Atrophic gastritis

Atrophic gastritis is a process of chronic inflammation of the gastric mucosa of the stomach, leading to a loss of gastric glandular cells and their eventual replacement by intestinal and fibrous tissues. As a result, the stomach's secretion of essential substances such as hydrochloric acid, pepsin, and intrinsic factor is impaired, leading to digestive problems. The most common are vitamin B12 deficiency which results in a megaloblastic anemia and malabsorption of iron, leading to iron deficiency anaemia.[2] It can be caused by persistent infection with Helicobacter pylori, or can be autoimmune in origin. Those with the autoimmune version of atrophic gastritis are statistically more likely to develop gastric carcinoma, Hashimoto's thyroiditis, and achlorhydria.

Atrophic gastritis
Other namesType A or type B gastritis[1]
Atrophic gastritis
SpecialtyGastroenterology

Type A gastritis primarily affects the body/fundus of the stomach, and is more common with pernicious anemia.[1]

Type B gastritis primarily affects the antrum, and is more common with H. pylori infection.[1]

Signs and symptoms

Some people with atrophic gastritis may be asymptomatic. That said, symptomatic patients are mostly females and signs of atrophic gastritis are those associated with iron deficiency: fatigue, restless legs syndrome, brittle nails, hair loss, impaired immune function, and impaired wound healing.[3] And other symptoms such as: delayed gastric emptying (80%), reflux symptoms (25%), peripheral neuropathy (25% cases), autonomic abnormalities and memory loss are less common and occur in 1%–2% of cases. Other psychiatric disorders are also reported such as: mania, depression, obsessive compulsive disorder, psychosis and cognitive impairment. [4]

Associated conditions

People with atrophic gastritis are also at increased risk for the development of gastric adenocarcinoma.[5] The optimal endoscopic surveillance strategy is not known but all nodules and polyps should be removed in these patients.

Causes

Recent research has shown that AMAG is a result of the immune system attacking the parietal cells.[6]

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
Atrophic gastritis under low power. H&E stain.

Autoimmune metaplastic atrophic gastritis (AMAG) is an inherited form of atrophic gastritis characterized by an immune response directed toward parietal cells and intrinsic factor.[6] The presence of serum antibodies to parietal cells and to intrinsic factor are characteristic findings. The autoimmune response subsequently leads to the destruction of parietal cells, which leads to profound Achlorhydria (and elevated gastrin levels). The inadequate production of intrinsic factor also leads to vitamin B12 malabsorption and pernicious anemia. AMAG is typically confined to the gastric body and fundus.

Achlorhydria induces G cell (gastrin-producing) hyperplasia, which leads to hypergastrinemia. Gastrin exerts a trophic effect on enterochromaffin-like cells (ECL cells are responsible for histamine secretion) and is hypothesized to be one mechanism to explain the malignant transformation of ECL cells into carcinoid tumors in AMAG.

Diagnosis

Detection of APCA, anti-intrinsic factor antibody (AIFA) and Helicobacter pylori (HP) antibodies in conjunction with serum gastrin are effective for diagnostic purposes.[7]

Classification

The notion that atrophic gastritis could be classified depending on the level of progress as "close type" or "open type" was suggested in early studies,[8] but no universally accepted classification exists as of 2017.[7]

Treatment

Immunosupressive drugs and chemotherapy with antineoplastic drugs are potential treatment options for AMAG. In the case of confirmed stomach cancer, stomach resection may be required.

See also

References
  1. Blaser MJ (May 1988). "Type B gastritis, aging, and Campylobacter pylori". Arch. Intern. Med. 148 (5): 1021–2. doi:10.1001/archinte.1988.00380050027005. ISSN 0003-9926. PMID 3365072.
  2. Annibale B, Capurso G, Lahner E, Passi S, Ricci R, Maggio F, Delle Fave G (April 2003). "Concomitant alterations in intragastric pH and ascorbic acid concentration in patients with Helicobacter pylori gastritis and associated iron deficiency anaemia". Gut. 52 (4): 496–501. doi:10.1136/gut.52.4.496. ISSN 0017-5749. PMC 1773597. PMID 12631657.
  3. Stefanie Kulnigg-Dabsch (2016). "Autoimmune gastritis". Wien Med Wochenschr. 166: 424–430. doi:10.1007/s10354-016-0515-5. PMID 27671008.CS1 maint: uses authors parameter (link)
  4. Sara Massironi, Alessandra Zilli, Alessandra Elvevi, Pietro Invernizzi (2019). "The changing face of chronic autoimmune atrophic gastritis: an updated comprehensive perspective". Autoimmun Rev. 18: 215–222. doi:10.1016/j.autrev.2018.08.011. PMID 30639639.CS1 maint: uses authors parameter (link)
  5. Giannakis M, Chen SL, Karam SM, Engstrand L, Gordon JI (March 2008). "Helicobacter pylori evolution during progression from chronic atrophic gastritis to gastric cancer and its impact on gastric stem cells". Proc. Natl. Acad. Sci. U.S.A. 105 (11): 4358–63. Bibcode:2008PNAS..105.4358G. doi:10.1073/pnas.0800668105. PMC 2393758. PMID 18332421.
  6. Nimish Vakil, MD, Clinical Adjunct Professor, University of Madison School of Medicine and Public Health. "Autoimmune Metaplastic Atrophic Gastritis: Gastritis and Peptic Ulcer Disease: Merck Manual Professional". MSD Manual Professional Version. Merck & Co.
  7. Minalyan A, Benhammou JN, Artashesyan A, Lewis MS, Pisegna JR (2017). "Autoimmune atrophic gastritis: current perspectives". Clin Exp Gastroenterol. 10: 19–27. doi:10.2147/CEG.S109123. PMC 5304992. PMID 28223833.
  8. Kimura, K.; Takemoto, T. (2008). "An Endoscopic Recognition of the Atrophic Border and its Significance in Chronic Gastritis". Endoscopy. 1 (3): 87–97. doi:10.1055/s-0028-1098086. ISSN 0013-726X.
Classification
External resources
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