The shape of sickle cell blood cells resembles a curved blade knife called a sickle. These cells are stiff and inflexible, so they cannot move through small blood vessels as easily as healthy red blood cells.
Sickled cells can become stuck in blood vessels and block the blood flow, leading to pain and other health problems.
A group of inherited health conditions called sickle cell disease (SCD) causes a person to have sickle cell blood cells. SCD is the
Keep reading to learn more about sickle cell blood cells and how they are different than normal red blood cells.
Usually, red blood cells are round and flexible. They contain an iron-rich protein called hemoglobin, which allows them to carry oxygen to all parts of the body.
Sickle cell blood cells resemble a curved, crescent-shaped farm tool called a sickle. These cells contain abnormal hemoglobin molecules called hemoglobin S (HbS), which may be responsible for distorting them into the sickle shape.
This distortion means that they are stiff and inflexible and cannot move through small blood vessels as easily as healthy red blood cells. As a result, they can become stuck.
What effect do they have on the body?
When the cells stick, they
The ischemia has various effects, including:
- elevated HbS formation
- the release of inflammatory mediators that can cause significant inflammation
- the formation of damaging free radicals, molecules that can injure the cells of the body
These processes result in reperfusion injury. This refers to damage that occurs when the blood supply returns to the body’s tissues after a period of ischemia.
Due to these effects, a person may experience pain, organ damage, and other health complications. In addition, sickle-shaped red blood cells can die prematurely, leading to anemia.
Learn more about sickle cell anemia and the symptoms it can cause.
The main difference between sickle cell blood cells and typical blood cells is the type of hemoglobin they contain.
Hemoglobin consists of four protein chains, typically two of alpha-globin and two of beta-globin.
Abnormal hemoglobin in sickle cells
The sickle cell mutation occurs when a genetic change causes a change in the amino acids within one of the four protein chains in hemoglobin. Namely, an amino acid called valine, which is neutral, replaces one called glutamine, which is negatively charged.
This switch leads to changes in the physical properties of the protein chain and the shape of the red blood cell.
Genetic mutations cause sickle cell disease, specifically changes in the HBB gene. This gene contains the code for the production of beta-globin.
Different mutations can cause various versions of beta-globin to develop. In people with sickle cell anemia, HbS replaces both beta-globin subunits. Sickle cell anemia is typically the
In other types of SCD, HbS replaces only one beta-globin subunit. A different abnormal hemoglobin variant may replace others. For example, individuals with sickle-hemoglobin C (HbSC) disease have hemoglobin containing HbS and HbC instead of the typical beta-globin.
These abnormal versions of beta-globin distort the red blood cells and can lead to serious medical complications.
Sickle cell anemia does not directly affect white blood cells by changing their shape or function. However, the presence of sickle cells can lead to an
People with SCD who develop complications may have higher white blood cell counts than asymptomatic people. Doctors recognize that high white blood cell counts are a major risk factor for hospital admission and frequent emergency department visits.
Doctors can also use white blood cell count as an accurate test for detecting a condition called acute chest syndrome in people with SCD. This is one of the complications associated with the disease.
Learn more about the link between SCD and acute chest syndrome.
Sometimes, doctors may diagnose SCD while the baby is in the womb if they are performing tests to check for chromosomal or genetic abnormalities. These tests include chorionic villus sampling, which tests a small piece of the placenta, and amniocentesis, which tests a small sample of the amniotic fluid surrounding the baby.
SCD is an inherited disorder that runs in families. People with SCD inherit one abnormal hemoglobin gene from each parent. If they inherit only one gene, they have sickle cell trait. This means that they are generally healthy but can pass the sickle cell gene on if they have children.
Many people from Hispanic, southern European, Middle Eastern, or Asian Indian backgrounds may also have an increased risk of developing SCD.
Sickle cell blood cells are crescent-shaped and contain abnormal hemoglobin. They can appear because of genetic changes to the hemoglobin in the blood. People with sickled cells may have a condition called sickle cell disease, which runs in families.
The sickle cells are stiff and inflexible, so they cannot move through small blood vessels as easily as healthy red blood cells and can become stuck. Their lifespan is also shorter.
Due to these abnormalities, people with SCD may experience pain, organ damage, and other serious health problems.