Typical relationships between the indexes of lipid peroxidation/ antioxidant protection and immune regulation in the patients with chronic atrophic gastritis and stomach cancer

Abstract

Chronic atrophic gastritis and gastric cancer represent distinct steps of one pathogenic process. The risk of developing cancer of the stomach is directly proportional to the degree of atrophic changes simultaneously detected in antral segment and in the body of the stomach. The role of immune system in transformation of precancerous diseases into cancer is beyond doubt. During development of the malignant disease, the changes in lipid peroxidation systems – antioxidant defense become significant and contribute to the progression of the tumor and the development of metastases. A simultaneous study of lipid peroxidation and antioxidant defense indices along with phagocytic activity will allow us to evaluate relative contribution of these processes to development of chronic atrophic gastritis and gastric cancer. Purpose of the present study was to assess correlations between the lipid peroxidation indices, i.e. antioxidant protection, and chemiluminescent activity of neutrophilic granulocytes and monocytes in chronic atrophic gastritis and gastric cancer. Forty patients with chronic gastritis, 22 patients with chronic atrophic gastritis and 40 patients with gastric cancer were examined. The control group consisted of 50 practically healthy age-matched volunteers. Evaluation of spontaneous and induced production of reactive oxygen species by neutrophils and monocytes was carried out by chemiluminescent analysis. The parameters of lipid peroxidation/ antioxidant protection were determined by spectrophotometric methods. Statistical data processing was carried out using the Statistica v. 8.0 program (StatSoft Inc., USA). The normal distribution of indices was tested using the Kolmogorov–Smirnov method (adjusted by Lillefors). Quantitative indicators, given the normal distribution, were described using the median (Me) and interquartile scatter (Q0.25-Q0.75). To study statistical significance of differences between quantitative characteristics, the Mann–Whitney test was used. To study strength of relationships of these indicators, the Pearson rank correlation coefficient (r) was calculated. The critical significance level (p) when testing statistical hypotheses was taken equal to 0.05. Correlation analysis showed that the weight of positive correlations increases in patients with chronic atrophic gastritis, and it decreases in patients with gastric cancer, the strength of the correlation dependence and new relationships appear between chemiluminescent activity of neutrophils and monocytes in a spontaneous and induced state, and the amounts of malonic dialdehyde, enzyme activities of superoxide dismutase and catalase. In chronic atrophic gastritis and gastric cancer we have established the features of correlation patterns between lipid peroxidation/antioxidant protection indices, and activity of neutrophils and monocytes.