Sickle Cell Disease Overview
All red blood cells (erythrocytes) contain a protein called hemoglobin. This protein allows the blood cells to carry oxygen to the body’s tissues.
Sickle cell disease is an inherited blood disorder in which the body produces red blood cells with abnormal hemoglobin, known as hemoglobin S (HbS).
Sickle cell disease is a lifelong condition; people with sickle cell disease have it from birth, inheriting two genes for the abnormal, sickle hemoglobin — one from each parent.
Who Sickle Cell Disease Affects
Over 70,000 Americans, and millions globally, have sickle cell disease and suffer from its complications.
While sickle cell disease typically affects those with African heritage and Hispanics with Caribbean ancestry, other heritages found to carry the trait include:
- Indian
- Mediterranean
- Latin American
- Native American
- Middle Eastern
Sickle Cell Anemia
When your red blood cell count is lower than normal, your doctor will refer to the condition as anemia. Sickle cell anemia is the most common form of sickle cell disease.
Healthy red blood cells versus sickle cells
- Have a disc-like shape with a concave center — much like a doughnut without a hole.
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- Have a crescent or sickle shape.
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- Glide easily through blood vessels.
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- Stick together in clumps and become lodged in blood vessels.
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- Carry oxygen to all parts of the body and remove carbon dioxide.
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- Block the flow of healthy, oxygenated blood to the body’s organs and tissues.
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- Have a life cycle of about 120 days. The bone marrow constantly makes new red blood cells to replace the ones that die.
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- Only live for 10 to 20 days. The bone marrow cannot produce red blood cells quickly enough to replace the dying sickle cells.
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Healthy red blood cells (view larger image)
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Multiple sickle cells (view larger image)
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The signs and symptoms of sickle cell disease involve those associated with anemia in general and pain.
Complications from sickle cell disease cause other types of symptoms.
Sickle Cell Trait
People with the sickle cell trait (HbAS):
- Carry only one sickle cell gene, the HbS gene.
- Also have the gene for normal hemoglobin, HbA.
- Don’t have symptoms of sickle cell disease, but can pass the trait on to their child. If the other parent also passes the HbS gene trait to their child, that child will have sickle cell disease.
In rare cases, people with sickle cell trait can develop complications similar to those of sickle cell disease.
Factors that may increase this risk, include:
- Severe dehydration
- Extreme physical exertion
- Exposure to very high altitude
Sickle Cell Gene Variations
The various sickle cell gene variations cause different forms of the disease. All forms can cause an individual to suffer complications associated with it.
Sickle cell hemoglobin S disease or homozygous SS disease
With this variant, the person has no (or very little) normal hemoglobin (HbA). Doctors refer to this gene variation as HbSS.
Unfortunately, it's the most common and most severe type of sickle cell disease.
Sickle cell hemoglobin C disease
People with this type have both HbS and HbC (HbSC) and don’t suffer symptoms of sickle cell anemia.
But, when the HbS and C genes combine, people will develop sickle cell disease. Sickled cells will block blood vessels (vaso-occlusions), resulting in organ damage and other complications commonly associated with HbSS.
Sickle cell hemoglobin E disease
Common in populations of Southeast Asia, people with this variant may not exhibit any symptoms, or they may experience mild to moderate anemia symptoms.
Hemoglobin S-beta-thalassemia
When a person inherits the gene for thalassemia along with the gene for sickle cell disease, they have this form of the disease.
It generally causes milder symptoms than those associated with sickle cell disease, but can also cause severe symptoms and complications as dangerous as those of sickle cell disease.
Anyone who has sickle cell disease should seek care from a health care facility with a specialized adult sickle cell disease program. Contact the UPMC Adult Sickle Cell Disease Program at 412-692-4724 to schedule an appointment.
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Sickle Cell Disease Diagnosis
Sickle cell disease is an inherited blood disorder usually diagnosed at birth. Most people with the disease begin to show symptoms by 4 months of age or shortly thereafter.
Adult sickle cell disease can cause the same signs and symptoms as in children.
Early diagnosis is crucial, so doctors can take measures to ease some of the devastating effects of sickle cell anemia. Preventive steps can significantly increase life expectancy and decrease the risk of infection or other complications of sickle cell disease.
At UPMC's Adult Sickle Cell Disease Program, we're here to help you take those steps to manage your adult sickle cell disease.
Signs and Symptoms of Adult Sickle Cell Disease
Although the signs and symptoms of sickle cell disease vary from person to person, most people experience anemia-like symptoms and pain.
Anemia symptoms associated with adult sickle cell disease
Common symptoms include:
- Fatigue (feeling weak and unusually tired)
- Dizziness
- Headaches
- Cold hands and feet
- Jaundice (yellow tinted skin or whites of eyes)
- Unusually pale skin and mucous membranes (tissue inside the nose, mouth, and elsewhere inside the body)
Pain symptoms associated with sickle cell anemia
Individuals with sickle cell anemia often experience sudden, intense pain throughout the body. These vaso-occlusive crises occur when sickle cells block the proper flow of blood to the extremities (i.e. arms and legs) and organs.
These crises can affect any area of the body, but often involve the:
- Lungs
- Abdomen
- Bones
- Joints
Although the pain is most often acute — lasting for a relatively short time, such as hours to several days — some people experience chronic pain. Chronic pain can endure for weeks or months.
Coping with this pain may cause mental exhaustion and diminish a person’s ability to engage in normal daily activities.
Repeated bouts of sickle cell crises can permanently damage organs. This damage occurs more frequently in adults than in children.
Some things that can contribute to a sickle cell crisis include:
- Dehydration
- Infection
- Menstruation
- Sudden changes in temperature
While you can’t control all factors that may cause a sickle cell crisis, you can take preventive measures to reduce the risk of sickle cell complications.
Common Complications of Adult Sickle Cell Disease
Some adults with sickle cell disease may develop complications and experience associated symptoms.
Pulmonary hypertension
Sickle cells hemolyze inside blood vessels in the lungs, causing them to narrow and making it difficult for the heart to pump blood through the lung system. This causes blood pressure to rise in the lungs' blood vessels, resulting in pulmonary hypertension (PH). Primary symptoms include fatigue and shortness of breath. At UPMC, our adult sickle cell disease patients receive the latest PH treatments available through our Comprehensive Pulmonary Hypertension Program.
Acute chest syndrome
This life-threatening condition is a form of lung injury linked directly to sickle cell anemia. Causes of acute chest syndrome include blockage of the blood vessels in the lungs by sickle cells or bone marrow fat, or an infection like pneumonia.
Multiple episodes may result in permanent lung damage. Treatment often requires emergency transfusion of normal blood.
Signs and symptoms may include:
- Chest pain
- Shortness of breath
- Fever
- Abnormal chest x-ray
Stroke
People with sickle cell disease are at risk for two types of stroke.
The first, occurring more frequently in children than in adults, happens when a blood vessel in the brain becomes damaged or blocked with sickle cells. The other occurs when a blood vessel in the brain ruptures.
Both types of stroke can result in permanent brain damage, paralysis, or death.
Priapism
This painful condition occurs when sickle cells obstruct blood flow out of the erect penis.
Untreated, priapism can damage penile tissue and lead to permanent impotence.
Leg ulcers
These ulcers occur on the lower third of the leg around the ankle bones. An individual may develop one or several ulcers; they cause severe pain and often take months to heal.
Experts don’t have a clear understanding why sickle cell ulcers develop, but they happen more in people with hemolytic anemia and pulmonary hypertension.
Splenic crisis
Damage to the spleen begins at 6 months of age. A splenic crisis occurs when the spleen becomes blocked with sickle cells. The spleen may enlarge and cause intense abdominal pain.
Depending on the type of splenic crisis, either the spleen swells full of blood or the blocked blood flow causes damage and death to parts of the spleen. Loss of splenic function increases the risk of serious blood infections.
Multiple organ failure
While multiple organ failure rarely occurs in adults with properly managed sickle cell disease, it is a serious complication. It can occur during an unusually intense and severe pain crisis.
Common symptoms include:
Tests for Diagnosing and Monitoring for Sickle Cell Disease
At the UPMC Adult Sickle Cell Disease Program, we will obtain a complete medical history and conduct a physical exam. We may also discuss your family history and review newborn screening results.
Tests may include:
- Sickle cell test (sickledex or Hgb S test) — Determines if you have the abnormal hemoglobin that causes sickle cell trait and sickle cell disease.
- Hemoglobinopathy test — Checks for hemoglobin abnormalities (many states include this in routine newborn blood screening tests).
- Hemoglobin electrophoresis — Determines the specific type of abnormal hemoglobin present and at what levels it exists in the blood stream. Abnormal test results may indicate sickle cell disease or another hemoglobinopathy.
- Echocardiogram (Doppler ultrasound of the heart) — Screens for pulmonary hypertension.
Adult sickle cell disease requires ongoing monitoring and treatment, even when you feel healthy. Contact the UPMC Adult Sickle Cell Disease Program at 412-692-4724 to schedule an appointment.
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Adult Sickle Cell Disease Treatment
Sickle cell disease is a lifelong condition that requires close monitoring by health care providers who specialize in managing and treating adult sickle cell disease.
The team at UPMC's Adult Sickle Cell Disease Program in Pittsburgh, Pa., has this expertise. We use a holistic treatment approach, focusing on both the medical and psychosocial needs of our patients.
The primary goals of adult sickle cell disease treatment are to control symptoms and reduce the number of pain crises.
Monitoring People with Adult Sickle Cell Disease
Testing the bilirubin and serum creatinine levels in your blood can help us better manage your sickle cell disease.
Bilirubin
People with sickle cell anemia are at risk for developing jaundice and painful gallstones (caused by too much bilirubin) because their red blood cells die much more rapidly than those of healthy individuals. We monitor bilirubin so we can take measures to lower your levels and reduce your chance getting gallstones.
Serum creatinine
This test evaluates kidney function. People with sickle cell disease can experience diminished kidney function and intense pain when sickle cells block tiny blood vessels in the kidneys. When the kidneys are not functioning properly, creatinine levels in the blood rise.
Other blood tests for monitoring the health of adults with sickle cell disease include:
- Blood oxygen level test
- Complete blood count (CBC)
- Serum potassium
Treatments for People with Adult Sickle Cell Disease
To manage pain and other common complications of sickle cell disease, we offer the following treatments at the UPMC Adult Sickle Cell Disease Program:
| Pain crises |
- Blood transfusions
- Pain medications
- Fluids
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| Acute chest syndrome |
- Hydroxyurea — A new treatment that may help reduce the need for frequent blood transfusions and diminish the frequency of acute chest syndrome and pain crises.
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| Pulmonary hypertension (PH) |
- UPMC's Comprehensive Pulmonary Hypertension Program offers a number of treatment options for adults who have sickle cell disease with PH (high blood pressure in the lungs), or whose lungs have become damaged by multiple incidents of sickle cell blockage.
- Support groups help people with adult sickle cell anemia cope with the psychosocial aspects of PH and provide a venue to discuss new treatments and medical information.
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| Stroke |
- Frequent blood transfusions
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| Gallstones |
- Surgery to remove the gallbladder
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Sickle cell leg ulcers |
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| Kidney disease due to multiple vaso-occlusive episodes involving the renal system |
- Kidney dialysis
- Kidney transplant therapies
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| Avascular necrosis of the hip (death of the hip bone due to poor blood supply) |
- Hip replacement surgery
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| Eye problems |
- Laser surgery. The retina can become damaged when sickle cells block blood vessels of the eye. Laser surgery can treat the damaged area and prevent further vision loss.
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Other sickle cell disease treatments and support services
- Bone marrow and stem cell transplants — Although these therapies have the potential to cure sickle cell disease, they are currently not an option for the majority of people with sickle cell disease. Frequently, people with sickle cell disease cannot locate well-matched stem cell donors.
- Support services for adults with sickle cell disease — We offer counseling to address emotional and social complications. We also provide treatment for the overuse or abuse of narcotic pain medications used to alleviate the intense pain that occurs during pain crises.
Preventive Measures for Managing Adult Sickle Cell Disease
Here are some other ways you can manage your adult sickle cell disease to help prevent complications.
To reduce the risk of infection:
- Take prophylactic antibiotics, such as penicillin
- Stay up to date on certain vaccinations, especially:
- Haemophilus influenzae vaccine (Hib)
- Pneumococcal conjugate vaccine (PCV)
- Pneumococcal polysaccharide vaccine (PPSV)
Be sure to stay hydrated and take a folic acid vitamin supplement every day. The body needs folic acid to produce red blood cells.
Contact the UPMC Adult Sickle Cell Disease Program at 412-692-4724 to schedule an appointment.
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