Dyspepsia is associated with CagA-positive Helicobacter pylori

OBJECTIVE: The role of Helicobacter pylori in nonulcer dyspepsia is controv ersial. Speculation has arisen that only strains of H. pylori carrying the CagA virulence factor are important in the development of dyspepsia. The ob jective of this study was to determine whether nonulcer dyspepsia correlate d with CagA-positive H. pylori infection. METHODS: A total of 435 healthy blood donors and 102 general medicine clini c respondents completed the Bowel Disease Questionnaire and the PRIME-MD su rvey, a validated screen for common psychiatric disorders. Subjects were cl assified as cases of nonulcer dyspepsia if they reported pain in the upper abdomen more than six times in the previous year and denied a past or curre nt history of peptic ulcer disease. Study participants were tested for IgG antibodies to H. pylori and the CagA protein. RESULTS: Clinic respondents were more likely than healthy blood donors to m eet the case definition for nonulcer dyspepsia (34% vs 13%, p < 0.001), to be seropositive for H. pylori (54% vs 18%, p < 0.001), and to be CagA serop ositive (41% vs 10%, p = 0.01). Logistic regression identified CagA seropos itivity (p = 0.03), race (p = 0.001), and positive screens for depression ( p = 0.007) or somatization (p < 0.001) as variables independently associate d with nonulcer dyspepsia. CONCLUSION: Infection with a CagA-positive strain of H. pylori is associate d with a clinical diagnosis of nonulcer dyspepsia. However, nonulcer dyspep sia was also strongly and independently associated with positive screens fo r depression or somatization disorder as well as with ethnicity. These pote ntial sources of variance should be considered in the design of future stud ies evaluating nonulcer dyspepsia. (C) 2000 by Am. Cell. of Gastroenterolog y.