Shape can change your life be it your waistline, bank account, age, etc. But what is surprising is that your life can change too if your blood cell shape is not correct. Yes, we are talking about Sickle Cell Anemia, a hereditary disorder in which the shape of a red blood cell is distorted into a crescent shape from the normal disc shape. So, let’s learn more about the most common blood disorder (anemia) present in human beings.
What Is Sickle Cell Anemia?
Sickle cell Anemia is a hereditary disorder of red blood cells (RBC). Red blood cells contain hemoglobin (Hb), a protein that acts as a vector to carry oxygen. Healthy RBCs are round disc-like structures and they move through blood vessels to carry oxygen to all parts of the body. A person with sickle cell anemia has abnormal Hb, due to which the RBCs become hard and sticky and look like a C-shaped farm tool called a “sickle.” That is how it is called sickle cell anemia or sickle cell disease.
Sickled RBCs are not like normal RBCs. They are not flexible and can stick to blood vessel walls, leading to blockages which slows or stops the flow of blood. The sickle-shaped RBCs are not competent enough in delivering oxygen to the rest of the body. Lack of oxygen can cause attacks of sudden severe pain, called pain crises. These pain crises come without warning, and a person who has them often needs to go to the hospital for effective treatment.
Normal RBCs live for 90 to 120 days, on the contrary sickle RBCs can survive 10 to 20 days only. Our body produces new RBCs to replace the old ones. But, in sickle cell disease, the RBCs are being destroyed at a much higher pace due to which the RBC count is lower as compared to people without sickle cell disease. Scientifically low RBC value is termed as Anemia, therefore this condition is called Sickle Cell Anemia.
Types Of Sickle Cell Anemia
There are several types of SCD. The specific type of SCD a person has depends on the genes they inherited from their parents. These genes carry genetic codes of the abnormal Hb. Based on the abnormal Hb it is classified as
1. HbSS
In this type of SCD a person inherits two genes, one from each parent, that code for hemoglobin “S.” Hb S is an abnormal form of hemoglobin that causes the red cells to become rigid, and sickle shaped. This is commonly called sickle cell anemia and is usually the most severe form of the disease.
2. HbSC
In this form of SCD, a person inherits a hemoglobin “S” gene from one parent and a gene for a different type of abnormal hemoglobin called “C” from the other parent. This is a milder form of SCD.
3. HbS beta thalassemia
In this type of SCD, a person inherits a hemoglobin “S” gene from one parent and a gene for beta thalassemia, another type of hemoglobin abnormality, from the other parent. There are two types of beta thalassemia: “zero” (HbS beta0) and “plus” (HbS beta+). Those with HbS beta0-thalassemia usually have a severe form of SCD. People with HbS beta+-thalassemia tend to have a milder form of SCD.
There are some rare types of SCD also which includes: HbSD, HbSE, and HbSO
HbAS (Carrier Of sickle cell anemia) people who have HbAS or Sickle Cell Trait (SCT) inherit a hemoglobin “S” gene from one parent and a normal gene (one that codes for hemoglobin “A”) from the other parent. SCT usually does not have any signs of the disease; they are basically carriers of sickle cell disease. In rare cases, a person with SCT may develop health problems; usually under extreme physical stresses on the body. People who have SCT can pass the abnormal hemoglobin “S” gene on to their children.
Sickle Cell Anemia Symptoms
As it is a type of anemia. So, common symptoms are
- Fatigue.
- Irritability.
- Trouble breathing.
- Pale skin color.
- In children and young kids growth is hindered.
But the severity of anemia and its manifestation may vary. Beside these SCD is characterized by the following group of symptoms :
1. Acute Pain Crisis
Acute pain crisis also called Vaso-Occlusive crisis (VOC), is the most common reason that sends people to hospitals and emergency care suffering from sickle cell anemia. It is characterized by :
- Sudden intense unbearable pain.
- Pain can be sharp or stabbing.
- Abdomen, lower back, arms and legs are commonly affected although can occur in any part of the body.
2. Acute Chest Syndrome (ACS)
ACS is the most common cause of death as well as the second most common cause of hospitalization in sickle cell anemia patients. It happens due to clumping and clogging of blood vessels of your lungs by the sickle cells. It is characterized by symptoms given below :
- Sudden chest pain.
- Cough.
- Fever.
3. Stroke
Anyone who has sickle cell anemia is at risk for stroke, including babies. Approximately 11% of people with sickle cell anemia have strokes by age 20, and 24% have strokes by age 45. Here is information on stroke symptoms:
- Severe headache.
- Sudden weakness on one side of your or your child’s body.
- Change in alertness.
- Trouble speaking.
- Trouble seeing.
4. Spleen Sequestration
It is a complication of SCD when sickled cells become stuck in the spleen it causes spleen enlargement . It is common in children. It can be fatal too as it may cause severe acute anemia. Symptoms include:
- Pain in the left abdominal region with swelling.
- Pale skin, fatigue, dizziness, increased heart beat, etc (anemia symptoms)
5. Chronic kidney disease
Kidneys in SCD are affected in at least 30% of cases and the common manifestations of SCD includes :
- Increased frequency of urination
- Fatigue, dizziness, numbness
- Loss of appetite.
- Swollen hands, feet and ankles.
- Shortness of breath.
- Blood in urine
- Puffy eyes.
- Dry and itchy skin
- Trouble sleeping.
- Nausea or vomiting.
- Muscle cramps.
- High blood pressure.
6. Detached Retina / Retinopathy
In SCD retinas may detach due to blocking of blood vessels of your retinas. Common symptoms of detached retina are :
- Seeing flashes of light.
- Seeing many flecks, threads, dark spots and squiggly lines that drift across your vision.
- Darkening of side vision.
- Darkening or shadows covering part of your vision.
- Trouble walking due to poor vision
7. Bacterial infections
People with SCD are prone to infections caused by Streptococcus pneumoniae, Haemophilus influenzae and non-Typhi Salmonella species. The common symptoms of bacterial infections are :
- Fever.
- Coughing.
- Trouble breathing.
- Pain in bones.
- Headaches.
8. Pulmonary hypertension (PH)
About 6% to 11% of people with sickle cell anemia develop pulmonary hypertension. Symptoms include:
- Racing pulse.
- Fainting (passing out) or dizziness.
- Feeling short of breath during exercise or activity and difficulty breathing when at rest.
9. Priapism
Priapism or painful erections that last four hours or more are seen in males. This happens due to blockage of blood vessels of the penis.
10. Leg ulcers
Leg ulcers can occur after age 65 and are more common in males. Symptoms are painful ankle sores that don’t heal.
Causes Of Sickle Cell Anemia
As discussed SCD is a genetic inherited disorder. In SCD the gene for normal Hb (HBB) is mutated and results in HBS, the mutated Hb. This mutated Hb results in sickle shape of RBCs thus causing SCD.
Diagnosis Of Sickle Cell Anemia
SCD is diagnosed with a simple blood test.
In new born children in many developed countries newborn screening tests at the hospital can diagnose SCD.
SCD in the fetus can be diagnosed with chorionic villus sampling and amniocentesis.
Treatment Of Sickle Cell Anemia
Over the years with increased knowledge and better facilities in medicine the life expectancy of SCD has increased up to 50 years in almost 65% cases earlier it was around 20 years.
Management of SCD is based on preventing and treating pain episodes and other complications. Prevention strategies include lifestyle changes, medical screening and interventions to prevent SCD complications.
Lifestyle Changes
People with SCD can take following measures to prevent and reduce the occurrence of pain crises
- Keep yourself well hydrated always.
- Avoid extreme temperature variations. That is not to get too hot or too cold.
- Avoid places or situations that can cause exposure to high altitudes. Try to avoid activities that can lead to exposure to low oxygen levels for example, strenuous exercise, mountain climbing, military boot camp or an athletic competition.
Simple steps to prevent harmful infections include the following:
- Washing your hands with soap and clean water as many times as possible each day is one of the best ways to prevent an infection.
- Prepare food safely.
Medical Screenings & Interventions to Prevent SCD Complications
Vaccination –
In children vaccination plays an important role in management of SCD.
- Vaccines can protect against harmful infections. It is important that children with SCD get all regular childhood vaccines. Similarly, it is important for children and adults to get the flu vaccine every year, as well as the pneumococcal vaccine and any others recommended by a doctor.
- Penicillin greatly reduces the risk of infections in people with HbSS. Penicillin on a daily basis is usually not prescribed for children with other types of SCD unless the severity of the disease is similar to that of HbSS, such as HbS beta0-thalassemia.
Prevention of Vision Loss
- Yearly visits to an eye doctor to look for damage to the retina.
- If the retina is damaged by excessive blood vessel growth, laser treatment often can prevent further vision loss.
Prevention of Stroke –
- Children who are at risk for stroke can be identified using a special type of exam called transcranial Doppler ultrasound (TCD).
- People who have frequent blood transfusions are usually watched closely because there can be serious side effects. Iron overload can cause life-threatening damage to the liver, heart, and other organs. Therefore, it is important for people with SCD receiving regular blood transfusions to also receive treatment to reduce excess iron in the body. This type of treatment is known as iron chelation therapy.
Prevention of Severe Anemia –
- Blood transfusions may be used to treat severe anemia.
- As with preventing stroke, frequent blood transfusions can cause iron overload, and iron chelation therapy may be needed to reduce excess iron in the body.
Management of Pain Crises –
When pain crises do occur, clinical management may include the following:
- Intravenous fluids (giving fluids directly into a person’s vein)
- Pain-reducing medicine
- Hospitalization for severe pain crises
Conclusion
Sickle Cell Anemia is the most common blood disorder with which people live and depending on the type of abnormal Hb, life expectancy and severity is determined. SCD is a genetic disorder that needs medical prevention as it may hinder day to day activities due to anemia. Severity of anemia also plays a crucial role in prognosis of the condition of the patient. It also leads to various complications involving eyes, kidneys, heart spleen and other organs too.