Download Case studies of different diseases and more Assignments Pathophysiology in PDF only on Docsity!
Blood Disorders - Anemia Introduction Anemia, a condition marked by a deficiency of red blood cells or hemoglobin, can result from excessive blood loss, increased destruction of red blood cells (hemolysis), the production of abnormal red blood cells, or insufficient red blood cell production. Blood loss anemia occurs when iron-containing red blood cells are lost from the body, while hemolytic anemia is characterized by the breakdown of red blood cells within the body, with iron being retained (Porth et al., 2019). Anemia is not a disease itself but rather a sign of an underlying condition or disruption in normal body function. Its effects can be categorized into, symptoms arising from reduced oxygen transport and the body's compensatory mechanisms, decreased red blood cell indices and hemoglobin levels and signs and symptoms related to the underlying condition responsible for the anemia (Porth et al., 2019). Case 3A. Iron Deficiency Anemia Iron deficiency is a prevalent cause of anemia affecting individuals of all ages. This type of anemia arises from inadequate dietary intake, blood loss, or increased iron requirements. Since iron is an essential component of heme, its deficiency reduces hemoglobin production, leading to impaired oxygen transport in the body. Dietary iron deficiency remains the leading cause of anemia worldwide (Safiri et al., 2021).
Underlying Cause Chronic blood loss is the most common cause of iron deficiency in adults, as it limits the availability of iron for recycling. In men and postmenopausal women, this blood loss often results from gastrointestinal bleeding due to conditions such as peptic ulcers, vascular abnormalities, intestinal polyps, hemorrhoids, or cancer (Porth et al., 2019). Mechanism Resulting in Anemia Chronic blood loss depletes iron stores, leading to insufficient hemoglobin production. Iron is required for heme synthesis, a key component of hemoglobin. As iron stores become depleted, red blood cells (RBCs) become microcytic (small) and hypochromic (pale) due to decreased hemoglobin content (Porth et al., 2019). Tests to Confirm the Iron Deficiency Anemia Diagnosis Iron deficiency anemia is characterized by low hemoglobin and hematocrit levels, reduced iron stores, and low serum iron and ferritin (Porth et al., 2019). The red blood cells are fewer in number, and they are microcytic (small) and hypochromic (pale). Additionally, there is poikilocytosis (irregular cell shape) and anisocytosis (irregular cell size). Laboratory tests will show a decrease in MCHC (mean corpuscular hemoglobin concentration) and MCV (mean corpuscular volume). Tests to be ordered include, Complete Blood Count (CBC), which will show low hemoglobin and hematocrit and microcytic, hypochromic RBCs (low mean corpuscular volume [MCV]) and increased red cell distribution width (RDW). Iron blood tests
Vitamin B12 Deficiency Resulting in Anemia Vitamin B12 is necessary for DNA synthesis, particularly in rapidly dividing cells like red blood cells (RBCs). A deficiency leads to impaired nuclear maturation, causing ineffective erythropoiesis and macrocytic (large) RBCs. This results in megaloblastic anemia, characterized by large, immature, and dysfunctional RBCs. Without proper DNA replication, bone marrow produces fewer, but larger, RBCs, leading to anemia (Porth et al., 2019). Blood Tests to be Ordered and Expected Results Blood tests to be ordered include, complete blood count (CBC), which should show low hemoglobin and hematocrit, elevated mean corpuscular volume indicating macrocytic anemia and vitamin B12 Level, which should be low. Blood test for Methylmalonic Acid (MMA) and Homocysteine Levels should show elevated MMA (specific for B12 deficiency) and elevated homocysteine. Tests to Differentiate the Various Causes of Vitamin B12 Deficiency To differentiate between the various causes of vitaminB12 deficiency, several tests can be performed such as anti-parietal cell and anti-intrinsic factor antibodies in which as positive result will indicate pernicious anemia. A schilling test can be used to differentiates between pernicious anemia from malabsorption. An endoscopy/Gastric Biopsy can be used to assess for atrophic gastritis seen in pernicious anemia. A stool test for parasites can be used to look for Diphyllobothrium latum, a tapeworm that can cause B12 deficiency.
Pathogenesis of this Disease Pernicious anemia is a specific type of megaloblastic anemia caused by atrophic gastritis and the inability to produce intrinsic factor, which leads to impaired vitamin B12 absorption. It is thought to result from an immune-mediated, possibly autoimmune, destruction of the gastric mucosa. This chronic atrophic gastritis leads to the loss of parietal cells and the production of antibodies that disrupt the binding of vitamin B12 to intrinsic factor, further hindering absorption (Porth et al., 2019). Vitamin B12 deficiency anemia can also result from conditions such as gastrectomy, ileal resection, inflammation or tumors in the terminal ileum, and malabsorption disorders. A defining characteristic of vitamin B12 deficiency is megaloblastic anemia, where the red blood cells produced are unusually large. Conclusion Treatment for anemia will vary depending on the underlying cause, therefore treating the underlying cause will resolve anemia in the long term. In the short term, the management of iron deficiency anemia in both children and adults focuses on addressing chronic blood loss, enhancing dietary iron intake, and providing iron supplementation. Ferrous sulfate is the standard oral therapy, effectively restoring iron levels over the course of several months. Long-term treatment is typically required for malabsorption conditions. Since standard doses of vitamin B are insufficient for proper absorption, treatment involves intramuscular injections, intranasal sprays, or high-dose oral supplementation to correct anemia and alleviate neurological symptoms.
