Sickle Cell Anemia

By: | Updated on: Sep 26, 2024

An inherited form of anemia — a condition in which there aren’t enough healthy red blood cells to carry adequate oxygen throughout your body, which produces abnormally shaped red blood cells that have a crescent or sickle shape. These cells do not last as long as normal, round, red blood cells, which leads to anemia (low number of red blood cells). The sickle cells also get stuck in blood vessels, blocking blood flow. Signs and symptoms of sickle cell disease usually begin in early childhood and may include anemia, repeated infections, and periodic episodes of pain (called crises). This condition is caused by mutations in the HBB geneand is inherited in an autosomal recessive pattern. Treatment typically focuses on controlling symptoms and may include pain medicines during crises; hydroxyurea to reduce the number of pain episodes; antibiotics and vaccines to prevent bacterial infections; and blood transfusions. 
There’s no cure for most people with sickle cell anemia, but treatments can relieve pain and help prevent problems associated with the disease. On July 7, 2017, the FDA in the United States approved the use of Endari (prescription grade L-glutamine) to reduce the number of sickle cell crisis. Endari is the first FDA approved treatment that is also available for children with sickle cell disease five years of age and older.

 

 

 

 

Signs and Symptoms

  • Anemia. Sickle cells break apart easily and die, leaving you without enough red blood cells. Red blood cells usually live for about 120 days before they need to be replaced. But sickle cells usually die in 10 to 20 days, leaving a shortage of red blood cells (anemia).
  • Episodes of pain. Periodic episodes of pain, called crises, are a major symptom of sickle cell anemia. Pain develops when sickle-shaped red blood cells block blood flow through tiny blood vessels to your chest, abdomen and joints. Pain can also occur in your bones.
  • Painful swelling of hands and feet. The swelling is caused by sickle-shaped red blood cells blocking blood flow to the hands and feet.
  • Frequent infections. Sickle cells can damage an organ that fights infection (spleen), leaving you more vulnerable to infections. Doctors commonly give infants and children with sickle cell anemia vaccinations and antibiotics to prevent potentially life-threatening infections, such as pneumonia.
  • Delayed growth. Red blood cells provide your body with the oxygen and nutrients you need for growth. A shortage of healthy red blood cells can slow growth in infants and children and delay puberty in teenagers.
  • Vision problems. Tiny blood vessels that supply your eyes may become plugged with sickle cells. This can damage the retina — the portion of the eye that processes visual images, leading to vision problems.

 

Causes

This disease is genetic, and is passed down from parents. It is autosomal recessive. The HBB gene is the gene that the mutation occurs on for Sickle Cell to develop.

 

Diagnosis

For many, it begins at a front-line health care service, such as a primary care doctor’s office, urgent care center, or an emergency room. A diagnosis may become clear through these visits or only after specialized testing and referrals. In an exam of the patient the doctor will administer both a physical examination, and then the doctor will look into medical histories of the patient and their family. Depending on the results of medical history and physical exam, the doctor may then decide whether lab tests, imaging studies, clinical procedures, or referrals to other medical specialists are needed to diagnose the cause of the patient’s health problems.

 

Management Strategies / Treatments

Standard treatment is standard treatment is blood transfusions and pain management.

In terms of clinical trials, preliminary clinical data on the use of TALGlobin01 in sickle cell anemia patients were presented at The American Society of Hematology Meeting & Exposition (ASH 2021). This data indicates that the use of TALGlobin01 resulted in up to 70% of Homology Directed Repair (HDR)-mediated HBB gene correction in the hematopoietic stem and progenitor cells (HSPCs) of sickle cell anemia patients.

Some other drugs used for help managing the disease are

  • Hydroxyurea (Droxia, Hydrea, Siklos). Daily hydroxyurea reduces the frequency of painful crises and might reduce the need for blood transfusions and hospitalizations. But it can increase the risk of infections. Don’t take the drug if you’re pregnant.
  • L-glutamine oral powder (Endari). The FDA recently approved this drug for treatment of sickle cell anemia. It helps in reducing the frequency of pain crises.
  • Crizanlizumab (Adakveo). This drug, given by injection, can help reduce the frequency of pain crises in adults and children older than 16. Side effects can include nausea, joint pain, back pain and fever.
  • Voxelotor (Oxbryta). This drug is used to treat sickle cell disease in adults and children older than 12. Taken orally, this drug can lower the risk of anemia and improve blood flow throughout the body. Side effects can include headache, nausea, diarrhea, fatigue, rash and fever.
  • Pain-relieving medications. Your doctor might prescribe narcotics to help relieve pain during sickle cell pain crises.

 

 

 

Other Names

HbS disease; Hemoglobin S Disease; Sickling disorder due to hemoglobin S.

Contact the Genetic and Rare Diseases (GARD) Information Center for more information on Sickle Cell Anemia.

 

To learn more about Sickle Cell and other hematologic disorders, visit https://checkrare.com/diseases/hematologic-disorders/ and https://www.mayoclinic.org/diseases-conditions/sickle-cell-anemia/diagnosis-treatment/drc-20355882 

 

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