TLR1 and PRKAA1 Gene Polymorphisms in the Development of Atrophic Gastritis and Gastric Cancer.

BACKGROUND AND AIMS: Previous genome-wide association studies showed that genetic polymorphisms in toll-like receptor 1 (TLR1) and protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) genes were associated with gastric cancer (GC) or increased Helicobacter pylori (H. pylori) infection susceptibility. The aim of this study was to evaluate the association between TLR1 and PRKAA1 genes polymorphisms and H. pylori infection, atrophic gastritis (AG) or GC in the European population. METHODS: Single-nucleotide polymorphisms (SNPs) were analysed in 511 controls, 340 AG patients and 327 GC patients. TLR1 C>T (rs4833095) and PRKAA1 C>T (rs13361707) were genotyped by the real-time polymerase chain reaction. H. pylori status was determined by testing for anti-H. pylori IgG antibodies in the serum. RESULTS: The study included 697 (59.2%) H. pylori positive and 481 (40.8%) H. pylori negative cases. We observed similar distribution of TLR1 and PRKAA1 alleles and genotypes in H. pylori positive and negative cases. TLR1 and PRKAA1 SNPs were not linked with the risk of AG. TC genotype of TLR1 gene was more prevalent in GC patients compared to the control group (29.7% and 22.3% respectively, p=0.002). Carriers of TC genotype had a higher risk of GC (aOR=1.89, 95% CI: 1.26-2.83, p=0.002). A similar association was observed in a dominant inheritance model for TLR1 gene SNP, where comparison of CC+TC vs. TT genotypes showed an increased risk of GC (aOR=1.86, 95% CI: 1.26-2.75, p=0.002). No association between genetic polymorphism in PRKAA1 gene and GC was observed. CONCLUSIONS: TLR1 rs4833095 SNP was associated with an increased risk of GC in a European population, while PRKAA1 rs13361707 genetic variant was not linked with GC. Both genetic polymorphisms were not associated with H. pylori infection susceptibility or the risk of AG.

Primary antibiotic resistance of Helicobacter pylori strains among adults and children in a tertiary referral centre in Lithuania.

The study evaluated primary antibiotic resistance of Helicobacter pylori within the period 2013-2015 and trends of antibiotic consumption over the last decade in Lithuania; 242 adults and 55 children were included in the study. E-tests were performed for amoxicillin, metronidazole, clarithromycin, ciprofloxacin, rifampicin and tetracycline. The presence of H. pylori and clarithromycin resistance was additionally tested by PCR. Helicobacter pylori culture was positive in 67 of 242 (28%) adult and in 12 of 55 (21.8%) children samples. Resistance rates among adults by E-tests were as follows: metronidazole - 32.8% (95% confidence interval (CI): 22.7-44.7%), ciprofloxacin - 7.5% (95% CI: 3.2-16.3%), rifampicin - 7.5% (95% CI: 3.2-16.3%), amoxicillin - 0%, whereas resistance rates in children were as follows: metronidazole - 25% (95% CI: 8.9-53.2%), rifampicin - 8.3% (CI: 1.5-35.4%), amoxicillin and ciprofloxacin - 0%. Accumulated clarithromycin resistance rates by E-tests and PCR were 8.2% (95% CI: 4.1-16.0%) in adults and 17.7% (95% CI: 6.2-41.0%) in children. Total use of macrolides and lincosamides in Lithuania increased from 1.26 to 1.86 defined daily dose (DDD)/1000 inhabitants/day among adults, while it has doubled from 1.10 to 2.22 DDD/1000/children/day in children within 2003-2015. There are no significant changes in the susceptibility of H. pylori to the most widely used antibiotics in adults over the last years in Lithuania; however, clarithromycin resistance among children exceeds 15% and mandates further larger-scale studies in paediatric population.