High prevalence of cytotoxin positive Helicobacter pylori in patients unrelated to the presence of peptic ulcers in Japan.
BACKGROUND
It has been reported that infection with vacuolating cytotoxin positive Helicobacter pylori strains is associated with gastroduodenal disease in Western countries.


OBJECTIVE
To evaluate the prevalence of cytotoxin producing strains among patients with H pylori infection in relation to gastrointestinal diseases in Japan.


METHODS
Ninety seven patients undergoing endoscopy.


METHODS
A Western blot assay was conducted to detect serum antibodies against the cytotoxin using recombinant cytotoxin (VacA protein) as an antigen. To obtain a purified recombinant cytotoxin, the vacA gene (2233 nucleotides) was cloned into an expression vector to produce the protein (744 amino acids), which was expressed in Escherichia coli.


RESULTS
Serum IgG antibodies to the cytotoxin were present in 85%, 95%, 95%, and 100% of infected patients with gastric ulcer (n = 26), duodenal ulcer (n = 21), chronic gastritis (n = 19), and endoscopically normal mucosa (n = 14), respectively.


CONCLUSIONS
The western blot method using recombinant VacA protein is simple and useful for detecting antibody to vacuolating cytotoxin. This method showed antibodies against cytotoxin were highly prevalent, even in subjects with endoscopically normal mucosa in Japan, indicating that the cytotoxin may not be an independent cause of gastrointestinal diseases induced by H pylori infection.
Ogura
K
K
Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Kanai
F
F
Maeda
S
S
Yoshida
H
H
Ogura
M
M
Lan
K H
KH
Hirota
K
K
Kawabe
T
T
Shiratori
Y
Y
Omata
M
M
D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology*; D015153:Blotting, Western; D003603:Cytotoxins / Q000235:genetics / Q000276:immunology*; D004381:Duodenal Ulcer / Q000276:immunology / Q000382:microbiology; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology; D005756:Gastritis / Q000276:immunology / Q000382:microbiology; D005767:Gastrointestinal Diseases / Q000276:immunology / Q000382:microbiology*; D016481:Helicobacter Infections / Q000276:immunology*; D016480:Helicobacter pylori; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007564:Japan; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013276:Stomach Ulcer / Q000276:immunology / Q000382:microbiology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003603:Cytotoxins; D007074:Immunoglobulin G; C074689:VacA protein, Helicobacter pylori