title: Serological response to Epstein-Barr virus early antigen is associated with gastric cancer and human immunodeficiency virus infection in Zambian adults: a case-control study.
abstract: BACKGROUND
  Gastric cancer is one of the major causes of cancer related deaths, but data from sub-Saharan Africa are very scanty. The cancer genome atlas (TCGA) initiative confirmed Epstein-Barr virus (EBV) related cancer as a distinct subtype, and we set out to look for serological evidence of its role in a sub-Saharan African patient group.
  
  
  METHODS
  We used stored serum samples obtained from a gastric cancer case-control study conducted between 2010 and 2012 in Lusaka, Zambia. A total of 147 patients were included with 51 gastric adenocarcinoma cases and 96 age and sex matched controls. The presence of antibodies to EBV nuclear antigen-1 (EBNA-1) and early antigen (EA) was determined using commercially available ELISA kits. Data were analysed in STATA Stata Corp, College Station TX.
  
  
  RESULTS
  Over 90% of all the samples analysed were positive for antibodies to EBNA-1. The presence of antibodies to EBV EA was significantly higher in gastric cancer cases than in controls, (OR 4.38; 95% CI 1.53-13.06, P = 0.0027), with an attributable risk of 23%. HIV infection was also associated with EBV EA seroprevalence (OR 10.97; 95% CI 2.26 -13.06, P = 0.001) but not EBNA-1 (OR 0.81; 95% CI 0.10 -38.75, P = 0.596). There was no association of EBV infection with age below 45 years, Helicobacter pylori infection, intestinal metaplasia, gastric atrophy or inflammation.
  
  
  CONCLUSIONS
  We therefore conclude that EBV exposure is common among Zambian adults and that EBV EA seropositivity is associated with gastric cancer and HIV infection, but not premalignant lesions.
authors.affiliation: Tropical Gastroenterology & Nutrition Group, University of Zambia School of Medicine, Nationalist Road, Lusaka, Zambia.
authors.forename: Violet
authors.initials: V
authors.lastname: Kayamba
authors.affiliation: University Teaching Hospital, Nationalist Road, Lusaka, Zambia.
authors.forename: Mwaka
authors.initials: M
authors.lastname: Monze
authors.affiliation: Division of Gastroenterology and Hepatology, University of Missouri-Columbia School of Medicine, MO, USA.
authors.forename: Akwi Wasi
authors.initials: AW
authors.lastname: Asombang
authors.affiliation: Tropical Gastroenterology & Nutrition Group, University of Zambia School of Medicine, Nationalist Road, Lusaka, Zambia.
authors.forename: Kanekwa
authors.initials: K
authors.lastname: Zyambo
authors.affiliation: Tropical Gastroenterology & Nutrition Group, University of Zambia School of Medicine, Nationalist Road, Lusaka, Zambia; Blizard Institute, Barts & The London School of Medicine and Dentistry, Turner Street, London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Kelly
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology / Q000821:virology*; D000328:Adult; D000956:Antigens, Viral / Q000276:immunology; D016022:Case-Control Studies; D020031:Epstein-Barr Virus Infections / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000453:epidemiology / Q000821:virology; D012189:Retrospective Studies; D016036:Seroepidemiologic Studies; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000821:virology*; D015024:Zambia / Q000453:epidemiology
chemical_list: D000956:Antigens, Viral; D019309:Epstein-Barr Virus Nuclear Antigens; C033305:Epstein-Barr virus early antigen; C417029:EBV-encoded nuclear antigen 1
keywords: EBNA-1; EBV- EA; Epstein-Barr virus; Gastric cancer; HIV