Helicobacter pylori seroprevalence in patients with autoimmune hepatitis.

Autoimmune hepatitis is characterized by a continuing hepatocyte necrosis that usually progresses to liver cirrhosis. Autoimmunity is also a feature of chronic infection by Helicobacter pylori, a gram-negative bacterium involved in the pathogenesis of peptic ulcer and upper gastrointestinal bleeding, with both events frequently occurring in patients with chronic liver disease. A newly described pathogenetic mechanism for chronic hepatitis and hepatocellular carcinoma in the mouse is linked to Helicobacter spp. infection. A high prevalence of H. pylori infection was demonstrated in patients with viral-related cirrhosis but never studied in cases of autoimmune hepatitis. In a case-control study, we examined 31 consecutive patients (25 women and 6 men, age range 20-66, mean age 46 +/- 4.3 years) suffering from autoimmune hepatitis and 62 sex- and age-matched blood donors (50 women, 12 men, age range 20-65, mean age 46 +/- 5.4 years) resident in the same area. Antibodies to H. pylori were present in 20 of 31 (64.5%) autoimmune patients compared to 33 of 62 (53.2%) controls (P = 0.3, odds ratio 1.60, 95% CI 0.60-4.28). The difference was not statistically significant either in female or male patients. In conclusion, the prevalence of H. pylori infection in patients and controls was similar in our study of patients with chronic autoimmune hepatitis.