Complement C3

[SjoGirl]

Anyone else have low Complement C3? I was hoping to take part in a clinical trial and complement was tested as part of the process. My reading was at the very bottom of the scale, just above negative. The report said that the result was not clinically significant, but I've learned over the years not to trust such comments because sometimes being that low on a scale is really and issue.

[bluegardenia]

mine is 17. seems it should be >20.

[irish]

I think this is an inflammatory marker that is significant in some autoimmune diseases. I would guess that with a really low score it could make a difference in what they want to test. Just my memory and guessing. Others should show up with more info. Irish

[eye2dry]

I thought I read somewhere in some sjogrens literature that they
(rheumatologist) watch for changes in C3 and c4 d/t it can be
a signal for developing lymphoma. I can't remember if they are looking for
low compliment numbers or high.



shelly

[SunshineDaydream]

Have you had your C3 and C4 complements tested before? If so, how have your numbers been?

This mentions SJS and C3 / C4 complements.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3602968/

[irish]

I think the C3 and C4 are elevated in lupus. Irish

[Navigator]

Low C3 and C4 are associated with potentially more serious disease and development of lymphoma. It is not the only marker for more serious disease however so you could be actually fine...but it is an indication that the doctor should be monitoring you.   You can confirm see the Table 2 in  SunshineDay Dreams post.

My C3 is 15 and my C4 is normal.  I am positive Ro and negative La. It is complicated.  But my doctor referred me to a hematologist just to establish a relationship in case.  I would consider my symptoms to be middle of the road having read posts here.

[SjoGirl]

Thanks all, my rheumatologist said that according to their lab my reading would have been normal. He saw now issue with it.

[SunshineDaydream]

Yay, SjoGirl! Glad your doctor had good news!

[Way2dry]

I was just looking over some test results from last year and discovered that my c3 levels had dropped from 90 in 2015 to 74 in 2016.  The normal range is 90-180.  After reading some info. in this thread, I am very worried that I have or will develop lymphoma.

My other tests have been fairly normal except for A/G Ratio which is 2.1 (normal range 0.9-1. and my ferritin levels which keep creeping up and are now 232 (normal range 10-120). 

I have a lousy rheumatologist who never followed through with me about the drop in my c3 levels.  I am very discouraged and worried.  Can you have low c3 and not develop lymphoma?

[Milly]

I've had low C3 for over 2 years (72 average, normal >90). My rheumatologist calls this "mildly low" and isn't worried at all, he just says that it is a sign I have an autoimmune disease.

[irish]

The important thing to remember with autoimmune disease is that just because we have a weird number on a blood test we are not to panic and lose sleep. First of all, the labs can make mistakes, the number on your blood test can be from a lab that uses a different procedure from the one that we read about on line.

Then comes the big thing, with autoimmune disease it is not one individual test that can make or break us. Usually it is a number of tests and a constellation of symptoms. As an example, I have 5 autoimmune diseases and 2 immune deficiencies ( I thought it was only one for years but immunologist told me lately that it was in fact 2) and I have never, ever had an increased see rate. In fact, mine is usually around 5-8 and when it got up to 18 once (normal is below 20) my immunologist was actually excited. Alas, it went back down and has not reached that high again.

The thing to do is call the doctor and issue a desire for further investigation and/or a second opinion. Make sure that doc knows you know the implications and you want an answer. Be assertive but not aggressive which is bloody hard!!! All people with autoimmune disease are at risk for lymphoma. All people who have cancer and are on chemo are at higher risk for cancer. All people who live and breath in our chemically laden society are at risk for lymphoma and in fact the run of the mill public are having increased cases of lymphoma due to chemical exposure in our environment. It is pretty much the same as every one of us is at risk for being in a car accident or getting hit by a bus/car when we step off the curb. Risk is apart of our lives and we must roll with it. Just be vigilant and deal with whatever happens when it happens. Hard to do but part of live in every generation. Good luck. Irish

[SjoGirl]

Thanks Irish, my rheumy said not to worry the test is actually in the normal range.

Interestingly, my SSB is now also normal, weird since it was quite high about 6-9 months ago.

I agree, it's a constellation of things and after nearly 10 years of this I don't panic anymore, I just pray that this good place that I am in will last.

[Way2dry]

Thanks, Irish.  This is all so complicated.  I am concerned about the drop in c3 in one year from 90 to 74.  I had been low normal range fairly consistently before.  Since I have several other abnormal test results I guess I need to pursue this further.