Atrophic gastritis is a process of chronic

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

of the

gastric mucosa The gastric mucosa is the mucous membrane layer of the stomach, which contains the gastric pits, to which the gastric glands empty. In humans, it is about one mm thick, and its surface is smooth, soft, and velvety. It consists of simple secretor ...

of the

stomach The stomach is a muscular, hollow organ in the upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical t ...

, leading to a loss of gastric glandular cells and their eventual replacement by intestinal and

fibrous tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesode ...

s. As a result, the stomach's secretion of essential substances such as

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

pepsin Pepsin is an endopeptidase that breaks down proteins into smaller peptides and amino acids. It is one of the main digestive enzymes in the digestive systems of humans and many other animals, where it helps digest the proteins in food. Pe ...

, and

intrinsic factor Intrinsic factor (IF), also known as cobalamin binding intrinsic factor, or gastric intrinsic factor (GIF), is a glycoprotein produced by the parietal cells (in humans) or chief cells (in rodents) of the stomach. It is necessary for the absorp ...

is impaired, leading to digestive problems. The most common are

pernicious anemia Pernicious anemia is a disease where not enough red blood cells are produced due to a deficiency of Vitamin B12, vitamin B12. Those affected often have a gradual onset. The most common initial symptoms are Fatigue, feeling tired and weak. Other ...

possibly leading to

vitamin B₁₂ deficiency Vitamins are organic molecules (or a set of closely related molecules called vitamers) that are essential to an organism in small quantities for proper metabolic function. Essential nutrients cannot be synthesized in the organism in suff ...

; and

malabsorption Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a varie ...

of iron, leading to iron deficiency anaemia. It can be caused by persistent infection with ''

Helicobacter pylori ''Helicobacter pylori'', previously known as ''Campylobacter pylori'', is a gram-negative, Flagellum#bacterial, flagellated, Bacterial cellular morphologies#Helical, helical bacterium. Mutants can have a rod or curved rod shape that exhibits l ...

'', or can be

autoimmune In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an " autoimmune disease" ...

in origin. Those with autoimmune atrophic gastritis (''Type A gastritis'') are statistically more likely to develop

gastric carcinoma Stomach cancer, also known as gastric cancer, is a malignant tumor of the stomach. It is a cancer that develops in the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes ...

(a form of

stomach cancer Stomach cancer, also known as gastric cancer, is a malignant tumor of the stomach. It is a cancer that develops in the Gastric mucosa, lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a numb ...

Hashimoto's thyroiditis Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, Hashimoto's disease and autoimmune thyroiditis, is an autoimmune disease in which the thyroid gland is gradually destroyed. Early on, symptoms may not be noticed. Over ti ...

, and

achlorhydria Achlorhydria and hypochlorhydria are states where the production of hydrochloric acid in gastric secretions of the stomach is absent or low, respectively. Achlorhydria is commonly a complication of some other disease, such as chronic '' Helicobac ...

. Type A gastritis primarily affects the fundus (body) of the stomach and is more common with

. Type B gastritis primarily affects the antrum, and is more common with ''H. pylori'' infection.

Signs and symptoms

Some people with atrophic gastritis may be asymptomatic. Symptomatic patients are mostly females and signs of atrophic gastritis are those associated with iron deficiency: fatigue,

restless legs syndrome Restless legs syndrome (RLS), also known as Willis–Ekbom disease (WED), is a neurological disorder, usually chronic, that causes an overwhelming urge to move one's legs. There is often an unpleasant feeling in the legs that improves temporaril ...

, brittle nails, hair loss, impaired immune function, and impaired wound healing. And other symptoms, such as delayed gastric emptying (80%), reflux symptoms (25%),

peripheral neuropathy Peripheral neuropathy, often shortened to neuropathy, refers to damage or disease affecting the nerves. Damage to nerves may impair sensation, movement, gland function, and/or organ function depending on which nerve fibers are affected. Neuropa ...

(25% of cases), autonomic abnormalities, and memory loss, are less common and occur in 1%–2% of cases. Psychiatric disorders are also reported, such as mania, depression, obsessive-compulsive disorder,

psychosis In psychopathology, psychosis is a condition in which a person is unable to distinguish, in their experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or inco ...

, and cognitive impairment. Although autoimmune atrophic gastritis impairs iron and vitamin B₁₂ absorption, iron deficiency is detected at a younger age than pernicious anemia.

Associated conditions

People with atrophic gastritis are also at increased risk for the development of gastric adenocarcinoma.

Causes

Recent research has shown that autoimmune metaplastic atrophic gastritis (AMAG) is a result of the immune system attacking the

parietal cell Parietal cells (also known as oxyntic cells) are epithelial cells in the stomach that secrete hydrochloric acid (HCl) and intrinsic factor. These cells are located in the gastric glands found in the lining of the fundus and body regions o ...

s. Environmental metaplastic atrophic gastritis (EMAG) is due to environmental factors, such as diet and '' H. pylori'' infection. EMAG is typically confined to the body of the stomach. Patients with EMAG are also at increased risk of gastric carcinoma.

Pathophysiology

Autoimmune metaplastic atrophic gastritis (AMAG) is an inherited form of atrophic gastritis characterized by an immune response directed toward parietal cells and intrinsic factor. Achlorhydria induces

G cell A G cell or gastrin cell is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasi ...

(gastrin-producing) hyperplasia, which leads to hypergastrinemia. Gastrin exerts a trophic effect on enterochromaffin-like cells (ECL cells are responsible for

histamine Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Discovered in 19 ...

secretion) and is hypothesized to be one mechanism to explain the malignant transformation of ECL cells into

carcinoid A carcinoid (also carcinoid tumor) is a slow-growing type of neuroendocrine tumor originating in the cells of the neuroendocrine system. In some cases, metastasis may occur. Carcinoid tumors of the midgut (jejunum, ileum, appendix, and cecum) ...

tumors in AMAG.

Diagnosis

Detection of APCA (anti-parietal cell antibodies), anti-intrinsic factor antibodies (AIFA), and ''

'' (HP) antibodies in conjunction with serum gastrin are effective for diagnostic purposes. File:Histopathology of antral mucosa with atrophy.png, Histopathology of antral mucosa with atrophy. H&E 10x. Antral gastric mucosa with accentuated atrophy because of replacement by extensive intestinal metaplasia. File:Histopathology of fundic mucosa with atrophy.png, Histopathology of fundic mucosa with atrophy. H&E 10x; square 20x. Fundic-corporal gastric mucosa with extensive loss of gastric glands, partially replaced by pseudo-pyloric metaplasia.

Classification

The notion that atrophic gastritis could be classified depending on the level of progress as "closed type" or "open type" was suggested in early studies, but no universally accepted classification exists as of 2017.

Treatment

Supplementation of

folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...

in deficient patients can improve the histopathological findings of chronic atrophic gastritis and reduce the incidence of gastric cancer.

References

External links

{{Digestive system diseases Aging-associated diseases Autoimmune diseases Stomach disorders