INFECTION WITH HELICOBACTER-PYLORI EXPRESSING THE CAGA GENE IS NOT ASSOCIATED WITH AN INCREASED RISK OF DEVELOPING PEPTIC-ULCER DISEASES INKOREAN PATIENTS

Background: Helicobacter pylori strains possessing the cagA gene have been postulated to have a disease-specific relationship to peptic ulce r. The purpose of this study was to investigate the relationship betwe en the infection with Helicobacter pylori expressing the cagA gene and the development of peptic ulcer diseases in Korean patients, Methods: Genomic DNA and bacterial mRNA in the gastric mucosa were amplified b y polymerase chain reaction (PCR) and reverse transcription PCR, using synthetic oligonucleotide primers to cagA genes to compare the preval ence of cagA genes in 35 patients with non-ulcer gastritis and 99 pati ents with gastric or duodenal ulcer disease (53 and 46, respectively). Two different primer sets for the cagA gene were used. The first prim er set amplified a 298-bp region (nucleotides 1751-2048), and the seco nd set amplified a 349-bp region (nucleotides 1228-1249). Results: The expected 298- and 349-bp PCR amplicons were identified as follows: 1) 32 (91.4%) and 30 (85.7%) of 35 non-ulcer gastritis patients; 2) 51 ( 96.2%) and 50 (94.3%) of 53 benign gastric ulcer patients; and 3) 46 ( 100.0%) and 40 (87.0%) of 46 duodenal ulcer patients, respectively. Co nclusion: These results strongly suggest that the cagA gene will not p rove to be a useful marker to distinguish disease-specific H. pylori s trains in the development of peptic ulcer diseases in Korean patients.