OVERVIEW
What is Hemoglobin?
A protein present in red blood cells responsible for carrying oxygen molecules from the lungs to the tissue & returning carbon dioxide from tissues to the lungs is known as Hemoglobin. Also abbreviated as Hgb or Hb, it is made up of four globulin chains (protein molecules) which are connected. Each of its globulin chain contains a significant iron-containing porphyrin compound termed as heme. The iron present is responsible for transporting oxygen/carbon dioxide & also for the red color of blood.
What is Hb. Electrophoresis Lab test?
Electrophoresis is a technique which under the influence of electric field, separates various DNA, RNA or protein molecules based on their size & electric charge. This test is used to separate and measure different types of hemoglobin present in blood. A normal Hb will carry & deliver oxygen well, but some abnormal Hb (hemoglobin variants) might hinder this function. Normal Hb types are Hemoglobin A, Hemoglobin A2, Hemoglobin F or fetal hemoglobin.
This test will not tell you the amount of hemoglobin in blood, rather it tells you the percentages of different types of hemoglobin found in blood.
Why is Hb. Electrophoresis Lab test done?
This test is sometimes also "hemoglobin evaluation" or "sickle cell screen". In some countries it is included in newborn screening, so most of the newborns automatically get this test.
As an adult you get this test because of:
- Diagnosis of anemia & sickle cell disease
- You show other blood disorder symptoms
- Ethnicity (race) leading to high risk of having a blood disorder
- Child has a blood disorder
- One of the other blood tests show abnormal results
- You have sickle cell anemia & just had blood transfusion; this helps the doctor evaluate if you have got enough normal Hb from new blood.
- What is the purpose of the Hemoglobin Electrophoresis blood test?
It simply measures the Hb levels & looks for abnormal types of hemoglobin. It mostly diagnoses anemia, sickle cell anemia, & hemoglobin disorders.
- How long will it take for my Hb electrophoresis results to come?
The test is done via a machine & results come within 1 to 2 days.
- How can you interpret results of Hb Electrophoresis?
When Hb S is found in moderate amounts then it means a sickle cell trait, while in high amounts denote sickle cell disease. When Hb C is in low amounts then it means hemoglobin C trait, while in high amounts denotes hemoglobin C disease that causes anemia & enlarged spleen.
- What is the basic principle of Hb Electrophoresis?
In laboratory, electric current is passed through Hb present in blood sample which leads to various hemoglobin types to separate in different bands.
Apart from normal Hbs mentioned above, hemoglobin C, D, E, G, H, J, M, S, Hb Barts & Hb constant spring, are all rare types of abnormal hemoglobin which occur due to genetic mutations. These mutated Hb cause too little oxygen to reach tissues and lead to anemia.
INTERPRETATION OF THE RESULTS:
Normal Hemoglobin Levels:
- Newborn Hemoglobin F Percentage "60%-80%"
- 1+ Year Hemoglobin F Percentage "1%-2%"
- Hemoglobin A= 95% to 98%
- Hemoglobin A2= 2% to 3%
- Hemoglobin F= 1% to 2%
- Hemoglobin S= 0%
- Hemoglobin C= 0%
Some Abnormal Hemoglobin Levels denote:
- Slightly decreased Hb A, Moderate amount Hb S (about 40%): Sickle cell trait (trait= genetically determined characteristic)
- Majority Hb S, Increased Hb F (up to 10%), No Hb A: Sickle cell disease
- Majority Hb C, No Hb A: Hemoglobin C disease
- Majority Hb A, Some Hb H: Hemoglobin H disease (alpha-thalassemia)
- Majority Hb F, Little or No Hb A: beta-thalassemia major
- Majority Hb A, Slightly increased Hb A2 (4% to 8%), Hb F maybe slightly increased: beta-thalassemia minor
Doctor recommends this test:
- As a routine checkup
- To diagnose blood disorders
- To monitor treatments like if you are getting treatment for a disease causing abnormal Hb then they monitor different Hb levels
- To screen for genetic conditions i.e. due to family history of inherited anemias.
