Complement levels - C3 and C4

Has anyone had their complement levels tested?
Is a low C3 relevant???

My C4 has come back at the bottom of the normal range, and my C3 is below the normal range.....

 

Yes. My C3 and C4 are normal. Those are the only ones that were checked. This was done because I have positive ANA.

I do not have chronic infections with my ME.

https://labtestsonline.org/tests/complement

https://www.urmc.rochester.edu/ency...ntentTypeID=167&ContentID=complement_c3_blood

https://primaryimmune.org/about-pri...ecific-disease-types/complement-deficiencies/

 

Yes, I had very low C3 and C4.

 

Low C3 woth antinuclear antibodies is significant. Otherwise I am not sure it helps much.

 

Thanks @Jonathan Edwards for that. I have anti-centromere levels of 1:1280. It was the rheumatologist who just ordered the latest round of tests.... I think she is wondering if progression of my CREST is a reason I am deteriorating overall. Don’t suppose there’s a magic wand?

 

I was tested in January and they were 'normal'.

 

Not sure how much your know about my story, but I was misdiagnosed with ME/CFS a few years ago by a doctor at Open Medicine Clinic. They ran a ton of blood tests on me and some of the tests run were complement tests. My complement C3 came back very low (only 30% of normal). After a little research I decided that a C3 level that low was worth investigating further.

I sought out an an immunologist who had some knowledge about the complement system (fyi: the complement system is VERY complex and only a small number of immunologists are proficient in it).

One important thing to know about complement testing is that the tests are quite finicky and if the blood samples are not handled correctly in the lab the results can easily become skewed. The first thing the immunologist did before proceeding was to re-test my complement levels at the lab at his hospital to make sure the first abnormal result was not just a false reading due to an error by the previous lab. My complement levels again came back low and it's now been determined that the cause is my autoimmune disease (my autoimmune disease is very rare and has no biomarker).

A C4 level within normal range is normal even if it's at the low end of the normal range. As for the low C3, how low is it?

 

@Daisybell

Feel free to private message me if you wanna discuss it further.

 

Anti-centromere antibodies are not typically associated with low C3 (which is more associated with immune complex pathology and anti-DNA). But ANA related disease is complex and can take almost any pattern.

Treatment for typical anticentromere associated features, including 'fatigue' is not well established. But drugs like rituximab are relevant to the anti-DNA/C3 side of things. It may be worth repeating your ANA subtype screen to see if it has changed.

 

Thanks!
Everything else is negative...anti-DNA, ENA, sceldroderma and lupus markers all clear....
My ANA result has been stable at that level for about 10 years now...

 

I would expect you to be fatigued with those, whatever fatigue might be!

 

About 7 years ago I had my c3b levels tested. They were 14 x the max of the normal range. I have no idea what that means, if that's significantly high. I'm pretty sure I wasn't sick at the time apart from me ME/CFS. The doc who ordered it was a Lyme doc and argued it was proof of a Lyme infection. At the point I had 8 lyme tests, all negative, 4 different kind of Lyme tests and a negative babesios test. So, I'm certain it wasn't that. And I never improved on years of abx.

I rediscovered it last week as I'm having some significant dysphagia and chest tightness but with a normal x-ray, ekg, esophogram and fees study, normal endocrinology except a riboflavin deficiency, negative sjorgens, normal environmental allergy testing. Even had mold testing in my house (negative). The dysphagia is my main concern at the moment and no one really has any idea what is causing it and the ENT and basically all I can think to do next is endoscopy.

I'm not soliciting specific medical advice, but wondering if further testing of complements (like ch50) would be the next step with high c3b. Unfortunately, the c3b test isn't available from quest anymore. Of course, it's probably just a sporadic weird result. Obviously, the complement component stuff is way above me as I have no medical education at all.

 

Has anyone suggested a modified barium swallow for investigating your dysphagia? I would do that, given that the FEES and eosophageal screen haven’t shown up the problem. In my opinion, best done with SLP and radiologist working together.....

 

Yes, sorry, that's what the esophogram was, modified barium swallow, but it only showed mildy delayed passage of hard food. Also had nerve conduction and needle emg of legs and arms. It's so frustrating and it's hard to stay motivated.

 

I just happened to have C3-C4 done this week along with a few other rheumatology tests, both middle of the road normal. My ANA is 1:640 and homogenous pattern.

 

I think I may have Partial compliment factor I deficiency at 4q25
Trying to understand what aHUS is

https://en.m.wikipedia.org/wiki/Complement_factor_I

Factor I Inactivator of C3b/C4b

It seems to be an area connected to macular degeneration and the eye

 

C3 low end of normal
C4 half of the low value (tested 3x)
Crp 0.8
Seronegative for "everything"

 

My C3 and C4 are constantly slightly under lower cut off. Latest C3 was 0,71g/L (lower cut off 0,74g/L) and C4 0,13g/L (lower cut off 0,14g/L). Based on litrature I have read about Lupus this should indicate a complement activation of some sort but no doctor has yet put any meaning into it since Im negative for all Lupus and Sjögrens titers.

I am however highly positive for RF IgG and IgA fragements. Always over 100 IU/ml when upper cutoff is 25 IU/ml. I have no clinical symptoms of rheumatoid arthritis so the doctors do not put any meaning into that either.

I also have mild neutrophenia of around 1,3-1,8 10^9/L when lower cutoff is 1,9 10^9/L. To me all these biomarkers are saying something about what I believe is some kind of autoimmune activity.

 

There’s a few papers out there mentioning covid and complement

 

https://ahusnews.com/2022/01/12/sam..._x4NqNEGTuW5rp2OrceLF8SJVQohew0&cn-reloaded=1


Same C5a Complement Protein Mechanisms Found in aHUS, COVID-19