C1Q

Immunology

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Description

C1q is the initiating molecule for the classical activation pathway of complement. Deficiencies or defects in the molecule lead to a reduced or absent CH50 value. Familial deficiency is rare but reduced levels may be associated with SLE, recurrent bacterial infections and with glomerulonephritis [1,2]. C1q levels are usually only measured in cases where CH50 is absent or the patient has increased susceptability to infection. The exception to this is in the identification of the consumptive defect in acquired angioedema, where levels are almost always low [1].

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Indications

Differential diagnosis of acquired angioedema. Low levels can be seen in SLE, glomerulonephritis and recurrent infections.

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Sample Type

2mL Serum (Gel 5mL Yellow tube). Transport fresh or freeze if sample is not sent on the day of venesection. br>Requests from outside Sheffield: transport at ambient temperature via Royal Mail or Courier (frozen samples can thaw in transit).

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Reference Range

50-250 mg/L.

Reference range established in house and PRU collaboration.

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Turnaround Time

Within 3 weeks

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Testing Frequency

1 - 4 weeks

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References

PRU Handbook of Clinical Immunochemistry. 9th Ed. 2007. [Ref 1]
Sjoholm AG, et al. Complement deficiency and disease: an update. Mol Immunology. 2006. 43(1-2):78-85. [Ref 2]
Norsworthy P, Davies KA. Complement components and their autoantibodies. Mol Biotechnol. 2003. 23(3):259-270.

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See Also

C3
C4
C1 Inhibitor
CH50

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.