Nasopharyngeal Epstein-Barr Virus Load: An Efficient Supplementary Method for Population-Based Nasopharyngeal Carcinoma Screening

• Published in: PloS one Vol. 10; no. 7; p. e0132669
• Main Authors: Chen, Yufeng, Zhao, Weilin, Lin, Longde, Xiao, Xue, Zhou, Xiaoying, Ming, Huixin, Huang, Tingting, Liao, Jian, Li, Yancheng, Zeng, Xiaoyun, Huang, Guangwu, Ye, Weimin, Zhang, Zhe
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 07.07.2015; Public Library of Science (PLoS)
• Subjects: Adult; Analysis; Antibodies; Antigens; Antigens, Viral - immunology; Area Under Curve; Assaying; Biopsy; Cancer; Capsid - immunology; Carcinoma; China - epidemiology; Deoxyribonucleic acid; Diagnostic systems; DNA; DNA, Viral - blood; Early Detection of Cancer - methods; Education; Endoscopy; Epidemiology; Epstein-Barr virus; Female; Females; Genomes; Herpesvirus 4, Human - immunology; Herpesvirus 4, Human - physiology; Hospitals; Humans; Immunoglobulin A; Immunoglobulins; Laboratories; Male; Males; Medical diagnosis; Medical research; Medicin och hälsovetenskap; Methods; Middle Aged; Multivariate Analysis; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms - blood; Nasopharyngeal Neoplasms - diagnosis; Nasopharyngeal Neoplasms - immunology; Nasopharyngeal Neoplasms - virology; Nasopharynx; Otolaryngology; Population; Population studies; Population-based studies; Prevention; Public health; Quantitative analysis; Risk; Risk Factors; Risk groups; Screening; Studies; Surgery; Throat cancer; Viral Load - immunology; Viruses; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0132669

Serological detection of Epstein-Barr virus (EBV) antibodies is frequently used in nasopharyngeal carcinoma (NPC) mass screening. However, the large number of seropositive subjects who require close follow-up is still a big burden. The present study aimed to detect the nasopharyngeal EBV load in a high-risk population seropositive for antibodies against EBV, as well as to examine whether assay for nasopharyngeal EBV DNA load might reduce the number of high-risk subjects for follow-up and improve early detection of NPC. A prospective and population-based cohort study was conducted in southern China from 2006 through 2013. Among 22,186 participants, 1045 subjects with serum immunoglobulin A (IgA) antibodies against viral capsid antigen (VCA) titers ≥ 1:5 were defined as high-risk group, and were then followed-up for NPC occurrence. Qualified nasopharyngeal swab specimens were available from 905 participants and used for quantitative PCR assay. Our study revealed that 89% (802/905) subjects showed positive EBV DNA in nasopharyngeal swab. The nasopharyngeal EBV load in females was higher than that in males. The nasopharyngeal EBV load increased with increasing serum VCA/IgA titers. Eight cases of newly diagnosed NPC showed an extremely elevated EBV load, and 87.5% (7 of 8 patients) were early-stage NPCs. The EBV loads of 8 NPCs were significantly higher than those of 897 NPC-free subjects (mean, 2.8 × 10(6) copies/swab [range 4.8 × 10(4)-1.1 × 10(8)] vs. 5.6 × 10(3) [range 0-3.8 × 10(6)]). Using mean EBV load in NPC-free population plus two standard deviations as cut-off value, a higher diagnostic performance was obtained for EBV load test than serum VCA/IgA test (area under ROC, 0.980 vs 0.895). In conclusion, in a prospective and population-based study we demonstrated that an additional assay of EBV load in the nasopharynx among high-risk individuals may reduce the number of subjects needed to be closely followed up and could serve as part of a NPC screening program in high-risk populations.