DIAGNOSTIC TEST 920

C1q

Diagnostic test for C1q. Suspicion of inflammatory system disorders, with recurrent urticaria/angioedema.

Indication

Suspicion of inflammatory system disorders, with recurrent urticaria/angioedema

Sample material

EDTA-plasma

  • Minim. volume: 0,5 mL

Transport

  • Within Sweden: frozen
  • International: frozen

Method

Nephelometry

Reference interval

182-288 mg/L

Result

Results are reported as normal, low, or elevated with a concentration (mg/L).

Interpretation

C1q is a component of the C1 complex in the classical pathway for complement activation. Multiple functions have been attributed to C1q, which includes antibody depended and nondependend immunological functions, and is considered to be mediatied by C1q receptors present on the effector cell surface.

In some patients C1q should be followed as an indicator for disease activity.

References

  • Alkaff FF et al. Clin Kidney J. 2025. Alternative pathway-mediated tubular complement activation in human proteinuric kidney diseases: a proof-of-concept study. PMID: 41215783
  • Uchida T et al. Int J Mol Sci. 2025. Possible Involvement of Circulating Immune Complex Containing IgG4 in the Pathogenesis of IgG4-Related Disease Complicated by Hypocomplementemia: A Case Report. PMID: 41226723
  • Pinto AJ et al. FEBS J. 2025. The fc fragment of IgMs binds C1q to activate the first step of the classical complement pathway, while inhibiting complement-dependent cytotoxicity. PMID: 41176693

Included in these panels

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How to order

This test is available worldwide for hospitals, clinics, and physicians.

  1. Print and complete the request form

    Download the request form. Clearly state the name and phone number of the referring hospital, clinic, or physician.

  2. Prepare your samples

    EDTA Plasma: At least 0.5 mL blood plasma (EDTA tubes).

  3. Send samples and request form

    Within Sweden
    Send samples frozen to:
    Envelopes and smaller boxes:
    Wieslab AB, Box 50117, 20211 Malmö, Sweden

    Larger boxes and frozen samples:
    Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden

    International
    Send samples frozen to:
    Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden

Read our sampling instructions for more information

Last updated: 2026-03-16