Sickle cell & bull; hello healthy

Definition

What are sickle cells?

The sickle cell test is a blood test that is done to check for the nature of sickle cell or sickle cell disease. Sickle cell disease is a congenital blood disease that causes a change in the shape of the red blood cells (shaped like a crescent moon). Changes in red blood cells occur because they contain abnormal hemoglobin, which is called hemoglobin S, not normal hemoglobin, hemoglobin A.

Sickle blood cells are destroyed by the body faster than normal blood cells. This causes anemia. Sickle cells can also become trapped in blood vessels and reduce or block blood flow. This can damage organs, muscles, and bones and can lead to life-threatening conditions.

The best way to check the nature of sickle cell or sickle cell disease is to look at the blood using a method called high-performance liquid chromatography (HPLC). This test identifies the type of hemoglobin present. To confirm the HPLC results, genetic testing can be done.

Sickle cell disease is an autosomal recessive disease. This means that to get the disease, a person must inherit the gene for the disease from both parents. Each person inherits two genes (one from each parent). As a result, a person may have:

• the two genes that make normal hemoglobin (hemoglobin A). These people have normal red blood cells, unless they have some other disease
• one of the genes that make hemoglobin A and one that makes hemoglobin S. These people carry the sickle cell trait (and are called "carriers"), but they do not have sickle cell disease. This sickle cell trait is usually in a benign condition.
• the two genes that make hemoglobin S. This person has sickle cell disease. Both parents may carry sickle cell trait or have the disease. Sickle red blood cells often carry a recurring problem known as a sickle cell crisis.
• one of the genes that make hemoglobin S and one that makes several other types of abnormal hemoglobin. Depending on other types of normal hemoglobin, these people may have mild or severe sickle cell disorder.

When should I have sickle cell?

Newborns should be checked for sickle cell disease immediately after birth. Early testing helps ensure that babies with sickle cells receive prompt treatment to protect their health.

Immigrants from abroad who have not been tested, or children who have not been tested, can also have sickle cell testing as a precaution.

One or more sickle cell tests may be done to help diagnose sickle cell disease if you have symptoms and / or complications such as:

• pain due to sickle cell crisis. The most common symptom of sickle cell disease is a painful occurrence that can last for a long time. The pain can occur all over the body and often involves the bones, joints, lungs, and stomach
• anemia. Sickle cell disease is hemolytic anemia, which means abnormal, sickle red blood cells break down (hemolyze) faster than normal red blood cells and cannot be replaced by the body as quickly as needed, leading to a decrease in the number of red blood cells and reduced ability of the cells. red blood to transport oxygen throughout the body
• an increasing number and frequency of infections, particularly pneumonia, which is the leading cause of death in children with sickle cell disease
• cough, chest pain, and fever are thought to be caused by a serious complication of sickle cell disease called acute chest syndrome

Precautions & warnings

What should I know before having sickle cell?

Sickle cell anemia symptoms and complications will vary widely from person to person, even within the same family. Recent blood transfusions, usually within the last three months of the test date, can cause false negative test results with some tests (for example, the Hb S solubility test) because normal red blood cell transfusions reduce the relative amount of hemoglobin S present in a person's system. who are affected.

People with sickle cell traits are generally healthy, but those who exercise vigorously such as athletes, and those who are exposed to dehydration or extreme altitude, sometimes experience symptoms of sickle cell anemia. Sickle cell carriers produce both Hb A and some Hb S. When they are subjected to significant stresses that reduce the amount of oxygen in the body, red blood cells containing Hb S can become sickle.

Process

What should I do before having the sickle cell test?

No preparation is required for this test. Be sure to tell your doctor if you have had blood transfusions in the past 4 months as they may interfere with the test results.

How is the sickle cell test process?

For the sickle cell test, you will need to provide a blood sample, which is usually taken from one of the blood vessels in the regular blood test. An elastic belt will be tied around your upper arm to cause the vein to swell with blood. Then, the needle will be gently inserted into the vein. Blood will naturally flow into the tube attached to the needle. When there is enough blood for the test, the health care professional will take a needle and cover the puncture site with a bandage.

When the test is done on babies or very young children, technicians can use a sharp instrument called a lancet to prick the skin in the heel or finger, and collect blood onto a test slide or strip.

What should I do after having the sickle cell test?

You will be given a date to get your test results. Your doctor will explain what your test results mean. Sometimes, your doctor may ask for further tests. Follow the doctor's instructions carefully.

Explanation of the Test Results

What do my test results mean?

The range of normal values ​​may vary slightly between different laboratories. Some laboratories use different measurements or test different samples. Talk with your doctor about what your specific test results mean.

Normal: there is normal hemoglobin

Abnormal: there is abnormal hemoglobin

In the sickle cell nature, there is more than half of normal hemoglobin (hemoglobin A) and less than half abnormal (hemoglobin S).

In sickle cell disease, nearly all of the hemoglobin is hemoglobin S with some hemoglobin called hemoglobin F. In infants, the sickle cell blood test can be repeated at 6 months of age, or a genetic information (DNA) test can be performed.