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Nashville, TN
A 33-year-old male 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?

2 doctor answers4 doctors weighed in
Dr. Thomas Namey
Rheumatology 48 years experience
CH50 is...: A test for both complement defieincy (congenital or caused by consumption). You should not have a normal ch50 with decreased C3 and/or C4 levels! C3 should be rarely ordered. C2 is best paired with c4!
Dr. Stevan Cordas
Internal Medicine 57 years experience
CH50: Ch50 measures the terminal or classical pathway. Deficiency of this test requires further investigation. Low C3 and C4 levels suggest activation of the classical pathway. Low C3 and normal C4 levels suggest activation of the alternate pathway. C4 could be low with a normal ch50.
Dr. Thomas Namey
Rheumatology 48 years experience
C4 and C2 deficiency, either complete are partial are common genetically and predispose to immune diseases!
Jul 7, 2013

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Last updated Jul 21, 2016

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