What is Sickle Cell Anemia?
Red Blood Cells and Anemia
Anemia is a very common condition in which the patient does not have enough red blood cells circulating through their body. Red blood cells are mostly comprised of hemoglobin. Hemoglobin is the protein in red blood cells that gives the red blood cells their red color. More importantly, hemoglobin carries oxygen from the lungs to every organ and tissue in the body. The cells that make up these organs and tissues take in the oxygen from the hemoglobin (contained in the red blood cells) and release carbon dioxide, which the hemoglobin picks up and carries back to the lungs where it is released through exhaling. Normal Hemoglobin is called Hemoglobin A (HbA). Normal red blood cells are round, shaped like a doughnut, but only indented in the center, not an actual hole. These cells are smooth and flexible and easily flow through the blood stream. They live about 120 days. When a person is anemic, there is a lack of hemoglobin or red blood cells. This can be caused by various reasons, and there are several types of anemia.
Red Blood Cells and Sickle Cell Anemia
One type of anemia is Sickle Cell Anemia. Sickle Cell Anemia is one of the most common types of Sickle Cell Disease. In people who have Sickle Cell anemia, the hemoglobin contained within the red blood cells is abnormal. The hemoglobin found in Sickle Cell is called Hemoglobin S (HbS). The abnormal hemoglobin causes the red blood cells to have a sickle shape, more like a crescent roll than a doughnut. These sickle shaped cells become stiff and sticky and tend to clump together; therefore, they are not able to easily pass through the blood stream. These clumps of sickle cells can not pass into the smaller blood vessels and therefore can not carry oxygen to those parts of the body. Another abnormality of the sickle cell is that they only live about 10 to 20 days (on average 16 days), unlike the normal red blood cells that live 120 days. Because they have such a short life span, red blood cells become low because the bone marrow that makes them can not produce them fast enough to make up for the ones that are dying so quickly.
Sickle Cell disease is caused by a genetic mutation. This genetic mutation is believed to have originated where malaria was most common, such as the Mediterranean areas of Europe and Africa, because people with Sickle Cell Disease do not get malaria. The mutation in the gene actually protects them from this disease carried by mosquitoes. (Information from the Childrens Hospital of Michigan website).
Sickle Cell Anemia vs. Trait
Sickle Cell Anemia is a serious lifelong disease that is genetically inherited the same way that hair and eye color is. The hemoglobin genes you get are dependent upon the types of hemoglobin genes your parents have. Like most genes, hemoglobin are also inherited in two sets. One set from each parent. If one parent has Sickle Cell Anemia and the other does not, the child will be born containing the genes to produce both Hemoglobin A (normal) and Hemoglobin S (not normal). When a person produces both types of hemoglobin, it is called Sickle Cell Trait. If one person has Sickle Cell Anemia and the other Sickle Cell Trait, the baby will have either Sickle Cell Disease or Sickle Cell Trait. If both parents have Sickle Cell Trait (meaning they each have one HbA and one HbS gene) there is a 1 in 4 chance that the child could have Sickle Cell Disease. The possibility of gene combinations received from the parents would be one of the following.
HbA/HbA = Normal, HbS/HbS = Sickle Cell Disease, HbS/HbA = Sickle Cell Trait, HbA/HbS = Sickle Cell Trait.
Based on those combinations there is a 25% chance of Sickle Cell Disease, and a 50% chance of Sickle Cell Trait, but there is also a 25% chance that the child could be born with normal hemoglobin genes
Symptoms and Complications
Sickle Cell Anemia is a very serious disease for which there is no available cure known. In a very few cases, bone marrow transplants may offer a cure. Through treatment improvements over the years, people with this disease are now living into their forties. Some have reported patients living in to their 50s. The disease can cause a variety of symptoms and complications. These symptoms can vary in severity and duration depending on the patient. Through modern treatments those with Sickle Cell Anemia have seen an improvement in quality of life, experiencing reasonable health for a majority of the time.
When the damaged cells cluster together they can not make their way through the blood stream. This creates blockages and blood and oxygen are not getting to all parts of the body. These blockages of sickle cells are what cause the pain and complications to the patients. The more severe symptoms are seen in those patients with Sickle Cell Anemia because they have most or all abnormal hemoglobin. The following is a list of the most common symptoms and complications.
Severe and chronic anemia is obviously the most common. This can lead to dehydration and fever. Severe and chronic anemia can delay growth and healing in children with Sickle Cell Disease. The blockages by these clumped sickle cells can occur anywhere in the body but are most common in the arms, legs and chest. This causes pain and swelling in these areas and risks death of the surrounding tissue due to lack of blood supply and oxygen to the tissue. When this clumping occurs in the chest, it can be life threatening as the cells are blocking oxygen from flowing in to the tiny vessels in the lungs. When this happens, it presents itself as pneumonia with pain, fever and a severe cough. If this happens too many times it could leave permanent damage. Clumping occurring in the spleen can lead to damage where the spleen can no longer filter infection from the blood and infection becomes a major health concern. Blockages of oxygen to the brain can lead to stroke. Since the red blood cells die more quickly than the liver can filter them out, jaundice can occur. Sickle Cell can affect any organ in the body. The liver, heart, kidneys, spleen, lungs, gallbladder, bones, eyes and joints can all suffer damage from the disease.
Those with Sickle Cell Trait typically do not experience a lot of symptoms or complications as they do have some normal hemoglobin. They may experience mild anemia and under severe cases of stress they may experience some of the other symptoms of Sickle Cell Disease such as fatigue, hypoxia (low oxygen) and infections that could be severe. When the body is under extreme stress the sickling of the abnormal hemoglobin may occur and cause some complications of the disease.
Treatment and care varies from patient to patient but could include any of the following:
Drink plenty of water, 8-10 glasses a day to prevent dehydration
IV fluids if dehydration occurs
Folic Acid Supplements to help decrease the severity of the anemia
Hydroxyurea, a fairly new medication to help reduce the occurrence of the pain and damage to the legs, arms and chest due to cells clumping and causing blockages. The long term affects of this medicine are not yet known.
Penicillin to help prevent infections
Other Antibiotics to treat infections that occurred
Bone Marrow Transplant
Surgery to remove gallstones, damaged spleen, etc.
Because patients with Sickle Cell Anemia often receive repeated blood transfusions there is a risk of iron building up and causing what is called Iron Overload. Because the body can not excrete iron on its own except for a very tiny amount that is dispersed through persperation or the sloughing off of the skin, but it is not enough to compensate for the excess iron from blood transfusions. Iron can reach toxic levels within the body and it is important to reduce the amount of iron in the body if it gets to high because it can collect in major organs and cause permanent damage. There are two ways to decrease iron blood levels. The first is through therapeutic phlebotomy or regularly donating blood. This treatment does not work for Sickle Cell Anemia since it removes blood (and red blood cells) from the body. The other alternative is Iron-Chelation. Chelation therapy is the method of taking medications, either orally or through an IV, that bind with the iron in the body so that it can be excreted.
Doctors and scientists are continually studying and learning about this disease. People are now living longer than they used to, some have reported in to their fifties. Hopefully soon they will find a cure!