C1Q Antibodies

Immunology

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Description

Anti-C1q antibodies are used in the diagnosis of HUV. They are also found in patients with SLE and in particular are markers of renal involvement in SLE. Patients with SLE often develop glomerulonephritis commonly referred to as lupus nephritis. Patients without C1q autoantibodies have a very low risk of developing an active lupus nephritis. In contrast, high titres of C1q autoantibodies indicate a high risk in developing an active lupus nephritis, particularly if they have previously suffered from lupus nephritis. Successful treatment of active lupus nephritis typically decreases C1q autoantibody titres. C1q autoantibodies are thought to play a pathogenic role in glomerular damage [1].

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Indications

Hypocomplementaemic Urticarial Vasculitis (HUV), Systemic Lupus Erythematosus (SLE) and Lupus Nephritis.

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Sample Type

2mL Serum (Gel 5mL Yellow tube).
Requests from outside Sheffield: transport at ambient temperature via Royal Mail or Courier.

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Reference Range

Negative result < 15 U/mL.
Positive result > 15 U/mL.

Reference range established by manufacturer and verified in house.

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Turnaround Time

Within 10 days

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Testing Frequency

Alternate weeks

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Patient Preparation

Lipaemic samples can be avoided by asking patients to fast for at least 12 hours prior to the sample being taken.

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References

Holers, VM. Anti-C1q antibodies amplify pathogenic complement activation in systemic lupus erythematosus. J. Clin. Invest. 2004. 114(5):616-619. [Ref 1]
Flierman R, Daha MR. Pathogenic role of anti-C1q autoantibodies in the development of lupus nephritis - a hypothesis. Mol. Immunol. 2007. 44:133-138.
Hermanova HP, et al. C1q complement component and antibodies reflect SLE activity and kidney involvement. Clinical Rheumatology. 2006. 25(4):532-536.
Sinico M, et al. Anti-C1q Autoantibodies in Lupus Nephritis: Prevalence and Clinical Significance. Annals of the New York Academy of Sciences. 2005. 1050:193-200.
Seelen S, et al. Diagnostic and prognostic significance of anti-C1q antibodies in systemic lupus erythematosus. Current Opinion in Nephrology & Hypertension. 2003. 12(6):619-624.
Marto N, et al. Anti-C1q antibodies in nephritis: correlation between titres and renal disease activity and positive predictive value in systemic lupus erythematosus. Ann Rheum Dis. 2005. 64:444-448.

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