title: Serum 8 Hydroxydeoxyguanosine and Cytotoxin Associated Gene A as Markers for Helicobacter pylori Infection.
abstract: BACKGROUND
  Helicobacter pylori (H.pylori) is associated with chronic gastritis, peptic ulcers, gastric adenocarcinomas and mucosa associated tissue lymphomas. Cytotoxin associated gene A (CagA) is one of the virulence factors of H.pylori. It is hypothesized that reactive oxygen species (ROS) play roles in H.pylori associated disease especially in development of gastric adenocarcinoma. Individuals infected with H.pylori bearing CagA produce more ROS than others. 8-hydroxydeoxyguanosine (8OHdG) is an in vitro marker of DNA damage and oxidative stress. The aim of this study was to investigate the relationship between 8OHdG level, H.pylori infection and CagA and alterations of serum 8OHdG level after H.pylori eradication.
  
  
  METHODS
  Patients admitted with dyspeptic complaints and upper gastrointestinal endoscopy were assessed. H.pylori was determined from histopathology of specimens. Serum 8OHdG levels of three groups (H.pylori negative, H. pylori positive CagA negative and H.pylori positive CagA positive) were compared. Patients with H.pylori infection received eradication therapy. Serum 8OHdG levels pretreatment and posttreatment were also compared.
  
  
  RESULTS
  In total, 129 patients (M/F, 57/72) were enrolled in the study. Serum 8OHdG level of H.pylori negative, H. pylori positive CagA negative and H.pylori positive CagA positive groups were significantly different (5.77±1.35 ng/ml, 5.43±1.14 ng/ml and 7.57±1.25 ng/ml respectively, p=0.05). Furthermore, eradication therapy reduced serum 8OHdG level (6.10±1.54 ng/ml vs 5.55±1.23 ng/ml, p=0.05).
  
  
  CONCLUSIONS
  Individuals infected with H.pylori bearing CagA strains have the highest serum 8OHdG level and eradication therapy decreases the serum 8OHdG level. To the best of our knowledge this is the first study that evaluated the effect of CagA virulence factor on serum 8OHdG level and the effect of eradication therapy on serum 8OHdG levels together. Eradication of CagA bearing H.pylori may prevent gastric adenocarcinoma by decreasing ROS. 8OHdG level may thus be a good marker for prevention from gastric adenocarcinoma.
authors.affiliation: Gastroenterology, Kecioren Teaching and Research Hospital, Ankara, Turkey E-mail : zgryeniova@yahoo.com.tr.
authors.forename: Abdullah Ozgur
authors.initials: AO
authors.lastname: Yeniova
authors.forename: Metin
authors.initials: M
authors.lastname: Uzman
authors.forename: Ayse
authors.initials: A
authors.lastname: Kefeli
authors.forename: Sebahat
authors.initials: S
authors.lastname: Basyigit
authors.forename: Naim
authors.initials: N
authors.lastname: Ata
authors.forename: Kursat
authors.initials: K
authors.lastname: Dal
authors.forename: Servet
authors.initials: S
authors.lastname: Guresci
authors.forename: Yasar
authors.initials: Y
authors.lastname: Nazligul
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000293:Adolescent; D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000378:metabolism; D005756:Gastritis / Q000097:blood / Q000175:diagnosis* / Q000821:virology; D016481:Helicobacter Infections / Q000097:blood / Q000175:diagnosis* / Q000821:virology; D016480:Helicobacter pylori / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010437:Peptic Ulcer / Q000097:blood / Q000175:diagnosis* / Q000821:virology; D011379:Prognosis; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; C080866:cagA protein, Helicobacter pylori; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine