Helicobacter pylori is a bacterium that can survive in an acidic environment such as the stomach because of an enzyme it releases called urease. Enzymes are proteins that speed up the time that a process will take. Helicobacter pylori uses the urease enzyme to make the environment it infects less acidic. It is then able to cause several diseases.
Peptic Ulcer Disease
A peptic ulcer is either a gastric ulcer or a duodenal ulcer. A gastric ulcer has damage in the lining of the stomach. When there is damage in the lining of the first part of the small intestines, or the duodenum, this is a duodenal ulcer. Thirty to 50 percent of people with a gastric ulcer have an H. pylori infection, while 50 to 70 percent of people with a duodenal ulcer have an H. pylori infection, according to Sidney Cohen, M.D., professor of medicine at Thomas Jefferson University Hospital in "The Merck Manual for Healthcare Professionals." Cigarette smoking and nonsteroidal anti-inflammatory drugs, or NSAIDs, can also cause peptic ulcers. People with a gastric ulcer usually have more pain when they eat. With a duodenal ulcer, they initially have less pain while eating, but the pain returns in about two to three hours. They may also have pain at night---enough to wake them from sleep.
MALT Lymphoma
A lymphoma is a cancer that develops in the lymphatic system, a system which is supposed to fight against infections and disease. MALT stands for mucosa-associated lymphoid tissue. This cancer may be found in several areas of the body, including the kidneys, skin, thyroid gland, bladder, salivary glands, lungs, stomach and intestines, but most are found in the stomach. Approximately 95 percent of people with a MALT lymphoma in the stomach have an H. pylori infection, writes Dan Longo, scientific director at the National Institutes of Health in "Harrison's Principles of Internal Medicine." Like peptic ulcer disease, the MALT lymphomas of the stomach are associated with H. pylori. The stomach does not normally have lymphoid tissue, but it develops in response to the H. pylori infection and leads to the development of an abnormal lymphocyte, which is a cell that normally fights infection. This process then results in a lymphoma.
Chronic Gastritis
Gastritis means the inflammation of the lining of the stomach. If people have gastritis for a long period of time, it is referred to as chronic gastritis. There are two types of chronic gastritis: type A and type B. Type A gastritis an autoimmune disorder in which antibodies that normally attack only foreign substances begin attacking some cells of the stomach. Type B gastritis is caused by H. pylori. In fact, gastritis caused by H. pylori is the most common infection that people develop, says Koenraad Mortele, M.D., associate professor of radiology at Harvard Medical School, in "Current Diagnosis & Treatment: Gastroenterology, Hepatology & Endoscopy." Most people who have chronic gastritis because of an H. pylori infection do not have any symptoms.
References
- "Current Diagnosis & Treatment: Gastroenterology, Hepatology & Endoscopy"; Norton Greenberger, M.D.; 2009
- "Harrison's Principles of Internal Medicine"; Anthony Fauci, M.D., Dennis Kasper, M.D., Dan Longo, M.D., et al.; 2008
- The Merck Manual for Healthcare Professionals: Peptic Ulcer Disease
