Recent research on sickle cell anemia has shown how improving nitric oxide production can make a significant difference in symptom severity. I’ve written about this in my article “Nitric Oxide and Sickle Cell Anemia!” The purpose of this article is to provide a basic understanding of this genetic disease.
Although African Americans are affected the most by sickle cell disease, it can affect Mediterranean, Middle Eastern, and Asian Indian ancestry. There is a growing segment in the Latino-American population particularly those of Caribbean, Central American, and South American ancestry who are also affected by this disease.
In the United States one out of every 400 births has this disease. The most common type of sickle cell disease is sickle cell anemia.
Definition and Description of Sickle Cell Disease
Sickle cell disease is a group of inherited blood disorders that center on red blood cells. These red blood cells can function abnormally resulting in small blood clots, chronic anemia, painful events, and potential complications associated with tissue and organ damage. These blood disorders include sickle cell anemia, Mediterranean blood disease, and the sickle beta thalassemia syndromes.
All types of sickle cell disease are caused by a genetic change in the hemoglobin portion of the red blood cell. Hemoglobin is the oxygen-carrying protein inside the red blood cell. Normal red blood cells are oval and flexible. Red blood cells in sickle cell disease have a tendency to reshape themselves into rod-like structures that resemble the curved blade of a sickle; thus, the term sickle cell.
Sickle cells have a shorter life span than normal red blood cells. This results in chronic anemia and reduced oxygen to the tissues of the body. Sickle cells are sticky and less flexible than normal red blood cells. This presents a problem since they can be trapped in the small blood vessels preventing proper blood flow to the tissues. This compromises the delivery of oxygen and results in tissue pain. It also has the potential to damage the associated tissues and organs.
Carriers of the sickle cell gene are referred to as having sickle cell trait. Most of the time sickle cell trait does not cause health problems. In fact, sickle cell trait can be beneficial because it provides protection against malaria, a disease caused by blood-borne parasites transmitted through mosquito bites. It is estimated that one in 12 African-Americans has sickle cell trait.
The Cause of Sickle Cell Disease!
The hemoglobin molecule of a red blood cell is made up of three components:
- Alpha or alpha-like globin
- Beta or beta-like globin.
Sickle cells contain a genetic change in the beta globin component of the hemoglobin molecule. This is caused by a change in the genetic coding on chromosome 11. One small change in a single DNA nucleotide results in a different amino acid being inserted into the beta globin protein of the hemoglobin molecule. This results in the unique properties of sickle cells. For simplicity we will call this altered gene the “sickle cell gene” and the regular gene the “normal red blood cell gene.”
For most individuals, they have two copies of the “normal red blood cell gene” to produce normal beta globin resulting in typical red blood cells. Individuals with sickle cell trait have one “normal red blood cell gene” and one “sickle cell gene” so they produce both normal red blood cells and sickle cells in roughly equal proportions. Because of this they do not usually experience significant health problems as a result of having sickle cell trait. Those with sickle cell anemia have two “sickle cell genes.”
Genetics play a significant role in both the disease, symptoms, and in family planning. If both members of a couple have sickle cell trait, then there is a 25% chance in each pregnancy for the baby to inherit two sickle cell genes. The resulting child will have sickle cell anemia. Correspondingly, there is a 50% chance the baby will have sickle cell trait and a 25% chance that the baby will have the “normal red blood cell genes”.
If both members of a couple have sickle cell anemia, then the baby will have sickle cell anemia 100% of the time. If one member of the couple has sickle cell anemia and the other has both “normal red blood cell genes”, then the resulting child will have sickle cell trait 100% of the time. Finally, if one member of the couple has sickle cell trait and the other has both “normal red blood cell genes”, then the resulting child has a 50% chance of having normal red blood cell hemoglobin or a 50% chance of having sickle cell trait.
The Need for Oxygen!
Oxygen is necessary for life and the optimal function of all cells. Red blood cells transport the oxygen from your lungs to the tissues of your body. It’s the hemoglobin molecule that binds oxygen to itself in the lungs. It then releases oxygen to the tissues for proper cell respiration. However, once the oxygen is released by the sickle cell hemoglobin it can cause the red blood cell to alter its normal oval shape into the rigid, sickle shape characteristic of sickle cells. Low oxygen can be a trigger for this change. Studies also seem to indicate that cold temperatures and dehydration can be additional factors in triggering this change.
Normal red blood cells can survive for approximately 120 days where as sickle cells typically last 10-12 days. This is an important factor because it leaves the bloodstream chronically short of red blood cells and hemoglobin which leads to anemia. This creates its own shortage of oxygen which could trigger a shape change in the oval red blood cell to the sickle shape. This rigid, sickle shape causes circulation problems especially in small blood vessels.
In addition, there are altered chemical properties that develop which increases the cells’ “stickiness”. This is why sickle cells tend to adhere to the inside surfaces of small blood vessels, as well as other blood cells, resulting in blockages. These blockages prevent oxygenated blood from reaching the tissues resulting in pain. If kept without oxygen long enough possible organ and tissue damage can occur.
Symptoms of Sickle Cell Anemia!
Common symptoms for those with sickle cell anemia include the following:
- Bloody urine
- Bone and/or abdominal pain
- Chest pain
- Delayed growth and delayed puberty
- Excessive thirst
- Fatigue, breathlessness, rapid heart rate
- Frequent urination
- Increased susceptibility to infections, fever
- Pain which can vary from moderate to intense
- Paleness, yellow eyes and/or skin, jaundice
- Poor eyesight or blindness
- Ulcers on the lower legs usually in adolescents and adults
For those with sickle cell anemia, the severity of symptoms varies widely and cannot be predicted solely on genetic inheritance. Some with sickle cell anemia develop health and life threatening problems in infancy while others only have mild symptoms throughout their lives. Others experience various degrees of health issues as they age. Certain variations of sickle cell disease tend to have less severe symptoms than other types of sickle cell disease.
Organs Affected by Sickle Cell Anemia
Various organs and body systems can be effect by sickle cell disease. As you will see from this list, sickle cell anemia has a wide range of effects on the body. The bottom line is that any tissue that needs oxygen and adequate blood flow can be at risk.
- Acute Chest Syndrome – Acute chest syndrome or ACS is a leading cause of death for those with sickle cell disease. It takes place in the lungs. Rapid diagnosis and treatment is very important. ACS can occur at any age. It is similar to pneumonia in symptoms but distinct in its damage.
- Anemia – As we learned early, sickle cells have a life span of 10-12 days resulting in a deficiency of red blood cells in the bloodstream. It is the hemoglobin of red blood cells that carry oxygen, so with this deficiency there is a reduction in oxygen to the tissues. Common symptoms of anemia include fatigue, paleness, and a shortness of breath. The heart rate will increase. This circulates more blood helping to make up for the lack of oxygen to the tissues.
- Delayed Growth – Because of the short life span of sickle cells, the demands on the bone marrow to produce more red blood cells compete with the demands of a growing body. Children with sickle cell anemia may experience delayed growth and reach puberty at a later age. However, by early adulthood, they catch up on growth and height but may still remain below average in weight.
- Infections and the Spleen – Children under the age of three with sickle cell anemia are particularly susceptible to life-threatening bacterial infections especially from Streptococcus pneumoniae. Unfortunately, 15% of these types of cases result in death. Since your spleen helps to fight bacterial infections, it is particularly vulnerable. For those with sickle cell anemia, it is not uncommon to see the loss of spleen function by late childhood.
- Jaundice and Gallstones – Jaundice is indicated by a yellow tone in the skin and eyes due to increased levels of bilirubin. Bilirubin is the final product of hemoglobin degradation when red blood cells are destroyed. Bilirubin is removed from the bloodstream by the liver. Elevated levels can increase the chance for gallstones.
- Joint Problems – The blood supply to the connective tissues, especially in the hip and shoulder joints, can be blocked by the sickle cells resulting in bone damage and poor healing. This complication can affect an individual’s physical abilities and result in substantial and chronic pain.
- Kidney Disease – Kidneys are particularly prone to damage from sickle cells. Adults with sickle cell disease often experience reduce kidney function which can progress to kidney failure.
- Painful Events – This is the hallmark symptom of sickle cell disease. The frequency and duration varies tremendously from individual to individual and over an individual’s lifetime. These painful events are also the most common cause for hospitalization. This hallmark symptom results when the small blood vessels become blocked by the sickle cells preventing oxygen from reaching the tissues. Although pain can affect any area of the body, the most frequent sites are the extremities, chest, abdomen, and bones.
- Priapism – Only males have to deal with this since it is a condition characterized by a persistent and painful erection. Blood vessels become blocked by sickle cells so that blood is trapped in the tissue of the male’s organ. It’s extremely painful and can result in damage to this tissue causing impotence.
- Retinopathy – The blood vessels that support the tissue at the back of the eye may be blocked by sickle cells resulting in this condition. Regular ophthalmology evaluations and effective treatment can help a person avoid permanent damage to their vision.
- Stroke – This is the most concerning complication of sickle cell disease. Approximately 11% of individuals with sickle cell anemia will have a recognizable stroke by the age of 20. A stroke in a person with sickle cell disease is usually caused by a blockage of a blood vessel in the brain by the sickle cells. This results in lack of oxygen to the affected area of the brain. The consequences are far ranging from undetectable effects, to apparent or subtle learning disabilities, to severe physical or cognitive impairment, to life-threatening situations.
Diagnosis and Treatment of Sickle Cell Anemia
The inheritance of sickle cell disease or sickle cell trait cannot be prevented but it can be predicted so screening is recommended. If you exhibit symptoms, then contact your physician so that accurate tests can be done. These tests can determine if you carry the “sickle cell gene” and what level of risk you are at. For newborns, more than 40 states include sickle cell screening as part of the battery of blood tests. However, don’t just assume the test is done. You must always be proactive.
Hemoglobin trait screening is always a good choice for any person of a high-risk ethnic background especially if you are planning on having children. If you and your partner are found to have sickle cell or any other hemoglobin traits, then you might want to receive genetic counseling to better understand the risk of sickle cell disease for your offspring. There are various testing options available to you to help you in your planning.
There are various treatment options to help prevent some of the symptoms and complications of sickle cell disease. These treatment options can include:
- Access to comprehensive health care
- Adequate nutrition
- Avoiding stresses and infection
- Blood transfusions
- Bone marrow transplantation
- Getting proper rest
- Good hydration
- Pain management
- Proper immunizations
- Supplementation with folic acid
- Support groups
- Use of preventative antibiotics
As with any disease condition, you want to always work with a qualified health professional to develop a course of action that best fits your individual situation.
New Research on Nitric Oxide!
There is new research that shows a direct correlation between nitric oxide deficiency and symptom severity for those with sickle cell anemia. I will discuss this in my companion article “Sickle Cell Disease – 14 Helpful Steps!” This article discusses the latest research. It also provides 14 suggestions you can use to help those with sickle cell disease.
I hope this article has given you a better understanding of sickle cell anemia. I encourage you to take the steps to educate yourself and any loved ones who may have this health issue. We can help empower them to take the necessary steps to improve their overall health and wellness.
Together we can work to save a million lives!