Complement C1q
Private Complement C1q blood test in London for £148.99, measuring one classical complement protein with results expected in around 1 week.
Turnaround time
1 week
Biomarkers count
1
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Overview of the Complement C1q
The Complement C1q blood test measures Complement Component C1q, a protein that initiates activation of the classical complement pathway.
The test contains 1 biomarker: Complement C1q.
The complement system is a network of circulating proteins that contributes to immune defence, inflammatory signalling and clearance of immune complexes.
C1q recognises and binds selected antibody-antigen complexes and initiates the C1 complement complex.
This subsequently activates other classical pathway proteins, including C4 and C2.
Low C1q can occur because of rare inherited deficiency or because C1q is being consumed during active immune-complex disease.
Complete inherited C1q deficiency is rare but is strongly associated with autoimmune disease and susceptibility to selected infections.
Acquired reduction can occur during conditions involving complement activation.
C1q should generally be interpreted alongside C3, C4 and functional complement testing, rather than as a standalone diagnostic result.
Complement C1q is different from anti-C1q antibodies and C1q Binding Immune Complex testing.
What Does the Complement C1q Test Check?
This test measures 1 biomarker.
Complement C1q
Measures the C1q component of the complement system, which helps initiate classical complement activation and clear immune complexes.
Who May Benefit From the Complement C1q Test?
C1q measurement may be useful during specialist investigation of complement abnormalities.
People with unexplained low complement levels - C1q can provide additional information where broader complement testing is abnormal.
People with suspected classical complement deficiency - Rare inherited C1q deficiency can be investigated.
People with recurrent severe infections - Complement dysfunction can impair immune defence.
People with early or unusual autoimmune disease - Classical complement deficiencies have strong associations with lupus-like autoimmunity.
People with immune-complex disease - Complement consumption can reduce circulating components.
People with a previous low C1q result - Repeat testing may help determine whether the abnormality persists.
People undergoing detailed complement assessment - C1q can complement C2, C3, C4 and functional assays.
People specifically advised to obtain Complement C1q - Testing is generally most useful when requested by a specialist.
How to Prepare
Do not stop immune-modifying treatment simply to alter a Complement C1q result.
C1q is normally interpreted as part of a broader complement assessment.
Symptoms and Reasons to Consider the Complement C1q Test
C1q abnormalities themselves do not cause one distinctive symptom pattern. Testing is usually prompted by recurrent infections, autoimmune features or abnormal complement results.
Recurrent serious infections - Complement deficiency can increase susceptibility to selected infections.
Unusually severe bacterial infections - Repeated or severe infections may prompt immune-system assessment.
Persistent joint pain or swelling with autoimmune features - Complement testing may form part of rheumatological investigation.
Unexplained autoimmune-type skin rashes - Complement abnormalities can occur in immune-complex conditions.
Early-onset lupus-like disease - Inherited classical complement deficiency can be associated with early autoimmunity.
Previously reduced C3 or C4 - Additional individual complement measurements may help clarify the pattern.
Unexplained immune-complex inflammation - C1q can be consumed when immune complexes activate the classical pathway.
A previously low Complement C1q result - Repeat testing can assess persistence.
These symptoms are not specific to C1q deficiency.
Complement results should be interpreted together with clinical history and other immune-system investigations rather than used as standalone evidence of autoimmune or immunodeficiency disease.
How to Book Your Complement C1q Test
Booking your Complement C1q blood test with London Blood Tests is straightforward.
Choose the Complement C1q
Select the individual Complement C1q test.
Select your sample collection option
Choose an in-clinic blood draw or professional home or hotel phlebotomy.
Attend your appointment
A trained professional collects the venous blood sample.
Laboratory analysis
Your serum undergoes specialist Complement C1q measurement.
Receive your results securely
Your authorised result is delivered securely.
When Will I Receive My Results?
The current expected turnaround is approximately 1 week after laboratory receipt.
Understanding Your Results
A reduced C1q result can occur because of inherited deficiency or increased consumption.
The clinical significance depends on the wider complement pattern.
Persistently very low C1q in someone with recurrent infections or early autoimmune disease may warrant specialist investigation for inherited complement deficiency.
A result within the reference interval means the measured concentration is not reduced but does not prove that the entire complement pathway is functioning normally.
Functional complement assays provide different information from individual protein measurements.
Why Book With London Blood Tests?
Private Complement C1q testing in London - Access specialist complement-system measurement.
Relevant to complement deficiency investigation - C1q deficiency is rare but clinically important.
Useful in autoimmune assessment - Complement consumption can occur during immune-complex disease.
Useful alongside C3 and C4 - Multiple complement markers can provide a clearer pattern.
Specialist immunology analysis - Samples undergo dedicated complement testing.
Clinic and home collection options - Professional phlebotomy can be arranged.
Secure reporting - Receive your authorised result securely.
Clear pricing - Complement C1q costs £148.99.
Private Complement C1q Blood Test in London
London Blood Tests provides private Complement C1q blood testing in London for people requiring specialist assessment of the classical complement pathway.
The test costs £148.99 and measures one biomarker: Complement C1q.
Results are expected approximately 1 week after laboratory receipt.