No association between a genetic variant of the p22PHOX component of NADPH oxidase C242T and ulcerative colitis.

Background/Aims: Reactive oxygen species has been implicated in the development of ulcerative colitis (UC). NADPH oxidase, a major source of superoxide generation play a critical role in H. pylori related gastric inflammation. We aimed to clarify the effect of G242T polymorphism of p22PHOX, an essential component of NADPH oxidase on the risk of UC in a Japanese population. Methodology: 123 UG patients and 459 healthy control (HC) subjects participated in this study. The p22PHOX C242T polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism. Results: In the HC group, the p22 PHOX genotype distribution was 379C/C (82.6%), 79C/T (17.2%), and 5T/T (1.2%). Meanwhile, the p22 PHOX geno type distribution in UC group was 96C/C (.78.0%), 26C/T (21.1%), and 1T/T (0.9%). No significant difference of the p22 PHOX genotype distribution was observed between HC and UC groups. (C/C vs. T/T; OR=0.80, 95%CI=0.09-6.84, C/C vs. C/T; OR=1.37, 95%GI=0.83-2.25, C/C. vs. T carriers; OR=1.33, 95%GI=0.82-2.18, T/T vs. others; OR=0.74, 95%CI =0.09-6.43). No association was also found between p22PHOX gene polymorphism and different clinicopathological features of UC such as gender, age, age of onset, clinical type, extension of colitis and response to treatment. Conclusions: It appears that the G242T polymorphism of p22 PHOX is not associated with the incidence of gastric cancer in the Japanese population.