There's a test used with organ transplant patients to measure the overall strength of their immune system.  This is very important, because if you have a transplanted organ the last thing you want is for your immune system to recognize it as a "foreign invader" and  start attacking it... as if it were a virus or parasite.  If that process goes too far it's called "rejection" and it can easily kill you.  Transplant patients are routinely given drugs like cyclosporine which are known as "non-steroidal immunosuppressants."  These are much safer for long-term use than prednisone, but still reduce the activity of your immune system.  The downside is that it leaves you vulnerable to infection.  You can't be around crowds or eat things that are raw.

I've had this test once... my immune system is VERY strong.  Keep in mind that the immune system is a complex thing!  You can't just look at the amounts of immunoglobulins (IgA, IgE, IgG, IgM, etc...).  You also have to consider all the different types of leukocytes (basophils, neutrophils, eosinophils, lymphocytes), plus your natural kills cells, bone marrow, spleen, and lymph nodes.  IGNORE all the mainstream advice about having a "low" or "weakened" immune system.  Most of it is pure $%#& written by people who want to sell you something.

A few things I do know...

• A high total IgE (in the thousands) is pretty much guaranteed to give you allergic reactions... not necessarily anaphylaxis.
• Eosinophilic disorders can behave like allergies.  You have to look at both serum levels and the level of eosinophils in specific tissues such as the intestines, esophagus, etc...
• Low NK (natural killer cells) is a common finding in people with autoimmune disorders... even though their immune systems, overall are very strong (hyperactive)
• A below-normal level of IgA or IgG can make you more vulnerable than the average person to life-threatening infections.  How low is too low?  That I'm not quite sure about... but I wouldn't get too worked up about a result that's still in the normal range.

"Allergic" symptoms can be caused by sooooo many different things.  For example... I've been reading about hereditary angioedema (HAE).  The kind of angioedema that some of us get is generally not hereditary... if it clears up when you take antihistamines it's the allergic kind, not the hereditary kind.  Types I and II HAE are caused by a deficiency of a substance called C1-INH.  How does that cause angioedema?  I'm not sure yet!  I just know it doesn't improve with antihistamines or even epinephrine... during a crisis you have to infuse C1-INH.  Type III HAE is even more mysterious, but it has to do with having too much "bradykinin," which is a vasodilator.  (Interesting little factoid... ACE inhibitors lower your blood pressure by increasing the amount of bradykinin in your body.  Now I see why ACE inhibitors are SO BAD for mast cell patients.  We already have too much vasodilation going on!)

Anyway... do you see how complicated this is?  If you're not dealing with constant infections then I wouldn't worry at all about the "low normal" immunoglobulin levels.  Just having a mast cell disorder doesn't mean your immune system is particularly weak or strong!

Heather