Question

Ms. Johnson, age 57, was referred to the gastroenterologist for chronic digestive problems. For at least a year, she said, her stomach ached after eating a small meal. It seemed like the dull pain she experienced, and the sensation of fullness, had increased recently. Ms. Johnson also felt abdominal cramping, and sometimes nausea, at times other than after eating.

After taking a complete history and performing a physical examination, the gastroenterologist ordered several tests. Her conclusion was that Ms. Johnson had chronic gastritis caused by an infection with a bacterium.

QUESTIONS

1. Which bacterium is the most common cause of chronic gastritis?

2. Explain how the bacteria survives in the harsh acidic environment? (mention the enzyme it uses and how it causes damage)

3. What is the pathophysiology behind chronic gastritis?

4. What are the protective factors in the stomach?

5. What are the damaging factors in the stomach?

6. What other conditions (other than the bacteria) can cause chronic gastritis?

7. Mention at least two manifestations and two complications of chronic gastritis.

8. What is peptic ulcer disease? How is it different from gastritis?

Answer 1

1. Helicobacter pylori (H pylori) bacteria is the most common cause of chronic gastritis.

2.

• To survive in the harsh, acidic environment of the stomach, H. pylori secretes an enzyme called urease, which converts the chemical urea to ammonia. The production of ammonia around H. pylori neutralizes the acidity of the stomach, making it more hospitable for the bacterium.
• Our stomach is very acidic, with a pH of 3.5 or below which enables it to break down food. Higher pH thus causes indigestion and weakens stomach's lining.

3.

• H pylori is a spiral gram-negative rod. It has lipopolysaccharides on its outer membrane which helps it in colonization and persistence.
• The bacteria survive within the mucous layer of gastric surface epithelium.
• Once present in the stomach, it causes an intense inflammatory response in the underlying tissue, leading to tissue damage.
• The immune response to H pylori and its secretions is composed of T and B lymphocytes, denoting chronic gastritis, followed by infiltration of the gastric epithelium by polymorphonuclear leukocytes (PMNs) that eventually phagocytize the bacteria.
• The presence of PMNs in the gastric mucosa is diagnostic of gastritis.

4.  Protective factors in the stomach are;

• A compact epithelial cell lining.
• A special mucus covering, derived from mucus secreted by surface epithelial cells and Foveolar cells.
• Bicarbonate ions, secreted by the surface epithelial cells.

Mucus and bicarbonate, create a pH gradient which maintainis the epithelial cell surface at near neutral pH.

5.

• If the mucus layer is damaged, the epithelial cells are exposed to concentrated gastric acid and the digestive enzymes.
• The stomach wall is made up of the same proteins and lipids of the many foods we eat. if this mucosal barrier is broken the stomach will begin to digest itself, forming a peptic ulcer.

6. Other causes of chromic gastritis are;

• long-term use of medications, such as aspirin and ibuprofen
• excessive alcohol consumption
• illnesses, such as diabetes, kidney failure
• a weak immune system
• stress
• bile reflux

7. Manifestations/symptoms of chronic gastritis include;

• Nausea, vomiting or recurrent upset stomach
• Abdominal bloating and pain
• Indigestion
• Burning sensation
• Loss of appetite

Complications of chronic gastritis:

As gastritis wears away at your stomach lining, it leads to

• stomach bleeding
• stomach ulcers and
• changes in the cells, which may lead to gastric cancer.

8.

• The word 'gastric' refers to the stomach, whereas the word 'peptic' refers to the entire digestive system. Thus, peptic ulcers affect both the stomach and small intestines.
• The most common causes of peptic ulcers is also infection with the bacterium H. pylori and long term use of aspirin, etc.
• Stress and spicy foods do not cause peptic ulcers, but they do cause gastritis.