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Epstein-Barr virus (EBV) infection is associated with multiple malignancies, including pulmonary lymphoepithelioma-like carcinoma (pLELC), a particular subtype of primary lung cancer. However, the genomic characteristics of EBV related to pLELC remain unclear. Here, we obtained the whole-genome data set of EBV isolated from 78 pLELC patients and 37 healthy controls using EBV-captured sequencing. Compared with the reference genome (NC_007605), a total of 3,995 variations were detected across pLELC-derived EBV sequences, with the mutational hot spots located in latent genes. Combined with 180 published EBV sequences derived from healthy people in Southern China, we performed a genome-wide association study and identified 32 variations significantly related to pLELC (P < 2.56 × 10-05, Bonferroni correction), with the top signal of single nucleotide polymorphism (SNP) coordinate T7327C (OR = 1.22, P = 2.39 × 10-15) locating in the origin of plasmid replication (OriP). The results of population structure analysis of EBV isolates in East Asian showed the EBV strains derived from pLELC were more similar to those from nasopharyngeal carcinoma (NPC) than other EBV-associated diseases. In addition, typical latency type-II infection were recognized for EBV of pLELC at both transcription and methylation levels. Taken together, we defined the global view of EBV genomic profiles in pLELC patients for the first time, providing new insights to deepening our understanding of this rare EBV-associated primary lung carcinoma. IMPORTANCE Pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare, distinctive subtype of primary lung cancer closely associated with Epstein-Barr virus (EBV) infection. Here, we gave the first overview of pLELC-derived EBV at the level of genome, methylation and transcription. We obtained the EBV sequences data set from 78 primary pLELC patients, and revealed the sequences diversity across EBV genome and detected variability in known immune epitopes. Genome-wide association analysis combining 217 healthy controls identifies significant variations related to the risk of pLELC. Meanwhile, we characterized the integration landscapes of EBV at the genome-wide level. These results provided new insight for understanding EBV's role in pLELC tumorigenesis.
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Carcinoma de Pulmón de Células no Pequeñas/virología , Infecciones por Virus de Epstein-Barr/virología , Genoma Viral/genética , Herpesvirus Humano 4/genética , Neoplasias Pulmonares/virología , Pueblo Asiatico , China , Metilación de ADN , Epítopos de Linfocito T/genética , Genes Virales/genética , Variación Genética , Estudio de Asociación del Genoma Completo , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Integración Viral , Latencia del Virus/genéticaRESUMEN
BACKGROUND: Nasopharyngeal carcinoma (NPC), an Epstein-Barr virus (EBV) associated cancer, exhibits an extremely high incidence in southern Chinese. Given that human leukocyte antigen (HLA) plays critical roles in antigen presentation and relates to NPC susceptibility, it is speculated that certain HLA variants may affect EBV reactivation, which is a key pathogenic factor of NPC. Therefore, we attempted to identify HLA alleles associated with the indicator of EBV reactivation, Zta-IgA, in healthy males from NPC endemic area. METHODS: HLA alleles of 1078 healthy males in southern China from the 21-RCCP study were imputed using genome-wide single nucleotide polymorphism data. EBV Zta-IgA in blood samples were measured using an enzyme-linked immunosorbent assay. Multiple logistic regression analysis was used to evaluate the effect of HLA allele on Zta-IgA serological status and its potential joint association with smoking. The binding affinity for Zta-peptide was predicted using NetMHCIIpan 4.0. RESULTS: HLA-DRB1*09:01 was found to be associated with a higher risk of Zta-IgA seropositivity (odds ratio = 1.80, 95% confidence interval = 1.32-2.45; p = 1.82 × 10-4 ). Compared with non-smokers without HLA-DRB1*09:01, the effect size increased to 2.19- and 3.70-fold for the light and heavy smokers carrying HLA-DRB1*09:01, respectively. Furthermore, HLA-DRB1*09:01 showed a stronger binding affinity to Zta peptide than other HLA-DRB1 alleles. CONCLUSIONS: Our study highlighted the pivotal role of genetic HLA variants in EBV reactivation and the etiology of NPC. Smokers with HLA-DRB1*09:01 have a significantly higher risk of being Zta-IgA seropositive, which indicates the necessity of smoking cessation in certain high-risk populations and also provide clues for further research on the etiology of NPC.
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Infecciones por Virus de Epstein-Barr/inmunología , Antígenos HLA/genética , Herpesvirus Humano 4/inmunología , Inmunoglobulina A/inmunología , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/inmunología , Transactivadores/inmunología , Adulto , Alelos , Anticuerpos Antivirales/inmunología , Pueblo Asiatico/genética , Infecciones por Virus de Epstein-Barr/virología , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Voluntarios Sanos , Humanos , Inmunoglobulina A/sangre , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/inmunología , Fumar/efectos adversos , Proteínas Virales/inmunologíaRESUMEN
Nasopharyngeal carcinoma (NPC), the most common head and neck cancer, is characterized by distinct geographic distribution and familial aggregation. Multiple risk factors, including host genetics, environmental factor, and EBV infection, have been linked to the development of NPC, particularly in the familial clustering cases. However, the cause of NPC endemicity remains enigmatic due possibly to the complicated interplay between these risk factors. Recently, positive Epstein-Barr virus (EBV) DNA loads at nasopharyngeal (NP) cavity has been found to reflect NPC development and applied in NPC screening. To examine whether the increased NP EBV loads could aggregate in the families and be affected by host genetics and environmental factor, EBV loads were obtained by 510 NP brushing samples from eligible unaffected individuals, who have two or more relatives affected with NPC, in 116 high-risk NPC families. The correlation of relative pairs was estimated using S.A.G.E. (version 6.4, 2016), and host heritability of NP EBV loads was calculated with variance component models using SOLAR (version 8.4.2, 2019). In result, significant correlations of EBV loads were observed between parent-offspring pairs and sibling-sibling pairs (P < .001), but not in distant kin relationship pairs. Interestingly, after excluding the shared environmental factor within families, host genetics contributes significantly to NP EBV loads with a heritability of 56.41% (P = 1.00 × 10-7 ), and its effect was slightly elevated (68.86%, P = 3.40 × 10-6 ) in families with more NPC cases (≥3). These findings indicate that additional host-genetic variants involved in the EBV local NP mucosal behavior may be especially important for the development of NPC.
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The synthesis of zeolites through more efficient, environmentally friendly, and cost-effective methods was deemed significant in both industrial applications and academic fields. Conventional hydrothermal synthesis strategies have encountered difficulties in producing pure silica MFI zeolite (silicalite-1) under amine-free conditions. This was primarily attributed to the competitive growth of quartz, keatite, or magadiite during the crystallization process. In this work, it was found that the lack of nucleation ability was an important reason for the poor crystallization stability of the methanol solution. Well-crystallized silicalite-1 zeolites with uniform particle sizes were achieved through the cooperative guidance of methanol and seed crystals. Large-scale experiments with silicalite-1 zeolite demonstrated good reproducibility. Combined with the TG-IR and N2 adsorption-desorption results, it was observed that, when an extremely small amount of seed (0.97 wt %) was introduced, methanol could play a role as a crystallization promoter in the hydrothermal synthesis system. Furthermore, a lower alkaline-to-silica ratio and water-to-silica ratio were conducive to the progression of the crystallization process. In summary, this work presented a hydrothermal synthesis strategy for the synthesis of silicalite-1 zeolite in a methanol solution without the need for a large amount of seeds and provided an effective pathway for the low-cost, large-scale production of silicalite-1 zeolite.
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The presence of oral microbes in extra-oral sites is linked to gastrointestinal cancers. However, their potential ectopically colonization in the nasopharynx and impact on local cancer development remains uncertain. Our study involving paired nasopharyngeal-oral microbial samples from nasopharyngeal carcinoma (NPC) patients and controls unveils an aberrant oral-to-nasopharyngeal microbial translocation associated with increased NPC risk (OR = 4.51, P = 0.012). Thirteen species are classified as oral-translocated and enriched in NPC patients. Among these, Fusobacterium nucleatum and Prevotella intermedia are validated through culturomics and clonal strain identification. Nasopharyngeal biopsy meta-transcriptomes confirm these microbes within tumors, influencing local microenvironment and cytokine response. These microbes correlate significantly with the Epstein-Barr virus (EBV) loads in the nasopharynx, exhibiting an increased dose-response relationship. Collectively, our study identifies oral microbes migrating to the nasopharynx, infiltrating tumors, impacting microenvironments and linking with EBV infection. These results enhance our understanding of abnormal microbial communication and their roles in carcinogenesis.
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Infecciones por Virus de Epstein-Barr , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/complicaciones , Herpesvirus Humano 4/genética , Neoplasias Nasofaríngeas/patología , Translocación Genética , Boca , Microambiente TumoralRESUMEN
Microbiota has recently emerged as a critical factor associated with multiple malignancies. Nasopharyngeal carcinoma (NPC) is highly associated with Epstein-Barr virus (EBV); the oncovirus resides and is transmitted in the oral cavity. However, the alternation of oral microbiota in NPC patients and its potential link to EBV reactivation and host cell response under the simultaneous existence of EBV and specific bacteria is largely unknown. Here, oral microbiota profiles of 303 NPC patients and controls with detailed clinical information, including serum EBV anti-virus capsid antigen (VCA) IgA level, were conducted. A distinct microbial community with lower diversity and imbalanced composition in NPC patients was observed. Notably, among enriched bacteria in patients, Streptococcus sanguinis was associated with anti-VCA IgA, an indicator of NPC risk and EBV reactivation. By measuring the concentration of its metabolite, hydrogen peroxide (H2O2), in the saliva of clinical patients, we found the detection rate of H2O2 was 2-fold increased compared to healthy controls. Further coculture assay of EBV-positive Akata cells with bacteria in vitro showed that S. sanguinis induced EBV lytic activation by its metabolite, H2O2. Host and EBV whole genome-wide transcriptome sequencing and EBV methylation assays showed that H2O2 triggered the host cell signaling pathways, notably tumor necrosis factor alpha (TNF-α) via NF-κB, and induced the demethylation of the global EBV genome and the expression of EBV lytic-associated genes, which could result in an increase of virus particle release and potential favorable events toward tumorigenesis. In brief, our study identified a characterized oral microbial profile in NPC patients and established a robust link between specific oral microbial alteration and switch of latency to lytic EBV infection status in the oral cavity, which provides novel insights into EBV's productive cycle and might help to further clarify the etiology of NPC. IMPORTANCE EBV is classified as the group I human carcinogen and is associated with multiple cancers, including NPC. The interplays between the microbiota and oncovirus in cancer development remain largely unknown. In this study, we investigate the interactions between resident microbes and EBV coexistence in the oral cavity of NPC patients. We identify a distinct oral microbial feature for NPC patients. Among NPC-enriched bacteria, we illustrated that a specific species, S. sanguinis, associated with elevated anti-IgA VCA in patients, induced EBV lytic activation by its by-product, H2O2, and activated the TNF-α/NF-κB pathway of EBV-positive B cells in vitro, together with increased detection rate of H2O2 in patients' oral cavities, which strengthened the evidence of bacteria-virus-host interaction in physiological circumstances. The effects of imbalanced microbiota on the EBV latent-to-lytic switch in the oral cavity might create the likelihood of EBV infection in epithelial cells at the nasopharynx and help malignant transition and cancer development.
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Infecciones por Virus de Epstein-Barr , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo , Herpesvirus Humano 4/genética , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/genética , Neoplasias Nasofaríngeas/genética , FN-kappa B , Peróxido de Hidrógeno , Factor de Necrosis Tumoral alfaRESUMEN
The dysbiosis of oral microbiota is linked to numerous diseases and is associated with personal lifestyles, such as alcohol drinking. However, there is inadequate data to study the effect of alcohol drinking on oral microbiota from the Chinese population. Here, we profiled the oral microbiota of 150 healthy subjects in the Chinese population by 16S rRNA gene sequencing. The results showed that drinkers had significantly higher alpha diversity than non-drinkers. A significant difference in overall microbiota composition was observed between non-drinkers and drinkers. Additionally, using DESeq analysis, we found genus Prevotella and Moryella, and species Prevotella melaninogenica and Prevotella tannerae were significantly enriched in drinkers; meanwhile, the genus Lautropia, Haemophilus and Porphyromonas, and species Haemophilus parainfluenzae were significantly depleted in drinkers. PICRUSt analysis showed that significantly different genera were mainly related to metabolism pathways. The oxygen-independent pathways, including galactose, fructose and mannose metabolism pathways, were enriched in drinkers and positively associated with genera enriched in drinkers; while the pyruvate metabolism pathway, an aerobic metabolism pathway, was decreased in drinkers and negatively associated with genera enriched in drinkers. Our results suggested that alcohol drinking may affect health by altering oral microbial composition and potentially affecting microbial functional pathways. These findings may have implications for better understanding the potential role those oral bacteria play in alcohol-related diseases.
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Microbiota , Consumo de Bebidas Alcohólicas/epidemiología , China/epidemiología , Disbiosis/microbiología , Humanos , ARN Ribosómico 16S/genéticaRESUMEN
Background: It remains controversial who would benefit from adjuvant chemotherapy (ACT) in patients with early-stage non-small cell lung cancer (NSCLC). We aim to construct a polygenic hazard score (PHS) to predict prognosis and ACT benefit among NSCLC patients. Methods: We conducted a retrospective study including 1,395 stage I-II NSCLC patients. We performed a genome-wide association study (GWAS) on overall survival (OS) in patients treated with ACT (SYSUCC ACT set, n=404), and then developed a PHS using LASSO Cox regression in a random subset (training, n=202) and tested it in the remaining set (test, n=202). The PHS was further validated in two independent datasets (SYSUCC surgery set, n=624; PLCO cohort, n=367). Results: The GWAS-derived PHS consisting of 37 single-nucleotide polymorphisms (SNPs) was constructed to classify patients into high and low PHS groups. For patients treated with ACT, those with low PHS had better clinical outcomes than high PHS (test set: HR =0.21, P<0.001; PLCO ACT set: HR =0.33, P=0.260). Similar results were found in the extended validation cohorts including patients with or without ACT (SYSUCC: HR =0.48, P<0.001; PLCO: HR =0.60, P=0.033). Within subgroup analysis by treatment or clinical factors, we further observed consistent results for the prognostic value of the PHS. Notably, ACT significantly improved OS in stage II patients with low PHS (HR =0.26, P<0.001), while there was no ACT survival benefit among patients with high PHS (HR =0.97, P=0.860). Conclusions: The PHS improved prognostic stratification and could help identify patients who were most likely to benefit from ACT in early-stage NSCLC.
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BACKGROUND: Nasopharyngeal carcinoma (NPC) is closely associated with genetic factors and Epstein-Barr virus infection, showing strong familial aggregation. Individuals with a family history suffer elevated NPC risk, requiring effective genetic counseling for risk stratification and individualized prevention. METHODS: We performed whole-exome sequencing on 502 familial NPC patients and 404 unaffected relatives and controls. We systematically evaluated the established cancer predisposition genes and investigated novel NPC susceptibility genes, making comparisons with 21 other familial cancers in the UK biobank (N = 5218). RESULTS: Rare pathogenic mutations in the established cancer predisposition genes were observed in familial NPC patients, including ERCC2 (1.39%), TP63 (1.00%), MUTYH (0.80%), and BRCA1 (0.80%). Additionally, 6 novel susceptibility genes were identified. RAD54L, involved in the DNA repair pathway together with ERCC2, MUTYH, and BRCA1, showed the highest frequency (4.18%) in familial NPC. Enrichment analysis found mutations in TP63 were enriched in familial NPC, and RAD54L and EML2 were enriched in both NPC and other Epstein-Barr virus-associated cancers. Besides rare variants, common variants reported in the studies of sporadic NPC were also associated with familial NPC risk. Individuals in the top quantile of common variant-derived genetic risk score while carrying rare variants exhibited increased NPC risk (odds ratio = 13.47, 95% confidence interval = 6.33 to 28.68, P = 1.48 × 10-11); men in this risk group showed a cumulative lifetime risk of 24.19%, much higher than those in the bottom common variant-derived genetic risk score quantile and without rare variants (2.04%). CONCLUSIONS: This study expands the catalog of NPC susceptibility genes and provides the potential for risk stratification of individuals with an NPC family history.
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Infecciones por Virus de Epstein-Barr , Neoplasias Nasofaríngeas , Masculino , Humanos , Carcinoma Nasofaríngeo/genética , Secuenciación del Exoma , Neoplasias Nasofaríngeas/epidemiología , Neoplasias Nasofaríngeas/genética , Predisposición Genética a la Enfermedad , Herpesvirus Humano 4/genética , Estudios de Casos y Controles , Proteína de la Xerodermia Pigmentosa del Grupo D/genéticaRESUMEN
The oral microbiota has been observed to be influenced by cigarette smoking and linked to several human diseases. However, research on the effect of cigarette smoking on the oral microbiota has not been systematically conducted in the Chinese population. We profiled the oral microbiota of 316 healthy subjects in the Chinese population by 16S rRNA gene sequencing. The alpha diversity of oral microbiota was different between never smokers and smokers (P = 0.002). Several bacterial taxa were first reported to be associated with cigarette smoking by LEfSe analysis, including Moryella (q = 1.56E-04), Bulleidia (q = 1.65E-06), and Moraxella (q = 3.52E-02) at the genus level and Rothia dentocariosa (q = 1.55E-02), Prevotella melaninogenica (q = 8.48E-08), Prevotella pallens (q = 4.13E-03), Bulleidia moorei (q = 1.79E-06), Rothia aeria (q = 3.83E-06), Actinobacillus parahaemolyticus (q = 2.28E-04), and Haemophilus parainfluenzae (q = 4.82E-02) at the species level. Two nitrite-producing bacteria that can increase the acidity of the oral cavity, Actinomyces and Veillonella, were also enriched in smokers with FDR-adjusted q-values of 3.62E-06 and 1.10E-06, respectively. Notably, we observed that two acid production-related pathways, amino acid-related enzymes (q = 6.19E-05) and amino sugar and nucleotide sugar metabolism (q = 2.63E-06), were increased in smokers by PICRUSt analysis. Finally, the co-occurrence analysis demonstrated that smoker-enriched bacteria were significantly positively associated with each other and were negatively correlated with the bacteria decreased in smokers. Our results suggested that cigarette smoking may affect oral health by creating a different environment by altering bacterial abundance, connections among oral microbiota, and the microbiota and their metabolic function.
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Fumar Cigarrillos , Microbiota , China , Humanos , Micrococcaceae , Prevotella , ARN Ribosómico 16SRESUMEN
Background: Plasma Epstein-Barr virus (EBV) DNA load has been widely used for nasopharyngeal carcinoma (NPC) prognostic risk stratification. However, oral EBV DNA load, a non-invasive biomarker that reflects the EBV lytic replication activity, has not been evaluated for its prognostic value in NPC yet. Methods: A total number of 1,194 locoregionally advanced NPC (LA-NPC) patients from south China were included from a prospective observational cohort (GARTC) with a median follow-up of 107.3 months. Pretreatment or mid-treatment mouthwashes were collected for EBV DNA detection by quantitative polymerase chain reaction (qPCR). The difference of pre- and mid-treatment oral EBV DNA load was tested by the Wilcoxon signed-rank test. The associations of oral EBV DNA load with overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRFS) were assessed using the log-rank test and multivariate Cox regression. Results: The high level of the oral EBV DNA load (>2,100 copies/mL) was independently associated with worse OS (HR = 1.45, 95% CI: 1.20-1.74, p < 0.001), PFS (HR = 1.38, 95% CI: 1.16-1.65, p < 0.001), DMFS (HR = 1.66, 95% CI: 1.25-2.21, p = 0.001), and LRFS (HR = 1.43, 95% CI: 1.05-1.96, p = 0.023). Similar and robust associations between oral EBV DNA load and prognosis were observed for patients in both the pretreatment and mid-treatment stages. The detection rate (71.7 vs. 48.6%, p < 0.001) and the median load of oral EBV DNA (13,368 vs. 382 copies/mL, p < 0.001) for patients in the pretreatment stage were significantly higher than those in the mid-treatment stage. The combination of the oral EBV DNA load and TNM staging provided a more precise risk stratification for the LA-NPC patients. Conclusion: Oral EBV DNA load was an alternative non-invasive predictor of prognosis and may facilitate risk stratification for the LA-NPC patients.
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Epstein-Barr virus (EBV) reactivation, reflected by aberrantly increased levels of various serological antibodies, has been suggested to be an early indicator of nasopharyngeal carcinoma (NPC) onset and progression. We have previously suggested that certain lifestyle and dietary factors were associated with elevated serological levels of the antibody against various EBV antigens namely VCA, Zta, EBNA1, and oral EBV DNA loads among healthy population. It remains unclear whether these potential environmental factors would also influence EBV serological antibodies in NPC patients. We conducted an epidemiological study to evaluate the associations between such environmental factors and EBV antibody levels among 1701 NPC patients in South China. Pretreatment serums were collected and examined for VCA-IgA and EA-IgA by immunoenzymatic assays and antienzyme rate (AER) of EBV DNase-specific neutralizing antibody. We found that consumption of Canton-style herbal tea was significantly correlated with increased serological antibody levels of VCA-IgA and EA-IgA, with adjusted ORs of 1.35 (95% CI: 1.03-1.76) and 1.32 (95% CI: 1.01-1.73), respectively, in the weekly intake frequency stratum, while not related to AER of EBV DNase-specific neutralizing antibody. Smoking was found to be not only an apparent risk factor for higher antibody levels of AER in stage III-IV patients (OR = 1.60, 95% CI: 1.11-2.30), but also associated closely with NPC stage at diagnosis (OR = 2.17, 95% CI: 1.47-3.22), with dose-response effects. In conclusion, we found consumption of Canton-style herbal tea and cigarette smoking were in positive associations with elevated EBV antibodies in NPC patients, which may be of public health significance for the primary prevention of EBV-associated diseases especially NPC.
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Anticuerpos Antivirales/metabolismo , Infecciones por Virus de Epstein-Barr/inmunología , Herpesvirus Humano 4/inmunología , Carcinoma Nasofaríngeo/virología , Neoplasias Nasofaríngeas/virología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , China/epidemiología , Fumar Cigarrillos/efectos adversos , Fumar Cigarrillos/epidemiología , Infecciones por Virus de Epstein-Barr/patología , Femenino , Humanos , Estilo de Vida , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo/inmunología , Carcinoma Nasofaríngeo/patología , Neoplasias Nasofaríngeas/inmunología , Neoplasias Nasofaríngeas/patología , Estadificación de Neoplasias , Tés de Hierbas/efectos adversos , Adulto JovenRESUMEN
Introduction: Self-reported smoking has been associated with higher seropositivity for the IgA response to Epstein-Barr virus (EBV) viral capsid antigen (VCA-IgA) and transcription activator protein (Zta) in healthy men in southern China where nasopharyngeal carcinoma (NPC) is endemic. Results on the association of biochemically verified smoking status with EBV reactivation are scarce. We aimed to investigate the relations of serum cotinine level with serological markers of EBV in healthy women, in addition to men. Methods: We collected information on demographic, lifestyle, environmental factors, and EBV serological markers in a cross-sectional study on 2,275 healthy subjects who were recruited from physical examination centers in Guangdong Province, China. In the present analysis, 901 subjects' serum cotinine levels have been measured by enzyme-linked immunosorbent assay (ELISA). Odds ratios (seropositivity of four EBV serological markers vs. seronegativity) for categorical serum cotinine levels were calculated by unconditional logistic regression with a group-specific confidence interval (CI). Results: In women, compared with lower serum cotinine level (0-0.71 ng/ml), higher cotinine level (>0.71-1.20 ng/ml; >1.20-228.40 ng/ml) was associated but non-significantly with higher seropositivity for EBV VCA-IgA (age- and education-adjusted OR = 1.18, 95% CIs = 0.84-1.64, 1.06, 0.75-1.50). These associations remained but still non-significant after adjusting for 5-year age group, education, family history of cancer, consumption of tea, Chinese herbal tea, salted fish at childhood, and exposure to occupational dust, chemical, fume, and radiation (multivariable adjusted OR = 1.21, 95% CIs = 0.85-1.71, 1.09, 0.76-1.55). In men, compared with lower serum cotinine level (0-2.15 ng/ml), higher cotinine level (>2.15-103.6 ng/ml; >103.6-419.4 ng/ml) was significantly associated with higher seropositivity for EBV VCA-IgA and Zta-IgA (age- and education-adjusted OR = 2.16, 95% CIs = 1.37-3.41, 1.79, 1.11-2.90; 1.98, 1.17-3.34, 1.95, 1.14-3.34). The association remained significant after adjusting for potential confounders for Zta-IgA (OR = 2.32, 95% CI = 1.37-3.93 for >2.15-103.6, and 2.50, 1.43-4.38 for >103.6-419.4 ng/ml), but not for VCA-IgA (2.06, 1.29-3.27, and 1.61, 0.96-2.71). Conclusions: Higher serum cotinine level is associated with higher seropositivity for EBV serological markers in healthy men in southern China. Such positive association was also observed in women but became non-significant. If confirmed to be causal, this finding has important implications for tobacco control and prevention of EBV-related disease, particularly for NPC.