Test Overview

A hemoglobin electrophoresis test is a blood
test done to check the different types of
hemoglobin in the blood. Hemoglobin is the substance
in red blood cells
that carries oxygen.

The most common types of
normal hemoglobin are:

  • Hemoglobin A. This
    is the most common type of hemoglobin found normally in adults. Some diseases,
    such as severe forms of
    thalassemia, may cause hemoglobin A levels to be low
    and hemoglobin F levels to be high.
  • Hemoglobin F (fetal hemoglobin). This type is normally found in
    fetuses and newborn babies. Hemoglobin F is replaced
    by hemoglobin A (adult hemoglobin) shortly after birth; only very small amounts
    of hemoglobin F are made after birth. Some diseases, such as
    sickle cell disease,
    aplastic anemia, and
    leukemia, have abnormal types of hemoglobin and higher
    amounts of hemoglobin F.
  • Hemoglobin A2. This is a normal type of hemoglobin found in small amounts in
    adults.

There are more than 350 types of abnormal hemoglobin.footnote 1 The most common are:

  • Hemoglobin S. This type
    of hemoglobin is present in sickle cell disease.
  • Hemoglobin C. This type of hemoglobin does not carry oxygen well.
  • Hemoglobin E. This type
    of hemoglobin is found in people of Southeast Asian descent.
  • Hemoglobin D. This type of hemoglobin is present in some sickle cell disorders.

Hemoglobin S and hemoglobin C are the most common types of
abnormal hemoglobin that may be found by an electrophoresis test.

Electrophoresis uses an electrical current to separate normal and
abnormal types of hemoglobin in the blood. Hemoglobin types have different
electrical charges and move at different speeds. The amount of each hemoglobin
type in the current is measured.

An abnormal amount of normal
hemoglobin or an abnormal type of hemoglobin in the blood may mean that a
disease is present. Abnormal hemoglobin types may be present without any other
symptoms, may cause mild diseases that do not have symptoms, or cause diseases
that can be life-threatening. For example, hemoglobin S is found in sickle cell
disease, which is a serious abnormality of the blood and causes serious
problems.

Why It Is Done

Hemoglobin electrophoresis is done
to:

  • Find each type of hemoglobin in the blood. This
    can be used to diagnose certain types of
    anemia (such as thalassemia).
  • Check
    treatment for diseases that have abnormal types of hemoglobin in the
    blood.
  • Help couples find out how likely they are to have a child
    with certain forms of anemia that can be passed from a parent to a child
    (inherited).

How To Prepare

Tell your doctor if you are getting
iron therapy for
iron deficiency anemia.

How It Is Done

The health professional drawing blood
will:

  • Wrap an elastic band around your upper arm to
    stop the flow of blood. This makes the veins below the band larger so it is
    easier to put a needle into the vein.
  • Clean the needle site with
    alcohol.
  • Put the needle into the vein. More than one needle stick
    may be needed.
  • Attach a tube to the needle to fill it with
    blood.
  • Remove the band from your arm when enough blood is
    collected.
  • Put a gauze pad or cotton ball over the needle site as
    the needle is removed.
  • Put pressure on the site and then put on a
    bandage.

How It Feels

The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
pinch.

Risks

There is very little chance of a problem from
having a blood sample taken from a vein.

  • You may get a small bruise at the site. You can
    lower the chance of bruising by keeping pressure on the site for several
    minutes.
  • In rare cases, the vein may become swollen after the blood
    sample is taken. This problem is called phlebitis. A warm compress can be used
    several times a day to treat this.

Results

A hemoglobin electrophoresis test is a
blood test done to check the different types of
hemoglobin in the blood. Results are ready in several
days.

Normal

The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what’s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.

Hemoglobin electrophoresis footnote 1

Hemoglobin
A1:

96.5%-98.5% of total
hemoglobin or 0.96-0.985 mass fraction

Hemoglobin
A2:

1.5%-3.5% of total
hemoglobin or 0.015-0.035 mass fraction

Hemoglobin
F:

0%-1% of total
hemoglobin or 0-0.01 mass fraction

Abnormal
hemoglobin types:

None

High and low values

  • Higher-than-normal amounts of both hemoglobin
    A2 and
    hemoglobin F may mean a mild form of
    thalassemia is present. A very low level of hemoglobin
    A and a high level of hemoglobin F may mean a more severe form of thalassemia.
    High levels of hemoglobin F may be seen in a rare condition called hereditary
    persistence of fetal hemoglobin.
  • Hemoglobin S in moderate amounts
    can mean that
    sickle cell trait is present. Hemoglobin S in high
    amounts means
    sickle cell disease.
  • Hemoglobin C in low
    amounts can mean that
    hemoglobin C trait is present. Hemoglobin C in high
    amounts means hemoglobin C disease, which causes anemia and an enlarged
    spleen.
  • Hemoglobin types S and C mean hemoglobin S-C disease, which
    causes a mild or moderate form of sickle cell disease.
  • Hemoglobin E
    in low amounts means the presence of
    hemoglobin E trait. Hemoglobin E in high amounts means
    hemoglobin E disease, which causes anemia and smaller-than-normal red blood
    cells.
  • Hemoglobin types other than S, C, D, and E are rare. But
    over 350 types of abnormal hemoglobin have been found.footnote 1

What Affects the Test

Reasons you may not be able to
have the test or why the results may not be helpful include:

  • Having a blood transfusion in the past 3
    months.
  • Having
    iron deficiency anemia. This can cause falsely low
    results for hemoglobin A2.

What To Think About

If you are planning to have
children and are found to have abnormal types of hemoglobin in your blood, you
might consider
genetic counseling. This can help you and your partner
see how likely you are to have children with certain inherited forms of anemia
(such as sickle cell disease or thalassemia).

References

Citations

  1. Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

Other Works Consulted

  • Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
  • Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
  • Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.

Credits

ByHealthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD – Internal Medicine
Adam Husney, MD – Family Medicine

Current as ofOctober 9, 2017