title: Impairment of cytochrome P-450-dependent liver activity in cirrhotic patients with Helicobacter pylori infection.
abstract: BACKGROUND
  Helicobacter pylori gastric infection has been associated with various digestive and extra-digestive diseases. The systemic influence of gastric H. pylori infection seems to be mediated by the release of various cytokines. In liver disease, bacterial infections have been associated with the impairment of liver metabolic function.
  
  
  OBJECTIVE
  To evaluate the influence of H. pylori infection on liver function as assessed by means of the monoethylglycinexylidide test, which depends upon liver blood flow and cytochrome P-450 activity, and the 13C-galactose breath test, which depends on cytosolic enzymatic activity and is correlated with hepatic functional mass. Moreover, to evaluate whether H. pylori-associated modifications of liver function may be related to tumour necrosis factor-alpha serum levels.
  
  
  METHODS
  Thirty-five patients with liver cirrhosis of various aetiologies, who underwent monoethylglycinexylidide and 13C-galactose breath tests, were retrospectively evaluated for H. pylori infection by means of anti-H. pylori immunoglobulin G. The main clinical, biochemical and functional characteristics of the patients as well as their tumour necrosis factor-alpha serum levels were then analysed on the basis of the presence of H. pylori infection.
  
  
  RESULTS
  Twenty-one patients tested positive for H. pylori infection (60%), and 11 tested negative (31.4%). No clinical or biochemical differences were observed between H. pylori-infected and non-infected patients. H. pylori infection showed no difference in distribution according to Child-Pugh classes (A, 55%; B and C, 67%). The monoethylglycinexylidide test results were significantly lower at each sampling time in H. pylori-positive patients compared to H. pylori-negative patients (MEGX15, P=0.027; MEGX30, P=0.014; MEGX60, P=0.028), while 13C-galactose breath test showed no significant differences considering both cumulative percentage dose and percentage dose/h. The median tumour necrosis factor-alpha serum levels were no different between H. pylori-positive (16.1 pg/mL, 95% confidence interval, 8.7-28.7) and H. pylori-negative (12.3 pg/mL, 95% confidence interval, 8.7-23.4) patients.
  
  
  CONCLUSIONS
  In cirrhotic patients, H. pylori infection seems to selectively affect cytochrome P-450 liver activity, while hepatic functional mass does not seem to be impaired. Tumour necrosis factor-alpha does not seem to be the mediator of this impairment. Further studies are needed to evaluate the impact of H. pylori eradication on parameters of liver function.
authors.affiliation: Gastroenterology Unit and Postgraduate School of Gastroenterology and Digestive Endoscopy, Department of Internal Medicine, University of Genoa, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Giannini
authors.forename: A
authors.initials: A
authors.lastname: Fasoli
authors.forename: P
authors.initials: P
authors.lastname: Borro
authors.forename: B
authors.initials: B
authors.lastname: Chiarbonello
authors.forename: F
authors.initials: F
authors.lastname: Malfatti
authors.forename: P
authors.initials: P
authors.lastname: Romagnoli
authors.forename: F
authors.initials: F
authors.lastname: Botta
authors.forename: E
authors.initials: E
authors.lastname: Testa
authors.forename: A
authors.initials: A
authors.lastname: Fumagalli
authors.forename: S
authors.initials: S
authors.lastname: Polegato
authors.forename: V
authors.initials: V
authors.lastname: Savarino
authors.forename: R
authors.initials: R
authors.lastname: Testa
mesh_terms: D000368:Aged; D001944:Breath Tests; D002250:Carbon Radioisotopes; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005260:Female; D005690:Galactose / Q000378:metabolism; D016481:Helicobacter Infections / Q000276:immunology / Q000378:metabolism*; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D008099:Liver / Q000276:immunology / Q000378:metabolism*; D008103:Liver Cirrhosis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha; D003577:Cytochrome P-450 Enzyme System; D008012:Lidocaine; C001173:monoethylglycinexylidide; D005690:Galactose