Interplay between autophagy and CncC regulates dendrite pruning in Drosophila.

Autophagy is essential for the turnover of damaged organelles and long-lived proteins. It is responsible for many biological processes such as maintaining brain functions and aging. Impaired autophagy is often linked to neurodevelopmental and neurodegenerative diseases in humans. However, the role of autophagy in neuronal pruning during development remains poorly understood. Here, we report that autophagy regulates dendrite-specific pruning of ddaC sensory neurons in parallel to local caspase activation. Impaired autophagy causes the formation of ubiquitinated protein aggregates in ddaC neurons, dependent on the autophagic receptor Ref(2)P. Furthermore, the metabolic regulator AMP-activated protein kinase and the insulin-target of rapamycin pathway act upstream to regulate autophagy during dendrite pruning. Importantly, autophagy is required to activate the transcription factor CncC (Cap "n" collar isoform C), thereby promoting dendrite pruning. Conversely, CncC also indirectly affects autophagic activity via proteasomal degradation, as impaired CncC results in the inhibition of autophagy through sequestration of Atg8a into ubiquitinated protein aggregates. Thus, this study demonstrates the important role of autophagy in activating CncC prior to dendrite pruning, and further reveals an interplay between autophagy and CncC in neuronal pruning.

Kinetics of EBV antibody-based NPC risk scores in Taiwan NPC multiplex families.

Nasopharyngeal carcinoma (NPC) risk prediction models based on Epstein-Barr virus (EBV)-antibody testing have shown potential for screening of NPC; however, the long-term stability is unclear. Here, we investigated the kinetics of two EBV-antibody NPC risk scores within the Taiwan NPC Multiplex Family Study. Among 545 participants with multiple blood samples, we evaluated the stability of a 2-marker enzyme-linked immunosorbent assay score and 13-marker multiplex serology score using the intra-class correlation coefficient (ICC) by fitting a linear mixed model that accounted for the clustering effect of multiple measurements per subject and age. We also estimated the clustering of positive tests using Fleiss's kappa statistic. Over an average 20-year follow-up, the 2-marker score showed high stability over time, whereas the 13-marker score was more variable (p < .05). Case-control status is associated with the kinetics of the antibody response, with higher ICCs among cases. Positive tests were more likely to cluster within the same individual for the 2-marker score than the 13-marker score (p < .05). The 2-marker score had an increase in specificity from ~90% for single measurement to ~96% with repeat testing. The 13-marker score had a specificity of ~73% for a single measurement that increased to ~92% with repeat testing. Among individuals who developed NPC, none experienced score reversion. Our findings suggest that repeated testing could improve the specificity of NPC screening in high-risk NPC multiplex families. Further studies are required to determine the impact on sensitivity, establish optimal screening intervals, and generalize these findings to general population settings in high-risk regions.

Outcomes in solid organ transplant recipients with a pretransplant diagnosis of melanoma.

Melanoma causes significant morbidity in solid organ transplant recipients (SOTRs). Melanomas diagnosed before transplantation can recur with intensive immunosuppression, but outcomes have not been well studied. We evaluated 901 non-Hispanic White SOTRs with a pretransplant melanoma identified using linked transplant and cancer registry data in the United States. Most pretransplant melanomas were invasive (60.7%), and the median time from diagnosis to transplantation was 5.1 years. After transplantation, 41 SOTRs developed a new invasive melanoma, corresponding to 9-fold increased risk compared with the general population (standardized incidence ratio, 9.2; 95% confidence interval [CI], 6.6-12). Twenty-two SOTRs died from melanoma after transplantation, corresponding to 52-fold increased risk (standardized mortality ratio, 52; 95% CI, 33-79). Risk factors for posttransplant melanoma included age at transplantation (adjusted hazard ratio [HR], 2.86; 95% CI, 1.24-6.60; for age 55+ vs <55 years) and maintenance immunosuppression with cyclosporine/azathioprine (adjusted HR, 2.53; 95% CI, 1.08-5.90). Melanoma mortality was strongly elevated after a posttransplant melanoma diagnosis (HR, 35.6; 95% CI, 14.0-90.4; adjusted for cyclosporine/azathioprine maintenance therapy and calendar year of transplantation). In conclusion, SOTRs with a pretransplant melanoma are at risk of adverse melanoma-related outcomes after transplantation. These findings support thorough dermatologic evaluation prior to transplantation and frequent posttransplant surveillance.

Biomarkers of gut barrier dysfunction and risk of hepatocellular carcinoma in the REVEAL-HBV and REVEAL-HCV cohort studies.

Gut barrier dysfunction can result in the liver being exposed to an elevated level of gut-derived bacterial products via portal circulation. Growing evidence suggests that systemic exposure to these bacterial products promotes liver diseases including hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). However, prospective studies have not examined the association between biomarkers of gut barrier dysfunction and HCC risk in a population of hepatitis B or C viral (HBV/HCV) carriers. We investigated whether prediagnostic, circulating biomarkers of gut barrier dysfunction were associated with HCC risk, using the Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer (REVEAL)-HBV and REVEAL-HCV cohorts from Taiwan. REVEAL-HBV included 185 cases and 161 matched controls, and REVEAL-HCV 96 cases and 96 matched controls. The biomarkers quantitated were immunoglobulin A (IgA), IgG, and IgM against lipopolysaccharide (LPS) and flagellin, soluble CD14 (an LPS coreceptor), and LPS-binding protein (LBP). Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between biomarker levels and HCC were calculated using multivariable-adjusted logistic regression. A doubling of the circulating levels of antiflagellin IgA or LBP was associated with a 76% to 93% increased risk of HBV-related HCC (OR per one unit change in log2 antiflagellin IgA = 1.76, 95% CI: 1.06-2.93; OR for LBP = 1.93, 95% CI: 1.10-3.38). None of the other markers were associated with an increased risk of HBV-related or HCV-related HCC. Results were similar when cases diagnosed in the first 5 years of follow-up were excluded. Our findings contribute to understanding the interplay of gut barrier dysfunction and primary liver cancer etiology.

Mortality among solid organ transplant recipients with a pretransplant cancer diagnosis.

Little is known about the outcomes among solid organ transplant recipients with a pretransplant cancer diagnosis. We used linked data from the Scientific Registry of Transplant Recipients with 33 US cancer registries. Cox proportional hazards models assessed associations of pretransplant cancer with overall mortality, cancer-specific mortality, and development of a new posttransplant cancer. Among 311 677 recipients, the presence of a single pretransplant cancer was associated with increased overall mortality (adjusted hazard ratio [aHR], 1.19; 95% CI, 1.15-1.23) and cancer-specific mortality (aHR, 1.93; 95% CI, 1.76-2.12); results for 2+ pretransplant cancers were similar. Cancer-specific mortality was not significantly increased for uterine, prostate, or thyroid cancers (aHRs were 0.83, 1.22, and 1.54, respectively) but strongly elevated for lung cancer and myeloma (aHRs were 3.72 and 4.42, respectively). A pretransplant cancer diagnosis was also associated with increased risk of developing posttransplant cancer (aHR, 1.32; 95% CI, 1.23-1.40). Among 306 recipients whose cancer death was confirmed by cancer registry data, 158 deaths (51.6%) were from a de novo posttransplant cancer and 105 (34.3%) from the pretransplant cancer. Pretransplant cancer diagnoses are associated with increased mortality after transplantation, but some deaths are related to posttransplant cancers and other causes. Improved candidate selection and cancer screening and prevention may reduce mortality in this population.

The implementation of chatbot-mediated immediacy for synchronous communication in an online chemistry course.

Low student engagement and motivation in online classes are well-known issues many universities face, especially with distance education during the COVID-19 pandemic. The online environment makes it even harder for teachers to connect with their students through traditional verbal and nonverbal behaviours, further decreasing engagement. Yet, addressing such problems with 24/7 synchronous communication is overly demanding for faculty. This paper details an automated Question-Answering chatbot system trained in synchronous communication and instructor immediacy techniques to determine its suitability and effectiveness in attending to students undergoing an online Chemistry course. The chatbot is part of a new wave of affective focused chatbots that can benefit students' learning process by connecting with them on a relatively more humanlike level. As part of the pilot study in the development of this chatbot, qualitative interviews and self-report data capturing student-chatbot interactions, experiences and opinions have been collected from 12 students in a Singaporean university. Thematic analysis was then employed to consolidate these findings. The results support the chatbot's ability to display several communication immediacy techniques well, on top of responding to students at any time of the day. Having a private conversation with the chatbot also meant that the students could fully focus their attention and ask more questions to aid their learning. Improvements were suggested, in relation to the chatbot's word detection and accuracy, accompanied by a framework to develop communication immediacy mechanics in future chatbots. Our findings support the potential of this chatbot, once modified, to be used in a similar online setting. Supplementary Information: The online version contains supplementary material available at 10.1007/s10639-023-11602-1.

Cancer risk associated with cytomegalovirus infection among solid organ transplant recipients in the United States.

BACKGROUND: Cytomegalovirus (CMV) is among the most common viral infections after solid organ transplantation (SOT). Associations of CMV with cancer risk among SOT recipients have been incompletely evaluated. METHODS: The authors used linked data from the US SOT registry and 32 cancer registries. Poisson regression was used to compare cancer incidence across CMV risk groups based on donor (D) and recipient (R) immunoglobulin G (IgG) serostatus: high risk (R-negative/D-positive), moderate risk (R-positive), and low risk (R-negative/D-negative). RESULTS: In total, 247,318 SOT recipients were evaluated during 2000-2017 (R-negative/D-positive, 20.3%; R-positive, 62.9%; R-negative/D-negative, 16.8%). CMV-seropositive recipients were older, more racially/ethnically diverse, and had lower socioeconomic status than CMV-seronegative recipients. Compared with R-negative/D-negative recipients, recipients in the R-negative/D-positive and R-positive groups had a lower incidence of diffuse large B-cell lymphoma (DLBCL; R-negative/D-positive: adjusted incidence rate ratio [aIRR], 0.74; 95% confidence interval [CI], 0.59-0.91; R-positive: aIRR, 0.83; 95% CI, 0.69-1.00). CMV serostatus modified the association between Epstein-Barr virus (EBV) status and DLBCL (p = .0006): DLBCL incidence was increased for EBV R-negative/D-positive recipients (aIRR, 3.46; 95% CI, 1.50-7.95) among CMV R-negative/D-negative recipients but not among the other CMV risk groups. Compared with recipients who were CMV R-negative/D-negative, those who were R-negative/D-positive had a lower incidence of small intestine cancer (aIRR, 0.23; 95% CI, 0.09-0.63), and R-positive recipients had a higher incidence of lung cancer (aIRR, 1.24; 95% CI, 1.05-1.46). CMV status was not associated with risk for other cancers. CONCLUSIONS: CMV status was not associated with risk for most cancers among SOT recipients. The inverse association with DLBCL may reflect the protective effects of CMV prophylaxis or treatment with off-target efficacy against EBV infection (the major cause of lymphoma in SOT recipients).

Cancer risk in living kidney donors.

Living kidney donors are screened for transmissible diseases including cancer. Outcomes following donation are excellent, but concern exists regarding development of chronic kidney disease, and cancer risk is unknown. We used linked transplant and cancer registry data to identify incident cancers among 84,357 kidney donors in the United States (1995-2017). We compared risk with the general population using standardized incidence ratios (SIRs). For selected cancers, we used Poisson regression to compare donors with 47,451 Adventist Health Study 2 (AHS-2) participants, who typically have healthy lifestyles. During follow-up, 2843 cancers were diagnosed in donors, representing an overall deficit (SIR 0.79, 95%CI 0.76-0.82). None of 46 specified cancer sites occurred in excess relative to the general population, and 15 showed significant deficits (SIR < 1.00). Compared with AHS-2 participants, donors had similar incidence of liver cancer, melanoma, breast cancer, and non-Hodgkin lymphoma but, starting 7 years after donation, elevated incidence of colorectal cancer (adjusted incidence rate ratio 2.07, 95%CI 1.54-2.79) and kidney cancer (2.97, 1.58-5.58, accounting for the presence of a single kidney in donors). Elevated kidney cancer incidence may reflect adverse processes in donors' remaining kidney. Nonetheless, cancer risk is lower than in the general population, suggesting that enhanced screening is unnecessary.

Utility of Epstein-Barr Virus DNA in Nasopharynx Swabs as a Reflex Test to Triage Seropositive Individuals in Nasopharyngeal Carcinoma Screening Programs.

BACKGROUND: Epstein-Barr virus (EBV) DNA detection in the nasopharynx is considered a biomarker for nasopharyngeal carcinoma (NPC). We evaluated its performance as a reflex test to triage EBV seropositives within an NPC screening program in China. METHODS: The study population was embedded within an ongoing NPC screening trial and included 1111 participants who screened positive for anti-EBV VCA (antibodies against EBV capsid antigens)/EBNA1 (EBV nuclear antigen1)-IgA antibodies (of 18 237 screened). Nasopharynx swabs were collected/tested for EBNA1 gene EBV DNA load. We evaluated performance of EBV DNA in the nasopharynx swab as a reflex test to triage EBV serological high-risk (those referred to endoscopy/MRI) and medium-risk (those referred to accelerated screening) individuals. RESULTS: By the end of 2019, we detected 20 NPC cases from 317 serological high-risk individuals and 4 NPC cases from 794 medium-risk individuals. When used to triage serological high-risk individuals, nasopharynx swab EBV DNA was detected in 19/20 cases (positivity rate among cases: 95.0%; 95% CI, 75.1%-99.9%), with a referral rate of 63.4% (201/317, 95% CI, 57.8%-68.7%) and NPC detection rate among positives of 9.5% (19/201, 95% CI, 5.8%-14.4%). The performance of an algorithm that combined serology with triage of serology high-risk individuals using EBV DNA testing yielded a sensitivity of 72.4% (95% CI, 3.0%-81.4%) and specificity of 97.6% (95% CI, 97.2%-97.9%). When used to triage EBV serological medium-risk individuals, the positivity rate among cases was 75.0% (95% CI, 19.4%-99.4%), with a referral rate of 61.8% (95% CI, 58.4%-65.2%) and NPC detection rate among positives of 0.6% (95% CI, 0.1%-1.8%). CONCLUSIONS: Nasopharynx swab EBV DNA showed promise as a reflex test to triage serology high-risk individuals, reducing referral by ca. 40% with little reduction in sensitivity compared to a serology-only screening program.

Epstein-Barr Virus-Based Nasopharyngeal Carcinoma (NPC) Risk Prediction Scores Are Elevated in NPC Multiplex Family Members in Taiwan.

Nasopharyngeal carcinoma (NPC) is caused by Epstein-Barr virus (EBV) and is more likely to occur in susceptible families. Whether genetic susceptibility operates through altered EBV control is incompletely understood. We used a NPC risk prediction model based on 14 EBV markers to compare risk score distribution in unaffected members from multiplex families with that in population-based controls. Despite the absence of NPC at the time of antibody measurement, we observed an upward shift in risk score among multiplex family members compared to the general population, consistent with the possibility that genetic factors affect NPC risk through alterations in EBV control.

HLA Zygosity Increases Risk of Hepatitis B Virus-Associated Hepatocellular Carcinoma.

BACKGROUND: Diversity in the HLA genes might be associated with disease outcomes-the heterozygote advantage hypothesis. We tested this hypothesis in relation to hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). METHODS: We utilized DNA from > 10 000 Taiwanese individuals with current or past HBV infection to examine the association between HLA diversity and critical natural history steps in the progression from HBV infection to HCC. Individuals were classified as homozygotes at a given locus when imputed to carry the same 4-digit allele for the 2 HLA alleles at that locus. RESULTS: Increase in number of homozygous HLA class II loci was associated with an increased risk of chronic HBV infection (Ptrend = 1.18 × 10-7). Among chronic HBV carriers, increase in number of homozygous HLA class II loci was also associated with an increased risk of HBV-associated HCC (Ptrend = .031). For individual HLA loci, HLA-DQB1 homozygosity was significantly associated with HCC risk (adjusted hazard ratio = 1.40; 95% confidence interval, 1.06-1.84). We also found that zygosity affects risk of HCC through its ability to affect viral control. CONCLUSIONS: Homozygosity at HLA class II loci, particularly HLA-DQB1, is associated with a higher risk of HBV-associated HCC.

Cancer patterns in nasopharyngeal carcinoma multiplex families over 15 years.

BACKGROUND: Genetic and environmental factors are important determinants of nasopharyngeal carcinoma (NPC). NPC is associated with Epstein-Barr virus (EBV) infection. Studies have reported familial aggregation of NPC, but evidence has been mixed for elevated rates of cancers other than NPC. METHODS: The authors reassessed their previous evaluation of familial aggregation of cancer in 348 high-risk Taiwanese multiplex families with 2 or more NPC cases enrolled between 1980 and 2003. Participants were linked to the Taiwan National Cancer Registry and National Death Registry to identify cancers. RESULTS: In all, 2590 individuals contributed 37,959 person-years over an average of 15 years of follow-up; 314 incident cancers were identified. The authors computed multiple primary standardized incidence ratios (MP-SIRs) to evaluate the overall risk and the risk of infection-associated, EBV-associated, and individual cancers. The overall MP-SIR was 1.24 (95% confidence interval [CI], 1.10-1.38). The exclusion of excess NPC risk led to an overall MP-SIR of 1.11 (95% CI, 0.98-1.25). Similarly, the risk of cancers associated with infectious agents was driven by the excess in NPC, and its exclusion led to an MP-SIR of 1.22 (95% CI, 0.99-1.48) for infection-associated cancers and to an MP-SIR of 1.18 (95% CI, 0.72-1.82) for EBV-associated cancers. The authors observed a significant excess of second cancers among NPC cases (oral cancer, mouth cancer, tongue cancer, gum cancer, nasal cavity cancer, bone cancer, and non-Hodgkin lymphoma). CONCLUSIONS: This reassessment of the largest NPC multiplex family study confirms the presence of NPC coaggregation within families in Taiwan but does not provide evidence for a broader familial syndrome involving NPC and other tumors. Among NPC cases, elevated rates of secondary cancers, mostly at the, head and neck and hematopoietic cancers suggest radiation treatment effects on subsequent cancer risk.

Comparison of new magnetic resonance imaging grading system with conventional endoscopy for the early detection of nasopharyngeal carcinoma.

BACKGROUND: Although stratifying individuals with respect to nasopharyngeal carcinoma (NPC) risk with Epstein-Barr virus-based markers is possible, the performance of diagnostic methods for detecting lesions among screen-positive individuals is poorly understood. METHODS: The authors prospectively evaluated 882 participants aged 30 to 70 years who were enrolled between October 2014 and November 2018 in an ongoing, population-based NPC screening program and had an elevated NPC risk. Participants were offered endoscopy and magnetic resonance imaging (MRI), and lesions were identified either by biopsy at a follow-up endoscopy or further contact and linkage to the local cancer registry through December 31, 2019. The diagnostic performance characteristics of endoscopy and MRI for NPC detection were investigated. RESULTS: Eighteen of 28 identified NPC cases were detected by both methods, 1 was detected by endoscopy alone, and 9 were detected by MRI alone. MRI had significantly higher sensitivity than endoscopy for NPC detection overall (96.4% vs 67.9%; Pdifference = .021) and for early-stage NPC (95.2% vs 57.1%; P = .021). The sensitivity of endoscopy was suggestively lower among participants who had previously been screened in comparison with those undergoing an initial screening (50.0% vs 81.2%; P = .11). The authors observed a higher overall referral rate by MRI versus endoscopy (17.3% vs 9.1%; P < .001). Cases missed by endoscopy had early-stage disease and were more commonly observed for tumors originating from the pharyngeal recess. CONCLUSIONS: MRI was more sensitive than endoscopy for NPC detection in the context of population screening but required the referral of a higher proportion of screen-positive individuals. The sensitivity of endoscopy was particularly low for individuals who had previously been screened.

Prediagnostic concentrations of circulating bile acids and hepatocellular carcinoma risk: REVEAL-HBV and HCV studies.

Hepatocellular carcinoma (HCC) is the dominant histologic type of liver cancer, accounting for 75% of cases. Growing evidence suggests that the cross-talk between the gut microbiome and metabolome (ie, gut-liver axis) are related to the development of hepatic inflammation, and ultimately, HCC. Bile acids are metabolites, derived from cholesterol and synthesized in the liver, which may have a critical role in regulation of the gut-liver axis. We investigated whether prediagnostic circulating bile acids were associated with HCC risk, using the Risk Evaluation of Viral Load Elevation and Associated Liver Disease/Cancer (REVEAL)-Hepatitis B Virus (HBV) and REVEAL-Hepatitis C Virus (HCV) cohorts from Taiwan. Fifteen bile acids were quantitated using liquid chromatography, from 185 cases and 161 matched controls in REVEAL-HBV and 96 cases and 96 matched controls in REVEAL-HCV. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations between bile acid levels and HCC were calculated using multivariable-adjusted logistic regression. Higher levels of glycine and taurine conjugated primary bile acids were associated with a 2- to 8-fold increased risk of HBV- (eg, glycocholic acid ORQ4vsQ1 = 3.38, 95% CI: 1.48-7.71, Ptrend < .003) and HCV-related HCC (eg, OR = 8.16, 95% CI: 2.21-30.18, Ptrend < .001). However, higher levels of the secondary bile acid deoxycholic acid were inversely associated with HBV-related HCC risk (OR = 0.41, 95% CI: 0.19-0.88, Ptrend = .02). Our study provides evidence that higher concentrations of bile acids-specifically, conjugated primary bile acids-are associated with increased HCC risk. However, our study does not support the hypothesis that higher levels of secondary bile acids increase liver cancer risk; indeed, deoxycholic acid may be associated with a decreased HCC risk.

Evaluation of the antibody response to the EBV proteome in EBV-associated classical Hodgkin lymphoma.

The humoral immune response to Epstein-Barr virus (EBV) in classical Hodgkin lymphoma (cHL) stratified by EBV tumor status is unclear. We examined IgG and IgA antibody responses against 202 protein sequences representing 86 EBV proteins using a microarray and sera from 139 EBV-positive cHL cases, 70 EBV-negative cHL cases and 141 population-based controls frequency matched to EBV-positive cHL cases on sex and age by area (UK, Denmark and Sweden). We leveraged existing data on the proportion of circulating B-cells infected by EBV and levels of serum CCL17, a chemokine secreted by cHL tumor cells, from a subset of the cHL cases in the UK. Total IgG but not IgA response level was significantly different between EBV-positive cHL cases and controls. The distinct serological response included significant elevations in 16 IgG antibodies and 2 IgA antibodies, with odds ratioshighest vs. lowest tertile > 3 observed for the following EBV proteins: LMP1 (oncogene), BcLF1 (VCAp160, two variants) and BBLF1 (two variants). Our cHL IgG signature correlated with the proportion of circulating EBV-infected B-cells, but not serum CCL17 levels. We observed no differences in the anti-EBV antibody profile between EBV-negative cHL cases and controls. BdRF1(VCAp40)-IgG and BZLF1(Zta)-IgG were identified as the serological markers best able to distinguish EBV-positive from EBV-negative cHL tumors. Our results support the hypothesis that differences in the EBV antibody profile are specific to patients with EBV-positive cHL and are not universally observed as part of a systematically dysregulated immune response present in all cHL cases.

Validation of an Epstein-Barr Virus Antibody Risk Stratification Signature for Nasopharyngeal Carcinoma by Use of Multiplex Serology.

Serological testing for nasopharyngeal carcinoma (NPC) has recently been reinvigorated by the implementation of novel Epstein-Barr virus (EBV)-specific IgA and IgG antibodies from a proteome array. Although proteome arrays are well suited for comprehensive antigen selection, they are not applicable for large-scale studies. We adapted a 13-marker EBV antigen signature for NPC risk identified by proteome arrays to multiplex serology to establish an assay for large-scale studies. Taiwanese NPC cases (n = 175) and matched controls (n = 175) were used for assay validation. Spearman's correlation was calculated, and the diagnostic value of all multiplex markers was assessed independently using the area under the receiver operating characteristic curve (AUC). Two refined signatures were identified using stepwise logistic regression and internally validated with 10-fold cross validation. Array and multiplex serology showed strong correlation for each individual EBV marker, as well as for a 13-marker combined model on continuous data. Two refined signatures with either four (LF2 and BGLF2 IgG, LF2 and BMRF1 IgA) or two (LF2 and BGLF2 IgG) antibodies on dichotomous data were identified as the most parsimonious set of serological markers able to distinguish NPC cases from controls with AUCs of 0.992 (95% confidence interval [CI], 0.983 to 1.000) and 0.984 (95% CI, 0.971 to 0.997), respectively. Neither differed significantly from the 13-marker model (AUC, 0.992; 95% CI, 0.982 to 1.000). All models were internally validated. Multiplex serology successfully validated the original EBV proteome microarray data. Two refined signatures of four and two antibodies were capable of detecting NPC with 99.2% and 98.4% accuracy.

Multilaboratory Assessment of Epstein-Barr Virus Serologic Assays: the Case for Standardization.

IgA antibodies targeting Epstein-Barr virus (EBV) have been proposed for screening for nasopharyngeal carcinoma (NPC). However, methods differ, and the antigens used in these assays differ considerably between laboratories. To enable formal comparisons across a range of established EBV serology assays, we created a panel of 66 pooled serum samples and 66 pooled plasma samples generated from individuals with a broad range of IgA antibody levels. Aliquots from these panels were distributed to six laboratories and were tested by 26 assays measuring antibodies against VCA, EBNA1, EA-EBNA1, Zta, or EAd antigens. We estimated the correlation between assay pairs using Spearman coefficients (continuous measures) and percentages of agreement (positive versus negative, using predefined positivity cutoffs by each assay developer/manufacturer). While strong correlations were observed between some assays, considerable differences were also noted, even for assays that targeted the same protein. For VCA-IgA assays in serum, two distinct clusters were identified, with a median Spearman coefficient of 0.41 (range, 0.20 to 0.66) across these two clusters. EBNA1-IgA assays in serum grouped into a single cluster with a median Spearman coefficient of 0.79 (range, 0.71 to 0.89). Percentages of agreement differed broadly for both VCA-IgA (12% to 98%) and EBNA1-IgA (29% to 95%) assays in serum. Moderate-to-strong correlations were observed across assays in serum that targeted other proteins (correlations ranged from 0.44 to 0.76). Similar results were noted for plasma. We conclude that standardization of EBV serology assays is needed to allow for comparability of results obtained in different translational research studies across laboratories and populations.

Evaluation of Total and IgA-Specific Antibody Targeting Epstein-Barr Virus Glycoprotein 350 and Nasopharyngeal Carcinoma Risk.

Background: We previously reported that higher levels of antibody targeting Epstein-Barr virus (EBV) glycoprotein350 (gp350), an EBV vaccine candidate, were protective against nasopharyngeal carcinoma (NPC) in genetically high-risk families from Taiwan. The current study attempted to extend this association to a general population cohort. Methods: We compared total and IgA-specific gp350 antibody levels in 35 incident NPC cases and 81 disease-free controls from the Cancer Screening Program in Taiwan (23943 individuals recruited 1991-1992). Luciferase immunoprecipitation assays quantified gp350 antibody. Results: Total EBVgp350 antibody levels were not higher in individuals who remained disease free compared to those who developed NPC (P = .11). This lack of a protective gp350 association persisted for cases diagnosed ≥5 years (odds ratio [OR] = 1.05; P = .91) and <5 years (OR = 1.85; P = .40) after blood draw. IgA-specific gp350 antibody levels were higher in cases than controls (OR = 7.03; P = .001). This increased risk was most pronounced for cases diagnosed <5 years after blood draw (OR = 11.7; P = .004). Conclusion: Unlike our prior findings in those with a strong family history of NPC, total gp350 antibody levels were not protective against NPC development in this general population setting.

Patterns of Interindividual Variability in the Antibody Repertoire Targeting Proteins Across the Epstein-Barr Virus Proteome.

Background: Little is known about variation in antibody responses targeting the full spectrum of Epstein-Barr virus (EBV) proteins and how such patterns inform disease risk. Methods: We used a microarray to measure immunoglobulin G (IgG) and immunoglobulin A (IgA) antibody responses against 199 EBV protein sequences from 5 EBV strains recovered from 289 healthy adults from Taiwan. We described positivity patterns, estimated the correlation between antibodies, and investigated the associations between environmental and genetic risk factors and variations in antibody responses. Results: Healthy adults were more likely to mount IgG antibody responses to EBV proteins (median positivity frequency, 46.5% for IgG and 17.3% for IgA; P = 1.6 × 10-46, by the Wilcoxon rank sum test). Responses against glycoproteins were particularly prevalent. The correlations between antibody responses of the same class were higher than correlations across classes. The mucosal exposure to proteins involved in EBV reactivation (as determined by the IgA response) was associated with smoking (P = .002, by the sequence kernel association test-combined), and approximately one quarter of adults displayed antibody responses associated with EBV-related cancer risk. Conclusions: These data comprehensively define the variability in human IgG and IgA antibody responses to the EBV proteome. Patterns observed can serve as the foundation for elucidating which individuals are at highest risk of EBV-associated clinical conditions and for identifying targets for effective immunodiagnostic tests.