title: Race, African ancestry, and Helicobacter pylori infection in a low-income United States population.
abstract: BACKGROUND
  Gastric cancer incidence in African Americans is twice that of whites, and differing prevalence of Helicobacter pylori strain-specific isolates may help explain the disparity.
  
  
  METHODS
  Serum levels of antibodies to each of 15 H. pylori proteins were assessed using multiplex serology for a sample of 689 African American and white participants from the Southern Community Cohort Study. African and European admixture was estimated using a panel of 276 ancestry genetic markers, with "low," "medium," and "high" categories of African ancestry defined as <85%, 85% to 95%, and ≥95%.
  
  
  RESULTS
  The majority (79%) of our study population were sero-positive for H. pylori. African American race was associated with a two- to sixfold increased odds for sero-positivity to eight H. pylori proteins, including the cancer-associated virulence constituents CagA [odds ratio (OR), 6.4; 95% CI, 4.5-9.1], and VacA (OR, 2.3; 95% CI, 1.5-3.5). Compared to whites, African Americans of low, medium, and high African ancestry had 1.6-, 4.1-, and 5.2-fold increased odds of sero-positivity to H. pylori, primarily related to CagA sero-positive strains, for which increasing African ancestry led to 2.5-, 9.6-, and 13.1-fold increased odds. Among African Americans alone, compared to those of low African ancestry, African Americans of medium and high African ancestry had 2.5- and 3.4-fold increased odds of sero-positivity to H. pylori, and 3.5- and 4.9-fold increased odds of CagA sero-positive H. pylori strains.
  
  
  CONCLUSIONS
  Host genetic variation and/or lifestyle factors associated with African ancestry contribute to the likelihood of infection with H. pylori, particularly its virulent strains, in this low-income U.S. southern population.
  
  
  CONCLUSIONS
  Our findings that low-income African Americans of high African ancestry have a particularly high prevalence of antibodies against H. pylori provides a framework for further research into better detection and prevention of gastric cancer in this population.
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37203-1738, USA. meira.epplein@vanderbilt.edu
authors.forename: Meira
authors.initials: M
authors.lastname: Epplein
authors.forename: Lisa B
authors.initials: LB
authors.lastname: Signorello
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Richard M
authors.initials: RM
authors.lastname: Peek
authors.forename: Angelika
authors.initials: A
authors.lastname: Michel
authors.forename: Scott M
authors.initials: SM
authors.lastname: Williams
authors.forename: Michael
authors.initials: M
authors.lastname: Pawlita
authors.forename: Pelayo
authors.initials: P
authors.lastname: Correa
authors.forename: Qiuyin
authors.initials: Q
authors.lastname: Cai
authors.forename: William J
authors.initials: WJ
authors.lastname: Blot
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D016481:Helicobacter Infections / Q000150:complications* / Q000453:epidemiology / Q000208:ethnology*; D016480:Helicobacter pylori / Q000472:pathogenicity; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011203:Poverty / Q000706:statistics & numerical data*; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000209:etiology*; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data; D001741:Black or African American