title: High frequency of CagA+ Helicobacter pylori infection in high-grade gastric MALT B-cell lymphomas.
abstract: A high incidence of Helicobacter pylori infection has been found in patients with gastric MALT (mucosa-associated lymphoid tissue) B-cell lymphoma. Recent studies have indicated that the aggressive strains of the bacterium containing the CagA gene may have direct effects on tumourigenesis. To investigate the involvement of CagA+ strains in MALT lymphomagenesis, a sensitive polymerase chain reaction (PCR)-based detection assay for the gene was developed. DNA extracts from paraffin sections of 123 H. pylori-related gastric biopsies from Italy were analysed, including 56 cases of chronic gastritis, 37 low-grade, and 30 high-grade MALT lymphomas: 30.3 per cent (17/56) of the gastritis cases, 37.8 per cent (14/37) of the low-grade, and 76.7 per cent (23/30) of the high-grade MALT lymphomas were found to contain the CagA gene. The frequency of CagA+ strain infection was significantly higher (P < 0.05) in high-grade than in low-grade MALT lymphoma or gastritis. These results suggest that high-grade gastric MALT lymphoma transformation may be more likely to occur following infection by CagA+ strains of H. pylori.
authors.affiliation: Department of Histopathology, University College London Medical School, U.K.
authors.forename: H
authors.initials: H
authors.lastname: Peng
authors.forename: R
authors.initials: R
authors.lastname: Ranaldi
authors.forename: T C
authors.initials: TC
authors.lastname: Diss
authors.forename: P G
authors.initials: PG
authors.lastname: Isaacson
authors.forename: I
authors.initials: I
authors.lastname: Bearzi
authors.forename: L
authors.initials: L
authors.lastname: Pan
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D002908:Chronic Disease; D005756:Gastritis / Q000382:microbiology; D005798:Genes, Bacterial; D016481:Helicobacter Infections / Q000150:complications* / Q000382:microbiology; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000382:microbiology*; D008228:Lymphoma, Non-Hodgkin / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000382:microbiology*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori