title: Intestinal helminthiasis in Colombian children promotes a Th2 response to Helicobacter pylori: possible implications for gastric carcinogenesis.
abstract: BACKGROUND
  Colombians living in coastal Tumaco have a lower incidence of Helicobacter pylori-associated gastric cancer compared with residents of Pasto in the high Andes. Considering the risk for H. pylori disease seems affected by features of bacterial virulence and host polymorphisms, other poorly understood influences, such as concurrent helminthiasis, may also be important.
  
  
  METHODS
  Fecal samples from 211 children were tested for parasites and sera from another cohort of 159 children and 92 adults were tested for IgE and H. pylori-specific IgG.
  
  
  RESULTS
  Most individuals (95%) from both areas were H. pylori seropositive, with a predominant response of IgG1 followed by IgG2 and low IgG3 and IgG4 antibodies. Compared with Pasto children, Tumaco children were more commonly infected with helminths (P = 0.000), had higher serum IgE levels (P < 0.03), and had higher Th2-associated IgG1 responses to H. pylori (P < 0.0002). Other IgG isotype responses all increased with age but were not significantly different between children and adults from either area.
  
  
  CONCLUSIONS
  These results suggest that intestinal helminthiasis in children promotes Th2-polarizing responses to H. pylori and may decrease gastric cancer risk in these individuals later in life. Concurrent helminthiasis may alter inflammatory responses to H. pylori and thus affect the progression of gastritis to gastric atrophy, dysplasia, and cancer.
authors.affiliation: Division of Comparative Medicine, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 16-825A, Cambridge, Massachusetts 02139, USA. mwhary@mit.edu
authors.forename: Mark T
authors.initials: MT
authors.lastname: Whary
authors.forename: Nataliya
authors.initials: N
authors.lastname: Sundina
authors.forename: Luis E
authors.initials: LE
authors.lastname: Bravo
authors.forename: Pelayo
authors.initials: P
authors.lastname: Correa
authors.forename: Francisco
authors.initials: F
authors.lastname: Quinones
authors.forename: Fanny
authors.initials: F
authors.lastname: Caro
authors.forename: James G
authors.initials: JG
authors.lastname: Fox
mesh_terms: D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003105:Colombia; D005243:Feces; D005260:Female; D016481:Helicobacter Infections / Q000276:immunology / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000472:pathogenicity*; D006373:Helminthiasis / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis*; D007223:Infant; D007249:Inflammation; D008297:Male; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000209:etiology / Q000517:prevention & control; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007073:Immunoglobulin E