Atrophy, gastric

Fox, J.G., Beck, P., Dangler, C.A., Whary, M.T., Wang, T.C., Shi, H.N. and Nagler-Anderson, C. (2000) Concurrent enteric helminth infection modulates inflammation and gastric immune responses and reduces helicobacter-induced gastric atrophy. Nature Medicine 6, 536-542. 

Infection with Helicobacter pylori is widely spread in the world and as many as 50% of the population is estimated to be infected, with the highest incidence in Asia and developing countries. The bacterial toxins of Helicobacter pylori damage the epithelial cells in the stomach and can in the long term lead to gastric atrophy (Pilotto 1996, Faisal et al. 1990, Pilotto et al. 1999). The consequential decrease in secretion of acid causes a higher gastric pH level which can increase the risk of enteric infections, for example, with Campylobacter and Clostridium difficile. 

Enzymatic-metabolic activation (in part unknown)/phenobarbital-like promotion Hepatic enzyme induction, thyroid enzyme inhibition/axazepam, amobarbital, sulphonamides, thioureas Gastric secretory suppression, gastric atrophy induction (climetidine, omeprazole, butachlor... 

Pernicious anemia results from defective secretion of intrinsic factor by the gastric mucosal cells. Patients with pernicious anemia have gastric atrophy and fail to secrete intrinsic factor (as well as hydrochloric acid). The Schilling test shows diminished absorption of radioactively labeled vitamin B12, which is corrected when intrinsic factor is administered with radioactive B12, since the vitamin can then be normally absorbed. 

Pernicious anemia associated with gastric atrophy is the most common cause of clinically apparent vitamin B12 deficiency in North American and European populations. 

Gastrointestinal signs and symptoms of vitamin B12 deficiency occur in 26% of cases. These include sore tongue, stomatitis, mucosal ulceration, appetite loss, flatulence, and constipation or diarrhea. Appetite loss, excess gas, and diarrhea are probably related to the underlying gastric disorder (i.e., gastric atrophy) in pernicious anemia. Gastrointestinal symptoms may occur in the absence of symptomatic anemia or macrocytosis. 

Patients with iron deficiency anemia present with fatigue, weakness, and pallor, and possibly also with glossitis, headache, dysphagia, fingernail changes, gastric atrophy, and paresthesias. Inadequate intake of iron, malabsorption, and blood loss from any origin are the principal causes of iron deficiency anemia. 

Examination of the bone marrow, although important, will only confirm that the hemopoiesis is megaloblastic. A deficiency of folic acid will also cause a megaloblastic anemia and it is not possible to identify the cause on the basis of morphology. A serum assay of both vitamins will usually indicate which is responsible. If the patient is vitamin B12 deficient, the next step is to carry out a vitamin B12 absorption test to confirm that the deficiency is due to a lack of intrinsic factor. Preferably this should not be done until the patient s vitamin B12 and hemoglobin levels have returned to normal, since the gastric and intestinal cells are also affected by a lack of vitamin B12 aborption may be less than optimal if it is attempted too early. Patients with pernicious anemia also have a histamine-fast achlorhydria and gastric atrophy. The disease appears to have an autoimmune basis and antibodies to intrinsic factor can be demonstrated in the serum of more than half of affected patients. 

Other causes of gastric atrophy, such as those due to Helicobacter pylori,AIDS, or radiation injury, can lead to a similar outcome but from different pathogenic mechanisms. Therefore, vitamin B12 deficiency, resulting in neurological, psychiatric, metabolic, and hematological disorders, can arise from any one of the many causes listed in Table 28-1. For this reason, the term pernicious anemia (PA) is used here to describe only the classical disease that is associated with IF deficiency due to autoimmune gastritis. 

Severe gastric atrophy due to Helicobacter pylori infection Congenital abnormalities of intrinsic factor... 

Peptic ulcer Gastric cancer Gastric atrophy... 

Duodenal ulcer Gastric ulcer Gastric atrophy Gastric cancer... 

Material Inhibitory to Gastric Secretion (Gastrone) and the Gastric Atrophy-Producing Factor... 

Sircus, W., Preshaw, R. M., Wynn-Williams, A., and McConnell, R. B., A failure to induce gastric atrophy in dogs by administration of histamine-stimulated gastric juice. Gastroenterology 45, 384-387 (1963). 

Smith, W. O., DuVal, M. K., Joel, W., Honska, W. L., and Wolf, S., Gastric atrophy in dogs induced by administration of normal human gastric juice. Gastroenterology 39, 55-60 (1960). 

Vitamin B] deficiency is commonly caused by pernicious anemia (PA). TA is an autoimmune disease resulting from the body s production of antibodies that recognize inlrinsic factor or other proteins of the parietal cell. The binding of antibodies to these proteins results in loss of their function. The parietal cells may be destroyed and be undetectable in patients with PA. The major defect in PA is gastric atrophy. 1 here may be a lack of all gastric secretions, including intrinsic factor, gastric acid, and pepsin. 

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