Non-zero antibody levels

[bspg]

This might be a question best suited to @Jonathan Edwards but maybe others can answer as well.

What does it mean when a person has antibodies to an antigen but they're not high enough to garner a positive or equivocal result?

Examples:

AChR Blocking Abs, Serum

Your value: 15%

Interpretation: Negative: 0 - 25%
Borderline: 26 - 30%
Positive: >30%


GM-1 Ganglioside IgG Antibody

Your value: 8 IV

Interpretation: Negative: <29 IV
Equivocal: 30-50 IV
Positive: 51-100 IV


In both of these examples, the antibodies aren't zero but they're not high enough for a diagnosis either. So why do these antibodies exist? What do they mean?

 

[Jonathan Edwards]

This might be a question best suited to @Jonathan Edwards but maybe others can answer as well.

What does it mean when a person has antibodies to an antigen but they're not high enough to garner a positive or equivocal result?

Examples:

AChR Blocking Abs, Serum

Your value: 15%

Interpretation: Negative: 0 - 25%
Borderline: 26 - 30%
Positive: >30%


GM-1 Ganglioside IgG Antibody

Your value: 8 IV

Interpretation: Negative: <29 IV
Equivocal: 30-50 IV
Positive: 51-100 IV


In both of these examples, the antibodies aren't zero but they're not high enough for a diagnosis either. So why do these antibodies exist? What do they mean?

Everybody has antibodies to everything in small amounts.

 

[bspg]

@Jonathan Edwards even autoantibodies?

Is this normal or just a consequence of certain immune systems?

 

[Gingergrrl]

@Jonathan Edwards even autoantibodies?

Is this normal or just a consequence of certain immune systems?

I am curious about this too @bspg and thank you for asking the question! When I did some tests that were sent to Mayo Clinic in early 2016, the Neuro told me in advance that I would be negative for all of the autoantibodies b/c they were rare and then when I was positive for two of them, he was quite surprised and I was treated badly (he was a consult and not my regular doctor).

This started me to do further testing which led to finding additional autoantibodies that were all quite high and above the range. But I've talked to many on PR and other groups who got borderline or equivocal results and I always wondered what that really meant?!

 

[bspg]

@Gingergrrl in my case I'm especially curious because of a Lyme result I had.

The test was ELISA to Western Blot for Borrelia burgdorferi antibodies.

The units were "LIV", which I don't understand, and my value was 0.41 LIV (standard range: 0.00 - 1.20 LIV).

I've never understood what this means. Was I exposed to Borrelia burgdorferi but don't have a lyme infection? Was the test just not very specific and reacting to something else? I don't understand why there would be a non-zero value.

 

[Gingergrrl]

@bspg I know nothing about Lyme and am the wrong person to answer (but wish I could help you)! I am very curious re: the autoantibodies though b/c it seems like either a person would have them or not like I do (vs. the lower borderline and equivocal ranges).

 

[TrixieStix]

@Gingergrrl in my case I'm especially curious because of a Lyme result I had.

The test was ELISA to Western Blot for Borrelia burgdorferi antibodies.

The units were "LIV", which I don't understand, and my value was 0.41 LIV (standard range: 0.00 - 1.20 LIV).

I've never understood what this means. Was I exposed to Borrelia burgdorferi but don't have a lyme infection? Was the test just not very specific and reacting to something else? I don't understand why there would be a non-zero value.

It is also possible, however, to test positive with an ELISA test (and also IFA) even when you do not have Lyme disease. This can occur because of other medical conditions, including:

• Tick-borne relapsing fever
• Syphilis
• Anaplasmosis (formerly known as granulocytic ehrlichiosis)
• Leptospirosis
• Some autoimmune disorders (e.g., lupus)
• Bacterial endocarditis
• Infection with Helicobacter pylori, Epstein Barr virus, or Treponema denticola (bacteria found in the mouth that can cause gum disease and/or infection after dental procedures)

I've been tested twice using standard Lyme testing, once via ELISA which was negative, and more recently by IFA which was positive. I even tested "CDC positive" on the IGM western blot portion (negative IGG), but I still don't believe I have Lyme. I believe in my case it's much more likely to be other things that are causing me get a false positive result.

 

[Jonathan Edwards]

@Jonathan Edwards even autoantibodies?

Is this normal or just a consequence of certain immune systems?

Yes,even autoantibodies.

It is because of the way the immune system works.

The B cells of the immune system are unable to invent new antibodies in response to meeting microbes - there is no biological mechanism for building a 'lock and key' fitting molecule to order. So the system works on the basis that it makes every sort of antibody it can think of in small amounts and if it meets a microbe the antibodies that bind are made more of - by expanding the clone that makes that antibody. So in effect thiamine system can nevermore an antibody to something in any useful amount unless has already made little bit of antibody to that thing. So we all carry around small amounts of antibody to everything. We tend not to carry around much autoantibody because autoantibody producing clones tend to get eliminated by control mechanisms. But even there, they are not completely removed because all antibodies show a low level of 'cross -reactivity' to everything, so some of your anti-microbe antibodies will bind a bit to self antigens.

So all antibody tests give a lower level rather than a zero for negative. The normal level of antinuclear antibodies is often given as less than a 1/20 titre (a positive reaction at a 1/20 dilution of serum). At 1/5 dilution pretty much everyone may give a positive result. Moreover, we all have antibodies to plastic so in an ELISA test you will get a reading from the antibodies to the plastic even if there are no antibodies to the test microbe. You can try to factor that out but there is never a truly zero result.

 

[Gingergrrl]

We tend not to carry around much autoantibody because autoantibody producing clones tend to get eliminated by control mechanisms. But even there, they are not completely removed because all antibodies show a low level of 'cross -reactivity' to everything

That was sort of my understanding, too, (that we do not carry around a lot of autoantibodies) unless they are actually doing something harmful or pathogenic? I have the two Hashimoto's autoantibodies and my Endo said that I always will and they will never go to zero. They fluctuate greatly and were in the thousands prior to starting thyroid med in 2013 but then went much lower. At one point, one of the auto-antibodies was around 30-40 (inside of the "normal" range) but it was brief and did not stay there.

My Endo said that the gluten molecule is similar to whatever the Hashi's auto-antibodies attack so by not eating gluten, you lower the autoantibody and therefore lower the attack on your thyroid (I am paraphrasing and these are not his exact words)! This is why I have been gluten free for four years.

But for other autoantibodies (like the one I have that attacks the calcium channel), it seems like they should not be there at all! The Neuro who tested me said that I would be negative (and was very confident in this) but then the results came back positive and he was quite surprised.

It seems like this autoantibody (and all of the paraneoplastic autoantibodies) are doing something negative. The tests do have an equivocal range (which I don't really understand!) but I was not in the equivocal range and was positive for these auto-antibodies on all tests.

Could paraneoplastic auto-antibodies be showing "cross reactivity" to something else, or would this concept not apply to them?

 

[bspg]

@Jonathan Edwards this is a super helpful! Thank you for the explanation!