Objectives:

Although Helicobacter pylori (Hp) infects about 50% of the population, only a small proportion of individuals develop gastritis, peptic ulcer, MALT lymphoma or cancer. This may be due to factors influencing bacterial virulence or the host response to Hp. In this study, we aimed to find out systemic immune response changes in Hp positive peptic ulcer and chronic gastritis before and after eradication treatment.

Methods:

Ten patients with Hp associated peptic ulcer or chronic antral gastritis (Group 1), and 10 controls consisted of Hp negative patients with dyspepsia (Group 2) were enrolled to the study. CD3, CD4, CD8, CD19, CD16+56+, CD25, and CD54 expression on lymphocytes were evaluated by flow cytometry and cytokines (IL-2, IL-4, IL-10, TGF- ß, IFN-?) were analysed by ELISA in group 1 before and after eradication treatment and in group 2.

Results:

Peripheral T-lymphocytes and CD25 expression of Hp(+) patients were significantly increased compared to Hp(-) patients (47.7±5.1% vs 40.6±2.0% respectively, p<0.001; 14.4±7.5% vs 5.9±0.7% respectively, p<0.05). After eradication treatment circulating T- lymphocytes decreased significantly compared to pretreatment levels (41.9±4.2% vs 47.7±5.1% respectively, p<0.01) and the ratio of CD25(+) lymphocytes decreased down (14,4±7,5% vs 7,7±1,8% respectively, p<0.05).

Conclusions:

Although increased T lymphocyte proliferation and activation observed in Hp(+) patients, no change was observed in cytokine levels. Concluding a definite decision about the systemic response to Hp infection is difficult due to these conflicting results. Therefore, more comprehensive studies, including more patients with gastric ulcer, duodenal ulcer, gastritis and/or duodenitis and with a wider panel of immune response measurands, should be performed to clarify this subject.

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