Host single nucleotide polymorphisms of MMP-9 -1562/TIMP-1 372 have gender differences in the risk of gastric intestinal metaplasia after helicobacter pylori infection

Background: Helicobacter pylori infection causes chronic gastric inflammation and intestinal metaplasia (IM), related with deregulation of Wnt pathway and over-expressions of COX-2, matrix metalloproteinase (MMP), and tissue inhibitors of matrix metalloproteinase (TIMP). We thus test the host genomic predispositions related to the risk of IM after H. pylori infection. Methods: We enrolled 296 H. pylori-infected patients to provide gastric biopsies for histology and genomic DNA for genotypes of single nucleotide polymorphisms (SNPs), including APC, COX-2, IL-1B, IL-1RN, IL-10, MMP-2, MMP-9, TIMP-1, and TIMP-2 determined by sequence specific oligonucleotide probe, sequence specific primers, restriction fragment length polymorphism, or real-time polymerase chain reaction. Results: There was no association between the presence of IM and SNPs in APC, COX-2, IL-1B, IL-1RN, IL-10, MMP-2, and TIMP-2. The risk of IM was increased up to 2.29-folds in males with TIMP-1 372 C, and 3.03-fold in females with T carrier (p <.05). The combination genotype of MMP-9 -1562/TIMP-1 372 as CC/C and CT/T in males had a 4.5-fold increased risk of IM, as compared to CC/T (p <.05). Females with such combination genotype as CC/T-carrier had a 3-fold risk of IM than males with CC/T (p <.05). In contrast, males' combination genotype as CC/C had a 3-fold risk of IM than females with CC/CC (p =.05). Conclusions: The host MMP-9 -1562/TIMP-1 372 SNPs had gender differences in the risk of IM after H. pylori infection, and could possibly serve as a host factor to identify the risk group harboring gastric precancerous changes after H. pylori infection.