Describe the morphology of erythrocytes, the mechanism, and primary cause of the following anemias: Pernicious anemia, folate deficiency anemia, iron deficiency anemia, thalassemia, and sickle cell anemia.

Describe the morphology of erythrocytes, the mechanism, and primary cause of the following anemias: Pernicious anemia, folate deficiency anemia, iron deficiency anemia, thalassemia, and sickle cell anemia.

DQ 1 Nurse 530B

Anemia

Anemia refers to a reduction in the red blood cell mass that interferes with the body’s ability for gaseous exchange. Importantly, the hemoglobin levels are age and sex-dependent. For instance, in the United States, hemoglobin levels less than 13.5g/dl and 12.5g/dl are considered cut-offs for anemia in adult males and females respectively (Chaparro & Suchdev, 2019).Etiologically, anemia can result from increased destruction of red blood cells (RBCs), diminished production of RBCs, or blood loss. Chaparro and Suchdev (2019) describe anemia as a sign that necessitates further investigation to determine the underlying cause. Numerous causes of anemia have been elaborated including but are not limited to genetic, physical, infectious, nutritional, and chronic, and malignant etiologies. This assignment will elaborate on the morphology of RBCs followed by mechanisms and etiologies of pernicious anemia, folate deficiency anemia, iron deficiency anemia, thalassemia, and sickle cell anemia.

ORDER A PLAGIARISM-FREE PAPER HERE ON;Describe the morphology of erythrocytes, the mechanism, and primary cause of the following anemias: Pernicious anemia, folate deficiency anemia, iron deficiency anemia, thalassemia, and sickle cell anemia.

Morphology of Erythrocytes

A mature erythrocyte is pale red, biconcave, and discoid shaped with no nucleus, cell organelles, or granules with an approximate diameter of 6.2 to 8.2 micrometers (Barbalato & Pillarisetty, 2021). The biconcave shape enables flexibility and enhances navigation in narrow blood vessels. Similarly, it provides a large surface area to volume ratio with a resultant rapid gas exchange (Barbalato & Pillarisetty, 2021). This cell is encased by a phospholipid membrane bilayer that is sustained by a framework of proteins that forms the cytoskeleton. These proteins include actin, spectrin, protein 4.1, ankyrin, and band 3 which guarantee malleability and cellular structural integrity (Barbalato & Pillarisetty, 2021). Finally, erythrocytes have a well hemoglobinized cytoplasmic rim with a central pallor corresponding to the inner third of the red cell. Consequently, variation in size, shape, and color of the erythrocytes is of clinical significance.

Pernicious Anemia

Pernicious anemia refers to a type of vitamin B12 deficiency resulting from autoantibodies against intrinsic factor and or gastric parietal cells(Htut et al., 2021).Antiparietal cell antibodies result in achlorhydria and atrophic gastritis that decreases intrinsic factor production and subsequent vitamin B12 absorption in the terminal ileum. On the other hand, anti-IF antibodies bind intrinsic factor occluding the vitamin B12 binding site (Htut et al., 2021).Subsequently, cobalamin deficiency results in dysfunctional methionine synthase with decreased levels of tetrahydrofolate which impairs DNA synthesis with resultant megaloblastic anemia (Htut et al., 2021). Similarly, Vitamin B12 deficiency results in a dysfunctional methylmalonyl CoA mutase with resultant demyelination and neurological disturbances. Finally, pernicious anemia is associated with other autoimmune diseases and a stretched risk of gastric cancer.

Folate Deficiency Anemia

Vitamin B9 is an essential coenzyme in single carbon transfer as well as methylation reactions. As a result, folate deficiency causes megaloblastic anemia by hindering thymidylate synthesis due to low levels of tetrahydrofolate which impairs DNA synthesis and amino acid metabolism(Chaparro & Suchdev, 2019). Additionally, folate deficiency increases the risk of cardiovascular events through increased homocysteine levels. Folate deficiency results from several etiologies including malnutrition from insufficient intake and chronic alcohol use, malabsorption from small bowel disease and surgical resection, increased demand as in pregnancy, and drug-related especially in anticonvulsant, sulfonamides, methotrexate, and trimethoprim therapy(Chaparro & Suchdev, 2019).

Iron Deficiency Anemia

IDA is the most common cause of anemia globally. Iron is critical for heme synthesis. Consequently, in iron deficiency, there is diminished binding of iron to protoporphyrin hence decreased production of hemoglobin (Cappellini et al., 2020). IDA is ordinarily develops slowly once iron deficiency sets in. The principal causes of iron deficiency are based on the pathophysiologic mechanisms as well as the age group. They include chronic blood loss, increased demand, reduced iron intake, and decreased iron absorption (Cappellini et al., 2020). Morphologically, iron deficiency results in microcytic hypochromic anemia.

Sickle Cell Anemia

Sickle cell anemia is a collection of hemoglobin disorders resulting from the inheritance of the sickle beta-globin gene. According to da Guarda et al. (2020), this abnormality is caused by the substitution of valine for glutamic acid at the sixth position of the beta-globin chain. Homozygous sickle cell anemia (HbSS), common in tropical Africa and the Mediterranean, is autosomal recessive and the most devastating of all sickle cell syndromes. The HbS is usually insoluble and polymerizes when exposed to low oxygen causing deformation of erythrocytes and entrapment in microcirculation (da Guarda et al., 2020). Similarly, sickle cells are inelastic and adhere to vascular endothelium. Subsequently, the overwhelming intra- and extravascular hemolysis result in hemolytic anemia. Morphologically, the anemia is normocytic normochromic.

Thalassemia

Thalassemias refer to a heterogeneous group of hereditary hemoglobin disorders distinguished by a mutation on the alpha or beta globin chains resulting in alpha and beta thalassemias respectively (Bajwa & Basit, 2021). Eventually, anemia results from the amalgamation of ineffective erythropoiesis and increased hemolysis. According to Bajwa and Basit (2021), hemolysis results from instability created by compensatory overproduction and precipitation of other chains. Morphologically, the anemia is microcytic hypochromic.

Conclusion

Anemia is a sign with vast etiologies. Understanding the morphology of the red blood cells and their associated variations is crucial as it can help outline the associated pathologies. Folate deficiency and pernicious anemia result in macrocytic anemia while iron deficiency and thalassemia produce microcytic anemia. Lastly, sickle cell culminates in normocytic anemia.

References

Bajwa, H., & Basit, H. (2021). Thalassemia. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK545151/

Barbalato, L., & Pillarisetty, L. S. (2021). Histology, red blood cell. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK539702/

Cappellini, M. D., Musallam, K. M., & Taher, A. T. (2020). Iron deficiency anemia revisited. Journal of Internal Medicine, 287(2), 153–170. https://doi.org/10.1111/joim.13004

Chaparro, C. M., & Suchdev, P. S. (2019). Anemia epidemiology, pathophysiology, and etiology in low‐ and middle‐income countries. Annals of the New York Academy of Sciences, 1450(nyas.14092), 15. https://doi.org/10.1111/nyas.14092

da Guarda, C. C., Yahouédéhou, S. C. M. A., Santiago, R. P., Neres, J. S. D. S., Fernandes, C. F. de L., Aleluia, M. M., Figueiredo, C. V. B., Fiuza, L. M., Carvalho, S. P., Oliveira, R. M. de, Fonseca, C. A., Ndidi, U. S., Nascimento, V. M. L., Rocha, L. C., & Goncalves, M. S. (2020). Sickle cell disease: A distinction of two most frequent genotypes (HbSS and HbSC). PloS One, 15(1), e0228399. https://doi.org/10.1371/journal.pone.0228399

Htut, T. W., Thein, K. Z., & Oo, T. H. (2021). Pernicious anemia: Pathophysiology and diagnostic difficulties. Journal of Evidence-Based Medicine, 14(2), 161–169. https://doi.org/10.1111/jebm.12435

Describe the morphology of erythrocytes, the mechanism, and primary cause of the following anemias: Pernicious anemia, folate deficiency anemia, iron deficiency anemia, thalassemia, and sickle cell anemia.