Discuss the defect of gastric secretion of intrinsic factor (IF) that leads to anemia. Identify the type of anemia this defect can cause and the risk factors that can lead to this anemia to develop. Briefly discuss the treatment options for this type of anemia.
Peer Response 1:
Luisa Perez posted
Intrinsic factor (IF) combines with vitamin B12 in the stomach and is a mucoprotein produced by parietal cells (McCance & Huether, 2019). This is needed for the absorption of vitamin B12 by the ileum (McCance & Huether). Defects in intrinsic factor production lead to decreased B12 absorption and pernicious anemia (McCance & Huether). This discussion post will identify the type of anemia this defect can cause, the risk factors that can lead to this anemia to develop, and the treatment options for this type of anemia.
It is stated by Harvard Health that “an absence of intrinsic factor is the most common cause of pernicious anemia (Harvard Heath, 2019). This absence is at times associated with atrophic gastritis which is the thinning of the lining of the stomach and is commonly seen in elderly people of African American or Northern-European descent (Harvard Health). Pernicious anemia is caused by atrophic gastritis and failure to absorb vitamin B12 (McCance & Huether, 2019). It is also stated by McCance & Huether that “deficiency in IF secretion may be congenital; however, it is often considered an autoimmune (and possibly innate) process directed against gastric parietal cells” (p. 932).
Harvard Health (2019) states, “Pernicious anemia occurs more commonly in people who already have diseases that are linked to immune-system abnormalities, such as Graves’ disease, hypothyroidism (under-functioning thyroid gland), thyroiditis (inflammation of the thyroid), vitiligo and Addison’s disease (adrenocortical insufficiency). Family history of the condition can also predispose someone to get this type of anemia. Other risk factors include surgical removal of the stomach, resection of the ileum, and infestation with tapeworms (McCance & Huether, 2019). Conditions that increase the demand of vitamin B12 can also pose a risk. Such conditions include, hyperthyroidism, pregnancy, chronic infection, and disseminated cancer (McCance & Huether).
Pernicious anemia is diagnosed based on the clinical manifestations that are present as well as a variety of test results. These tests include blood tests, bone marrow aspiration, gastric biopsy, and serologic studies (McCance & Huether, 2019). The following treatment options are available for this type of anemia. The treatment of choice is replacement of vitamin B12 by injections. These vitamin B12 injections are administered weekly until the deficiency is corrected, and then there are monthly injections for the remainder of the individual’s life (McCance & Huether).
Harvard Health. (2019). Vitamin B12 deficiency. Retrieved from https://www.health.harvard.edu/a_to_z/vitamin-b12-deficiency-a-to-z
McCance, K. & Huether, S. (2019). Pathophysiology: The Biologic Basis for Disease in Adults and Children (8th ed.). St. Louis, MO: Elsevier.
Peer Response 2:
Vitamin B12 is needed for healthy red blood cell production in the body (McCance & Huether, 2019). Intrinsic factor is imperative for Vitamin B12 absorption in the digestive tract, specifically the small intestine, where it acts to attach to the vitamin for cellular uptake. Some individuals cannot absorb adequate amounts of B12 because of issues making intrinsic factor. This can be from damage to parietal cells located in the stomach that secrete this needed substance. This can be affected by autoimmune disorders like chronic gastritis (McCance & Huether, 2019).
This process is called pernicious anemia, which is a megaloblastic anemia, characterized by larger red blood cells due to issues with the nucleus (McCance & Huether, 2019). Symptoms include weakness, changes in skin color, glossitis, fatigues, parentheses, decreased appetite, pain, and decreasing weight. It can contribute to neurologic disorders with ongoing anemia. If no interventions are sought, this disorder can be deadly. Diagnostic testing for this condition entails lab work like FBC, serum B12, and tHcy (Gilbert, 2017), gastric biopsy, and bone marrow sampling (McCance & Huether, 2019). Treatment includes vitamin B12 injections; they are administered every week until desired effect, then are administered monthly. This intervention usually shows an increased blood count (McCance & Huether, 2019). With neurologic disorders, hydroxocobalamin injections can be helpful (Gilbert, 2017).
Some risk factors include digestive surgeries, pregnancy, tapeworms or other autoimmune disease. These include type 1 diabetes, Hashimoto’s thyroiditis, Addison’s disease, myasthenia gravis, and Graves disease. Certain factors can flare up gastritis like chronic alcohol use and smoking (McCance & Huether, 2019). More cases are also seen in those with type A blood (Gilbert, 2017).
Gilbert, L. (2017). Diagnosis and treatment of pernicious anemia. Practice Nurse. 47(4), 20-23. Retrieved from https://web-a-ebscohost-com.ezproxy.snhu.edu/ehost/detail/detail?vid=2&sid=0dfc8703-9f69-4ca9-a43d-cc18d705e738%40sessionmgr4007&bdata=JnNpdGU9ZWhvc3QtbGl2ZSZzY29wZT1zaXRl#db=ccm&AN=122680895
McCance, K.L, Huether, S.E. (2019). Pathophysiology: the biologic basis for disease in adults and children. (8th ed.) St Louis: MO: Elsevier.