for the ME panel in diagnosing central nervous system infection. The risk of false-negative HSV-1 results, however, warrants additional testing when encephalitis is suspected. Uncertainties in interpretation of enterovirus and S. pneumoniae results represent other limitations.

Clinical relevance of endoscopy with histopathological assessment in children with suspected gastrointestinal graft-versus-host disease

Endoscopy with histopathological assessment is an established practice to confirm gastrointestinal graft-versus-host disease (GI-GVHD). However, the clinical relevance of this approach in children is incompletely evaluated. In a retrospective cohort study, we investigated the frequency of treatment changes in response to histopathological findings in all children (<18 years) in Sweden who underwent endoscopy for suspected GI-GVHD (2000-2013) after receiving hematopoietic stem cell transplantation. Sixty-eight children with ninety-one endoscopic occasions were enrolled. At the time of endoscopy, anti-GI-GVHD treatment was ongoing in 71% (65/91). In 18% (12/65) with ongoing treatment, no histopathological evidence of GI-GVHD or another cause to justify anti-GI-GVHD treatment was found. In 48% (44/91), endoscopy with histopathological assessment led to changes in the treatment regimen. Re-endoscopy was more frequent among those with treatment changes, versus unchanged treatment, 39% (17/44) and 13% (6/47), respectively (P = .007). Histopathological findings generating treatment changes were as follows: GI-GVHD in 68% (30/44), normal histology in 25% (11/44), and an alternative diagnosis in 7% (3/44). In conclusion, this study supports that endoscopy with histopathological assessment should be considered in all children with suspected GI-GVHD.

Viral Respiratory Tract Infection During the First Postoperative Year Is a Risk Factor for Chronic Rejection After Lung Transplantation

Supplemental digital content is available in the text.

Background

Chronic lung allograft dysfunction (CLAD) is the major limiting factor for long-term survival in lung transplant recipients. Viral respiratory tract infection (VRTI) has been previously associated with CLAD development. The main purpose of this study was to evaluate the long-term effects of VRTI during the first year after lung transplantation in relation to CLAD development.

Method

Ninety-eight patients undergoing lung transplantation were prospectively enrolled between 2009 and 2012. They were monitored for infections with predefined intervals and on extra visits during the first year, the total follow-up period ranged between 5 and 8 years. Nasopharyngeal swab and bronchoalveolar lavage samples were analyzed using a multiplex polymerase chain reaction panel for respiratory pathogens. Data regarding clinical characteristics and infectious events were recorded.

Results

Viral respiratory tract infection during the first year was identified as a risk factor for long-term CLAD development (P = 0.041, hazard ratio 1.94 [1.03-3.66]) in a time-dependent multivariate Cox regression analysis. We also found that coronavirus in particular was associated with increased risk for CLAD development. Other identified risk factors were acute rejection and cyclosporine treatment.

Conclusions

This study suggests that VRTI during the first year after lung transplantation is associated with long-term CLAD development and that coronavirus infections in particular might be a risk factor.

Choice of Endoscopic Procedure in Children With Clinically Suspected Gastrointestinal Graft-versus-host Disease

OBJECTIVES

Gastrointestinal graft-versus-host disease (GI-GVHD) is a potentially life-threatening complication after hematopoietic stem cell transplantation. Symptoms indicating GI-GVHD motivates endoscopy with biopsy sampling and histopathological confirmation. Optimal extent of endoscopy in children is, however, presently unknown. Therefore, we aimed to evaluate whether biopsies from the rectosigmoid area versus the rest of the colon/ileocolon with or without biopsies from simultaneous upper endoscopy, were equally reliable for detection of GI-GVHD and relevant differential diagnoses.

METHODS

Retrospective multicenter study based on histopathological re-evaluation of biopsies and hospital record data, collected from children with suspected GI-GVHD.

RESULTS

Forty-four children with 51 endoscopic occasions (81 procedures) were included. Thirty-nine of 51 (76.5%) were diagnosed as GI-GVHD, 14 (27.4%) received a differential diagnosis and 7 (13.7%) had normal histology findings. Comorbidity, that is, simultaneous detection of a differential diagnosis and GI-GVHD, was observed in 9 (23.1%) cases. Cytomegalovirus infection was the most frequent differential diagnosis, 6 of 7 were detected in biopsies from rectosigmoid and esophagogastroduodenal areas. Sensitivity for detection of GI-GVHD in biopsies collected from rectosigmoid-ileocolonic-, rectosigmoid-, or esophagogastroduodenal areas were 97.4%, 84.6%, 83.3%, respectively, and 97.4% when the latter 2 were merged. The difference, nondetected GI-GVHD in the rectosigmoid area versus detected elsewhere in the GI tract, was statistically significant (P = 0.03).

CONCLUSIONS

Biopsies collected from the rectosigmoid area solely were not optimal for detection of pediatric GI-GVHD. When biopsy sampling from rectosigmoid and upper GI tract areas was combined, the sensitivity for GI-GVHD was, however, equally high as for ileocolonoscopy or full upper and lower endoscopy.

Quantification of Torque Teno Virus and Epstein-Barr Virus Is of Limited Value for Predicting the Net State of Immunosuppression After Lung Transplantation

Background

Major hurdles for survival after lung transplantation are rejections and infectious complications. Adequate methods for monitoring immune suppression status are lacking. Here, we evaluated quantification of torque teno virus (TTV) and Epstein-Barr virus (EBV) as biomarkers for defining the net state of immunosuppression in lung-transplanted patients.

Methods

This prospective single-center study included 98 patients followed for 2 years after transplantation. Bacterial infections, fungal infections, viral respiratory infections (VRTI), cytomegalovirus (CMV) viremia, and acute rejections, as well as TTV and EBV levels, were monitored.

Results

The levels of torque teno virus DNA increased rapidly after transplantation, likely due to immunosuppressive treatment. A modest increase in levels of Epstein-Barr virus DNA was also observed after transplantation. There were no associations between either TTV or EBV and infectious events or acute rejection, respectively, during follow-up. When Tacrolimus was the main immunosuppressive treatment, TTV DNA levels were significantly elevated 6–24 months after transplantation as compared with Cyclosporine treatment.

Conclusions

Although replication of TTV, but not EBV, appears to reflect the functionality of the immune system, depending on the type of immunosuppressive treatment, quantification of TTV or EBV as biomarkers has limited potential for defining the net state of immune suppression.

Long-term outcome of Epstein-Barr virus DNAemia and PTLD with the use of preemptive rituximab following allogeneic HSCT

We studied retrospectively the outcome of Epstein-Barr virus (EBV)-related disease with EBV monitoring and preemptive rituximab to prevent post-transplant lymphoproliferative disorder (PTLD) in 319 consecutive allogeneic stem cell transplantations 2004-2012. Patients who received anti-thymocyte globulin (ATG) or alemtuzumab were regarded as high-risk for PTLD (n = 214). EBV DNAemia ≥1000 copies/mL plasma was observed in 50 (23%) of the high-risk patients. Thirty-three of the high-risk (15%) and one of the low-risk (1%) patients received rituximab, in combination with reduction of immunosuppression (n = 24) or chemotherapy (n = 4). Although rituximab was initiated only 5 d after first EBV load ≥1000 copies/mL, 85% of the rituximab-treated patients developed symptoms (lymphadenopathy 50%, fever 76%, and encephalitis/meningitis 12%). Response-rate to EBV treatment was 88%. Overall survival at 1- and 5-year was 71 and 52% for rituximab-treated patients, which was not inferior to all other patients post-transplant. In conclusion, rituximab therapy for EBV DNAemia does not affect long-term survival negatively.

Epstein-Barr virus DNA monitoring in serum and whole blood in pediatric liver transplant recipients who do or do not discontinue immunosuppressive therapy

The rate of PTLD can be reduced by weaned IS guided by monitoring of EBV DNA. In this single-center retrospective case series study, we analyzed how reduction in IS influenced EBV DNA levels in whole blood and serum in 30 children during the first year after liver transplantation, and how these levels were related to symptoms putatively due to EBV. Primary and reactivated EBV infection was seen in 18 (60%) and eight patients (27%), respectively. Thirteen patients (42%) developed chronic high load the first year post-transplant. IS was successfully discontinued in six patients the first year post-transplant and in another two patients within 3 years. EBV DNA levels were reduced, but persisted long term in all the eight patients who had IS completely withdrawn. There was no case of PTLD. In summary, EBV DNAemia and chronic high load were very common after pediatric liver transplantation. Liver graft tolerance facilitates radical reduction in IS treatment, which may prevent PTLD, but EBV DNAemia may persist long term after discontinued IS.

Quantification of BK Virus Standards by Quantitative Real-Time PCR and Droplet Digital PCR Is Confounded by Multiple Virus Populations in the WHO BKV International Standard

BACKGROUND

The WHO recently released a BK virus (BKV) international standard. This study evaluated the WHO international standard and commercially available BKV standards by quantitative real-time PCR (qPCR) and droplet digital PCR (ddPCR).

METHODS

WHO, Exact Diagnostics, Acrometrix, and Zeptometrix BKV standards were tested by qPCR and ddPCR. Two preparations of NIST BKV clones were also tested. Nucleic acid was extracted with the Roche MP96 and MPLC, followed by quantification in duplicate. To resolve discrepancies, we sequenced the WHO and NIST materials.

RESULTS

Manufacturers' expected copies/mL were close to WHO IU/mL: linear regression of qPCR data revealed 1.12 Exact copies/IU, 0.76 Acrometrix copies/IU, and 0.70 Zeptometrix copies/IU. For ddPCR, similar concentrations were measured when either the VP1 region or the T region was targeted, and concentrations were almost 2-fold higher when both regions were targeted simultaneously. ddPCR results for the VP1 and T regions were similar for all commercial standards, but targeting the T region of the WHO standard led to a 4-fold lower result than the VP1 region. Next-generation sequencing revealed no primer or probe mismatches. However, large differences in coverage across the WHO standard and junctional reads were observed, indicating subpopulations of the WHO standard with deletions in the T region.

CONCLUSIONS

BKV standards showed concordance among providers, but the WHO standard contains subpopulations of viruses with various deletions in the T region. PCR results will vary depending on which region of the WHO standard is targeted.

High Cytokine Levels in Tonsillitis Secretions Regardless of Presence of Beta-Hemolytic Streptococci

Acute pharyngotonsillitis denotes tonsillar inflammation caused by bacteria or viruses. Here, we investigated if beta-hemolytic streptococci (β-HS) tonsillitis would differ in inflammatory mediator response from tonsillitis of other causes. Tonsillar secretions were obtained from 36 acute pharyngotonsillitis patients and 16 controls. Bacteria were cultured quantitatively and 18 different viruses were quantified by real-time polymerase chain reaction. Cytokine and prostaglandin E2 (PGE2) levels were determined by enzyme-linked immunosorbent assays. Almost half of the patients' tonsillar secretions yielded high counts of β-HS, and most samples contained viruses, irrespective of whether β-HS were present or not. The Epstein-Barr virus (EBV) was the most common virus (patients 62% and controls 13%). Compared to controls, patients' secretions had higher levels of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF), and PGE2, while few samples contained IL-12, IL-10, or interferon-gamma (IFN-γ). The presence of β-HS in tonsillitis secretions could not be distinguished by any of the measured mediators, while the presence of EBV DNA tended to be associated with enhanced levels of IL-1β and IL-8. The results suggest a common inflammatory response in acute pharyngotonsillitis, regardless of causative agent. The suggested correlation between intense inflammation and the presence of EBV DNA in tonsillitis secretions may be due to reactivation of the virus and/or the EBV-containing B cells.

Epstein-Barr virus serology and PCR: conflicting results in an immunocompetent host. A case report and review of literature

We present the case of a 27-year-old immunocompetent man who progressively developed a generalized lymphadenopathy and B symptoms. Results of Epstein-Barr virus (EBV) serology were suggestive for a past infection, but the EBV viral load in whole blood was high. Also, core needle biopsy of the largest lymph node showed an image which could fit an EBV-driven reactive lymphoproliferation. Despite the absence of an immune disorder, all medical evidence points to an EBV-driven lymphoproliferative proces. In immunocompetent patients, it seems extremely uncommon to detect a high EBV viral load in the absence of serological evidence of an acute EBV infection or reactivation. We reviewed literature on this topic and on the selection of the appropriate sample type for EBV PCR, as this is known to be a critical point. Serological testing for the diagnosis of EBV infection is the gold standard in immunocompetent patients. Measuring EBV viral load is only recommended when dealing with immunocompromised patients. Although extremely rare, this case report shows that there is a place for EBV PCR in certain situations in immunocompetent patients. Besides, there is still no consensus regarding the specimen of choice for the determination of the EBV viral load. The preferred specimen type seems to depend on the patient's underlying condition.

Quantification of cytomegalovirus viral load

Cytomegalovirus (CMV), a member of the Herpesviridae family, is worldwide distributed. After the primary infection, CMV induces a latent infection with possible reactivation(s). It is responsible for severe to life-threatening diseases in immunocompromised patients and in foetuses and newborns of infected mothers. For monitoring CMV load, classical techniques based on rapid culture or pp65 antigenemia are progressively replaced by quantitative nuclear acid tests (QNAT), easier to implement and standardize. A large variety of QNAT are available from laboratory-developed assays to fully-automated commercial tests. The indications of CMV quantification include CMV infection during pregnancy and in newborns, and viral surveillance of grafted and non-grafted immunocompromised patients, patients with bowel inflammatory diseases and those hospitalised in intensive care unit. A close cooperation between virologists and clinicians is essential for optimizing the benefit of CMV DNA monitoring.

Determining EBV load: current best practice and future requirements

EBV, a gammaherpesvirus and the pathogenic agent for infectious mononucleosis, is also associated with a broad spectrum of lymphoid and epithelial malignancies in immunocompetent and immunosuppressed individuals. EBV-DNA-load measurement by PCR has been shown to be a potential tool for the diagnosis of these diseases, a prognostic factor of their outcome and a successful method to monitor immunosuppressed patients. Since the end of 2011, there is an international WHO standard reference for EBV quantification available; however, many questions still remain; for instance about the optimal amplified region of the EBV genome, or the best-used specimen for EBV detection. Additionally, the optimal specimen and amplified region may vary in different malignancies. In this article, the authors review the different methods to measure EBV load, focus on the best-used specimen for the different EBV-associated malignancies and discuss future requirements and opportunities for EBV-load measurement.

Frequent detection of cytomegalovirus and Epstein-Barr virus in cervical secretions from healthy young women

OBJECTIVE

To investigate asymptomatic shedding from the uterine cervix of five human herpes viruses: cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV) type 1 and type 2 and varicella zoster virus (VZV), in young women.

DESIGN

A descriptive study.

SETTING

Sahlgrenska University Hospital.

POPULATION

Three hundred and five young, healthy Swedish women.

METHODS

Cervical specimens were analyzed for the presence of viral DNA with a quantitative real-time PCR assay.

MAIN OUTCOME MEASURES

Detection of viral DNA.

RESULTS

Viral DNA was detected in 66 (21.6%) of the cervical samples. The most common findings were CMV DNA, detected in 35 (11.5%), and EBV DNA, found in 32 (10.5%) of the women. HSV-1 DNA was detected in 5 (1.7%) and HSV-2 DNA in 4 (1.4%), but VZV DNA was not found. The estimated DNA level for the detected viruses was similar with a mean DNA quantity of 2.6 log genome equivalents (Geq)/mL for CMV (range 1.7-4.3), 2.5 log Geq/mL for EBV (range 1.7-4.7), 2.4 log Geq/mL for HSV-1 (range 1.7-3.5) and 2.6 log Geq/mL for HSV-2 (range 1.7-4.1). The simultaneous presence of DNA from two or more herpes viruses was detected in eight specimens.

CONCLUSIONS

Asymptomatic shedding of CMV and EBV from the uterine cervix was found in one-fifth of young women. In four of the cervical samples; two with EBV, one with CMV, one with HSV-2, high amounts of viral DNA (>4 log Geq/mL) were detected suggesting a greater risk of transmitting the virus perinatally or sexually.

Enveloped virus but not bacteria block IL-13 responses in human cord blood T cells in vitro

Infections that occur early in life may have a beneficial effect on the immune system and thereby reduce the risk of allergen sensitization and/or allergic disease. It is not yet clear to what extent specific virus and/or bacteria can mediate this effect. The purpose of this study was to assess the role of virus and bacteria in CD4⁺ T cell‐derived cytokine production in newborns. We compared the effects of five bacteria (Staphlococcus aureus, Escherichia coli, Clostridium difficile, Lactobacillus rhamnosus and Bifidobacterium bifidus) and seven virus (adenovirus, coronavirus, cytomegalovirus, herpes simplex virus, influenza virus, morbillivirus and poliovirus) on the Th1/Th2 cytokine production in mixed lymphocyte reactions using CD4⁺ T cells from cord blood cocultured with allogenic myeloid or plasmacytoid dendritic cells. When comparing the baseline cytokine production prior to microbial stimulation, we observed that cord plasmacytoid DC were stronger inducers of Th2 cytokines (IL‐5 and IL‐13) compared with cord myeloid DC and to adult DC. When adding microbes to these cultures, bacteria and virus differed in two major respects; Firstly, all enveloped viruses, but none of the bacteria, blocked Th2 (IL‐13) production by cord CD4⁺ cells. Secondly, all Gram‐positive bacteria, but none of the virus, induced IL‐12p40 responses, but the IL‐12p40 responses did not affect Th1 cytokine production (IFN‐γ). Instead, Th1 responses were correlated with the capacity to induce IFN‐α secretion, which in cord cells were induced by S. aureus and influenza virus alone. These data imply that enveloped virus can deviate Th2 responses in human cord T cells.

Comparison of six different specimen types for Epstein-Barr viral load quantification in peripheral blood of pediatric patients after heart transplantation or after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Epstein-Barr Virus (EBV) a gamma-herpes virus is associated with a spectrum of lymphoid and epithelial malignancies including posttransplant lymphoproliferative disorders (PTLD). EBV-load measurement has been shown to be important for the monitoring of these patients. However, in contrast to the viral quantification of human immunodeficiency virus or human hepatitis C virus, the EBV-load measurement has not been completely standardized as yet.

OBJECTIVES

In this study, we compared the EBV DNA levels in whole blood (WB), plasma, peripheral mononuclear cells (PBMC) and B-cells (BC) in children and adolescents after heart transplantations (HTx) and allogeneic hematopoietic stem cell transplantations (HSCT).

STUDY DESIGN

In a period of 2 years (from May 2007 to May 2009) we collected 547 samples of 96 cardiac transplant recipients and 248 samples of 37 patients who underwent HSCT. For EBV DNA quantification we used a duplex real-time PCR (ABI Prism 7500, Applied Biosystems). Additionally, EBV-load of PBMC and BC were normalized with respect to endogenous cell DNA.

RESULTS

In both patient populations we found no significant difference of test sensitivity for the EBV detection. In PBMC as well as BC, there was a high correlation between the analysis of cells with and without normalization in both populations. Spearman's correlation coefficient ρ between PBMC without and PBMC with normalization was ρ=0.98 (P<0.0001) in patients after HTx and ρ=0.99 (P<0.0001) in patients after HSCT. Correlation between BC with and without normalization was ρ=0.98 (P<0.0001) in patients after HTx and ρ=0.995 (P<0.0001) in patients after HSCT. When comparing the different blood compartments for EBV quantification in both populations, the strongest correlations were found between the EBV DNA levels in WB and PBMC (HTx: ρ=0.93, P<0.0001; HSCT: ρ=0.81, P<0.0001) followed by PBMC and BC (HTx: ρ=0.87, P<0.0001; HSCT: ρ=0.81, P<0.0001) as well as WB and BC (HTx: ρ=0.86, P<0.0001; HSCT: ρ=0.75, P<0.0001). In contrast, the correlation coefficients between plasma and the other blood compartments (WB as well as PBMC or BC) were lower. Six patients developed seven episodes of PTLD (five patients after HTx and one after renal transplantation). Analyzing the different blood compartments, we found that a threshold of WB ≥20,000EBV-copies/ml and plasma ≥1000EBV-copies/ml had the highest sensitivities and specificities (WB: sensitivity 100%, specificity 87% and plasma: sensitivity 88%, specificity 98%).

CONCLUSION

Normalization towards an endogenous control does not seem to be necessary for EBV quantification in peripheral blood. The analysis of whole blood correlates well with B-cells and PBMC. Routine screening of EBV DNA in whole blood appeared to be a useful tool supplemented by EBV-load measurement in plasma to discriminate chronic high EBV-load carrier without risk for PTLD from those who are at risk for PTLD. Values in whole blood higher than 20,000EBV-copies/ml WB and plasma values higher than 1000EBV-copies/ml plasma indicated PTLD in our series.

Measurement of Epstein-Barr virus DNA load using a novel quantification standard containing two EBV DNA targets and SYBR Green I dye

Background

Reactivation of Epstein-Barr virus (EBV) infection may cause serious, life-threatening complications in immunocompromised individuals. EBV DNA is often detected in EBV-associated disease states, with viral load believed to be a reflection of virus activity. Two separate real-time quantitative polymerase chain reaction (QPCR) assays using SYBR Green I dye and a single quantification standard containing two EBV genes, Epstein-Barr nuclear antigen-1 (EBNA-1) and BamHI fragment H rightward open reading frame-1 (BHRF-1), were developed to detect and measure absolute EBV DNA load in patients with various EBV-associated diseases. EBV DNA loads and viral capsid antigen (VCA) IgG antibody titres were also quantified on a population sample.

Results

EBV DNA was measurable in ethylenediaminetetraacetic acid (EDTA) whole blood, peripheral blood mononuclear cells (PBMCs), plasma and cerebrospinal fluid (CSF) samples. EBV DNA loads were detectable from 8.0 × 10² to 1.3 × 10⁸ copies/ml in post-transplant lymphoproliferative disease (n = 5), 1.5 × 10³ to 2.0 × 10⁵ copies/ml in infectious mononucleosis (n = 7), 7.5 × 10⁴ to 1.1 × 10⁵ copies/ml in EBV-associated haemophagocytic syndrome (n = 1), 2.0 × 10² to 5.6 × 10³ copies/ml in HIV-infected patients (n = 12), and 2.0 × 10² to 9.1 × 10⁴ copies/ml in the population sample (n = 218). EBNA-1 and BHRF-1 DNA were detected in 11.0% and 21.6% of the population sample respectively. There was a modest correlation between VCA IgG antibody titre and BHRF-1 DNA load (rho = 0.13, p = 0.05) but not EBNA-1 DNA load (rho = 0.11, p = 0.11).

Conclusion

Two sensitive and specific real-time PCR assays using SYBR Green I dye and a single quantification standard containing two EBV DNA targets, were developed for the detection and measurement of EBV DNA load in a variety of clinical samples. These assays have application in the investigation of EBV-related illnesses in immunocompromised individuals.

Viral and bacterial aetiologies of male urethritis: findings of a high prevalence of Epstein–Barr virus

Male urethritis is one of the most common sexually transmitted infections (STIs). However, the aetiology is still unclear in many cases. In this study the prevalences of Epstein–Barr virus (EBV), herpes simplex virus type 1 (HSV-1), HSV-2, cytomegalovirus (CMV), adenovirus, Chlamydia trachomatis, Mycoplasma genitalium and Ureaplasma urealyticum (including subtyping) were investigated. Samples from 112 male STI attendants with microscopically verified urethritis and from a control group of 103 men without clinical or microscopic signs of urethritis were analysed. Prevalences in the urethritis group compared with the controls were as follows: EBV 21%, 6% ( P < 0.01); C. trachomatis 15%, 3% ( P < 0.01); M. genitalium 6%, 1% ( P = 0.067) and U. urealyticum 10%, 10% (ns). The results for HSV-1, HSV-2, CMV and adenovirus were negative in patients, and therefore not analysed in the controls. EBV was shown to be an independent predictor of urethritis and may play a role in its pathogenesis.

Comparative evaluation of a commercially available automated system for extraction of viral DNA from whole blood: application to monitoring of epstein-barr virus and cytomegalovirus load

The NucliSENS easyMAG automated system was compared to the column-based Qiagen method for Epstein-Barr virus (EBV) or cytomegalovirus (CMV) DNA extraction from whole blood before viral load determination using the corresponding R-gene amplification kits. Both extraction techniques exhibited a total agreement of 81.3% for EBV and 87.2% for CMV.

Activation of host antiviral RNA-sensing factors necessary for herpes simplex virus type 1-activated transcription of host cell fucosyltransferase genes FUT3, FUT5, and FUT6 and subsequent expression of sLe(x) in virus-infected cells

Herpes simplex virus type 1 (HSV-1) induces expression of a selectin receptor, the carbohydrate epitope sialyl Lewis X (sLe(x)), at the surface of infected cells. The molecular background to this phenomenon is that a viral immediate early RNA interacts with as yet unidentified host factors, eventually resulting in transcription of three dormant host fucosyltransferase genes (FUT3, FUT5, and FUT6), whose gene products are rate-limiting for synthesis of sLe(x). The aim of the present study was to define the immediate targets for the viral RNA in this process. We found that the Protein Kinase R (PKR) inhibitors 2-aminopurine (2-AP) and C16 inhibited FUT3, FUT5, and FUT6 expression as well as HSV-1-induced expression of sLe(x), indicating a primary role of PKR as a viral RNA target. The PKR-dependent activation of the FUT genes seemed neither to involve PKR effects on translation nor to involve NF-kappaB- or JNK-dependent activation. IMD-0354, known as an inhibitor of the NF-kappaB-activating factor IKK-2, induced FUT transcription via a novel IKK-2-independent mechanism, irrespective of whether the cells were virus-infected or not. Altogether, the results suggested that PKR is the primary target for HSV-1 early RNA during induction of FUT3, FUT5, and FUT6, and that the subsequent steps in the transcriptional activation of these host genes involve a hitherto unknown IMD-0354, yet IKK-2-independent, pathway.