Complement Factor H Related 3

Complement factor H-related protein 3 (CFHR3) is a five-domain member of the FHR family that binds C3b and C3d as well as apoptotic cells, C-reactive protein, and heparin. In contrast to several relatives, CFHR3 appears to dampen complement activation and to possess anti-inflammatory properties, and it competes with factor H for ligand binding in a manner that modulates rather than abolishes regulation. The common CFHR1-CFHR3 deletion affects circulating levels of both proteins and has been associated with autoimmune conditions such as lupus nephritis as well as protection from typical hemolytic uremic syndrome.