Classical and alternate pathway for complement activity

Description: 
When genetic complement deficiency is suspected it is necessary to assess the functional integrity of the pathways of complement activation to help localise the deficiency and then identify the particular deficient component. The common practice is to test for complement C3, C4, alternative and classical pathway of complement activation. Samples that are haemolysed or delayed in processing are subject to auto activation and unsuitable for functional complement assay. Please contact the Immunology laboratory before ordering the test.

The complement system which is part of the innate immune system is a cascade of protein proteases, activator and inactivator proteins.

Reference range: 

Classical pathway 66 - 113%

Alternate pathway 30 - 113%

Synonyms or keywords: 
Complement, Complement function, Classical pathway activity, alternative pathway activity
Units: 
% Activity
Sample type and Volume required: 
Clotted (Gold top vacutainer)
Turnaround time: 
14 working days
Special sample instructions: 

All tests are compromised by prolonged transit times. For this reason, date of bleed and date of postage must be provided with each request.

Storage and transport: 
Sample must arrive in Immunology within 2 hrs, or for outside laboratories be separated and frozen within 2 hours and sent on ice.
Time limit for extra tests: 
10 days
Contacts:
Diagnostic Immunology and Allergy Department at King's College Hospital
General Enquiry : 020 3299 8752 / 020 3299 1171
King's College Hospital
Bessemer Wing - 1st Floor
Denmark Hill
London SE5 9RS
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 23/05/2023