title: Association of Toll-like receptor-4 (Asp299Gly and Thr399Ileu) gene polymorphisms with gastritis and precancerous lesions.
abstract: A Toll-like receptor-4 (TLR-4) Asp299Gly and Thr399Ileu substitution reduces responsiveness to Helicobacter pylori (H. pylori) lipopolysaccharide. CagA+ strains of H. pylori are known to be associated with gastroduodenal diseases. Therefore we aimed to evaluate association of TLR-4 substitutions and CagA seropositivity with gastritis and precancerous lesions in a northern Indian population. After upper gastrointestinal endoscopy, 130 rapid urease test (RUT)-positive patients with nonulcer dyspepsia (NUD) were included. Patients with NUD were also screened for H. pylori infection using modified Giemsa staining and anti-CagA IgG enzyme-linked immunoabsorbent assay. All patients and 200 asymptomatic control subjects were genotyped for TLR-4 substitutions using polymerase chain reaction-restriction fragment length polymorphism. We observed that frequencies of TLR-4 Asp299Gly variants were comparable between patients and control subjects, and also between positive and negative groups of precancerous lesions in patients. Frequencies of TLR-4 399Ileu allele (8% vs 3%, p = 0.008) and Asp299-Ileu399 haplotype (6.5% vs 3%, p = 0.022) were higher in patients than in control subjects at risk for gastritis (OR = 2.6 and 2.5, respectively). TLR-4 399Ileu allele carriers had higher risk for plasma cell infiltration (p = 0.023, OR = 10.6) that led to atrophy (p = 0.028, OR = 4.2) and intestinal metaplasia (p = 0.009, OR = 4.7). CagA positivity was more frequently associated with lymphoid follicle formation (p = 0.033, OR = 2.53). In conclusion TLR-4 Thr399Ileu substitution may be a risk factor for gastritis and precancerous lesions. CagA positivity may be a risk factor for lymphoid follicle development but not for other precancerous lesions in a northern Indian population.
authors: Department of Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors: B R
authors: BR
authors: Achyut
authors: Uday C
authors: UC
authors: Ghoshal
authors: Nikhil
authors: N
authors: Moorchung
authors: Balraj
authors: B
authors: Mittal
mesh_terms: D000328:Adult; D000483:Alleles; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D005260:Female; D005756:Gastritis / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D016481:Helicobacter Infections / Q000276:immunology / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D011230:Precancerous Conditions / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D013274:Stomach Neoplasms / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D051197:Toll-Like Receptor 4 / Q000097:blood / Q000235:genetics*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; C080866:cagA protein, Helicobacter pylori