Anatomy & Physiology II
Lab Practical 2

A Case of Iron Deficiency Anemia

Dolores Welborn is a 28 year old in her second trimester of pregnancy with her first child. Recently she noticed she would get tired easier, short of breath from even the slightest exertion and she had periods of light-headedness. She notices her legs were cramping, a desire to eat ice and her tongue was sore. She sought an appointment with her physician and throughout her exam they find that she has tachycardia (an abnormally rapid heart rate), pale gums and nail beds, and her tongue is swollen. Her physician diagnosed her with anemia due to iron deficiency and an oral iron supplement was prescribed. Below are some questions with the explanation of why this might have happened. 1. Describe the structure of a molecule of hemoglobin and explain the role played by iron in the transport of oxygen. Found in red blood cells, hemoglobin is a protein that carries oxygen molecules and carbon dioxide molecules throughout the body and are responsible for making the red blood cells red. Made up of red heme pigment bound the protein globin it makes up the hemoglobin. Hemoglobin consists of four subunits, two alpha and two beta polypeptide chains and a non-protein heme group, which is an assembly of cyclic ring structures surrounding an iron ion that is surrounded by a nitrogen atom. A hemoglobin molecule can transport four molecules of oxygen because each iron atom can combine reversibly with one molecule of oxygen. Leading to a change in oxidation state for iron from +2 to +3 the iron atom of each heme group can bind to diatomic oxygen. It delivers oxygen easily when it exhibits a relaxed state that will release the oxygen and it will reduce the iron atoms from +3 to +2. It becomes easier for oxygen to increase when more oxygen bind to the heme groups. 2. How is iron stored and transported in the body? Most of the iron within the body is found and stored in the hemoglobin within the red blood cells. Iron that is taken in excess is stored in two forms ferritin (a protein that stores iron in the tissues) and hemosiderin (composed of ferric oxide left from the breakdown of hemoglobin). It is stored in the MPS or RE cells of the bone marrow, liver and spleen. Ferritin is used as a buffer from potential iron shortages in the body. Most absorbed iron is transported in the bloodstream bound to the glycoprotein transferrin. Transferrin is a carrier protein that plays a role in regulating the transport of iron from the site of the absorption to virtually all tissues. 3. What is Iron Deficiency Anemia (IDA) and how frequently does it occur? Iron deficiency anemia occurs when your body doesn’t have enough iron. It results from inadequate intake of iron containing foods and impaired iron absorption. Iron is important because it helps you get enough oxygen throughout your body. Your body uses iron to make hemoglobin. Hemoglobin is a part of your red blood cell and hemoglobin carries oxygen through your body. The red blood cells produces are small and pale because they cannot synthesize their normal complement of hemoglobin, resulting insufficient transport of oxygen to your system. It is believed to affect over one billion people. 4. What are the most common causes of IDA? Iron deficiency anemia is caused by low levels of iron in the body. Some things that could be causing this are not getting enough iron in food (this can happen in people who need a lot of iron, such as small children, teens, and pregnant women), heavy menstrual bleeding, different types of blood loss like bleeding inside your body (this bleeding may be caused by problems such as ulcers, hemorrhoids, cancer, or bleeding can also happen with regular aspirin use.) or you are just not able to absorb iron well in your body for example if you have celiac disease. 5. Why are women prone to IDA than men? Women are prone to this because of menstruating cycles, which sometimes can be extremely heavy or because of pregnancy. Endometriosis or fibroids are also a cause for chronic blood loss in women which require a great amount of blood before they are detected and removed. The more blood loss means more iron loss. 6. What are the red blood cell indices, and what tests are diagnostic for IDA? RBC indices are calculations derived from the complete blood count (CBC) in order to diagnose various anemias. The measurements that are needed to calculate indices are the RBC count, hemoglobin and hematocrit. Hematocrit is a measure of RBC mass or how much space in the blood is occupied by RBC. Hemoglobin test is a measure of how much hemoglobin protein is in the blood. The three RBC indices are: (1) Mean corpuscular volume (MCV) is the index most often used because it categorized RBC by size and it measures the average volume of a red blood cell by dividing the hematocrit by the RBC. (2) Mean corpuscular hemoglobin concentration (MCHC) is the measurement of the average concentration of hemoglobin in a red blood cell. (3) Mean corpuscular hemoglobin (MCH) is the measure of weight of the hemoglobin in the RBC. 7. How is IDA treated and prevented? It is treated from iron supplement (oral or IV), and a change in diet with iron rich foods. 8. What is the relationship between her symptoms and IDA? The insufficient delivery of oxygen to all of her extremities is directly related to the lightheadedness she felt to the cramping of her legs. Also the blood sample results show low Serum Iron, low MCV and MCHC which is also symptoms of IDA.

The Chemistry of Cooley’s Anemia

This case study is about a child named Peter; his parents are Max and Andrea Foresti a young couple that has only been married for two years. They are waiting to be seen the family physician, Dr. Mary Litton. They are worried about the number of infection Peter has been suffering from. They are worried it might be anemia but the doctor had order blood work at his last appointment and informed them she has a diagnosis of thalassemia. Thalassemia is a genetic blood disorder that causes hemoglobin, the protein in your body that binds and transports oxygen, to be malformed. The doctor proceeds to go over the complications of this and explains in detail what they will have to do, if they choose to do so. It will entail blood transfusions on an outpatient basis every two to four weeks that will last four to six hours and they will have to administer the deferoxamine each night by placing a needle under Peter’s skin. This will only prolong his life to a 90% chance of surviving to age 25. 1. What is the basic structure and function of hemoglobin? The structure of the hemoglobin are small cells shaped like biconcave discs with depressed centers. They are lighter in color in their center than at their edges. The hemoglobin’s structure makes it a highly efficient oxygen carrier. There are two components to hemoglobin call the alpha protein and the beta protein and it consists of four subunits, two alpha and two beta polypeptide chains. A non-protein heme group, which is an assembly of cyclic ring structures surrounding an iron ion that is surrounded by a nitrogen atom. A hemoglobin molecule can transport four molecules of oxygen because each iron atom can combine reversibly with one molecule of oxygen. If the body does not produce enough of either of the alpha protein and the beta protein then it cannot get sufficient oxygen to the body. 2. Which proteins transport and store iron in the body? Most of the iron within the body is found and stored in the hemoglobin within the red blood cells. Iron that is taken in excess is stored in two forms ferritin (a protein that stores iron in the tissues) and hemosiderin (composed of ferric oxide left from the breakdown of hemoglobin). It is stored in the MPS or RE cells of the bone marrow, liver and spleen. Ferritin is used as a buffer from potential iron shortages in the body. Most absorbed iron is transported in the bloodstream bound to the glycoprotein transferrin. Transferrin is a carrier protein that plays a role in regulating the transport of iron from the site of the absorption to virtually all tissues. 3. What is thalassemia and what are its causes? Thalassemia is a genetic or inherited blood disorder which means it’s passed from parent to children. Thalassemia is caused by mutation in the DNA of cells that make hemoglobin. Thalassemia causes the body to make fewer hemoglobin or “healthy” red blood cells. Hemoglobin carries oxygen to all parts of the body and also carries carbon dioxide from the body to the lungs, as you exhale. People who have thalassemia have mild to severe anemia. 4. What are the different types of thalassemia? There are two main types of thalassemia. They are alpha and beta whereas beta is the most common. In order to make hemoglobin you need both alpha and beta globin to make hemoglobin. Beta thalassemia occurs when the gene that controls the production of beta globin is defective. It can be mild to severe and is more common in people of Mediterranean, African, and Southeast Asian descent. You need two genes (one from each parent) to make enough beta globin protein chains. If one or both of these genes are altered, you will have beta thalassemia. This means your body won’t make enough beta globin protein. To make enough alpha globin protein you need four genes (two from each parent). If one or more of the genes are missing, you’ll have alpha thalassemia. This means that your body doesn’t make enough alpha globin protein. 5. What are the symptoms of beta thalassemia major (Cooley’s anemia)? Why don’t these symptoms appear at birth? Signs and symptoms for beta thalassemia major also called Cooley’s anemia usually occur within the first 2 years of age. Some of the signs are poor appetite, a pale and listless appearance, slowed growth or failure to thrive, jaundice, an enlarged spleen, liver or heart, bone problems or dark urine. These symptoms do not appear at birth because babies still have hemoglobin F or the fetal hemoglobin, which consists of two alpha chains and two delta chains per globin molecule instead of the paired alpha and beta chains typical of hemoglobin A. After birth the liver rapidly destroys the fetal erythrocytes carrying hemoglobin F and the baby eventually develops the beta chains producing hemoglobin A. 6. What are the current treatments for thalassemia? What are their problems? The main treatment for this condition is to receive blood transfusion every couple of weeks. This treatment gives you healthy red blood cells with normal hemoglobin. This is done on an outpatient basis through IV and the procedure usually takes 1 to 4 hours. Red blood cells only live for about 120 days so this is why it has a time limit. Another treatment may be Iron Chelation Therapy which is used to remove excess iron from the body because the hemoglobin in red blood cells is an iron rich protein and regular blood transfusion can lead to a buildup of iron in the blood which can cause a condition called iron overload. It can damage the heart, liver and other parts of the body. This is a medicine that’s given slowly by needle under the skin attached to a small subcutaneous pump five to seven times a week for up to 12 hours. It can be mildly painful. Unfortunately deferoxamine is poorly absorbed if taken orally and can have awful side effects. Then you may also have to take folic acid supplement in addition to treatment with blood transfusion and/or chelation therapy. The problem with therapy like this is that they are life consuming and they do not ever stop. It is intensive home care for these families and patients although it does have a 90 percent chance of surviving to the age of 25 if you continue with the therapy as you should. 7. What is iron overload? What are its causes? The hemoglobin in red blood cells is an iron rich protein and regular blood transfusions or too much iron supplements can lead to a buildup of iron in the blood which can cause a condition called iron overload which can lead to hemochromatosis. This is a disorder that can result in organ damage due to high absorption and storage of iron. The iron builds up in body tissues, where it oxidizes to form compounds that poison those organs like the pancreas, liver and especially joints. 8. What are chelators? A molecule that binds to metal ion and often used in chemistry and in industrial settings is called a chelator. Chelators are used to clear excess metals such as calcium from plaque or lead and other heavy metals used in medicine. This can lead to a variety of health complication and even death. Iron chelators are commonly used in the treatment of iron overload. 9. What is chelation therapy and why is this treatment necessary to combat iron-overload? Chelation therapy is a type of treatment indicated to remove excess iron from the body. Desferrioxamine is the primary FDA approved prescription medication used to treat this. The drug does not absorb in the digestive tract and therefore must be given through injections or through an infusion pump in small doses over time. The major goal of iron chelation therapy is to prevent heart attacks.