The Disease Spectrum ofHelicobacter Pylori: The Immunopathogenesis of Gastroduodenal Ulcer and Gastric Cancer

Abstract

Helicobacter pylori is a gram-negative bacterium that resides under microaerobic conditions in a neutral microenvironment between the mucus and the superficial epithelium of the stomach. From this site, it stimulates cytokine production by epithelial cells that recruit and activate immune and inflammatory cells in the underlying lamina propria, causing chronic, active gastritis. Although epidemiological evidence shows that infection generally occurs in children, the inflammatory changes progress throughout life. H. pylori has also been recognized as a pathogen that causes gastroduodenal ulcers and gastric cancer. These more severe manifestations of the infection usually occur later in life and in a minority of infected subjects. To intervene and protect those who might be at greatest risk of the more severe disease outcomes, it is of great interest to determine whether bacterial, host, or environmental factors can be used to predict these events. To date, several epidemiological studies have attempted to define the factors affecting the transmission of H. pylori and the expression of gastroduodenal disease caused by this infection. Many other laboratories have focused on identifying bacterial factors that explain the variable expression of clinical disease associated with this infection. An alternative hypothesis is that microorganisms that cause lifelong infections can ill afford to express virulence factors that directly cause disease, because the risk of losing the host is too great. Rather, we propose that gastroduodenal disease associated with H. pylori infection is predominantly a result of inappropriately regulated gastric immune responses to the infection. In this model, the interactions between the immune/inflammatory response, gastric physiology, and host repair mechanisms would dictate the disease outcome in response to infection.

Seroprevalence of Helicobacter pylori in Hispanics living in Puerto Rico: A population‐based study

“…The questions were based on the questionnaire developed by the ARIBBA (Alliance for Research in El Barrio, New York, and Bayamón) Project, a study that evaluated factors that influenced risk behaviors among Puerto Rican injection drug users 19. Two field managers visited every selected occupied household, where subjects that agreed to participate in the study completed the following procedures:1 informed consent and pretest counseling;2 a personal interview to obtain information about sociodemographic characteristics, medical history, tattooing and body piercing practices, knowledge on viral infections, and self‐report of hepatitis A and hepatitis B vaccination;3 an audio computer‐assisted self‐interview to ascertain cigarette and alcohol use, drug use, sex‐related risk behaviors, and history of incarceration; and4 collection of blood and urine samples. Of the selected residents, 1654 (77.9%) participated in the study.…”

“…Helicobacter pylori is strongly associated with chronic gastritis, peptic ulcers, and gastric cancer 2. Approximately 10%‐15% of H. pylori‐ infected individuals develop peptic ulcers and 1%‐2% develop gastric adenocarcinomas 3, 4. Gastric cancer is the most common infection‐associated cancer worldwide, which led to the classification of H. pylori as a class I human carcinogen by the International Agency for Research on Cancer (IARC) 5.…”

Status of Helicobacter pylori Infection among Migrant Workers in Shijiazhuang, China

“…Helicobacter pylori is an important etiologic agent of gastritis, peptic ulcers, and gastric cancer (Blaser et al, 1997;Ernst and Gold, 2000). In 1994, the International Agency for Research on Cancer categorized H. pylori infection as a group I carcinogen (IARC, 1994).…”

Targeting Inflammation to Improve Tumor Drug Delivery

“…Indeed, mutations in the tumor suppressor p53 gene are equally frequent in tumors and in chronic inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease [29]. Similarly, patients with inflammatory bowel disease or chronic ulcerative colitis are prone to developing colon cancer [32][33][34]; hepatitis C patients are predisposed to developing liver carcinoma [35]; chronic Helicobacter pylori infection is the world's leading cause of stomach cancer [36];…”