Atrophic gastritis (AG) is a condition that develops when the stomach’s lining has been inflamed for many years. The inflammation is most often caused by an infection of the bacterium H. pylori. The infection gradually destroys cells in your stomach lining. It is thought that the bacteria cause inflammation by disrupting the barrier of mucus that protects your stomach lining from the acidic juices that help it digest food. Less often, AG occurs because your immune system mistakenly attacks the cells in your stomach lining. This is known as autoimmune atrophic gastritis.
H. pylori usually infects your stomach in childhood and the infection progresses if not treated. This type of bacteria can be passed from person to person through direct contact with feces, vomit, or saliva, and can also be spread through contact with contaminated food or water.
Autoimmune AG occurs when your body produces antibodies that attack the stomach cells responsible for acid production. Antibodies also attack a substance released by these cells known as intrinsic factor. Intrinsic factor helps you absorb vitamin B12. Its destruction can cause an illness known as pernicious anemia, in which a lack of B12 leaves you unable to make enough red blood cells.
For both causes, the condition is usually found later in life. According to Medscape, most of those diagnosed with AG are 50 or older. (Medscape, 2010)
The main risk factor for AG is having an H. pylori infection. These infections are associated with areas of poverty and overcrowding. However, nearly half of the world’s population is infected with H. pylori. Consequently, AG is extremely common. Your risk is greater if you are Hispanic or Asian.
Autoimmune AG is quite rare, and you are more at risk if you are African American or of Northern European origin. People with thyroid disease and diabetes are more likely to have autoimmune gastritis.
If you have either type of AG, your risk of stomach cancer is higher than normal. (Medscape, 2010)
Often there are no symptoms, and as a result, many cases of AG go unrecognized.
An H. pylori infection may cause:
- stomach pain
- nausea and vomiting
- loss of appetite
- weight loss
- stomach ulcers
- stomach cancer
- iron deficiency anemia that does not respond to treatment
Autoimmune AG can lead to B12 deficiency, with symptoms of anemia, including:
- feeling weak
- chest pain
- tinnitus (ringing in the ears)
B12 deficiency can also cause nerve damage, leading to:
- limb numbness and tingling
- unsteadiness when walking
- mental changes
Diagnosis of AG relies on a combination of clinical observation and testing. In a physical exam, your doctor will examine you for:
- any tenderness over your stomach
- signs of B12 deficiency, such as paleness and a rapid pulse (autoimmune)
Your doctor might order blood tests to check for:
- low levels of pepsinogen, a protein secreted by the stomach’s acid-producing cells
- high levels of gastrin, a hormone that stimulates stomach acid production
- antibodies against stomach cells and intrinsic factor (autoimmune)
- low B12 levels (autoimmune)
In some cases, your doctor may need to perform a biopsy of tissue from the stomach to look for evidence of AG. This is normally done with an endoscope, a long slender instrument that is inserted down your throat into your stomach. Stomach tissue samples can also be analyzed to detect the presence of H. pylori.
If you have AG associated with an H. pylori infection, treatment usually involves eradicating the infection using antibiotics. Drugs that lower stomach acid or neutralize it are also prescribed, as a less acidic environment helps your stomach lining to heal.
People with autoimmune AG usually receive treatment with B12.
Doctors are unsure whether antibiotic treatment to remove H. pylori from your stomach reduces the progression of AG. Treatment might make your risk of stomach cancer smaller, but more research is needed.
It is difficult to prevent AG, but it might be possible to reduce the spread of H. pylori infection by practicing good hygiene. As an individual, you should wash your hands after using the bathroom and before and after handling food. Parents or caregivers for young children should wash their hands after handling soiled diapers or linens, and should instill good hygiene practices in children to avoid the spread of bacteria.