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A member asked:

Complement c3 & c4 tests done 3 times. c3 normal but twice c4 was borderline normal or borderline low, 3rd time it was well within range. deficiency?

A doctor has provided 1 answer
Dr. John Chiu answered

Why the tests?: If the values were either borderline low or borderline normal, then one would call the value low normal. Whether it means anything or not would depends on whether you have a disease condition associated with complement consumption. A low C4 is usually found in patients with hereditary angioedema.

Answered 1/24/2017

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Related Questions

A member asked:

Repeated blood tests show I have VERY low complement C3 @ 41 and not sure is C4 @ 12 is also considered low. What tests should be done next?

2 doctors weighed in across 2 answers

A member asked:

I have normal levels of complement C2 and c4. C3 level is low. Ch50 is high-normal(57 u/ml)-(all are serum tests)-what are the possible causes?

A doctor has provided 1 answer

A member asked:

Can you have a normal ch50 (total complement) blood test result, but still have low C3 and/or C4 levels?...Or would low C3 or C4 show up on ch50 test?

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A member asked:

My C4 complement level is low and C3 complement is at the low end of the range (90, ref range 90-180). What could this mean?

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A member asked:

What does it mean if my complement C3 serum was 4 points low on a scale of 90-180 and my C4 was normal? Could there be something wrong?

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