title: CagA protein seropositivity in a random sample of adult population and gastric cancer patients in Estonia.
abstract: OBJECTIVE
  The prevalence of antibodies to CagA protein, associated with the risk of developing gastric cancer (GC), was studied in an Estonian adult population with a high prevalence of Helicobacter pylori (HP) infection and in a group of GC patients.
  
  
  METHODS
  In a representative sample of a random adult population from the South Estonian town of Karksi-Nuia, containing 199 subjects (86 M, 113 F, mean age 42.4) and in 45 (22 M, 23 F, mean age 64.5) consecutive patients with gastric adenocarcinoma, recruited during the periods 1986-87 and 1995-96 in the Hospital of Oncology, University of Tartu, anti-CagA IgG antibodies were determined by enzyme-linked immunosorbent assay (ELISA) using a recombinant fragment of CagA protein. The occurrence of anti-CagA IgG in ELISA was compared with immunoblot results for 141 subjects.
  
  
  RESULTS
  Seropositivity to acid glycine extracted cell surface proteins of HP was 85% in the population and 91% in GC patients (p = 0.39). Anti-CagA IgG antibodies were present in 63% of the population and in 87% of GC patients (p = 0.004). The highest prevalence of anti-CagA IgG in the population sample occurred in the age group 20-29 (76%). A comparison of anti-CagA positivity evaluated by using ELISA and immunoblot showed an agreement of results in 80% of cases.
  
  
  CONCLUSIONS
  HP seropositivity was similarly high in the Estonian random adult population sample and in GC patients, however, the prevalence of anti-CagA IgG was significantly higher in GC patients. Moreover, persons aged 20-29 years in the population possess the highest prevalence of anti-CagA IgG and should be given further attention with respect to the development of GC later in life.
authors.affiliation: Department of Immunology, University of Tartu, Hospital of Oncology, Estonia.
authors.forename: T
authors.initials: T
authors.lastname: Vorobjova
authors.forename: I
authors.initials: I
authors.lastname: Nilsson
authors.forename: K
authors.initials: K
authors.lastname: Kull
authors.forename: H I
authors.initials: HI
authors.lastname: Maaroos
authors.forename: A
authors.initials: A
authors.lastname: Covacci
authors.forename: T
authors.initials: T
authors.lastname: Wadström
authors.forename: R
authors.initials: R
authors.lastname: Uibo
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000276:immunology* / Q000382:microbiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis*; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D004957:Estonia / Q000453:epidemiology; D005260:Female; D016481:Helicobacter Infections / Q000276:immunology*; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000276:immunology* / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C080866:cagA protein, Helicobacter pylori