Association of polymorphism of the p22PHOX component of NADPH oxidase in gastroduodenal diseases in Japan.
OBJECTIVE
Superoxide has been implicated in the pathogenesis of Helicobacter pylori-related diseases through inflammation. NADPH oxidase, a major source of superoxide generation, plays a critical role in H. pylori-related gastric inflammation. The aim of this study was to clarify the effect of the p22PHOX C242T polymorphism, an essential component of NADPH oxidase in the risk of gastroduodenal diseases, on the severity of H. pylori-induced gastritis in a Japanese population.


METHODS
The study comprised 436 patients attending the Endoscopy Center of Fujita Health University Hospital. The p22PHOX C242T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system.


RESULTS
The 436 patients represented 106 gastric ulcers (24.3%), 48 duodenal ulcers (11.0%), and 282 non-ulcer subjects (64.7%). No association was found between p22PHOX polymorphism and the risk of ulcer diseases compared to non-ulcer subjects. However, among H. pylori-positive subjects, the degree of intestinal metaplasia tended to be lower in 242T carriers aged more than 60 years (p=0.0488). The same allele also decreased the risk of developing a more severe intestinal metaplasia in H. pylori-positive female subjects (p=0.0441).


CONCLUSIONS
Our data suggest that the p22PHOX 242T allele is associated with a reduced risk of developing a more severe intestinal metaplasia in subjects older than 60 years of age and in female subjects with H. pylori infection.
Tahara
Tomomitsu
T
Department of Gastroenterology, Fujita Health University School of Medicine Toyoake, Aichi, Japan. tomomiccyu@yahoo.co.jp
Shibata
Tomoyuki
T
Wang
Fangyu
F
Nakamura
Masakatsu
M
Okubo
Masaaki
M
Yoshioka
Daisuke
D
Sakata
Mikijyu
M
Nakano
Hiroshi
H
Hirata
Ichiro
I
Arisawa
Tomiyasu
T
D000367:Age Factors; D000483:Alleles; D001706:Biopsy; D016009:Chi-Square Distribution; D005260:Female; D005773:Gastroscopy; D005838:Genotype; D016481:Helicobacter Infections / Q000235:genetics*; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D019255:NADPH Oxidases / Q000235:genetics*; D010437:Peptic Ulcer / Q000235:genetics / Q000382:microbiology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D012737:Sex Factors; D018709:Statistics, Nonparametric
D019255:NADPH Oxidases; C086986:CYBA protein, human