What does this puzzling and outrageous IgG result actually mean?
December 12, 2015
Working through some confusion with information above my pay grade.
Is this in any way an odd or unusual result? What are typical or otherwise ranges for this measure?
The biggest difficulty is finding some kind of comparative scale and conversions.
The Gamma Dynacre blood test results show an IgG of 160 U/ml for Casein. I can find information that says 620–1400 mg/dL or similar ranges of 650 to 1600 to be normal. I can only assume ‘U’ is in mg, so, online calculators and converters yield 1600. On the high side, or just elevated above normal.
Otherwise 160 is absurdly low.
If I move the decimal… 620–1400 mg/dL becomes 62–140 mg/mL …. (?). So 160 would be high. The GD chart shows 24–30 as moderate, and 30+ in a logarithmic scale, as elevated. So what does ‘U’ mean as a unit?
Is this IgG merely a reaction to exposure? A residual response? Or an actual active live allergy.
IgG is first line immune response attacking foreign bodies – proteins – and coating them as markers for other antibodies to deal with. These things are just in the wrong place. IgG is a response to the presence of the protein. Doesn’t mean it’s an allergy. (?)
Total IgG versus IgG4 food allergy
Immunoglobulin G (IgG) is classified into several subclasses termed 1, 2, 3, and 4. IgGs are composed of two heavy chain–light chain pairs (half-molecules), which are connected via inter–heavy chain disulfide bonds situated in the hinge region (Figure 1). IgG4 antibodies usually represent less than 6% of the total IgG antibodies. IgG4 antibodies differ functionally from other IgG subclasses in their lack of inflammatory activity, which includes a poor ability to induce complement and immune cell activation because of low affinity for C1q (the q fragment of the first component of complement). Consequently, IgG4 has become the preferred subclass for immunotherapy, in which IgG4 antibodies to antigens are increased to reduce severe antigen reactions mediated by IgE. If antigens preferentially react with IgG4 antibodies, the antigens cannot react with IgE antibodies that might cause anaphylaxis or other severe reactions. Thus, IgG4 antibodies are often termed blocking antibodies. Another property of blood-derived IgG4 is its inability to cross-link identical antigens, which is referred to as “functional monovalency”. IgG4 antibodies are dynamic molecules that exchange half of the antibody molecule specific for one antigen with a heavy-light chain pair from another molecule specific for a different antigen, resulting in bi-specific antibodies that are unable to form large cross-linked antibodies that bind complement and thus cause subsequent inflammation(16). In specific immunotherapy with allergen in allergic rhinitis, for example, increases in allergen-specific IgG4 levels indeed correlate with improved clinical responses. IgG4 antibodies not only block IgE mediated food allergies but also block the reactions of food antigens with other IgG subclasses, reducing inflammatory reactions caused by the other IgG subclasses of antibodies to food antigens.
In IgG mediated food allergy testing, the goal is to identify foods that are capable of causing inflammation that can trigger a large number of adverse reactions. IgG1, IgG2, and IgG3 all are capable of causing inflammation because these antibodies do not exchange heavy and light chains with other antibodies to form bispecific antibodies. Thus, IgG1, IgG2, and IgG3 antibodies to food antigens can and do form large immune complexes or lattices that fix complement and increase inflammation. The presence of IgG4 antibodies to food antigens indicates the presence of antibodies to foods that will not usually cause inflammation even though high amounts of these antibodies do indicate the presence of immune reactions against food antigens. Testing only for IgG4 antibodies in foods limits the ability of the clinician to determine those foods that are causing significant clinical reactions that are affecting their patients. The importance of measuring other subtypes of IgG antibodies is highlighted in an article by Kemeny et al. (17). They found that IgG1 antibodies to gluten were elevated in all 20 patients with celiac disease but none of the patients had elevated IgG4 antibodies to gluten.
… is from greatplainslaboratory.com which, in a cursory reading, seems a bit of new age woo site (?), but this seems a clear explanation.
These are for the most part the most common allergens. Aren’t they rare however in a senior adult?
I’ve had allergy testing twice across two decades with no findings, and displayed, all that time, allergy symptoms. We chalked it up to some occult environmental allergen. My family doctor always tracked a slightly elevated IgE, a sign of a low grade chronic infection, viral perhaps, perhaps some kind of Liver difficulty.
On October 1st, I started a FODMAP diet based on the MONASH University app, and the sinus effects have subsided — aside from the dramatic lessening of gut symptoms. Merely diet? Yes, Allergies and Intolerances aren’t the same thing.
UPDATE: 12/17/2015 a kind of stream of consciousness poem.
If low stomach acid
doesn’t metabolize B12
Due to age and buffering medicines
Is that inadequacy also
failing to digest
gluten and casein proteins
Into amino acids?
Should these proteins be in the blood
That is what the immune system responds to
Proteins viruses bacteria.
Another update 12/18/2015
Regarding a Sunflower and Sesame seeds. It seems that yes, an errant protein is the provocateur.
Even as this post discounts the IgG testing procedure, those FlaxSeeds – something that I haven’t knowingly consumed in years, yet is on. My list of newly discovered sensitivities- in that otherwise Gluten free granola sure did a job on provoking by IBS for a few days.
Later that same day:
Is a good place to look for information on IgE food allergies and information on the sources of the allergy in specific foods.