Influence of MDR1 polymorphism on H. pylori-related chronic gastritis

There is evidence that changes in MDR1 function and/or expression contribute to the pathogenesis of inflammatory disorders of the gastrointestinal tract.

We aimed to investigate the effect of C3435T polymorphism of the MDR1 gene on histological chronic gastritis, and on the risk of peptic ulcer diseases.

Restriction fragment length polymorphism analysis was performed for polymorphisms at C3435T in the MDR1 gene in 556 cancer-free subjects including 116 gastric and 60 duodenal ulcers, and 380 non-ulcer subjects. Gastritis scores in the antrum were assessed according to the updated Sydney system in 384 subjects.

We did not find a significant association between MDR1 genotype and gastritis scores in any of the 384 subjects. However, the 3435T carrier was significantly associated with a higher degree of neutrophil infiltration in H. pylori-positive subjects (CC vs. T carrier: p=0.0495). When the H. pylori positive subjects were divided according to generation, the 3435T carrier was significantly associated with a higher degree of neutrophil infiltration in subjects more than 65 years of age (CC vs. T carrier: p=0.03). Also, the MDR1 3435 TT genotype was significantly associated with a higher degree of atrophy and intestinal metaplasia in the same generation (atrophy, TT vs. C carrier: p=0.038, intestinal metaplasia, TT vs. C carrier: p=0.016). No association was found between MDR1 genotypes and risk of peptic ulcer diseases.

It appears that the C3435T polymorphism of MDR1 influences H. pylori-related inflammatory conditions in the stomach, especially in older subjects.