Molecule
C1q
Central autoantigen and complement initiator
- Expression change
- Depleted (consumed)
- Evidence level
- established
- Targeted by
- Anti-C1q autoantibodies (pathogenic)
Role in pathogenesis
C1q is the primary autoantigen in HUVS. Anti-C1q autoantibodies bind to the collagen-like region of C1q, forming immune complexes that activate the classical complement pathway. C1q levels are markedly reduced due to consumption. Low C1q is the most sensitive serologic marker.
Sources (4)
DetailsWisnieski JJ et al. (1989) Serum IgG antibodies to C1q in hypocomplementemic urticarial vasculitis syndromePubMed ↗
DetailsWisnieski JJ et al. (1992) Comparison of autoantibodies to the collagen-like region of C1q in hypocomplementemic urticarial vasculitis syndrome and systemic lupus erythematosusPubMed ↗