Impairment of cytochrome P-450-dependent liver activity in cirrhotic patients with Helicobacter pylori infection

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. Aims: To evaluate the influence of H. pylori infection on liver function as assessed by means of the mono-ethylglycinexylidide test, which depends upon liver blood flow and cytochrome P-450 activity, and the C-13-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-a serum levels. Patients and methods: Thirty-five patients with liver cirrhosis of various aetiologies, who underwent mono-ethylglycinexylidide and C-13-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 (MEGX(15), P = 0.027; MEGX(30), P = 0.014; MEGX(60), P = 0.028), while C-13-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.