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A B C D E F G H I J K L M N O P Q

Test Identifier Information

 
Registration CodeCOMP
Method

Immunoassay by Siemens BNII nephelometer.

Diagnostic Use / Indications

C3 and C4 levels would be expected to be raised in systemic inflammatory response, usually up to twice their resting levels. In this setting a normal or low level may reflect utilisation, such as in an overwhelming infection. C4 levels will be depressed if utilisation by the classical pathway (e.g. in immune complex disease such as SLE and vasculitis associated with rheumatoid arthritis) exceeds production. C4 levels are low in patients with C1 inhibitor deficiency, and may be absent during an attack - normal levels effectively exclude the diagnosis. Low C3 reflects activation of either the classical or alternate pathways. Low C3 with a normal C4 occurs with isolated alternative pathway activation (e.g. type II mesangiocapillary GN, due to production of an autoantibody (C3 nephritic factor) that activates this pathway directly).

 

External Price$33.28(Exclusive of GST)
  

Specimen Collection

 
Pre-Testing Requirements

None

Patient Specimen5 mL clotted blood (Red)
Paediatric Specimen1 mL clotted blood (Red)
Sample Delivery to LabRoom temperature
  

Instructions for Referral to CHLabs

 
Aliquot Instructions300 uL serum - minimum 1 mL serum - preferred Store in fridge
Aliquot Transport to CHLRoom temperature
  

CHLabs Laboratory

 
DepartmentBiochemistry - Protein Laboratory
Contact Details Email Email
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Contact Phone Number(03)3640334 | x80334
Test AvailabilityBatched at least weekly
Turnaround Time1 week
Reference Interval

C3: 0.9 - 1.8 g/L
C4: 0.10 - 0.4 g/L

Interpretation

Complement Levels
Elevated C3 & C4 concentrations occur in inflammatory disorders. Depressed C3 concentrations occur in SLE, post-infectious glomerulonephritis, glomerulonephritis associated with C3 nephritic factor, rheumatoid vasculitis, hereditary deficiency and severe liver disease. Depressed C4 concentrations occur in active SLE, hereditary angiooedema and hereditary deficiency states.

Delphic Number Test Number6836

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