The interrelationship between Helicobacter pylori vacuolating cytotoxin and gastric carcinoma.
OBJECTIVE
We aimed to determine whether cytotoxin-positive Helicobacter pylori strains are associated with gastric carcinoma.


METHODS
We studied 130 patients: 57 H. pylori-positive patients with gastric carcinoma, 53 H. pylori-positive patients without gastric carcinoma, and 20 H. pylori-negative subjects. The ability of H. pylori strains to produce vacuolating cytotoxin was tested in INT-407 and HeLa cells. The presence of antibodies to cytotoxin was investigated in blood serum from all subjects by immunoblotting. Fragments of the gastric mucosa from patients without gastric carcinoma and H. pylori-negative subjects were obtained for histopathological study.


RESULTS
Considering the results as a whole, 40 (70.2%) patients with and 22 (41.5%) without gastric carcinoma were colonized by cytotoxin-positive strains. Antibodies against cytotoxin were not observed in the serum from 17 (29.8%) gastric carcinoma patients and from 31 (58.5%) patients without gastric carcinoma. H. pylori strains isolated from these patients did not produce cytotoxin in vitro. In regard to cytotoxin positivity, a significant difference was observed between patients with and without gastric carcinoma (p=0.004; odds ratio [OR]: 3.3; 95% confidence interval [CI]: 1.4-7.9). Higher scores of mononuclear (p=0.0001) and polymorphonuclear (p=0.000003) cells were observed in the antral mucosa from H. pylori-positive patients without gastric carcinoma infected by cytotoxin-positive strains than in those harboring cytotoxin-negative strains.


CONCLUSIONS
Cytotoxin-producing H. pylori strains were more frequently observed in patients with gastric carcinoma and this aspect emphasizes the role of cytotoxin in the genesis of the tumor.
Department of Pathology, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
T
T
de Figueiredo Soares
D M
DM
de Magalhães Queiroz
E N
EN
Mendes
G A
GA
Rocha
A M
AM
Rocha Oliveira
M M
MM
Alvares Cabral
C A
CA
de Oliveira
D000907:Antibodies, Bacterial / Q000032:analysis; D001426:Bacterial Proteins / Q000276:immunology / Q000302:isolation & purification*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology / Q000382:microbiology; D016481:Helicobacter Infections / Q000150:complications / Q000276:immunology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013274:Stomach Neoplasms / Q000276:immunology / Q000382:microbiology*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori