An overview of Sickle anemia

Sickle cell anemia is a form of the inherited blood disorder, sickle cell disease. Sickle cell anemia affects your red blood cells, turning them from round flexible discs into stiff and sticky sickled cells. Sickled cells keep red blood cells from doing their job, which is carrying oxygen throughout your body. Sickled cells also don’t live as long as normal red blood cells. As a result, you don’t have enough healthy red blood cells and you develop anemia, the condition that gives sickle cell anemia its name.

Normal red blood cells can live up to 120 days. But, sickle cells only live for about 10 to 20 days. Also, sickle cells may be destroyed by the spleen because of their shape and stiffness. The spleen helps filter the blood of infections. Sickled cells get stuck in this filter and die. With less healthy red blood cells circulating in the body, you can become chronically anemic. The sickled cells also damage the spleen. This puts you are at greater at risk for infections.

Sickle cell anemia is caused by a change in the gene that tells the body to make the iron-rich compound in red blood cells called hemoglobin. Hemoglobin enables red blood cells to carry oxygen from the lungs throughout the body. The hemoglobin associated with sickle cell anemia causes red blood cells to become rigid, sticky and misshapen.

For a child to be affected, both mother and father must carry one copy of the sickle cell gene — also known as sickle cell trait — and pass both copies of the altered form to the child.

If only one parent passes the sickle cell gene to the child, that child will have the sickle cell trait. With one typical hemoglobin gene and one altered form of the gene, people with the sickle cell trait make both typical hemoglobin and sickle cell hemoglobin.

Their blood might contain some sickle cells, but they generally don't have symptoms. They're carriers of the disease, however, which means they can pass the gene to their children.

The following is a list of symptoms and complications associated with sickle cell disease. However, each person may experience symptoms differently. Symptoms and complications may include:

Anemia : Because sickled cells are short-lived or destroyed, there are less red blood cells available in the body. This results in anemia. Severe anemia can make you feel dizzy, short of breath, and tired.

Pain crisis, or sickle crisis : This occurs when the flow of blood is blocked to an area because the sickled cells have become stuck in the blood vessel. The pain can occur anywhere, but most often occurs in the chest, arms, and legs. Infants and young children may have painful swelling of the fingers and toes. Interruption in blood flow may also cause tissue death.

Acute chest syndrome : This occurs when sickling occurs in the chest. This can be life-threatening. It often occurs suddenly, when the body is under stress from infection, fever, or dehydration. The sickled cells stick together and block the flow of oxygen in the tiny vessels in the lungs. It resembles pneumonia and can include fever, pain, and a violent cough.

Splenic sequestration (pooling) : Crises are a result of sickle cells pooling in the spleen. This can cause a sudden drop in hemoglobin and can be life-threatening if not treated promptly. The spleen can also become enlarged and painful from the increase in blood volume. After repeated episodes, the spleen becomes scarred, and permanently damaged. Most children, by age 8, do not have a working spleen either from surgical removal, or from repeated episodes of splenic sequestration. The risk of infection is a major concern of children without a working spleen. Infection is the major cause of death in children younger than age 5 in this population.

Stroke : This is another sudden and severe complication of people with sickle cell disease. The misshapen cells can block the major blood vessels that supply the brain with oxygen. Any interruption in the flow of blood and oxygen to the brain can result in severe brain damage. If you have one stroke from sickle cell anemia, you are more likely to have a second and third stroke.

Jaundice, or yellowing of the skin, eyes, and mouth : Jaundice is a common sign and symptom of sickle disease. Sickle cells do not live as long as normal red blood cells and, therefore, they are dying faster than the liver can filter them out. Bilirubin (which causes the yellow color) from these broken down cells builds up in the system causing jaundice.

Priapism : This is a painful obstruction of the blood vessels in the penis by sickle cells. If not promptly treated, it can result in impotence.

The symptoms of sickle cell disease may look like other blood disorders or medical problems. Always consult your health care provider for a diagnosis.

Sickle cell anemia is an inherited disorder. You can have a blood test to find out if you have sickle cell trait that you could pass on to your children. People can have sickle cell trait without having sickle cell disease or sickle anemia.

Healthcare providers diagnose sickle cell anemia by taking blood samples. They may use a technique called hemoglobin electrophoresis or high-performance liquid chromatography. This test identifies and measures different types of hemoglobin in red blood cells, including the abnormal hemoglobin that causes sickle cell anemia. (Starting in 2007, all babies born in the United States have sickle cell anemia tests right after they’re born. Early diagnosis and treatment are why fewer babies and young children born in the United States die of sickle cell anemia.)

Right now, allogenic stem cell transplantation is the only way healthcare providers can cure sickle cell anemia and other forms of sickle cell disease. Healthcare providers typically recommend transplantation for people who have severe complications such as stroke, acute chest syndrome or recurring VOC/acute pain crises.

Healthcare providers typically treat sickle cell anemia with blood transfusions, antibiotics to treat infections and medications that reduce symptoms caused by sickle cell anemia complications. These medications may include hydroxyurea, voxlelotor, L-glutamine therapy and crizanlizumab.

Hydroxyurea (brand names Droxia®, Hydrea ®, Siklos®, Mylocel®) : Hydroxyurea (pronounced “hye drox ee ure ee a”) is an anticancer drug now used to treat sickle cell anemia. In 2017, the U.S. Food and Drug Administration (FDA) approved hydroxyurea as sickle cell anemia treatment for children age 2 and older, as well as adults.

Voxelotor (brand name Obryta®) : This medication prevents red blood cells with abnormal hemoglobin from becoming sickled cells. Voxelotor (pronounced “vox el oh tor”) may prevent some red blood cells from being destroyed faster than your bone marrow can replace them. In 2019, the FDA approved voxelotor for sickle cell disease treatment. In late 2021, the FDA approved voxelotor as treatment for children age 4 and older.

L-glutamine therapy (brand name Endari®) : L-glutamine helps reduce some of the complications linked to sickle cell anemia. Sickled cells develop over time. L-glutamine helps protect sickled cells from becoming more misshapen. In 2017, the FDA approved Endari for treatment of children age 5 and older and adults.

Crizanlizumab-tmca (brand name Adakveo®) : People with sickle cell anemia cope with sudden bouts of excruciating pain called VOC/acute pain crises. In 2019, the FDA approved crizanlizumab-tmca (pronounced “criz-l-izum-ab”) medication to treat people age 16 and older. This medication may help reduce how often VOC/acute pain crises happen.