Genetic Polymorphisms of Molecules Associated with Innate Immune Responses, TRL2 and MBL2 Genes in Japanese Subjects with Functional Dyspepsia

Inflammatory changes in the gastric mucosa are commonly observed in Japanese patients with functional dyspepsia (FD). However, detailed data regarding the possible association between the genetic factors of inflammation related molecules and FD are not available. Toll like receptor 2 (TLR2) and mannan-binding lectin (MBL) protein play important roles in the innate immune activation. We aimed to clarify the association between common polymorphisms of TLR2 and MBL2 genes with FD in Japanese subjects. TLR2 -196 to -174 del and MBL2 codon54 G/A polymorphisms were genotyped in 111 FD patients according to Rome III criteria and 106 asymptomatic controls. Non-significant correlation was found between TLR2 and MBL2 polymorphisms with FD. However, in Helicobacter pylori (H. pylori) positives, we found significant inverse association between TLR2 -196 to -174 del carrier and FD among H. pylori positive subjects (Adjusted odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.23-0.996, p = 0.0488). We also found significant inverse association between the same genotype with postprandial distress syndrome (PDS) among H. pylori positive subjects (Adjusted OR = 0.22, 95% CI = 0.07-0.69, p = 0.0099). Our data suggest that TLR2 -196 to -174 del carriers's status but not MBL2 codon54 G/A is inversely related to the risk with FD in H. pylori-infected subjects.