Complement in glomerular diseases.

Complement activation has been identified to play a vital role in the pathogenesis of many glomerulonephritis, either as direct complement activation-driven factor in thrombotic microangiopathy and C3 glomerulopathy, and/or as an important contributor in lupus nephritis and anti-neutrophil cytoplasmic antibody-associated vasculitis. Recent studies indicated that complement activation may also play roles in the pathogenesis of immunoglobulin A nephropathy and focal segmental glomerulosclerosis. Interestingly, monoclonal immunoglobulins/light chains from patients with monoclonal gammopathy may interfere with complement activation and thus indirectly result in complement-mediated glomerulonephritis. Understanding of the pathogenic roles of complement activation in various glomerulonephritis will facilitate the identification of potential novel therapeutic targets in complement system.