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.