Dear wma123-ga,
Firstly, please DONT take this as a definitive interpretation of this
diagnostic test. Based on the limited history available, i can
provide you with some GENERAL hints and Guidelines as to its
interpretation.
A test is ordered to answer a clinical question. What the clinical
question was that your doctor was trying to answer is something
probably only he knows, and it is best that you talk to him about
this. Immunoglobulins would not be first test ordered to investigate
palpitations and sore chest.
Immunoglobulins are produced by the B Lymphocytes of your immune
system. When an antigen (Antigen = anything capable of causing an
immune response) enters your system, it is picked up by certain cells
called antigen presenting cells (APC's). APC's present the antigen on
their surface and take them to certain areas in your body, like lymph
nodes. Here they present the cells to the B cells.
There are many billion B cells in your system. One or more recognise
the antigen, and that B cell then starts expanding and producing
Antibodys against these antigens. This B cell is now called a plasma
cell.
The antibody produced binds the antigen and neutralises it in many ways. It can :
- Opsonise it (or make it more tasty to the killer cells in your system)
- Neutralise it
- Make the antigen more recongnisable.
These antibodies are also known as Immunoglobulins, or Ig. Please
understand that this is gross oversimplification of one arm of your
immune system.
The following link has a cool animation explaining basic Antibody structure
http://www.wellesley.edu/Biology/Concepts/Html/antibody.html
There are 5 different classes of antibodies produced by your immune
system. These were named - A, D, E, G, and M. So they would be IgA,
IgD, IgE, IgG and IgM. There are also many little subtypes of these
antibodies. What is different about these antibodies is the
STRUCTURE.
IgG is a simple Y shaped structure. It is the most basic Immunoglobulin.
IgA is 2 Y's end on end. Please see
http://www.cat.cc.md.us/courses/bio141/lecguide/unit3/humoral/antibodies/abystructure/u3fg9c.html
IgM on the other hand is sort of 5 Y shaped Ig's joined at the base. Please see
http://www.cat.cc.md.us/courses/bio141/lecguide/unit3/humoral/antibodies/abystructure/u3fg9b.html
Now, different Antibodies are produced in response to different
things. If you are exposed to something that you have never been
exposed before, your body produced IgM.
These have many binding areas, with multiple random sites to bind the
antigen. Now one of these will bind the antigen best (sort of like a
lock and key). IgM is 5 random keys going around trying to bind a
lock. There are many billions of these keys around. Sooner or later,
one will fit perfectly. Once this happens, your body will switch
production and produce ONLY THAT KEY. So rather than make 5 headed
antibodies, it will make only one Y shaped one, that is IgG.
This is very helpful in medicine.
If you have a lot of IgM floating around, it means that you have an
ACUTE INFECTION, which your body is trying to fight off, but hasnt
found the key yet.
If you have a lot of IgG floating around, that means your body is
targeting something very very specific, and is fighting it.
Books say it usually takes about 48 hours for your body to find an IgG
for any given antigen.
Now, certain classes of antibodies are associated with certain kinds
of antigens. That is, your body does not always randomly produce IgM
then switch to IgG.
For Example
IgE - is commonly associated with allergic disorders
IgA - is associated with some auto-immune diseases
IgD - no specific role for this is known, but has been associated with
some infections.
There are MANY things that can cause a specific Immunoglobulin level
to go up. These are too numerous to list down. Looking at your test,
IgE seems to be the highest titre, so i will list some of the COMMON
causes of raised or lowered IgE
Raised IgE
- Allergic disorders including asthma, Hayfever, Atopic dermatitis,
Drug and food allergies etc.
- Parasites especially worms (eg hookworm, fluke etc)
- Certain Malignancies like Myeloma
Because Immunoglobulins are so NON SPECIFIC, this test is not usually
done. All it tells you is that your body is fighting something. It
doesnt tell you what, where or why.
It is cheaper just to measure the temperature of the patient to tell
him he is fighting off an infection.
It is ordered in certain cancers, where your B cells go nuts and keep
producing one kind of antibody for no reason. Then the test is done
to see what antibody they are producing, and whether the patient is
responding to the treatment. The antibody levels are usually very
very very high in these conditions.
It is also ordered in certain allegic conditions to assess disease
state and response to treatment.
The commonest cause of doing Immunoglobulin test is to see if you have
an immunodeficiency (i.e do you have some congenital B cell problem
that is stopping your immune system from fighting an infection). This
is just about the only thing this test is useful for. The test will
tell you that there are very low or no immunoglobulins circulating.
So what your test means, I dont know. Maybe you have an allergic
condition or asthma, maybe you have worms. Maybe you are in the
early phase of fighting an infection. Maybe you had a drug reaction.
So as i said earlier, the interpretation of the test depends on what
the clinical question was that was trying to be answered.
E.g you have allergic dermatitis, and your doctor started you on
treatment. He could order this test to see if you were improving.
Or you have asthma. The doctor ordered this test to see if you have
allergic asthma or otherwise
So i suggest talk to your doctor. He can also refer you to a
specialist immunologist for further opinion if necessary.
Hope this helps
Dr. Sharma |
