Molecule

Anti-C1q IgG autoantibodies

Pathogenic autoantibody

Expression change
Elevated (90-100% of patients)
Evidence level
established

Role in pathogenesis

IgG autoantibodies that bind the collagen-like region of C1q via their F(ab')2 fragments. Present in 90-100% of HUVS patients. Unlike SLE anti-C1q antibodies, HUVS antibodies can bind reduced/denatured C1q. Drive complement activation and immune complex deposition in vessel walls.

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
DetailsWisnieski JJ et al. (1992) IgG autoantibody to the collagen-like region of C1q in hypocomplementemic urticarial vasculitis syndrome, systemic lupus erythematosus, and 6 other musculoskeletal or rheumatic diseasesPubMed
DetailsMarzano AV et al. (2022) Urticarial vasculitis: Clinical and laboratory findings with a particular emphasis on differential diagnosisDOI