oipA "on" status of Helicobacter pylori is associated with gastric cancer in North-Eastern Brazil.

Background: Although, outer membrane protein OipA of Helicobacter pylori has been associated with gastric mucosal damage and gastroduodenal diseases, studies evaluating gastric cancer patients are scarce. We investigated whether the functional oipA "on" status was associated with gastric cancer in the North-eastern Brazil, region with high prevalence of gastric cancer.

Methods: We included samples from 95 H. pylori positive subjects (23 patients with gastritis, 24 with gastric cancer, 32 first-degree relatives of gastric cancer patients and 16 children). oipA was assayed by polymerase chain reaction (PCR) and DNA sequencing. cagA and vacA status were evaluated by PCR.

Results: Overall 81.1% of the H. pylori strains had functional oipA. In adults, the oipA "on" status (OR = 9.20; 95%CI = 1.45-58.48, P = 0.02) and increasing age (OR = 1.08; 95%CI = 1.03-1.14; P = 0.003) were independently associated with gastric cancer in a logistic model. The oipA "on" status (OR = 14.75; 95%CI: 2.53-86.13, P = 0.003) was also associated with first-degree relatives of gastric cancer patients when compared with gastritis. The frequency of oipA "on" status did not differ between children and adults (P = 0.87). The oipA "on" status was significantly correlated with the presence of cagA and vacA s1 m1.

Conclusion: oipA "on" status was independently associated with gastric cancer and first-degree relatives of gastric cancer patients in North-eastern Brazil.