Epstein-Barr Virus Antibody Titers Research Articles

Perceived income inadequacy is associated with Epstein-Barr Virus latency and mental health outcomes in informal caregivers who are also employed in the healthcare industry

Finances are a prevalent source of stress. In a sample of 799 nursing home workers measured multiple times over 18 months, we found that higher perceived income inadequacy, the perception that one's expenses exceeds one's incomes, was associated with poorer self-reported mental health indicators and Epstein-Barr Virus antibody titers (a marker of cell-mediated immune function). Perceived income inadequacy predicted outcomes over and above the role of other socioeconomic status variables (objective household income and education). Mental health variables were not related to Epstein-Barr Virus antibody titers. Additionally, we found an interaction between perceived income inadequacy and informal caregiver status on our mental health outcomes; informal caregivers with higher perceived income inadequacy had poorer mental health than non-caregivers with the same perceived income inadequacy. Our findings may add nuance to the reserve capacity model, which states that those at lower socioeconomic levels are at higher risk of adverse health outcomes partly because they have fewer resources to address demands and strain. Perceived income inadequacy may significantly predict mental and physical well-being beyond other socioeconomic status variables, especially among lower-income employees. Caregiving stress and perceived income inadequacy may have synergistic effects on mental health.

Diminished Cellular Immunity and Executive Cognitive Functioning Among Middle-Aged and Elderly Adults.

Within the field of psychoneuroimmunology, much attention has been given to immune dysregulation and its impact on cognitive functioning. Some of this work has focused on the association between high levels of basal proinflammatory cytokines and poorer performance on measures of executive functioning; however, effect sizes have been quite small in human studies. We investigated whether Epstein-Barr virus (EBV) antibody titers, a marker of immune dysregulation related to cellular immunity, may be associated with executive functioning while also attempting to replicate prior studies using two markers of proinflammatory cytokine production (i.e., circulating and lipopolysaccharide [LPS]-stimulated cytokines [interleukin 6, interleukin 1β, interferon-γ]). A total of 71 community-dwelling adults (mean [standard deviation] age = 60.87 [6.26] years) who were seropositive for EBV infection participated in the study. Findings indicated that greater EBV antibody titers were associated with poorer performance on measures of the executive functions of inhibition ( B = -2.36, standard error = 1.06, p = .028) and cognitive flexibility ( B = -2.89, standard error = 1.13, p = .013) when including circulating and LPS-stimulated cytokines and other relevant covariates (i.e., age, sex, and body mass index) in linear regression analyses. Neither circulating nor LPS-stimulated cytokines were associated with performance on the cognitive tasks in the regression analyses. These results suggest that EBV antibody titers may be an indicator of immune dysregulation that is more relevant to executive functioning performance than either circulating or stimulated proinflammatory cytokines among community-dwelling adults.

Epstein-Barr virus and multiple sclerosis: supporting causality

Epstein-Barr virus (EBV) is a γ-herpes virus that infects around 95% of individuals worldwide. Although the infection is generally asymptomatic when acquired in childhood, EBV can cause infectious mononucleosis in adolescents and several tumours, like lymphomas and nasopharyngeal carcinoma, in adults. EBV has also been associated with multiple sclerosis, the most common chronic inflammatory disease of the CNS. Robust evidence indicates that the risk of multiple sclerosis is nearly absent in EBV-seronegative individuals, increases considerably after EBV infection, and increases even more after infectious mononucleosis. 1 Jacobs BM Giovannoni G Cuzick J Dobson R Systematic review and meta-analysis of the association between Epstein-Barr virus, multiple sclerosis and other risk factors. Mult Scler. 2020; 26: 1281-1297 Crossref PubMed Scopus (22) Google Scholar Furthermore, people with multiple sclerosis have an increased antibody response to EBV that becomes detectable years before disease onset. 2 Levin LI Munger KL Rubertone MV et al. Temporal relationship between elevation of Epstein-Barr virus antibody titers and initial onset of neurological symptoms in multiple sclerosis. JAMA. 2005; 293: 2496-2500 Crossref PubMed Scopus (334) Google Scholar , 3 Sundström P Juto P Wadell G et al. An altered immune response to Epstein-Barr virus in multiple sclerosis: a prospective study. Neurology. 2004; 62: 2277-2282 Crossref PubMed Scopus (246) Google Scholar These findings suggest that multiple sclerosis might develop in susceptible individuals due to an alteration of the EBV–host homoeostasis that ordinarily ensures a life-long, pacific coexistence under continuous immune surveillance in healthy EBV carriers. 4 Läderach F Münz C Epstein Barr virus exploits genetic susceptibility to increase multiple sclerosis risk. Microorganisms. 2021; 92191 Crossref Scopus (4) Google Scholar To date, however, most of the available evidence has been correlative in nature and it has been difficult to prove that EBV causes multiple sclerosis. 5 Olsson T Barcellos LF Alfredsson L Interactions between genetic, lifestyle and environmental risk factors for multiple sclerosis. Nat Rev Neurol. 2017; 13: 25-36 Crossref PubMed Scopus (458) Google Scholar

Use of Monospot Testing in the Diagnosis of Infectious Mononucleosis in the Collegiate Student-Athlete Population.

To determine the utility of monospot testing in the diagnosis of mononucleosis in the collegiate student-athlete clinical setting. Retrospective cohort study. National Collegiate Athletic Association Division I sports medicine clinic. All varsity student athletes who had a monospot test and Epstein-Barr virus (EBV) titers obtained from January 1, 2016, through March 31, 2020, (n = 199) were included. Monospot, EBV antibody titers, and liver transaminase results. Using EBV titers indicating acute or recent infection as the gold standard for diagnosing infectious mononucleosis (IM), the reliability of a positive monospot test and elevated liver transaminases for the diagnosis of IM were examined. The monospot test had a sensitivity and specificity of 80.0% and 90.6%, respectively, with a positive predictive value of 36.4% and a negative predictive value of 98.5% in this cohort. All athletes diagnosed with IM also had elevated liver transaminases. The specificity of the monospot test is lower than previously reported in the literature, and a positive test is not sufficient to diagnose mononucleosis in this clinical setting. Positive monospot results should be confirmed with EBV antibody testing. Elevated transaminase levels are highly correlated with acute IM and could play a supporting role in the diagnosis.

Advanced baseline immunosuppression is associated with elevated levels of plasma markers of fungal translocation and inflammation in long-term treated HIV-infected Tanzanians

BackgroundFor over a decade, antiretroviral therapy (ART) in resource-limited countries was only recommended for patients with advanced HIV disease. We investigated this group of patients in order to determine any relationship between degree of immunosuppression during treatment initiation and the subsequent levels of inflammatory biomarkers, reservoir size and plasma marker of fungal translocation after achieving long-term virological control.MethodsWe analyzed 115 virally suppressed (female 83.5%) and 40 untreated (female 70%) subjects from Dar es Salaam, Tanzania. The size of HIV latent reservoir (proviral DNA copy) was determined using quantitative PCR. Inflammatory biomarkers; IL-6, IL-10, and soluble CD14 (sCD14), were measured using multiplex cytometric beads array. Antibody titers for Cytomegalovirus (CMV) and Epstein Barr virus (EBV), plasma level of 1-3-beta-d-Glucan (BDG) was measured using ELISA. High-sensitivity C-reactive protein (hsCRP) was measured using nephelometric method.ResultsThe median age was 36 (IQR 32-44) and 47 (IQR 43–54) years in untreated and virally suppressed patients respectively. Median duration of treatment for virally suppressed patients was 9 years (IQR 7–12) and median baseline CD4 count was 147 cells/mm3 (IQR 65–217). Virally suppressed patients were associated with significantly lower plasma levels of IL-10, sCD14 and BDG (P < 0.05) when compared to untreated patients. However, plasma level of IL-6 was similar between the groups. Baseline advanced level of immunosuppression (CD4 < 100cells/cm3) was associated with significantly higher plasma level of IL-6 (P = 0.02), hsCRP (P = 0.036) and BDG (P = 0.0107). This relationship was not seen in plasma levels of other tested markers. Degree of baseline immunosuppression was not associated with the subsequent proviral DNA copy. In addition, plasma levels of inflammatory marker were not associated with sex, CMV or EBV antibody titers, treatment duration or regimen.ConclusionsOur data suggest that advanced immunosuppression at ART initiation is associated with severity of inflammation and elevated fungal translocation marker despite long term virological control. Further studies are needed to evaluate the potential increased burden of non-AIDS comorbidities that are linked to elevated inflammatory and fungal translocation markers as a result of the policy of HIV treatment at CD4 count < 200 cells/cm3 implemented for over a decade in Tanzania.

Relationship satisfaction determines the association between Epstein-Barr virus latency and somatic symptoms after the loss of a spouse.

The loss of a spouse is associated with a host of negative health outcomes. While bereaved individuals commonly report somatic symptoms, no investigations exist of the association between reactivation of latent Epstein-Barr virus (EBV) and somatic symptoms among this population. Further, how an individual perceives the quality of their lost relationship in retrospect may impact loss outcomes. Among 99 bereaved spouses, elevated EBV antibody titers were associated with somatic symptoms for those who retrospectively reported high or mean levels of relationship satisfaction (RS), but not among those less satisfied. Further, higher RS was associated with greater grief symptoms. This study identifies higher retrospective RS as a possible risk factor for negative physical and mental health outcomes during bereavement.

Chronic stress and age-related pattern of blood pressure: A cross-sectional study in rural China.

Chronic stress is a risk factor for hypertension in adults. However, there is conflicting evidence for older adults. We hypothesized that age-related arterial stiffening, which leads to a lower blood pressure (especially diastolic blood pressure [DBP]), is more pronounced among older adults with high vs low stress. The objectives of this study were (a) to investigate age-related trends in systolic and DBPs among adults in rural Fujian, China, and (b) to examine differences in age-related blood pressure trends according to levels of stress by using Epstein-Barr virus (EBV) antibody titer as a marker of chronic stress status. We collected cross-sectional data from 764 rural community-dwelling adults in rural Fujian, China (mean age = 59.4). Participants were categorized into high and low stress groups by median split of EBV antibody titer. A least-squares regression analysis was used to investigate the association between age and blood pressures. We observed an inverted U-shaped association between age and DBP, while there was a linear association between age and systolic blood pressure in the overall sample. When stratified by stress, the inverted U-shaped associations with age (both systolic and DBPs) were seen only among those with high stress; DBP peaked at the age of ~68 years, and the declining trend later in life was more clearly observed among those with high chronic stress. Decrease of DBP was more pronounced among older adults with high vs low chronic stress in rural China.

Vitamin D and other environmental risk factors in Colombian patients with multiple sclerosis

ObjectiveThe aim of this study was to explore the association between MS and vitamin D levels, as well as Epstein-Barr virus (EBV) seropositivity and smoking history in a Colombian population. Methods: We conducted a cross-sectional study between 2017 and 2018. We measured vitamin D levels and EBV antibody titers and administered a questionnaire to assess dietary habits, smoking, second-hand smoking and duration of smoking, sunlight exposure, physical activity, and personal and family history in individuals with and without multiple sclerosis during adolescence. A multivariable logistic regression model was then performed to explore the association between vitamin D status and MS. Results: A total of 87 individuals with MS (mean age 40.9 years; 65.52% females) and 87 without MS (mean age 55 years; 65.52% females) were included in the analysis. In the multivariable analysis, after controlling for supplementation vitamin D levels did not differ between both groups and no difference was found regarding tobacco smoke exposure. The proportion of individuals who tested positive for anti-EBV nuclear antigen was significantly higher in individuals with MS (95.4% vs 82.76%, p = 0.028) Conclusion: We did not find a statistically significant association between MS and vitamin D levels while anti-EBV nuclear antigen titers behaved as previously described in the literature. This study provides new evidence of the association between MS and different risk factors in our country, reinforcing the hypothesis that the pathogenesis of MS is multifactorial. Further studies are needed to better define the association between environmental factors and the development of MS in low prevalence areas.

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

BackgroundSystemic chronic active Epstein-Barr virus infection is an extremely rare childhood disease. Since chronic active Epstein-Barr virus infection can trigger the onset of Epstein-Barr virus-associated lymphoproliferative disease. The clinical manifestations of the disease vary according to the site of involvement; therefore, management may be challenging. Currently, there are no standardized guidelines for treating Chronic active Epstein-Barr virus infection effectively.Case presentationWe report a case of chronic active Epstein-Barr virus infection in a 5-year-old Chinese boy with intestinal, vascular, and neurological involvement. At age of 2 years and 7 months old, he had hepatomegaly and been diagnosed with Epstein-Barr virus infection. After treatment, he showed some clinical improvement. At age of 3 years and 3 months old, he presented with recurrent fever and diarrhea. Then he received methylprednisolone for 1 year and his symptoms ameliorated. At the age of 5 years, his symptoms recurred and had gastrointestinal hemorrhage and developed polyuria, frequent convulsions and hyponatremia. He was transferred to our hospital for further management. He was unconscious on admission and was diagnosised Epstein-Barr virus-lymphoproliferative disorder, based on the results in situ hybridization of EBV-encoded miRNA in sigmoid colon. Three-dimensional CT angiography demonstrated an aneurysm in the right internal carotid artery. Abdominal CT showed dilatation of vessels in part of the intestinal wall. He was also diagnosised Epstein-Barr virus encephalitis based on the elevated Epstein-Barr virus antibody titers and presence of Epstein-Barr virus DNA in the Cerebrospinal Fluid.A repeated duodenal artery embolization and symptomatic therapy could not control the hemorrhage after admission. He subsequently received treatment with ganciclovir, glucocorticoid, thalidomide, and propranolol. Hemorrhage was controlled in 5 days; his symptoms improved. The fever did not recur and the CSF pressure was also normalized. A follow-up CT at 3 months after admission showed regression of the aneurysm in the right internal carotid artery and the vascular lesion in the duodenum.Discussion and conclusionsA new treatment protocol including thalidomide and propranolol resulted in a marked improvement in his clinical symptoms, and shows promise as a novel and effective therapeutic approach for Chronic active Epstein-Barr virus infection-associated lymphoproliferative disorder.

The association between family members' migration and Epstein-Barr virus antibody titers among people left behind in rural Fujian, China.

In contrast to the health of migrants, which has been extensively studied, little attention has been paid to the health of adults left behind by family members who out-migrated to other locations. This study was performed to investigate the association between being left behind and the Epstein-Barr virus (EBV) antibody titer, which is an indicator of cellular immune functioning previously shown to be associated with psychological stress. A cross-sectional survey was conducted in rural communities in Fujian, China, in 2015. Questionnaire data and dried blood spot samples were collected from 748 adults. A mixed effect regression analysis was conducted to investigate the association. Results indicated that the EBV antibody titers were higher among people who had been left behind compared with those who had not. Our findings suggest that, in rural Fujian, China, family separation following the out-migration of family members is an important determinant of psychological stress.

Sex differences in executive functioning and latent herpesvirus reactivation among bereaved and nonbereaved individuals.

The death of a spouse is a highly stressful event. Better executive functioning has been shown to benefit men to a greater degree than women during stress. We evaluated potential sex differences in stress and immune dysregulation among control and bereaved participants who completed a self-report measure of perceived stress, neuropsychological measures of inhibition and updating/monitoring of information in working memory, and a blood draw to measure Epstein-Barr virus (EBV) antibody titres. Moderation analyses were conducted to test the hypothesis that better inhibition would be associated with less stress and immune dysregulation among male bereaved participants compared with female bereaved participants. Bereaved females demonstrated greater EBV antibody titres than bereaved males. Male bereaved participants benefited from better inhibition, as evidenced by fewer EBV antibody titres, whereas bereaved female participants did not. In the control group, males with high inhibition reported lower stress than males with low inhibition. Present study results are an important step towards identifying those at greatest risk of stress and poor health.

Acute kidney injury in an adult patient with IgA nephropathy and chronic replicative Epstein–Barr virus infection

Most of the adult population are infected with Epstein-Barr virus (EBV), but as EBV replication is usually under immune system control, the majority of individuals remain asymptomatic. On the other hand, some individuals continuously retain a high EBV antibody titer and a high EBV DNA load in their blood, suggesting a defect of EBV replication control. To date, only a limited number of reports have addressed the relationship between this chronic form of EBV infection and renal involvement. Here, we describe an 80-year-old woman who developed acute kidney injury shortly after an episode of mosquito bites, accompanied by a severe skin rash, which raised a suspicion of chronic EBV infection. She was subsequently diagnosed as having chronic replicative EBV infection. Renal biopsy revealed a diagnosis of IgA nephropathy with crescent formation. Although the relationship between IgA nephropathy and EBV infection has been discussed, no substantial understanding has yet emerged. The patient's characteristic clinical course suggested that the renal failure may have been partly attributable to chronic EBV infection. This case suggests that physicians may need to consider the possibility that chronic EBV infection may affect the clinical course of IgA nephropathy, or exacerbate the disease.

Association between early parental deprivation and cellular immune function among adults in rural Fujian, China.

This study investigated the role of childhood parental deprivation in the association between quality of life (QOL) and the Epstein-Barr virus (EBV) antibody titer, a marker of cellular immune functioning, using data from 734 adults living in seven communities in rural Fujian, China. Parental deprivation was defined if either of their parents had died, divorced, or left them for migratory work for more than 1year before they turned (a) 16years of age (childhood and adolescence), or (b) 3years of age (early childhood). A mixed-effects regression analysis with a random effects model revealed that parental deprivation during early childhood was positively associated with the EBV antibody titer (coefficient=0.33, p=0.007), whereas parental deprivation during the first 16years was not. Further analysis incorporating an interaction term between QOL and parental deprivation revealed a significant interaction between QOL and parental deprivation during early childhood; a significant association between QOL and the EBV antibody titer was found only among those who reported parental deprivation during early childhood. This study suggests that parental deprivation during the period of immune system development may be linked with physiological responses to stressors later in life.

Epstein-Barr Virus Antibody Titers Are Not Associated with Gastric Cancer Risk in East Asia.

Epstein-Barr virus (EBV)-positive gastric cancers represent a distinct subtype of gastric cancers and account for nearly 10% of the gastric cancer burden, yet risk detection strategies for this cancer subtype are lacking. We conducted a nested case-control study where we assayed 4 EBV antigens [viral capsid antigen (VCA), early antigen (EA), Epstein-Barr nuclear antigen (EBNA), and BZLF1-encoded replication activator protein (ZEBRA)] in either sera or plasma from 1447 gastric cancer cases and 1797 controls obtained from seven prospective cohorts representing individuals from the high gastric cancer-risk countries of China, Japan, and Korea. The prevalence of EBV sero-positivity was universal with the exception of one sero-negative individual, and the highest titers of the EBV antigens VCA (OR 0.95, 95% CI 0.78-1.17), EBNA (OR 0.88, 95% CI 0.72-1.08), EA (OR 0.97, 95% CI 0.79-1.19), and ZEBRA (OR 0.87, 95% CI 0.71-1.07) were not associated with risk of incident gastric cancer. When we stratified these data by H. pylori status, there was no change in the association. Multiplex serology of the aforementioned EBV antigens in serum may not be a suitable biomarker for predicting gastric cancer risk in East Asian populations.

Epstein-Barr virus antibody titer as a stress biomarker and its association with social capital in rural Fujian communities, China.

There has been little research on the association between social capital and psychological stress measured by a biomarker, particularly in developing countries. Our objective was to investigate the association between Epstein-Barr virus (EBV) antibody titer, an indicator of cellular immune function previously shown to be associated with psychological stress, and social capital among rural community dwellers in Fujian Province, China. We conducted a cross-sectional survey in seven rural communities in Fujian in 2015. We used questionnaire data and dried blood spot samples for the measurement of biomarkers collected from 734 local residents for the analysis. We conducted a mixed effects regression analysis to investigate the association between EBV antibody titer and four social capital variables, which included cognitive and structural social capital assessed both at individual and community levels. Community-level structural social capital was inversely associated with psychological stress (coefficient = -0.96, 95% confidence interval [CI] = -1.91, -0.01) while individual-level structural social capital was positively associated with it (coefficient = 0.21, 95% CI = 0.07, 0.36). Neither individual- nor community-level cognitive social capital was associated with psychological stress status. In rural Fujian, China, social capital seemed to be an important determinant of psychological health. While living in a community with active social interaction may benefit the residents psychologically, social interaction in the form of strongly bonded relationships may be a source of psychological stress at the individual level due to the potential demands and obligations that may be associated with such connections.

Pain in the elderly and its association with latent Epstein-Barr virus reactivation

Background Stress promotes immune dysregulation, including reactivation of latent viral infections and inflammation. Immune dysregulation can have severe health consequences, including delayed wound healing, impaired responses to vaccination, development and progression of cancer, and onset of mood disorders. Little is known about how pain is associated with reactivation of herpesviruses. Objective To evaluate the effects of pain on reactivation of latent Epstein-Barr virus (EBV), c-reactive protein (CRP), and interleukin-6 (IL-6) after controlling for age, gender, body mass index (BMI), race and income. Methods 51 bereaved and 64 controls were examined for pain (SF-36_Pain_Subscale) and immune dysregulation (EBV antibody titers, CRP, and IL-6). Linear regression models, adjusted for age, gender, BMI, race, and income were used to examine the association between pain and immune dysregulation. Results Results showed that greater pain was associated with higher reactivation of EBV ( β = −0.30; p β = −0.22; p β = −0.14; p = 0.16). Moreover, being older was associated with reactivation of EBV ( β = 0.32; p β = 0.27; p β = 0.34; p Conclusion Our results add to growing evidence of how pain can promote immune dysregulation. To our knowledge, this study is the first to demonstrate an association between pain and reactivation of a latent herpesvirus, which provides important implications for health outcomes.

Spotlight on the September 26 issue

#### Notable in Neurology This issue features an article that analyzes gastrointestinal manifestations in patients with myotonic dystrophy types 1 and 2 and another that determines sex differences in the development of Alzheimer disease endophenotypes. A featured article investigates whether the manner of patient consent affects clinical characteristics of patients with stroke. ### Epstein-Barr virus, cytomegalovirus, and multiple sclerosis susceptibility: A multiethnic study![Graphic][1]</img> This study highlights how multiethnic studies can provide insight into multiple sclerosis (MS) susceptibility. The authors found a strong and consistent association of Epstein-Barr virus antibody titers, but not cytomegalovirus, with … [1]: /embed/inline-graphic-1.gif

The Effect of Perceived Stress on Epstein-Barr Virus Antibody Titers in Appalachian Ohio Women

Objective: The Appalachian population suffers a disparate burden of chronic stress leading to high perceived stress. The study aim was to determine the association between perceived stress and Epstein-Barr virus (EBV) antibody titers, along with the impact of perceived social support, Appalachian self-identify, and health behaviors. Methods: Serum EBV VCA-IgG antibody titer levels from 169 female Appalachian residents (aged 18-26 years) were examined. Perceived stress, perceived social support, Appalachian self-identity, and health behaviors were assessed via self-administered questionnaires. Results: There were 169 of 185 women positive for EBV. Among these women, the median EBV antibody titer level was 404 U/mL (range 101-6,464), and the overall geometric mean was 563.2 (95% CI 486.6-651.9). For a 1-point increase in perceived stress, the EBV antibody titer increased by 1.92% (95% CI 0.04-3.76%). For every point increase in perceived social support, the EBV antibody titer decreased by 1.00% (95% CI 0.06-1.98%). Perceived stress was significantly associated with sleep quality, BMI, and current smoking status, but not with binge-drinking, drug use, or Appalachian self-identity. No mediating effects of sleep quality, BMI, binge-drinking, current drug use, or >4 sexual partners were observed in the relationship between perceived stress and EBV titer level. Conclusion: Young Appalachian women reported high levels of perceived stress that were significantly associated with higher EBV titers. Higher perceived social support was associated with lower EBV titers. Health behaviors and Appalachian self-identity did not impact the relationship between perceived stress and EBV titers.

Effects of Lactobacillus casei Shirota ingestion on common cold infection and herpes virus antibodies in endurance athletes: a placebo-controlled, randomized trial.

AimsTo assess evidence of health and immune benefit by consumption of a Lactobacillus casei Shirota probiotic in highly physically active people.MethodsSingle-centre, population-based, randomized, double-blind, placebo-controlled trial. Daily ingestion of probiotic (PRO) or placebo (PLA) for 20 weeks for n = 243 (126 PRO, 117 PLA) university athletes and games players. Subjects completed validated questionnaires on upper respiratory tract infection symptoms (URS) on a daily basis and on physical activity status at weekly intervals during the intervention period. Blood samples were collected before and after 20 weeks of the intervention for determination of Epstein Barr virus (EBV) and cytomegalovirus (CMV) serostatus and antibody levels.ResultsURS episode incidence was unexpectedly low (mean 0.6 per individual) and was not significantly different on PRO compared with PLA. URS episode duration and severity were also not influenced by PRO. A significant time × group interaction effect was observed for plasma CMV antibody titres in CMV seropositive participants (p < 0.01) with antibody titre falling in the PRO group but remaining unchanged in the PLA group over time. A similar effect was found for plasma EBV antibody titres in EBV seropositive participants (p < 0.01) with antibody titre falling in the PRO group but increasing in the PLA group over time.ConclusionsIn summary, regular ingestion of PRO did not reduce URS episode incidence which might be attributable to the low URS incidence in this study. Regular ingestion of PRO reduced plasma CMV and EBV antibody titres, an effect that can be interpreted as a benefit to overall immune status.

Validation of an Optimized ELISA for Quantitative Assessment of Epstein-Barr Virus Antibodies from Dried Blood Spots

ABSTRACTOur objective was to validate a commercially available ELISA to measure antibody titers against Epstein-Barr virus (EBV) in dried blood spots (DBS) to replace a previously validated assay for DBS that is no longer available. We evaluated the precision, reliability, and stability of the assay for the measurement of EBV antibodies in matched plasma, fingerprick DBS, and venous blood DBS samples from 208 individuals. Effects of hematocrit and DBS sample matrix on EBV antibody determination were also investigated, and the cutoff for seropositivity in DBS was determined. A conversion equation was derived to enable comparison of results generated using this method with the former DBS method. There was a high correlation between plasma and DBS EBV antibody titers (R2 = 0.93) with very little bias (−0.07 based on Bland-Altman analysis). The assay showed good linearity and did not appear to be affected by the DBS matrix, and physiological hematocrit levels had no effect on assay performance. There was reasonable agreement between DBS EBV titer estimates obtained using this assay and the previously validated assay (R2 = 0.72). The commercially available ELISA assay for EBV antibody titers that we validated for use with DBS will facilitate continued investigation of EBV antibody titers in DBS.