Helicobacter pylori infection: old and new.

Helicobacter pylori is a spiral-shaped bacterium that grows in the digestive tract and may be present in more than half of the world's population. The clinical features of Helicobacter pylori range from asymptomatic gastritis to gastrointestinal malignancy. Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade B-cell marginal zone lymphoma and Helicobacter pylori has been detected in more than 75% of the patients with MALT lymphoma. Many tests for the detection of Helicobacter pylori are available, including antibody tests, urea breath tests, stool antigen tests and endoscopic biopsies. The eradication of Helicobacter pylori usually prevents the return of ulcers and ulcer complications even after appropriate medications such as PPIs are stopped. The eradication of Helicobacter pylori is important in the treatment of the rare condition of the stomach known as MALT lymphoma. The treatment of Helicobacter pylori to prevent stomach cancer is controversial. Confirmation of eradication is recommended in associated ulcers, persistent dyspepsia despite a test-and-treat approach, MALT lymphoma, and previous treatment for early-stage gastric cancer. The urea breath test and stool antigen test can be used to confirm the eradication and should be performed at least 4 weeks after the completion of therapy. Several diseases have been reported to be associated with Helicobacter pylori infection, including hematologic diseases, such as ITP, idiopathic iron deficiency anemia and vitamin B12 deficiency. There is a positive trend in the association between Helicobacter pylori infection and neurodegenerative disorders and new data showed a reduced risk of death due to stroke and lung cancer but an increased risk of preeclampsia in infected women, which requires further investigations.