Low IgG Antibodies and Fibromyalgia

Per my last post, I said I was going on Ocrevus for Multiple Sclerosis. Well, it turns out not so much.

You have to do blood work first. And most of my blood work is fine aside from two things. One has been off for a long time. That is that my platlets are higher than they should be.

IgG Immunoglobulin G

The other was low, in my blood, a year ago during my lumbar puncture and I am not sure how long before that. That would be the IgG Immunoglobulin G. The most common antibody in your blood. The range is 6.94-16.18 ad mine is 6.78. So not insanely low. But it means I am more prone to infections and such.

For me specifically it means

What it Also means is that he does not want me on Ocrevus or Kesimpta for MS because it will tank these numbers below what he is comfortable with. I assume, it means other medications are also out because he picked out that is not typical. The one he talked to me about instead is called Cladribine.

I looked up why this number might be chronically low in me.

Fibromyalgia and IgG levels

Study 1

First I looked at this research: Association of high complement and low
immunoglobulins with the clinical symptoms
of patients with fibromyalgia (Izuno et al. BioPsychoSocial Medicine
https://doi.org/10.1186/s13030-024-00321-9)

“In this study, we investigated the immunological characteristics of FM patients and the association between their clinical symptoms and immunological indices, including complement and immunoglobulins…The serum 50% hemolytic complement activity (CH50), C3, C4, IgG, IgM, and hsCRP of 36 FM patients and 30 healthy sex- and age-matched controls.”

What they found in this research specifically was that the FM group had significantly higher CH50 and lower IgG and IgM than their control group even after adjusting for BMI, sex and age. The CH50 was also associated
with the fatigue and trait anxiety of FM patients. Although I was most interested in the IgG levels. It should be noted my other levels IgM are not awesome either.

Study 2

Next I looked at: Unexpectedly High Prevalence of Immunoglobulin Deficiency in Fibromyalgia (2014 ACR/ARHP Annual Meeting, Abstract Number: 2061, American College of rheumatology)

Although this one is older it has more people in the study and is specific to IgG Immunoglobulins.

“We retrospectively reviewed serum Ig concentration values on all FM subjects seen between July 2012 and December 2013 in an outpatient, rheumatology office setting.  No other diagnosis precluded inclusion in the study unless it was likely that it might predispose to Ig deficiency.  Charts on a total of 120 FM subjects were screened; 13 were excluded (e.g., family history of PID, SLE, Sjögren’s syndrome, prior irradiation or cancer chemotherapy, or use of a DMARD).  Data on 107 remaining FM subjects were reviewed; 38 (36%) had coincident RA (47 % of RA/FM subjects were positive for IgM RF).  Ig deficiency was defined as an Ig value of at least 2 standard deviations (SD) below the mean reported by our reference laboratory; all deficient specimens were tested in duplicate.  Ig abnormalities were confirmed by repeat analysis 6 – 9 weeks later. “

What the study concluded was that Ig deficiency, particularly IgG subclass deficiency, is a common in Fibromyalgia.  “It also strengthens the argument that FM may be a disorder associated with immune dysregulation.” 

Why though and what questions then arise from this?

You have to be aware that

Just in case, if your numbers do show this sort of thing it could be something else. It could be an underlying condition that you are misdiagnosed with or have a comorbid condition. If you have a chronic infection of some sort these numbers should perhaps be reviewed.

Then the general research suggests:

• Research does show low IgG: Several research papers suggest statistically lower levels of IgG, particularly IgG1 and IgG3 subclasses, in fibromyalgia patients compared to healthy controls. This is often interpreted as a sign of immune dysfunction or exhaustion. As I have shown above.
• Research shows no change or even elevated IgG: Other research has not found a significant correlation, or has found elevated levels of antibodies, suggesting a different type of immune dysregulation (autoimmune-like activity). This is interesting to say the least and I found a few of these papers as well.
• Inflammation: While we know fibromyalgia isn’t a classic inflammatory disease, there is evidence of neuroinflammation  and elevated pro-inflammatory cytokines. This low-grade immune activation could theoretically, over a span of time, dysregulate other parts of the immune system.

Essentially,

Basically, we end up with the question of low IgG because of an infection which then worsens FM. Or the constant pain and stress of FM dysregulating the immune system. Chronic pain itself fatiguing the immune system. Either way, in my case, something like that. I guess it is not common practice to test these numbers and mine was only tested with the lumbar puncture and then again when I was to be put on this MS medication. And has been low both times.

It should be noted that chronic pain itself, by itself, can lower our IgG levels. By itself. Due to poor sleep, chronic stress, sympathetic nervous system overdrive… and just the fact our bodies are coping with pain for a very long time. I don’t just have FM, I have hypermobility and chronic migraine. That this number is out of whack doesn’t seem all that abnormal to me. Yes, it means I have a very fatigued immune system and get sick at the drop of a hat. And yes, it does mean it changes the medications I can take for MS.

When were you diagnosed with Fibromyalgia?

Sources:

https://www.sciencedirect.com/science/article/pii/S0889159125004271

https://acrabstracts.org/abstract/unexpectedly-high-prevalence-of-immunoglobulin-deficiency-in-fibromyalgia/

Click to access s13030-024-00321-9.pdf