Background. The main pathogenesis of gastritis is inflammation that closely related with free radicals.Malondialdehyde (MDA) is a free radical biomarker and is found to increase in gastritis patients. However, these studies are generally performed on experimental animals as well as MDA examination in gastric mucosa.

Aim.To determine the association of degrees of gastritis (degree of lymphocyte infiltration, neutrophil activity, atrophy, and intestinal metaplasia) with plasma MDA level.

Methods. A cross-sectional study of 80 consecutive gastritis patients who came to endoscopic unit of Adam Malik General Hospital in Medan, Indonesia, from May – September 2017. Assessed for severity of chronic inflammatory, neutrophil activity, atrophy, and intestinal metaplasia refers to Updated Sydney System. Plasma MDA levels were examined using an HPLC MDA kit. Univariate analysis, bivariate (chi square and fisher exact test), and multivariate (binomial logistic regression test) with SPSS version 22.

Results. There was no significant association between degree of lymphocyte infiltration with MDA level. There were significant associations between degree of neutrophil activity, atrophy, and intestinal metaplasia with MDA level (p = 0.039, 0.003, 0.021; respectively).

Conclusion. Moderate + severe degree of neutrophil activity, atrophy, and intestinal metaplasiawere associated with high level of MDA.

Keyword. Gastritis, Malondialdehyde, Updated Sydney System