title: Relationship between Helicobacter pylori virulence factors and regulatory cytokines as predictors of clinical outcome.
abstract: Helicobacter pylori infection is highly prevalent in Chile (73%). Usually a minority of infected patients develops complications such as ulcers and gastric cancer that have been associated with the presence of virulence factors (cagA, vacA) and host T helper response (Th1/Th2). Our aim was to evaluate the relationship between strain virulence and host immune response, using a multiple regression approach for the development of a model based on data collected from H. pylori infected patients in Chile. We analyzed levels of selected cytokines determined by ELISA (interleukin (IL)-12, IL-10, interferon (IFN)-gamma and IL-4) and the presence of cagA and vacA alleles polymorphisms determined by PCR in antral biopsies of 41 patients referred to endoscopy. By multiple regression analysis we established a correlation between bacterial and host factors using clinical outcome (gastritis and duodenal ulcer) as dependent variables. The selected model was described by: clinical outcome=0.867491 (cagA)+0.0131847 (IL-12/IL-10)+0.0103503 (IFN-gamma/IL-4) and it was able to explain over 90% of clinical outcomes observations (R(2)=96.4). This model considers that clinical outcomes are better explained by the interaction of host immune factors and strain virulence as a complex and interdependent mechanism.
authors.affiliation: Department of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Lira 85, Santiago, Chile.
authors.forename: Carolina
authors.initials: C
authors.lastname: Serrano
authors.forename: Maria Ines
authors.initials: MI
authors.lastname: Diaz
authors.forename: Alejandra
authors.initials: A
authors.lastname: Valdivia
authors.forename: Alex
authors.initials: A
authors.lastname: Godoy
authors.forename: Alfredo
authors.initials: A
authors.lastname: Peña
authors.forename: Antonio
authors.initials: A
authors.lastname: Rollan
authors.forename: Arturo
authors.initials: A
authors.lastname: Kirberg
authors.forename: Eduardo
authors.initials: E
authors.lastname: Hebel
authors.forename: Jaqueline
authors.initials: J
authors.lastname: Fierro
authors.forename: Gabriela
authors.initials: G
authors.lastname: Klapp
authors.forename: Alejandro
authors.initials: A
authors.lastname: Venegas
authors.forename: Paul R
authors.initials: PR
authors.lastname: Harris
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000276:immunology*; D004381:Duodenal Ulcer / Q000276:immunology / Q000821:virology; D005260:Female; D005756:Gastritis / Q000276:immunology / Q000821:virology; D016481:Helicobacter Infections / Q000276:immunology* / Q000821:virology*; D016480:Helicobacter pylori / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D016207:Cytokines; C074689:VacA protein, Helicobacter pylori; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori